Btrthanterrific

While I cannot determine the reason for the corrosion, I can assure you it has nothing to do with water. The engine cover and the way the ignition coils are mounted certainly surprised me that there would be corrosion on the third cylinder. I have never had the engine cleaned or pressure-washed. The spark plugs and coils had never been serviced either. The car has 88,000 miles. Many others have had the problem as well. The recommendation is to apply Dielectric grease to prevent further corrosion. But no one has designated a Cause for the corrosion especially with a single cylinder.

TabbyTy

Interesting to see similar issues happened to MB vehicles. I had a new 2018 GLA 250 with around 8500km and started to observe the lost power/limp mode issue. Especially very inconvenience when it happened on Highway. Vehicle must be restarted in order to be back to normal. Very frustrated.

HULKSTRONG

Jedi78

MB must be making a killing off these failing parts! Seems to happen to many folks, including myself I'm getting code p0002 on ODBCII/ loss of power on hard acceleration, but goes back to normal after turn car off/on.

I wanted to know if you usually replace all three parts when customers report the problem?
I'm referring to the 2 parts in the fuel tank pump/pump assembly (204-470-02-94-MBZ/212-470-13-94-MBZ) AND the high pressure fuel pump behind the engine (271-070-37-01-80-MBZ)
Or if you just replace the high pressure fuel pump?
Trying not to buy parts I don't need.

Also, wondering if I can continue driving the car until I get the parts without worrying about the car not starting. Does anyone have any history with car NOT starting at all?

Thanks.

Joe1959

Had a similar issue with my C180KBE (M271 Compressor engine) with the 5G-tronic last Friday on the Autobahn.
Was in top gear, doing approx. 75 mph and stepped on the gas somewhat harder but without inducing a downshift.
All of a sudden there was a knock and the engine started to run irregularly.
The Check Engine Light did not come on and there were no display messages.
Slowed down and cruising along without load the engine ran quite smoothly but the momentary fuel consumption was very high.
Stopped after a few miles at the next rest stop, shut the engine, pulled out the key and waited a few minutes.
Restarted the engine after a while and it ran perfectly fine and has done so ever since.
Called my Mercedes dealer on Monday and they recommended for me to just continue driving as there won’t be anything stored in the fault memory.
Since then I covered about 500 mls and everything is o.K.
Nevertheless I really love this car!

ItalianJoe1

No, it's only the high pressure pump, specifically the quantity control valve on it, that acts up. The low side pumps are not related to this issue.

Jedi78

Any tutorials out there on how to replace the HPFP on a 2014 C250/w204? Have you thought of making one perhaps? You have cut down a replacement to 27 min. lol

ItalianJoe1

I get paid the same whether I take all day or 1 hour to change it so speed helps. It's pretty simple to do, but for your first time it will take a little bit.

ruinedw204

Hey Joe,
I am undertaking this job this weekend and am going to go buy the specific parts to do so. After watching Audi A4 videos, because their's are also in the back, I made a list of tools.
This is the video I am referring to:

You Tube

How similar are the tools since I believe you have had experience with it? I have written 13mm, 14mm, and 1 long+1stubby17mm wrench, a T30 Torx, an 8mm triple square socket, some extensions for the banjo bolt and something magnetic to grab the banjo bolt when it comes off.

I also read you cranked the engine 57 degrees to set the camshaft to the correct location.

In the video, he removes the HPFP Fuse and then starts the engine and lets it run until it stalls so the engine depressurizes. After removing the fuel lines, PVC hoses, bleed valve, and connectors he removes the banjo bolt. He also disconnects the vacuum line nearby/above the HPFP area for more space when working on it. Then he removes the three Torx bolts to fully remove the HPFP.

• When he goes to put the new one in he cranks the engine a bit to turn the crankshaft so it's at the lowest point possible. What did you do or mean by cranking the engine 57 degrees?

For anyone reading that's looking for a similar DIY guide to at least go by, after cranking the engine to lower the camshaft the puts on the new HPFP by first pushing it in slightly and initially screwing all three bolts on. Then he tightens one at a time in a rotation and evenly. So he tightens one a little then the next a little and so on so the new HPFP goes in straight and not crooked. Make sure to replace the gasket before you put in your HPFP with a new gasket. After that, he reconnects the vacuum lines, PVC pipes, and banjo bolt.

If all goes well, I will be making a DIY video in the hopes that others can also fix their God Forsaken High-Pressure Fuel Pumps without having to go to the Stealership.

Jedi78

Good luck to you RUINEDW204!!!
And salute to you for making a DIY video... If that video was out there I would have attempted to do it myself as well.
Update on my W204 - it's MosDef the HPFP! I replaced it (shop- paid about $1,100 for NEW PART/LABOR) and the issue is now gone for good! THANK GOD!
After repairs, you'll notice your fuel efficiency back up, torque w/ HP off the jump again!

