Green E-300 DT

By BETTER he means:

Faster . . . yes, of that there is no doubt.

Better Fuel Economy . . . Of that there is no doubt. Check out all the entries on Fuelly including mine.

Easier to work on . . . Again, no doubt.

No choked off exhaust. All 2007s and later MBZ diesels have DPFs which is an exhaust restriction.

Beginning with the MY 2010, the W-212s are over three hundred pounds heavier and they are so much slower
because of not only their extra weight but because the engineers changed (lowered) the rear end gear
ratio to try and make up for them being sluggish when compared to the 2005-2006 W-211s.

Also, the W-212s use AdBlue fluid and because of that fluid, there is a small tank
for it which takes up the space for the spare tire, so the W-212s have run-flat tires
which not only cost more but cannot be repaired when there is a punture!
Hence you must, in most cases, replace run-flat tires when punctured, and they do cost more!
Also, those run-flats do not last as long and they ride harder.

The 2007s and later diesels have seven-speed transmissions which many say do not have
the ratios programmed properly for the diesel engines like the older five-speeds have.

So all and all, 240D 3.0T has is correct, and he should know as he works on 'em.

Comments welcomed.



DHG

Mbenz260e

It certainly seems the older engines have their advantages. I guess it's a matter of taste and use. I will take the disadvantages of the new motor for the peace of mind of a new car warranty and also some of the gimmicky new features others may not appreciate as much. I really like the old Benz's as well but have gotten used to the comfort features of the newer one's and don't want to have to deal with paying for repairs etc as I don't do that much work on my own cars.

Definitely arguments can be made either direction for pre or post 2007 car.

To the OP, (I know dated) I would definitely wouldn't be scared of the 2011 BTC. Perhaps the answer will change 20yrs and 100s of thousand from miles from now. But I have '09 and '12 BTC and love both vehicles.

scottp1111

So I just thought I would share my opinion. I just bought a 2012 e350 bluetec as stated above. I absolutely love it! I previously had a 2010 e63 which was an amazing car. The fuel mileage was terrible and for interstate driving just was economical anymore. Car was a great weekend car but time for some thing more practical. So about the diesel. 70mph on the interstate on cruise 36.5 mpg sometimes 38 mpg. Great mileage smooth ride extremely quiet. Power, great. It pulls hard from every speed and rpm combination, for a low horsepower engine it's really impressive for a large heavy car. As for looks, I removed all the nasty blue efficiency labels and rear bluetec And e350 placards for a cleaner sportier look. Then I put 19 inch e63 staggers wheels onit off of an e63 that was going off to insurance and put my stock wheels on there. So now it's has the sporty e63 look. Artic white with blacked out windows , looks really nice.

No problems with the car. Good power great mileage awesome car. Yeah you might pay more for diesel but the efficiency works it all out. One fill up gives a range of 640 miles avg. Great job Mercedes I'm satisfied with my diesel.

Green E-300 DT

Since you like the new W-212 E-Class diesel, you would love the older 2005-2006 CDIs.

No run flats.

Floor-shift lever where it belongs.

Faster and more economical plus it is lighter.

Any diesel car would be a big improvement on a Hotrod E-63 as far as fuel economy is concerned.

Those 19 inch heavy wide wheels and tires are costing you fuel economy.

What are your actual tank mileage readings and not what the computer states.

What are the figures on the door sticker as far as weighs and the total weight loaded?
Trying to discover how much more is the weight of the newer W-212 diesel compared to my '05 CDI.
Also, if you don't mind, what are your RPMs in seventh speed at exactly 60 mph?

Enjoy your new car.



DHG

stickygreen

Have both, I-6 in an E, and v6 in a GL

I-6 = smoother, torquier, stinkier, louder, better tuned 5spd trans

V6 = quieter, no diesel stink, not quite as smooth, and seemingly has less linear torque delivery. Also, 7spd in my GL likes to rev too high even under part throttle, taking the motor past it's power band.

