newtotheforums

Hi Guys. I bought a used ML550 (2013) from a used car dealership with the Carmax inspections and everything. The car's previous owner looked like he took very good care of it and recently had the spark plugs replaced. Unfortunately, after months of driving it, it came up with a check engine and, I took it to my local Mercedes Benz to check it out. Turns out my dealership misdiagnosed twice, with the first repair being the re-wiring of the engine harness for 5,500 dollars, and now they wanted to quote me for a fuel injector replacement for 7,500 dollars. I took it finally to another dealership where they did a quick diagnostic test and told me it was low compression in the cylinder 6 and 5 heads. I told my service advisor these were the codes I found in the car, but I guess he ignored what I suggested. I didn't act like I knew what I was exactly talking about. I figured that I'd tell him to help the mechanic narrow things down more (generic P0306). When I got the new quote for the cylinder head replacements it would come out to 14,000, and if I drive it any longer the engine might lock up, and it'll be 25,000 for a new engine. I can keep up with maintaining a luxury car, but this is not what I thought I signed up for when it came to taking care of the car. This is a long shot, and hopefully, this isn't wasn't too long to read, but I tried everything in my power to negotiate and look for alternatives, but not much has worked. Any suggestions are greatly appreciated.

Rainers

Time to sell

chassis

Sell or rebuild the engine yourself.

Low compression could be failed valve guides, failed head gasket, broken piston or cylinder scuffing. Scuffing is the least repairable/most expensive failure. Borescope inspection would be my next step if you choose the DIY rebuild route.

newtotheforums

Unfortunately, I have very little experience when it comes to this, but I'm more than willing to learn new things and have the time to do so. Do you think there's a good chance I could start with a trustworthy independent shop, do the inspection, and try to see my options from there?

chassis

Yes that is a good next step. Ask the shop to Confirm the low compression and identify the root cause of it, and to identify options to correct it.

newtotheforums

Ok thanks again for your input, and by chance, should I need to look at sourcing some parts, do you know any reputable websites yourself? I've found one site called FCPEuro, and it looks like they have a lot of what I might need, but just incase I might need to look at other options, I'd like to be able to. Thanks again.

chassis

mercedesbenzstarparts.com has been useful for me. Search this site, there are many recommendations. Also search google, there are MB dealers that offer fairly extensive online parts for sale.

OnlyGerman

This is very concerning with someone with 2 M278 motors!

Diabolis

Are you going to buy it?

OnlyGerman

How many miles?

newtotheforums

56,424

OnlyGerman

These early M278 motors did have various issues, which worsen if not corrected while under their original warranty or CPO. Your issue being the more rarer of failures... I would recommend you to contact CarMax, if the purchase was not made to long ago. Also, contact MBUSA customer care, given the lower mileage and previous service history, you have a good chance of assistance. If there is no help from either, I would start looking to for a used motor and a good indy to complete the job. Obviously the dealer quotes are unreasonable.

newtotheforums

The only person I may haven't contact and probably should have was Carmax, as you recommended. Unfortunately, I did waste a lot of time back and forth with my local MB dealership. Long story short, after the 5k rewiring and the 7.5k quote for a fuel injector replacement. I tried talking to the managers to see if there would be some sort of more reasonable compromise as they had my vehicle close a month each time they took it in. One manager said they'd take care of the costs until they changed their mind. They also did the fuel injector replacement without my authorization, and it had the car dismantled and refused to let me have the car until I threatened to have the cops called. The general manager never gave me a callback. I then tried calling MB USA, but they said there was nothing they could do as the dealerships are privately owned/run.

OnlyGerman

So you had to pay for the 5k rewire AND the 7.5k fuel injector replacement?

newtotheforums

I had to pay for the 5k rewire, and I forgot to mention they switched out the ignition coils, which were obviously unnecessary considering the problem I'm having is still there. They decided (I guess better for them) to finally give me back the car after I refused to shell out another 7,500 for one fuel injector replacement. I never authorized them to do so anyway. The service advisor called me after they did it and left the car dismantled. Only after I decided to threaten them with the police, the car somehow was put together quickly and ready to be given back to me. I tried to see if my bank could dispute the initial 5k charge, but they only will take cases if you can prove whether the work was done or not. It doesn't matter if the work was unnecessary or didn't give the intended result. I took the car to the original dealership, where the car was documented to have been serviced consistently. Even the service advisor there couldn't say whether if anything was replaced or not, and he was confused about how they misdiagnosed the car twice. The original MB dealership I took it to in my local area refused to provide me any work, service, or parts, orders, or receipts. At this point, I've given up there, and I'm trying to see what else I can still do to keep the car.

Isawelvis

Any Mercedes Dealer can provide you with a VMI on the Vehicle. It will show any work, parts order to include body parts, etc that any Mercedes Dealer performed on the car. Its a Merceds car history

newtotheforums

That's what I was told when I went outside of my local MB to get it looked at. The same service advisor there told me he couldn't tell if anything was replaced or not but then mentioned that everything done on the car was uploaded to that database so anyone anywhere could see it. He only mentioned that because I had told him my local Mercedes said they called this dealership, I took it to, with the original diagnosed problem. Where he then said dealerships don't do that because of the database (VMI).

Isawelvis

I had my Mercedes Service Advisor, whom I have worked with for several years, print off a copy of the VMI on my 2015 ML when I was working some issues with CarFax. They can do it, its nothing classified .

newtotheforums

I wish I could have known that sooner and thanks for mentioning that. I probably just could have asked him to print that out when he said he couldn't say whether parts were replaced or not. Curious as to why he said that now. The one thing he also mentioned was the Xentry diagnostic being "classified" as under some law he couldn't let me have any diagnostic information for the compression test. Is that true also? I assume I can go to another dealer and just ask that first thing and maybe send that information off to my bank. I originally asked my local MB dealership to provide me anything (service, parts, etc.), and they refused to give me anything.