Effen Dunn

My 2013 C250 with under 45k miles had this same issue occur last week.

Took it to the Mercedes Dealership near me today, and they reported Error Codes of 0705 & 0606

"the fully integrated transmission control unit is faulty. I tested the part electronically and it failed" from the shop manager

The Transmission Control Module costs 2070.00 parts Labor and tax included.

I think this is over inflated pricing and i'm worried the issue wont be resolved as many here are getting a variety of other responses.. Ughhhh

Oh!! and check this out. 197.00 diagnostic fee, will be put towards the repair if we choose to get it repaired there.
During the diagnosis they found we needed a new battery, I told them do the battery now, we'll do the transmission later... okay it'll be 414.00 for the battery, and 197.00 for the diagnosis!!!!!!

The battery issue came to light during the 27 point checklist they do with all cars. Not because of the diagnosis..

Yeah!

ItalianJoe1

Can't attach the workshop docs from my laptop, only pulls it as an XPS file and I can't upload that here. I'll try tomorrow from work, my home PC isn't working at the moment.

57degrees refers to the crank pulley mark, your HPFP is driven on the rear of the cam using a keyway, not a lobe and lifter like the Audi one shown so timing makes it slide in, but there is no high/low to worry about, the pump stops in one of 4 places though so you need it to be keyed right or it won't slide in easily.

I don't remove the intake manifold, the instructions tell you to. You need an E10 or 8mm socket for the bolts, a 17mm for the line, and a pick and or proper spring clamp pliers for the low pressure line. 24mm socket to turn the crank IIRC, and that's about all I used.

HenryJenks

If yours is sluggish take and occasionally blows black smoke take it to the dealer immediately that usually mean your turbo is Broken QUOTE=chuang;6006816]Hi strangebrew, thanks for your comment. I think that make sense.
In my case, the dealer did updated the software and after that, the lost power did go away. However, during those two days, the dealer gave us a 2014 loaner car (also C250 that only has around 3000 miles on it), and wow it drives like a totally different car!! It's so peppy and accelerate so good when compare to my wife's C250! As my wife also has a slow commute to work (95% city driving) so that might have explained it..

Anyway, right now we are not experiencing the "lost power" issue any more, but the car still drive much less peppy then that loaner car, and they are supposed to have the same type of engine... I might try to disconnect the battery to try out your tip. By the way do I need to know some sort of "radio code" after I reconnect the battery? Just curious. thanks![/QUOTE]

HBguy

Love that this topic is still being discussed. The new 2020 GLE is showing this symptom also. Also showing this symptom, and many dealership visits, my 2013 c250.

chuang

For me I just won't be purchasing another MB again. My next car will be a lexus

HBguy

Same. I test drove a gle450 and loved it. I didnt give the salesman my email, only my spare (real) cell number. He wound up following up with me on my email, which he got from the dealer. I had already told the dealer to never contact me vis email or that number. I replied upset, then he called me on my personal line, which again, he had to get from dealer.

Given the >12 visits to fix an alignment issue (pulling to tge right brand new, dealers trying to charge me AND telling me they couldnt fix it)...now this reoccuring gem.

I can live with bugs, but this can cause an accident. Hpfp my ****, this is a design flaw that is preaent in the new gle also. The best or nothing...right. i used to blame dealerships, but no, its the brand.

Im not a fan of lexus but I'm too impatient with arrogance to deal with german vehicles from now on. Ive bought new cars regularly for decades, their loss. The person who drives my c250 doesnt want me to sell it but i want it gone.

Btrthanterrific

I continue to have issues with codes p0002 and now p008a. I now have 102,000 miles on my 2014 c250. I've decided to live with the issue through fuel management and driving management. First and foremost is good quality gasoline with the highest octane available. Which unfortunately is only 91 here in California. I tend to put in octane booster in about every other tank. O'Reilly's seems to have the best bang for the buck with their brand under $4. Also, must put the car in S Mode, never Eco mode. I can drive for days without having a check engine light. The most unusual aspect of this problem is that if I let the car sit as it often does for weeks at a time, when I go to use the car there are no issues whatsoever. But usually within a week or two the problem will resurface. I have not replaced the high pressure fuel pump, the low-pressure fuel pump, or the fuel filter. I also have not had the ECU updated. This is because I continue to read that other people have tried these resolutions and the issue has recurred. I would be tempted to put in a new hpfp if there were some modification to ensure that it will resolve the problem and not have issue again.

Btrthanterrific

I've driven my 2014 c250 for three years and 50,000 miles with the issue. It has not deteriorated any further, but the failure is minimized buy premium fuel, octane booster, and s mode when driving. The only codes I get are p0002 and p008a. Turning the car on and off resets the car from limp mode, and the check engine light usually goes off within a day. My gripe is that this appears to be a design flaw. If one of the components was failing surely it would get worse over time. Too many people have replaced components multiple times and still had the issue.

onehighfocus

You would think with as many of these HPFPs that have been swapped out, someone would have done a comprehensive DIY how to...