That being said, I think it's hard to say the earlier model is a "better" car. I prefer the earlier model in the same way I'd take a 2003 m5 anyday over a 2006 m5, but objectively the newer model is always going to be better.

Other points:

Run flats - yes, they are heavy, ride rough, and are expensive. I prefer standard tires, BUT...the Runflats on my GL have worn very well and I have a newfound respect for the concept after bending a wheel & popping a tire on a pothole on a deserted & unlit 2-lane country road. Was still able to limp home at 40mph with no issue, and that safety factor can very well be worth the tradeoff

Floor shift - does it really matter? It's an automatic anyways, and steering wheel paddles offer better control.

Etc...

All moot points. People have different preferences, and you obviously prefer the previous model (as I do, for a diesel). Enough hating on people that are enjoying their new MB's

Green E-300 DT

Up until this last post, I had nothing but respect for you and your fine
(rare) Designo Edition 2005 CDI, but the former is no longer is true!

Taking your points, we shall examine each for what you have said and what they are worth:

All moot points? Some are true but many are false.

Comparing a fine older sedan with the better diesel engine to a truck (SUV) is not a good comparison!
The only things they both have in common is that they are both MBZs and both use diesel fuel.

If you had a later V6 CDI (2007 and a later E Class ) in a sedan and were comparing that to your 648.961
straight six engine in your 2005-2006 E class, then and only then could you be comparing these two completely
different vehicles. But you are not!
You are comparing two completely different types of vehicles to each other.
The sedan weighs less than 4K pounds, but the GL weighs how much more?

Since you have the deep pockets to pay what you did back when you bought the '05 CDI Designo Edition
E-Class CDI (I recall when you bought it used back then), that's great, but many of us do not.
Likewise, IF it does not bother you to shell out hundreds of dollars per tire for a run-flat tire that
rides harder, costs you fuel economy plus cannot be fixed when it gets a simple puncture
and does not last nearly as long as a regular radial, that's also entirely up to you.
The common fact is that most people do not care for run-flats and I'm among that majority.

I control my CDI engines' RPMs and do so all the time with the floor shift lever in my E-Class CDI.
Check my entrees on Fuelly.

Evidently, your steering wheel paddle shifter in your GL does not allow you to control your 7 G
transmission or you would be doing so as you say: "7 spd [7 G] in my GL likes
to rev too high even under part throttle, taking the motor past it's power band" you would
be making it up-shift earlier instead of allowing it to rev higher than is necessary.
This evidently bothers you enough to mention it but you think that is okay on such an
expensive machine? I do not, and for that fact alone, I would not own one.
Did you not 'test-drive' it prior to buying it?

So in the currect E-Class diesels which are over three hundreds pounds heavier that your '05, we find
a less satisfactory V6 3.0L V6 that puts out less horsepower and less torque, has a DPF which hurts fuel
economy, and must use run-flat tires and has no floor shift and the motor is not rebuildable.
Not only that, but it is much harder to work on and many of the things that go bad require
many expensive parts to fix which on the straight sixes are not nearly as expensive.
You must buy a complete new cylinder head if you have something so minor as a bad value cover.

Evidently MBZ has taken the attitude that all of the public that loves their cars are loaded.
Some of us are not. I've had thirteen MBZs since 1966 and all but two were gassers.
Eight I purchased new. The 450 SLC was only one year old when my wife simply had to have it.

Because of the way the new diesels are designed and built beginning with the MY 2007 in N A,
there will be no more new MBZ diesels for me.

Where did you get the stupid notion that I hate anyone that has a new MBZ?
Far from it. If they wish to spend their money on an expensive toy,
that is entirely their business and none of mine.
I am simply pointing out a few facts and perhaps preventing others from making those mistakes.

