190E disaster!
 

My '88 190E 2.3 is dead. Mrs was driving it home New Year's eve and it lost power on the highway. She pulled over and could not start it again. We towed it to my father-in -law's shop and actually got it running on 3 cylinders. Investigation showed ZERO compression in #4 cylinder. OK so i guess we pull the head. Having done that look at what we found! #4 piston was burned right through to the top ring. It looks like a great deal of pre igntion was happening for a long time to do this kind of damage. Strange thing is I did notice a knocking in the engine over the last 6 - 8 months but thought it was valve noise. Guess not! I do wonder though what could have caused this in just ONE cylinder. (all others look fine and so does the head (relatively speaking).

Before I rebuild this engine with new pistons i want to be sure this is not going to happen again. Any ideas?

sonnybuddy

What a bummer. Sorry to hear/see this happen to anyone.

Questions

- Honestly, what grade of fuel did you run in it?

- Plugs: Brand and type?

- Oil filter: Brand and type?

- Oil: Brand and weight?

Haasman

I have (since I had the car anyway) always used 91 octane fuel, bosch plugs, 10W30 Valvoline Oil and I don't recall the brand of filter. But I fail to see what bearing this has on only ONE cylinder being this bad? Surely there is some other reason, or all of 4 of the pistons would show signs of detonation......

Do you have another picture of the piston and its cylinder wall? Close-ups?

Could it be that the injector for that cylinder was bad and that particular cylinder was running extremely lean?

Any damage in the combustion chamber of the head? How do the valves look near the area of damage? Is it actually melted away or chipped/cracked away? Bad injector does sound like a likely cause. If the valve is burned near there, I would look for bad valve stem seals/guides.

that is odd
 

my 88 190 2.3 has the same promlem. this was going on for a while because the cylinder wall is scored very bad. looks like a rough bore job. took off a lot of metal. bad injector?
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Rich

Thanks for all your helpful responses. I've pulled the engine and I'm now in the process of rebuilding.
I will certainly be replacing #4 injector and seeing if this cures the pinging.

If it does not, would this indicate a problem with the fuel distributor? Are there kits available for overhauling this unit? Looks pretty straitforward.....no more complicated than a carbuerettor....

I'm with hs_300e, a bad injector (or wiring harness) would cause the engine to run lean on that cylinder and would melt a piston.

You would see this on the spark plug you pulled out of this cylinder. If it was running lean, the spark plug would appear more burnt than the others.

Sholin

Bad injector or seal causing lean running will do this.

Combine that with low grade fuel, and you get detonation on the highway (that isn't audible, BTW), and melted pistons, burned valves, etc.

Good reason to check the plugs once in a while, and investigate running problems funny noises pronto.

Peter

I will certainly be replacing #4 injector and seeing if this cures the pinging.


hello-saw this on the post. please do all 4 injectors, with the holders and seals. you'll love the results. let us know when you figure out what caused the damage. thanks, chuck.