GL 320 vs Gl 450 ..which one is more reliable ?? any takes ? also is the diesel gl320 more of a headache than the gas GL450 ? please advise im looking to buy

 

I'm a diesel fan - just want to say that upfront. But, if you're looking more for a "less hands on required" type of thing, the gasser would be the way to go. The diesel is fantastic - the increased gas mileage trumps the higher cost of fuel (in some areas), and the low end torque is great. But there are a few flaws with the accessory engine items. The engine, itself, is great - it's some of the add-ons (and EPA stuff) that cause the problems. These can be addressed and even eliminated as issues, but of course requires some "know how" to do it. Most noticeably are the oil cooler leaks (bad/old o-rings) and the PCV vent and EGR system. These are documented and talked about enough that you can find info on these. For me, though, I don't mind working through the couple of issues (and have done so). I've had mine for about 5 or 6 years now and really like it.

 

Sounds good on it being V6 thats why i want it...V8 on GL450 sounds like it can be a gas guzzler..i do light engine work..but never on a Diesel...would i have to be experienced on Diesel to work on these ?

 

No, not at all. It's pretty much just standard wrenching stuff. If you're comfortable with that, you'll be fine. I'm not a mechanic, at all - and I've been getting along just fine.

EDIT: I did NOT do the new oil cooler seals on mine - just didn't have much spare time and there was a local guy that doesn't charge much. It's just a pain because it's buried in the V of the engine. However, if you're not seeing any oil leaks that can be attributed to this (kind of looks like a rear main seal leak since there's a drain in the back of the valley), then it's probably already been done.

Regular oil changes are a GOOD thing, especially with the EGR things still hooked up!

 

ok so you would recommend over the GL450 ? how is good is the GL320 on mpg ?

 

I would recommend the 320 for me. It's really all opinion based and others will have a differing opinion. I think, though, that as long as you have good information, then you can make a decision that works best for you.

I typically get 26/27 on the highway - and if I keep the speed at the national speed limit (which I only did once as an experiment!) I can touch 30.

 

Woww ..what year do you own ?

 

Do a search for OM642 engine failure or diesel problems. Should scare you away from them. If you don't tow more than 50% of the time, I highly recommend you move on to a gasser. If you were to ignore good advice and buy one, a 320 is the one to get since they are not as problematic as the 350 diesels. Keep in mind the 450 runs fine on regular unleaded and in my neck of the woods, last time I checked, diesel was around 30% more expensive than regular so your MPG increase in the diesel will typically not offset the additional cost of diesel. As stated by others, the diesel will require much more maintenance and repairs. Do not buy one that was serviced per factory specifications. Why? You need to change the oil in these at 5k intervals and not the 10k the factory recommends. If the previous owner/s maintained per factory recommendations, the diesel engine will sludge and that sludge causes a world of other issues including engine failure.

My 450 has been running regular unleaded for approx 200k miles of the 250k+ miles on the car. It has been the most reliable and least costly to operate MB that I've ever owned. It is still going strong and requires only regular oil changes. Of course there have been repairs along the way but most have been DIY or common with all GL's regardless of the engine type. If you want reliable, get a gasser. If you plan to do a ton of towing or want the feeling high MPG is saving you money, get the diesel.

 

Wow thanks for your advise...i know what you mean...i have the R350 and everything you said sounds similar to me...i was just worried about it being V8 as i have the V6 in my R350 ...im also worried about any issues on diesel engine might be more of a pain in the a**

 

hows your Mpg ?

 

Before switching to 22's the combined mileage was 17.7 MPG.

 

BlownV8,
Didn't you have an engine failure in your previous GL 450?

 

Nope. It will eventually need to be repaired/replaced due to bad idler shaft sprocket from the factory but I will drive it until it fails. Used engines for the 450 are dirt cheap and plentiful due to totaled vehicles and it is actually cheaper to replace the engine than repair. It's still running great and uses no oil between oil changes.

 

Very interested in your experience using Regular vs Premium. What difference do you see? Any? MPG, performance, noise?, ETC?

 

No real differences. I don't beat on it or tow so I can see no difference in mileage or driveability. If it's 100 degrees outside, I may drive a little more gingerly but even if I don't the knock sensors will adjust the timing accordingly.

 

I've been doing the same thing with my BMW for about 5 years. Same thing - no issues. I imagine that's not making quite a s much power since maybe there's a tiny bit of pre-detonation - but my thoughts on that is that it's probably only measurable with tolls or in a lab. Maybe there's more a difference when the engine is new - but with lot's of miles on it, there HAS to be some wear that is lowering the compression.

 

What year is your Gl 450 ?

 

My GL450 is a 2007.

 

Thanks "

 

You probably want to get a 2009 or later. The early ones had issues with the idler gear wearing out. Mine is outside the range of the affected ones but it is still affected. Maybe they got it right later?

 

is that on both gas and diesel or just the diesel one ?

 

Pick up a GL450 for $4-5000, replace all airbags for $1000 and throw some nice wheels and tires on it for another $2000 - you’ll be hard pressed to find better value anywhere.

just look out for the early 2007s, some have the same issue your R350 M272 motor may have.

i get about 18 mph in my 450 but who cares when I have 0 car payments.

Just avoid the diesel if you’re not a engine out DIY type a guy.

 

Avoid the diesel. Try to find a 550. It's a far superior vehicle compared to the other two models.

 

is the 550 V8 a bigger Engine and would it consume more gas than the 450 or is it the same ?

 

Ok where can i find the tool to Vin find the faulty idler or etc on these ? i has searched this for my R350 and ML by a Vin search for the problematic engine types...