BTW, when you get tired of your old 2005 (Limited Designo Edition) CDI, please let me know,
and IF I am still kicking, I will buy it from you no matter how many more miles it has on its'
odometer. I wanted that car even before you found it back then!

Since I got mine but thirteen months ago and we have only put a little
over 28K miles on it,
I KNOW what a fine car they truly are. Take good care of that rare machine.

Question: Why do you prefer the older M5 to the later one? Is it because the newer one must
be wound up like a high speed sowing machine to put out any HP. Like well over 7000 rpms.
Got a kick when my son-in-law MS broker pointed out to me how
much the depreciation is on one of those 10 cylinder toys.

Speaking of fast cars, do you know what a well tuned 2005-2006 E-55 AMG can
do to one of those M5 10 bangers in a speed contest? There is no comparison!



DHG

stickygreen

alas...how will I be able to sleep tonite?

Ugh...where to start. Yes, the GL & E class are very different vehicles, and in now way would I expect the GL to be anywhere near as quick. I am only referring to the behavior & power delivery of both engine/trans combinations. The trans gearing & tuning seems to keep the cdi in it's power band (which seems much more linear), while the v6/7spd just don't seem to work that well together. Not sure if the GL has shorter final drive gearing (perhaps it does, to account for extra weight), but I have never driver an E Bluetec so can't really speak on that. Was not comparing vehicles, just powertrains.

I agree that most people don't care for Runflats - I am also one of those people. However, after experiencing first-hand the benefits of a Runflats tire, I can certainly say that I would not want my elderly mother or father be stranded roadside waiting for AAA if it can be avoided. Like I said, not my cup of tea, but I have respect for the technology and the extra measure of safety it can bring. As far as cost, Runflats aren't necessarily so expensive anymore - depending on size & application of course. The Bridgestone Runflats for my GL are among the cheapest tires in their size (275/50/20). And Runflats tires absolutely can be repaired in the event of a puncture under the same guidelines as a normal tire, unless they have actually been run on while flat - then they need to be replaced. I don't know about you, but I buy all my tires from Americas Tire (Discount tire outside CA) and always get the replacement warranty. Also, got 40k out of the original set of Runflats, and they easily had another 10k but replaced them due to inside wear from a bad alignment.

The shifting characteristics really do not bother me so much. Only time I ever really bring that up is when people ask I-6 vs v6 as I do feel that MB did a fantastic job on matching motor/trans/tuning on the cdi and perhaps fell a little short on the Bluetecs. Yes, I did test drive the GL and still love the vehicle, but it is not automotive diesel perfection (subjectively) like the e320 cdi is.

New model heavier...yes, that is usually the case with all the extra safety & tech features that come with model redesigns. Less power & torque - correct me if I'm wrong, but I thought the I-6 has around 370 lb ft while the v6 is closer to 400 lb ft. DPF does hurt fuel economy - no argument there. But something does have to be done to cut down emissions output in the long run. Don't believe me...visit a crowded city where there are really no emissions laws intact (ie Bombay) and you will see how bad it can get. Based on some online reading over the years (which makes us all experts, right?), overly aggressive EGR systems are what tend to create the most trouble with newer diesel engines. DPF's do burn more fuel, but cut down a bit on EGR and AdBlue helps even more. Yes, the v6's are harder to work on due to more compact packaging, but parts aren't really any more expensive than for the I-6. And as much as I prefer the inline-6 design, there are many benefits to a v6 - motor can be mounted more rearward for better weight distribution, greater occupant safety in a collision, and lower weight to name a few.

I guess my point about shift paddles didn't quite show through...in my OPINION, manually shifting an automatic transmission is pointless 99% of the time. Who cares where the shifter is - it's still an automatic! In our cars, upshifting manually does not cause the transmission to upshift any earlier than it would normally do based on throttle position. The only point it comes into play is when holding a lower gear longer before upshift, or manually downshifting to slow down. And especially in a diesel, I see no point to ever downshifting manually since the power band sits at lower revs. IMO, if you want to manually shift, get something with 2 clutches or 3 pedals.