I actually just finished mine and got it done in just under 2 hours without removing the intake manifold. Dealing with that dang low pressure line Clic-R clamp is the main pain followed by lining up the drive dogs on the pump would be next.

I did remove the intake filter (T25)and the oil filter housings to make room to work. Getting everything unbolted and free is no problem...

I used a E10 with long extension to get the wire connector bracket off and an 8mm ratcheting open end wrench for the pump to block bolts. It's getting the low pressure line into position where you can get the clamp off is where you gotta turn on puzzle solving mode.

Good thing the low pressure line has some slack on it. With the high pressure hard line disconnected, you can tip, twist and turn the pump into a better position. I was able to get the rubber line to come under the fixed hard line (moving towards the oils filter) and up over the hard line which made dealing with the clamp much easier.The spring clamp is actually reusable if you have the proper tool to unlatch it and then re-latch when installing.Clic-R is the brand name and the pliers can be found on Amazon or ebay pretty cheap.

Once that Clic-R clamp is opened, I did struggle a bit pulling the hose off the nipple. Its just a tight space and hard to get a grasp on it. I guess you could just yank the pump up and away but I didn't want to risk ripping the line or disconnecting it from whatever it may be hooked to under the intake manifold.

Now just put everything back in exact reverse order, including having the pump in that same position it was in to get the clamp off. Slip the rubber line back under the hard line and tip, twist and turn the pump back into its resting position ready to engage.

*I waited until the pump was bolted to the block to tighten on the hard line.*

My OEM re-manufactured pump came with the black "Iron Cross" adapter stuck to the pump with some heavy grease. I opted to take it off the pump and stick it to the engine side with that heavy grease. Cant say for sure if its better either way.

Not sure what ItallianJoe1 meant by setting the crank to 57 degrees as my pulley is only marked up to 30. All I did was stick my finger in the hole (giggity) and turned the crank (27mm bolt) till it felt like it was in the right position. Perhaps if you have two people, you can have one hold the pump in position with another turns the crank until it drops in.

Then just tighten all the bolts back up (don't forget the high pressure hard line) and you're done.

Raj Callychurn

You can try removing carbon deposit from the engine. There is a chemical it is unfortunately available only in Russia but it cleans your engine in one hour it drives like new. No need to strip your engine for that the chemical is added in the cylinder directly. LAVR 203.

Yogirldee

I was driving on the freeway and the car wouldn't accelerate I pressed on the gas and nothing for a whole than all of a sudden it picked back up, it was scary. I took if for a code read P0002 which Is super fuel injector. after reading all of these posts I am wondering why Mercedes didn't have to do a recall this is super dangerous, for one I am not about to start pouring money into a car that is subject to have the same issue over and over again my last car was like that to where my mechanic ask me not to bring it back because it was a bad year for the car, I looked it up and sure enough thousands of complaints I am not going through that again.

C250OLI

I've had the issue for at least 2 years but it only goes into limp mode when I have the accelerator floored. It has not deteriorated at all since it first started happening. I've been thinking about replacing the HPFP myself lately but I worry that the replacement pump will have the same problem eventually. It's not optimal but I can live without the way it is. Anyone have any idea if the replacements are more durable or is this something that will keep happening? Anyone had a pump replaced and no issues afterwards after a good amount of driving? I'm trying to decide if its worth the money and work for me to replace the pump.

Thanks

HBguy

is it worth it? No. I'm not sure if you can go non-OEM. I'm confident its a combination of things, including some part of the ECU program. Going from memory, its a false low pressure message sent from the fuel pump, so replacing it won't help. Maybe there's a software patch, it's been years since it happened to me.

Some people suggested keeping fuel level from dropping too low (less work for pump if the tank is fuller) but I'm not good at practicing that.

C250OLI

Thanks for the reply. It is an annoyance, I can only go about 90% throttle and it seems to happen right when the transmission is about to shift. I just don’t want to spend 700$ and a day fighting with the pump if replacing it won’t resolve the issue or will only resolve it until the new pump fails.

HBguy

you're right, it does seem to be right when it's expected to shift. it happens very infrequently for me, but like a cold, it has its moments for a day or two. Its a nightmare when merging onto a freeway. It's also an issue that's across many MB models.

Sorry for replying without a solution, but I'm experienced with technical issues and this on-going concern is something not enough people have complained about it seems. This is why I currently do not own a new benz that cost 2x the c250 when it was new. I'm actually turned off all new cars, except for a refound appreciation for Toyotas obsession on reliability (at expense of modern tech, efficiency, and performance).