results of compression test - ok? - PeachParts Mercedes-Benz Forum

Uk Merc Man · #1 09-01-2004, 04:58 AM

hi all,

I had several problems with my idle since my timing chain and tensioner replacement...see here http://www.peachparts.com/shopforum/showthread.php?t=101020

I bought a compression tester and ran a compression test this evening to see what’s occurring - results as follows:

1 12.2 bar
2 12.8 bar
3 12.9 bar
4 12.8 bar

So, cylinder 1 is slightly down, does anyone have thoughts on that? Bad valve or something? I have no blowback so am confident rings are ok, engine still runs as good as ever from 2000 rpm upwards.....

Ali Al-Chalabi · #2 09-01-2004, 08:57 AM

I say it looks good. All the numbers are pretty much in line with each other.

ctaylor738 · #3 09-01-2004, 11:58 AM

I thought it looked good as well, and then after thinking some more, it seems suspect. #1 is probably not out-of-spec, but something is going on, probably with the valves, given the closeness of the other readings. I would try a can or two of Techron in the gas tank and see what happens.

Did you ever resolve your idle problem?

Uk Merc Man · #4 09-01-2004, 05:53 PM

Quote:

Originally Posted by ctaylor738

I would try a can or two of Techron in the gas tank and see what happens.

Did you ever resolve your idle problem?

nope, idle still bad although after setting mixture correctly it got better. i accepted defeat - its in the garage now, I'll hear whats up soon. 1st time in years a car has beat me and I have had to use a garage....

also, what techron???

Tinker · #5 09-01-2004, 07:48 PM

You pussy, never surrender!!!!

Actually, I know exactly as you felt. I chased stalling/surging issues with my wife's 16V for over a year. I even tried to talk my neighbor into fixing it. He is an old German mechanic with a Audi/BMW/M.B. shop. He came over and threw out some suggestions, but didn't want anything to do with it. I could just hear that little voice inside his head saying this thing is going to waste many hours of his time.

Unfortunately, I haven't found an independent like Stevebfl, MB Doc or a few other good mechanics and big contributors to the success of this site, within my area. I've become rather self sufficient in diagnoising and repairing all the car's issues/problems, so far, (knock on wood).

If the Benz is your primary transportation, then it becomes that much more important to get it running correctly/quickly.

I hope your mechanic is qualified to diagnois it and won't simply throw parts at it.

Please let us know what they discover.

Best of luck.

Tinker

Uk Merc Man · #6 09-02-2004, 08:09 AM

Good News: car is back, running like a charm, repair bill was a quite reasonable £130.

Bad News: it was me

valve timing was out....

Oh well, it works now!!!

Quote:

Originally Posted by Tinker

You pussy, never surrender!!!!

Actually, I know exactly as you felt. I chased stalling/surging issues with my wife's 16V for over a year. I even tried to talk my neighbor into fixing it. He is an old German mechanic with a Audi/BMW/M.B. shop. He came over and threw out some suggestions, but didn't want anything to do with it. I could just hear that little voice inside his head saying this thing is going to waste many hours of his time.

Unfortunately, I haven't found an independent like Stevebfl, MB Doc or a few other good mechanics and big contributors to the success of this site, within my area. I've become rather self sufficient in diagnoising and repairing all the car's issues/problems, so far, (knock on wood).

If the Benz is your primary transportation, then it becomes that much more important to get it running correctly/quickly.

I hope your mechanic is qualified to diagnois it and won't simply throw parts at it.

Please let us know what they discover.

Best of luck.

Tinker

Tinker · #7 09-02-2004, 09:25 PM

Steve,

Congrats! Glad to hear its running and it didn't cost you an arm and a leg. You must have missed the cam timing by a tooth? In looking at your prior posted pitcures, does look like the dimples on the sprockets are a bit high?

Even doing the chain and tensioner yourself, you still probably came out ahead dollar wise. As long as you value your time at $0.10 an hour like me.

Enjoy.

Tinker

Uk Merc Man · #8 09-03-2004, 03:15 AM

the same garage quoted £500 for the job. it cost me £80 in parts plus the £130 for them to rectify my mistake, still loads cheaper than the garage doing the whole job......just glad its all sorted now

Quote:

Originally Posted by Tinker

Steve,

Congrats! Glad to hear its running and it didn't cost you an arm and a leg. You must have missed the cam timing by a tooth? In looking at your prior posted pitcures, does look like the dimples on the sprockets are a bit high?

Even doing the chain and tensioner yourself, you still probably came out ahead dollar wise. As long as you value your time at $0.10 an hour like me.

Enjoy.

Tinker