Motor not rebuildable? Very true, but how many people really care about that? In this day & age when most engines can easily run upwards of 200k miles with proper maintenance, it is an issue that I doubt more than 0.5% of people even think about when buying a car. Never heard of needing a new cylinder head if valve cover goes bad, but what exactly would damage a valve cover? In fact, that's probably one of the very few parts I've never heard of going bad.

Not sure why you think MB is only trying to appeal to "rich" people or what point you're trying to make. MB parts have always been quite pricey, and their cars used to be ALOT more expensive (accounting for inflation/dollar value). The difference is the newer models have many more components & technologies, so there are a lot more parts on newer cars that may someday need replacement.

Thie statement about '07+ diesels being designed & built in America doesn't make any sense. All Mercedes cars are still produced & assembled in Germany (for US market at least), and though the SUVs are built here, the majority of their parts including all drivetrain parts are sourced from Germany. In fact, the worst cars MB ever produced from a reliability standpoint were the early W220/w215, early w211, and w163.

Never said you hate anybody. The word "hating" is a slang term that refers to putting someone down because they have something nicer than you do. Honestly, I probably wouldn't have even responded to your previous post. But here is why I did:

The post previous was just one person sharing the positive experiences they've had with their new MB and how much they love the car. You proceed to explain why they should have bought an older model and then tell them why your car was so much better than their Bluetec. Then you ended your post with an obviously condescending & snide tone.

Frankly I too respected your opinion previously. But in that last post (not the one directed at me, but the one directed at scottp) you were a total dick.

Enjoy your cdi and I will continue to enjoy mine. If I do ever decide to sell (unlikely, because it really is an amazing car that still runs like a top), you will definitely be the first to know. At least I know you'll take care of the car as well as we have.

stickygreen

In regards to the M5, it is my opinion that the e39 m5 is the closest thing to all around automotive perfection that has ever been built. Fast enough, comfortable enough, handles great, and drop dead sexy (ESP in imola red/camel). More importantly, they were only available with a 6-speed manual. As much as I like the e55, just can't love a performance car with an automatic transmission. And the later m5 was just ugly, inside and out.

skromfols

Thanks to all for some interesting reading. As you may have noticed, this is my first post on this forum, so please don't be too harsh with me.

We presently have an 05 CLK 500 that I purchased new as my wife's daily driver. She loves the car and with 120,000 miles it still looks and runs like new, but she would like more room in a vehicle (she's tired of borrowing my Nissan Titan when she goes shopping). She would like a 4 door sedan, and would still like a vehicle with prestige, like she has with her CLK.

With today's economy I don't want to invest another $70,000 in a vehicle, and I'd like to get reasonable gas mileage and longevity, while still giving her a vehicle that she'll really enjoy. I've done a lot of shopping and a 2011 MB Certified lease return E350 Blutec seems to be exactly what we're looking for. I've looked at and test driven a couple, and like the comfort, looks and drivability of the Blutec.

This thread has given me some great information, and while some of you prefer the older I6 or the 320, I'm pretty much limited to the newer 350, as I prefer not to go with anything more than a couple years old.

I'll be spending more time on this forum over the next few months, as I'd like to gain as much information as I can before making the purchase (which will probably be in early Spring when I'll get the most when selling her CLK 500).

Again, thanks to all for the information both pro and con that you've provided on the Mercedes Diesel.

Green E-300 DT

Welcome to the wonderful World of Mercedes Benz Diesels.

Looking on the AutoTrader site alone, we find almost 150 used 2011 W-212 CDIs listed, ranging in price from $37K to over $52K.
Quite a range!

A person should be able to find a car just about like what they might have ordered had they ordered one out brand new.

A do not know what the small differences are between the MY 2011s and a new 2013 E-350 CDI Bluetec or IF there are indeed any?
My experience had been with the older 2005 - 2006 W-211 E-320 CDIs.

