Hi folks,
Sorry for the long, long post, but who knows what detail might be important to the trained eye

After many happy miles (from 64k-150k) with a 1987 190E 2.0, I bought a 'bargain' 1989 190E 2.6, 109k, full service history, one elderly user, who serviced it every 3,000 etc.
For a couple of weeks, 1,000 miles, it was a flying machine (though I didn't thrash it) . I had a full service (plugs, oils, filters, fanbelt, plus usual checks) - still fine, then...

Maybe coincindence, but after unusually driving in city traffic for a couple of hours (no visible signs of overheating), the idle gets rougher, though it's still easy to start. Engine seems to lack a little performance as if the handbrake binding!, or low-octane fuel. No weird noises, no massive oil consumption, a little bit of parping from the exhaust - though it's always sounded a bit more boy-racer than my old 190.
I'm commuting up the motorway a week or two later, when power seems noticably down (still able to do 70mph). I pull over into service station, listen to engine (nothing odd, though it's shaking around a bit!), gun the throttle - no smoke, a tiny, tiny backfire.
Back on the road, now it struggles to do 40mph, off the road again and get breakdown recovery.
He checks spark on all six cylinders - all fine. Then pulls lead while engine running - three cylinders down (3,4,5 counting from front of engine) so that the idle doesn't change when you pull off lead. Four and five look a bit wet (not oil?). Diagnoses blown head gasket. BUT no overheating, no loss of coolant, oil looks fine. Flatbed truck home.

My regular mechanic, who originally guessed split rubber somewhere on the inlet side, checks compression - "none" on 3, others ok. 4 and 5 plugs (300 miles old at most) covered in crud, ?carbon?. Now he guesses, in order of horror: broken rocker arm, burnt valve, holed piston, and I'm trying to be a big boy and not cry.
He is going to lift the top cover and check out his rocker arm theory, then it would have to be head off etc...

My questions are:
could it be something much cheaper, please? is my mechanic ignoring the obvious somewhere? might injector replacement/clean clear this whole mess up for me, without surgery? I've read the relavent posts but can't work out if this might be a cure at this stage, or just a cause.

I paid £1100 for the car ($1900?) - I love it and would pay the £500-ish for the top end job, replace the valve(s), guide seals etc if I knew we'd got to the cause of the problem too...but I'd need to cut my losses now if the car's going to be a money-pit - I've got a 110m/day commute.
Lucky I hung on to ol' Rusty.

Thanks for any advice you can offer,
best wishes
Alex
1987 190E 2.0 150k
1989 190E 2.6 110k

Can't see you getting off easy with a dead cylinder. There is an outside chance it could be the intake valve not opening, or the exhaust valve sticking. I sort of buy the head gasket theory because the neighboring plugs are crudded up.

Good luck and please keep us posted.

__________________
Chuck Taylor
Falls Church VA
'66 200, '66 230SL, '96 SL500. Sold: '81 380SL, '86 300E, '72 250C, '95 C220, 3 '84 280SL's '90 420SEL, '72 280SE, '73 280C, '78 280SE, '70 280SL, '77 450SL, '85 380SL, '87 560SL, '85 380SL, '72 350SL, '96 S500 Coupe

Zero compression on one cylinder means a major leak. You can remove the cam cover and rotate the engine to see if the valves actuate properly. They probably will, and the most likely culprit is a burned valve.

A holed piston is also a possibility, but the only way to verify and correct the problem is to remove the head and go from there.

Duke

Thanks guys,
Still waiting on verdict from cam-cover lift - now bracing myself for the worst! I'll post results.

Thinking about possible causes:
Forgot to mention in original post that someone had removed aux fan fuse (replaced). The rad fan always turned fairly quickly before and after fuse (unlike my old magno-clutch 190) but got the ok from mechanic.
Again, unlike old 190, the temp gauge never reached heights where fan would click in properly (it stayed just under/over 80C) - so I just forgot about it.
Now I'm thinking these were signs of an overheating problem - no coolant burn, no temp gauge in red, no excessive oil consumption - must be trouble

You've got at stuck and/or burned valve. -Possibly because of a broken rocker arm.
If you had a hole in a piston, thick oil-smoke would be billowing out your exhaust..

But think about how great it will drive after a complete valve job.

