1stmbenz

I recently purchased a 1993 400E with 111 miles. I recently took my car to a supposedly bimmer/ mercedes mechanic. When I went to pick up the car the car is now smoking excessively from the tailpipe, light blueish color, car is lazy and has a trembling feel. All these conditions were not present before taking to this mechanic. The mechanic told me the oil in the car before was very heavy and masked the true conditions of the car. Hard for me to believe. The mechanic said he changed plugs, gasket, my radiator was cracked. So the radiator was replaced. I would appreciate any input.

bamberger_1

The oil the "mechanics" mostly use is the most expensive synthetic oil. I would not recommend this for a car that age. My philosophy is rather to buy non expensive oil, and better change at half of the recommended milage. I have been driving MB since almost 20 years and never had a problem with that philosophy. Now back to your car. I guess you wanted to say your car has 111 kMls not 111 miles. Which gasket did he change? the head gasket or just the rocker chamber gaskets?
Normally heavier oil cannot mask a severe engine problem, since the "heavier" oil when under hot conditions becomes "light" anyway. Older oil tends to be "lighter" also. The question is whether the blueish smoke was present before the mechanic went in. On the other hand he could not damage the engine that bad now you have extensive (oil)smoke released. Can it be just condensate in the muffler systemevaporating? Which shall be just white and disappears as soon as the air desolves it. And that the car now appears "lazy" I cannot relate to the oil type.
Best would be to monitor the oil comsuption over a perilde of time, because if the release is extensive you will see the oil level dropping quick. Another recommendation is to have the compression of the cylinders tested. This would be shedding light on the conditions the cylinders and piston rings are. If this seems to be okay there are still the valve stem seals which can cause oil "flowing" into the cylinders, fouling the spark plugs and reduce the responsiveness of the engine since the mixture is spoiled by engine oil.
Hope it's nothing serious, since those cars are reliable and not receptive to those problems. Mine (inline 6) have both well over 180,000 miles on, and never let me down.

1stmbenz

The mechanic did a compression test and everything was fine. the mileage is 111 000miles. The car is smoking excessively from the tailpipe. Like a big cloud. I just don't understand how I can go from great acceleration and no visible signs of smoke to a smoking car with bad acceleration. I'm taking it the dealer.

tkd_M119

Beware of the dealership!!!!!!! I was having a minor coolant leak, so I went to the local dealership (Beverly Hills MBZ). Figured that it was probably something minor and my regular mechanic is bit hard for me to get to at times. Anyhow turned out that I needed a new radiator and hoses. They also told me that I need a new power steering pump (was replaced less than a year ago, was weeping a bit), a new coolant overflow tank (claimed it was begning to leak) as well as needing my accelerator cable tightend. I asked how much just for the radiator - their "estimate" was $1200!!! So I held off and went to my regular mechanic (Mr MB Motors in Tarzana, CA 818 708 8086). Still was not cheap but was some $400 LESS than the dealership. I DIDNOT need a new coolant overflow tank (no leaks) OR a new power steering pump (Enrique said that leaks are really common even if somewhat new) and my accelerator cable was just fine.

So if the dealership tells you things that don't seem to ad up, or simply seem too expensive, get another opnion! What I describe above is not uncommon and is why many refer to the dealership as the STEALERship!

bamberger_1

What the mechanic told you and what the tests show just does not add up. If compression was ok how can he say that the new oil "demasked" the true engine conditions? BS as to my opinion.
The other option are the valve stem seals, but they normally dont fail in an instand rather slowly and gradually. It can cause the blueish smoke. But also this seems far fetched. Generally heavy blue (oil moke) are broken piston rings or just worn piston/cylinder surfaces, but normally not at 111,000 mils.
Have the comprossion test done again, but somewhere else, and try to obtain the original protocol of the first compression test, then you may see a clue if there were differences between the two tests.

1stmbenz

My friend knows a mechanic who works for Mercedes. He looked at the car and found the following problems.
1) Too much oil in the car
2) Not enough coolant

The mechanic said its a possibity that the excess oil is causing oil to touch the plugs. Also, he said for the 1993 400E i should be using a 20 50 oil, not a 10 40 oil.

So this weekend, I'll drain the oil and replace the plugs. Can't be bothered to clean the old plugs. Also, add more coolant. I will get the compression test redone.

bamberger_1

My concerns are where did the coolant go if the mechanic replaced the radiator and refilled the system?? Or didn't he let the engine run to distribute the coolant and refill if necessary, before delivering the car to you again???
The oil story is another thing. The recommendation to use 20W50 is not bad, depending where you live. If you live in "Normal" climate it seems ok. As I said in my first post, dont use synthetic oil it is to light for older engines. On the other hand overfilling may not cause that severe oil smoke, unless something else comes with it, like the valve stem seals, which allow oil leaking into the upper part of the engine and burn there. So maybe the overfilling increases the oilpressure which then helps the oil to "break" through the valve stem seals and burn and foul the plugs. Under normal oil levels this may still be doing it, but with only little amounts which dont show visibly. this can also be the reason for the sluggish response of the engine since the extra oil is ruining the gasoline/air mixture.

richp

Overfilled oil will make almost any engine smoke. But it's not from valve stem seals. It's from excessive oil splashing in the crank case causing oil to coat the lower cylinder walls. Piston rings are, like any seal, only good at holding pressure from one direction - in this case its the combustion chamber. So, oil splashed on the lower cylinder walls can easily slip up into the combustion chamber and cause smoking.

I have had the same experience changing to synthetic oil on cars with only 10 or 20K. If the car isn't brand new, don't use it.