You do not say where you are located?
If I can be of any service here in Southern California, please don't hesitate to ask.

Good luck in your search.



DHG

skromfols

DHG, thank you for the welcome and for the offer of assistance. I'm in Valley Springs, about an hours drive East of Sacramento. Hopefully when I'm ready to buy there will be a fairly good supply of Lease Returns to choose from.

Loubud

Hi All.

I've been reading this forum on and off for many years. My interest this time around was the 2011 E Bluetec. I just bought one 6 days ago in Texas and drove the 1,500+ miles home to Ventura, CA.

I've owned a few MB diesels and I need to replace my 1995 E300D with 385,000 miles. The poor body is rusting starting from the TOP. I'll keep her till it needs something major and off she goes.

My 1st choice for replacement was a 2005 E320 CDI. I started looking last October and found a slew of 'em. I lost a few bargains being too slow on the trigger and lost 2 due to failed inspections. A 3rd was a CPO in N.Y. $15K in options, just what the Dr. ordered but...the mudflaps at the dealer tried really hard to nickle and dime the sale. The closer screwed things up so bad that I let them keep it. While this weeklong ordeal was going on, the supply of really loaded models soon vanished. I took a break from looking.

By accident I discover the MB Financial is doing a very large dump of lease returns. No one knew how many of these Bluetecs were out there and the MB dealers snapped up a slew of them and filled their lots. But they kept coming and soon independant used car dealers had a boatload of 'em too. To my surprise, by checking CarFaxes, a high percentage of them are CA. cars.

I used Autotrader, Carmax, Cargurus and Cars.com to do my search. The car I bought was a So.Cal. car. I paid $39,950 for mine (plus CA car tax). AMG Sport Package, P-2, Pano roof, Lane Keep Assist, Parktronic, Distronic, Blind Spot Assist, Driver Assist, Folding rear seats, and Leather. No Night Vision. If this thing parked itself it would be the complete drunk driver package.

14,017 miles

$15K in options. Cool. I'm certain that with soo many of these cars being sold that the current book price will crash even tho many that I kept track of sold rather high compared to mine.

My reason for posting is about tires. I really don't like not having a spare as Wifey will be the main driver. She works 48+- miles away and on Pacific Coast Hwy (PCH). Nice windy road with S curves tossed in. Whenever she gets a flat, it's on PCH in the middle of nowhere.

What do you folks think, and I don't really want a bonfire discussion, just a few thoughts about runflats or just tossing a spare in the trunk?

As an aside, this is my second Bluetec. I prefer cast iron blocks but what the heck? It is what it is. Fast and diesel.

Thanks,
Lou

VicLaw

+1 for the truk or for the cost of the tire buy her AAA membership.

Punchered a Bridgestone EL400 after 34k miles. Measurement showed it wouldhave gone another 10k. Even a VERY slow leak is not repairable. New one quotedat $300 to $350. Then what - one new tire at 34k? Bumped into a BMW owner whostopped buying run flats after the 3rd flat in 13 mos. Convinced me. Installed4 new Cont DWS for $720 all in. Now the ride is greatly improved, quieter andmuch better in the rain. I’m waiting for snow.

Loubud

Thanks for the info. I've talked it over with mire tire guy and my service guy at the dealer.
Neither one liked the runflats. I have Bridgestones on right now and seem to be holding ok but I may either try out some other brands or do what you did. Go with the Continentals and call it a day. The reviews I've read have them fairing very well.

Lou

skromfols

If you go with regular tires do you throw a spare in the trunk or just rely on AAA to come to your aid if you get a flat ?

Loubud

I have regular tires now and really don't like not having a spare. We're relying on AAA. Not the best solution if you're out of the city.

I'm thinking it's a good idea for me to get a spare so I don't get stuck if it's after hours at tire shops. No idea if it'll be full size or a mini pump up spare.

