Did Mechanic Kill My Mercedes Diesel Engine?

Reader Question Hi,

Help! I have a car, a diesel, which recently had the valves and rings replaced. The problems were burning oil and poor starting during cold mornings due to poor compression.

One of the valves was loud after the job was complete, and I complained 3 times to the mechanic that something was wrong. “No, that’s normal in a diesel” he assured me each time.

After about 4,000 miles, I noticed the car having trouble starting again. After several more thousand, I noticed smoke on startup.

Just before I took the car back to the garage, my girlfriend borrowed it. She phoned me saying that the car wasn’t running. She said it started making a noise like the spark plug fell out. She said she drove it slowly for another 10 miles to the next town.

The car was towed back to the garage, and the motor was disassembled. Upon examination, the head and the piston both looked like swiss cheese. The cam had two lobes with large chunks missing.

My guess is that the valve(s) were never properly installed, and eventually fell out and onto the piston, and the rest happened from this.

The garage owner maintains that since the car worked for 8,000 miles, that proves his work was good! I say hogwash, what say you?


Howdy Patrick,

Thanks for your email…..ouch, I feel your pain! I can only ASSUME from what I read in your email that either the original complaint was misdiagnosed or there was faulty workmanship during the repair.

In either case….the shop/mechanic SHOULD accept responsibility…..but you and I both know that will never happen.

I am not a lawyer, but trying to get any monetary return from the mechanic…..is probably nill. Seldom do I see or hear of customers (from other shops…not mine) getting money or any real return on their repair expenses.

The courts take WAY to long to get anything done, and the mechanic/shop is probably aware of ways to stay out of the court process anyway.

Bigger issue is what to do now? A new diesel engine could cost more than the actual cash value of the vehicle is worth??

Buying a used engine out of a wrecked vehicle in a junk yard could be an option, but you will have to take your chances, although you can sometimes buy an extended warranty policy from the junk yard on the actual engine itself…maybe not on the labor though.

You could have your engine overhauled….but as you have already found out, finding a reliable mechanic who is competent in overhauling a diesel engine can be hard to find.

Last option….cut your losses now, and sell the vehicle “as is” to a shady tree mechanic and buy another vehicle. This is a hard option for people to accept…but trust me, I have seen MANY people in similar situations that would have SAVED money/time/frustration had they accepted this fact and cut their loss.

I don’t know what kind of vehicle this is or what the cash value of it is at this point…or which options are feasible for you now, so those decisions are out of my scope.

Austin Davis

Posted in: Used Parts

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