With advice that I should have this checked out, I took it to an indy who did a compression test. He refused to do both dry and wet, so I only have dry numbers: 135 on #2, and the rest 145-150.

Is a dry number of 135 a definite evidence that the cylinder is ok? Or would a wet test provide that assurance?

I'm asking because the mechanic told me that he won't do a wet test because it means nothing, and that I've been reading too many weekend warrior websites. But, his assistant (who actually did the work) told me later that he didn't do a wet test because he was afraid that he might blow up the engine if he did. What the hell? I paid $240 for this ambiguous info! And he was only authorized for $120 to begin with....

To boot, I took the car in with 1 bad cylinder, and when I took the car back, it had two bad cylinders. He said I should replace all my plugs (only ~12,000 miles on them) to Bosch (I have NGK BCP5ES), all my plug connectors, and two coils.

The funny thing about this is that he said the #2 & #8 coils have to be replaced. But, I tested the car with just 4 cylinders (1,4,5,8) with the firing order 1-5-4-8-6-3-7-2. That means the engine was running 1-5-4-8-X-X-X-X, and it ran like that fine. If it were true that #8 was bad, that means I actually ran 1-5-4-X-X-X-X-X, and I seriously doubt the engine would have done that.

So, when I picked up the car, the car ran worse than ever. Before, the car shook like 7 cylinders. Now, with #8 gone after the mechanic touched it, the thing ran like the wheels were square. And at idle, the car shook violently like it was a gangster car on hydraulics.

Well, I'm pretty disappointed with this mechanic (a Mercedes Certified Factory Trained blah blah blah), but those dry numbers are all I have to go on.

If I had an OBD II reader, I could swap the coils and find the misfire codes jumping around as I move the coils. Without that, my method was to run the car at 1,4,5,8 and place the #2 coil/plug/connector in for #1 and see if there was any difference. There was none, so I'm skeptical that it's a coil/plug/connector issue.

What would you do? I'm thinking about changing the plugs first, then connectors, then coils....

__________________
Beware of stealers
(and shill posters who work for stealers)