Either way, it's my understanding that in a few years all passenger cars will come with run flat tires. I would think that many people won't drive at night anymore for fear of being stranded.

Imagine driving somewhere on vacation and you're out in a remote area and it's the middle of the night. Run flats or not, you can only travel so far and that's it.

VicLaw

We all go with decisions that make us comfortable and secure while traveling.

But I can't see todays run flats becoming the norm. Not at $300 to repair a tire by replacement. Look at my situation replace one tire while the others are 3/4 worn out? How does the different diameters effect the stability control system or thread performance on wet or snow roads? Or 4 new at $1200 and loose 25% of value?

Develop one that can be patched for $20 and I'll agree with your prediction.

PS I can't throw a spare into the trunk, with the loss of cargo space, my wife will not pack any of my stuff for the trip.

Loubud

My thinking behind the all cars will have run flats thing is because of the gas mileage rules coming down the pike. Less weight, better MPG. Something has to give.
I agree with your views on run flats 100%. There may be repairable run flats down the road to make them less costly or we find tiny blow up spares many cars now have. I prefer a choice verses some agency handing down laws. I choose a full size spare and am willing to pay the MPG price.
As far as a real spare, my Wifey wouldn't be very happy losing space in the trunk either. That's where I put her.

VicLaw

2011 E350 BT, 35,000 miles, saw 37MPG on highway driving each time going to Florida, the computer shows 24-26 in my mix of city driving.

For 2 weeks had engine light come on. Dealer replaced the EGR valve under warranty. Light on then off. 2 days ago light activated again, dealer adjusted the throttle body. Light back on yesterday. In dealer this AM diagnosed carbon build-up. $560 to clean out.

Tech said should be good for another 35 - 40K that is when this happens but not to "all cars". I figured I just lost almost 1/2 of my savings from fuel cost and better mileage.

Loubud

When I was researching the V6 and the 3.2 inline 6 I discovered that with the 3.2, some did get the carbon buildup you got. The prevention method was referred to as "The Lamborghini tuneup". It's driving the car like you stole it. Get the turbo hot and burn the carbon buildup off.
I noticed your city driving was 24-26 mpg. I get 22-24. My mileage may be lower as I drive a bit harder than others since I don't want the carbon buildup and I drive hard anyway. Not full race mode, just more than say, my wifey does. She gets mileage similar to what you posted and is the primary driver.
I don't know what distance it is when you say you drive to FL. but it would seem to me that if you're on the freeway for a few hours that that alone would've removed the carbon. The EGR could have been the main culprit. I don't know. I also don't know what the average lifespan is for one of those.
One thing that I did while researching 2005-2011 MB diesels was to check the recorded repairs listed by Carfax. MBUSA was one of the places I looked as the dealers all had the Carfax listed. Some of the 2011's had a series of computer resets and EGR replacements on a single car. Others never had a warranty problem. 2005-2011 showed cars that were in the shop very often and others that rarely went to the dealer.
The hardest part for me is did I buy a problem car or a good car. Mine didn't have enough miles to know. Fortunately, there aren't a lot of what I call problem cars out there. I sincerely hope that yours isn't one of them. No way to tell right now. Maybe that EGR is all that will ever go bad. It's distressing about the carbon but it may be a one time deal also.
Someone here at MBWorld knows more than I do. OK, most here know more than I do and maybe someone will pop in and give a definitive answer. I tend to ramble.

VicLaw

Bought this one new. Trip to FL is 1200 for me, we take 2 days will stop over night. Outside of most metropolitan area (55 MPH) we roll at 80+. Once, first thing in AM, got into a caravan doing 90+ (for well over an hour) my mileage fell from 36-37 to 33. For the most part I can't hot foot in my part of Chicago streets and lucky to do so on our highways.