Freestyler

__________________
Never criticize someone until you've walked a mile in his shoes. That way, when you do, you're a mile away -and you have his shoes!


'86 300E optically converted to '95 E300 (Sold)
-Blauschwarz on silver
-Black leather
-17" AMG & 15" AMG for winter

I bet it is the head gasket since this
is a common problem on the 190's.
There is a thread on this at 190rev and
most gaskets go before 100K. Mine was
done at about 75K before I bought the
car.

91 190 2.6

Burnt valve was the verdict - major surgery required.

Mechanic says: oil everywhere, so valve guide seals etc all round - basically reconditioning head, replacing chain etc.
Funny it didn't seem to smoke much.

Had banked on that verdict and he'd already quoted £800 ( $1400?) - but then the bombshell.....
He can't guarantee the problem won't simply arise again because, and I quote: "with that much oil getting burned, the drain holes will have become bunged up with carbon - I'll have to drop the engine, and take the pistons out to clean up properly"

Can we engine flush? "No"

I've searched the forum and find lots of valve guides/stem seals/burning oil/burnt valve threads - but no mention of there being such a dire consequence, piston-related consequence.

Any ideas would be greatly appreciated - or am I just being milked? This 'piston work' is nearly doubling the original total cost - and would obviously include new rings. What are the odds he subsequently suggests a rebore while we're at it?

For a $2000 car, spending $2500 on what seems like a complete engine overhaul is a worry - particularly as the car had apparently been very regularly serviced.
Can I smell lemon?

thanks for any help you can offer -

Alex

As stout as the bottom end is I would say "do the head work and drive the car."

Some updated pistons are available to address a thermal piston knock, clattering during cold acceleration. Should you decide to go that deep I strongly encourage the newer pistons.

thanks for the tip.
new pistons?!! aaargh!!

if - as my mechanic suggests - excessive oil burning means gummed up piston rings etc, could there be a less drastic cure than new rings?

and if it was just left, but the head work done, with new guides seals etc, would that really be a problem?

(crossing my fingers for a cheap solution)

sorry MrC, but I'm being a bit thick - I think it's the stress...

just re-read your post and I'm not sure if I understood you properly the first time -

Are you saying do the valves etc, forget about dropping the engine and cleaning up the pistons?
But if you do go the piston clean-up route, why not bung in these new better ones?

BTW Apparently the valve guides are 'totally shot', but the cam, rockers are all fine - suggesting, if the odo is accurate, a hell of a lot of idling in traffic, or short journeys?

thanks again

Upon visual appearance of the bottom end reconditioning the cylinder head may work just fine. This thought pattern is based solely on the bottom end being in good condiition. If the bottom end is all coked up than you may want to consider addressing it. Should you select to go into the bottom end I suggest exploring the cost difference between new Piston Rings vs. New Pistons with Rings.

I think you are getting a little ahead of yourself. First if the rings were gummed up then your oil comsumption would be high and according to your other posts it was not. The service intervals were 3000 miles which did not allow the oil to get too dirty. Also you indicated the valve guides were shot, that could be the cause of the heavy build up and not the piston rings.

Keep this in mind, the vehicle was running fine and when the valve failed you did not operate it for long thus minimizing the damage.

The bottom end of these engines are tough and can take a lot with out failure, go with the head job and use a good synthetic oil for lubercation, I believe you should be ok.

Just my two cents,

Check your records to see if you have original injectors. You can tell original from replacement one's ,original were steel and replacement one's are brass. #3 injector most likely died or went lean and burned your exhaust valve. Do your valve job and leave the bottom alone.

slewman,
do you know why they changed from steel to brass?
Does it bring more life time or just more money as spare parts?

__________________
Keep us posted especially if your problem is solved
Present cars:
My car: E-class 420CDI, 2008, W211, V8, 180 000km

Wife's one: C-class 220CDI Sport Coupé, Euro, 2002, W203. 345 000km

Son's one: GLK class, 220CDI, 2009, W204

Sold: E-class 260E, 1988, W124, Wonderfull car sold after 489 000 kilometres of reliable services (engine M103, clutch, brake system and 5 speed manual gear box all original).

Sold: E-class, 320CDI, W210, 2000, 225 000km

The brass one's are less likely to develop varnish build up and fouling.