My best guess an EGR is good for 35,000 miles. Got to go and dig for pocket change in the sofa cushions.

mikemargolis

I have 45,000 trouble free miles on my 2011 Bluetec. Can't talk about tomorrow, but my EGR valve (whatever that might be) is just fine.

Loubud

Well now. It's starting to look like we may drive the same. I'll gladly jump into a caravan and scoot along with them. Any opportunity is good for me.
It looks like my info is either wrong or I remember it wrong. I wouldn't have thought that you'd have any carbon buildup after runs like that. I do know that the MB book says that a freeway run is necessary if 325 miles of only street driving is done. That leads me to think that normal driving eliminates the carbon buildup.
The MB dealers here in So. Cal. like to restore customer cars to "as new" condition. A small superficial surface crack on weatherstripping prompts them to suggest replacement. I don't mean to suggest that this is normal practice across the Nation, just around here. I do wonder what prompted your dealer to take apart your turbo. And I also wonder if your dealer has a similar attitude that we have down here. See a spot of carbon somewhere and start the restoration to new condition. Just speculation on my part.
One question. What would have happened if only the EGR was replaced and they gave it back? How would the car run and would it improve once it had the opportunity to blow off whatever carbon existed.
Our car has a bit over 22K miles now. I think if the EGR goes out and the dealer wants to clean out carbon buildup, I'll pass and see what happens. UNLESS it voids the warranty.

Loubud

Thanks for your post. I'm hoping that Vic's EGR was just a bad part and won't happen again for a very long time. Mt '95 E300D has it's original EGR @385K miles and my '92 300SD just had it's EGR replaced 2 years ago @252K miles.

I buy these MB diesel cars for mpg and low maintenance. It's disappointing that Vic has had an out of pocket expense of this type, this soon. Hope it doesn't happen again.

VicLaw

Disappointing is not the word for it. Got the car back today final cost $777.12. They could not clean the Recirculation Pipe and had to replace it $60 a couple of $20 gaskets and a $10 the rest was in labor. Gave me the part as a trophy it’s difficult to photograph because of the black carbon. Look closely and you’ll see that the holes are almost completely blocked with carbon.



I'm in IL they DO NOT post the % of Bio in the diesel fuel just list 5-20%. I'm fighting with my state reps to modify the law so I know what quality of fuel I'm buying. Here there is a tax advantage to add the bio so it's not and easy fight because VW, Porsche, Audi and Chrysler say they are fine with 20%. MB says more than 5% is the main culprit for carbon and sludge.

I’m not a mechanic, just play one here. But Lou think hard about passing on the initial clean up. The original estimate was for $560 to clean EGR Assembly before they opened it up. The limited research I’ve done tells me that if you ignore this long enough you’ll have to clean what I did plus it will back up and you’ll have to do the heads as well. Acid in the oil can’t be good and will lead to sludge build up. On the Audi site, they are having carbon problems in the 3.2 gasoline engines. Goggle it on the web I (we) are not alone.

From Wikipedia:

In diesel engines[edit]

By feeding the lower oxygen exhaust gas into the intake, diesel EGR systems lower combustion temperature, reducing emissions of NOx. This makes combustion less efficient, compromising economy and power. The normally "dry" intake system of a diesel engine is now subject to fouling from soot, unburned fuel and oil in the EGR bleed, which has little effect on airflow, however, when combined with oil vapour from a PCV system, can cause buildup of sticky tar in the intake manifold and valves. It can also cause problems with components such as swirl flaps, where fitted. Diesel EGR also increases soot production, though this was masked in the US by the simultaneous introduction of diesel particulate filters EGR systems can also add abrasive contaminants and increase engine oil acidity, which in turn can reduce engine longevity.

Though engine manufacturers have refused to release details of the effect of EGR on fuel economy, the EPA regulations of 2002 that led to the introduction of cooled EGRwere associated with a 3% drop in engine efficiency, bucking a trend of a .5% ayear increase.