Gray smoke out back when accelerating

[tivoliman]

1992 190E 2.6, 204K miles

Seems to run well around town and such.

When accelerating to enter the highway - about 5,000RPM some smoke appears to be gray billows out the tail pipe.

The acceleration continues, though the 190E was never a rocket.

My concern is air pollution - I feel bad spraying that much ugly smoke.

Could it be Fuel Injectors - they have never been replaced?

Could it be Valve Seals - They have never been replaced, and I seem to notice a puff of black smoke at start up - though not much.

Currently adding 1 quart of oil at 500 miles.

I have the equipment and plan to do a cylinder pressure test.

Your thoughts and suggestions please.

[Bruno_300TE]

Could be coolant entering the combustion chamber due to a bad head gasket.
Bruno

[mctwin2kman]

If you are using a quart every 500 miles you most likely have some seriously worn wrings, seriously bad valve stem seals or a blown head gasket.

Grey smoke is a sign of oil burning. White would be coolant.

[t walgamuth]

i always think of oil as blue. is the grey dark or light? valve seals generally leak when decellerating with the foor off the gas. rings under acceleration. running too rich could be dark gray. coolant (steam) is easily distinguished because it disappears right away.

tom w

[blueranger]

your engine is wore out and need to be rebuilt...

it will be a great experience for you....do it now and it
wont cost a lot of money...

[tivoliman]

Thanks for the comments - Gray is my best description

I don't notice any ringing or exhaust output when I decelerate - that is let off on the gas and just coast.

I am thinking the engine could stand some attention. Perhaps a rebuilt head.

A friend drove behind me today in traffic; he didn't see anything emitted from the tail pipe.

[mctwin2kman]

Originally Posted by t walgamuth

i always think of oil as blue. is the grey dark or light? valve seals generally leak when decellerating with the foor off the gas. rings under acceleration. running too rich could be dark gray. coolant (steam) is easily distinguished because it disappears right away.

tom w

The biggest most noticeable part of the post was that he is using 1 quart of oil every 500 miles! That is some hefty oil loss and is most likely burning it due to the smoke he sees. Most likely a head gasket, but I was being nice and saying other things as well. Valve stem seals and rings even when worn pretty good will not allow a full quart in most cases to be burned in 500 miles. At higher RPM the head gasket will tend to leak more if it is going south. He should check his oil and coolant for any oil or coolant where it should not be. With that kind of loss it is either leaking out of the engine and down the block or into the combustion chamber. Either way something is seriously leaking. And the M103 motor is known to have head gasket issues after a certain amount of miles and time.

[tivoliman]

The radiator has plenty of antifreeze (nice and yellow).

There is no oil in the coolant.

I do suspect the head is ill.

Shall I have the timing chain replaced "while in there"?

This weekend I'll check the compression pressures between cylinders

BTW - there are drops on the driveway, but no big oil spots.

[kiwi_bloke]

I disagree, grey smoke is not oil burning.

Bright Blue smoke is a sign of burning oil, an easy way to check if oil is entering the combustion chamberi s to check the spark plugs, see if they are fouled.

My opinion on grey smoke is an over rich mixture.

The next statement is purely speculation however, My 190e had a faulty EHA valve, as a result the car was running overly rich and grey smoke was evident from the tail pipe over 3,500 revs under load.

When did the car have a service, IE air filter, plugs, mixture, etc. Because a clogged air filter will cause this, along with an over enriched mixture.

[JDmills]

Why not have a look at the spark plugs? If they are Oil fouled then you have a clue... if they are full of soot/carbon you have a clue.... Yes 1 quart of oil per 500 miles is heavy. are you sure that some of the oil is not leaking out of the engine due to old seals??

If the plugs imply it is oil:
I have used some snake oil called RESTORE on a briggs and stratton engine, that puffed white/blue smoke all day long, in fact it used half a pint every two hours, and the spark plug would foul almost daily.... I got sick of it, and added a half of a can of restore and it polluted less, had more power.. and got me through the season of resurfacing tennis courts.

If the plugs imply it is a fuel condition:
Does it only happen at 5000 RPM? and under a load? have you got a lot of oil/mist comming out of the valve cover when the engine is warm? It could be a overly rich condition, where the exhaust system is loading up with carbon, which does not come out until a High RPM load, thus high volume of exhaust sweeps carbon out... May be it is a lazy oxegen sensor....

May be it is none of the above.

[t walgamuth]

oil could be leaking out while underway and not dripping on dw. so i would be pretty sure before tearing into it mechanically.

tom w

[tivoliman]

Pulled the spark plugs - took a picture, but daughter is out with the camera.
No pictures to show.

What I saw - six spark plugs - all looking the same.
Ground Electrode - Whitish
Center Electrode - Edges rounded
Gap - twice as wide as it should be - should be .032 - .036
Black deposits near threads and "base'

Per the Haynes book - description of spark plugs - These plugs have "Carbon Deposits"

Then went to my logbook and saw that the spark plugs are 35K old, as is the air filter.

Actions taken: Readjusted the gap in the plugs (store closed or would have replaced) and replaced air filter - which I happened to have in stock.

I will report the results tomorrow.

[tivoliman]

I'm so confused?

How do these plugs look? Seem fine to me.

But if I'm adding oil - and the driveway looks good - where could the oil be going?

I still spray gray smoke or cloud when I accelerate past 5K RPM.

Air filter and plugs replaced - other than the gray stuff, car runs fine - though I think, the new plugs did add to the smooth ride.

Please review the picture and provide your assessment.

BTW - 91 octane is the standard fuel.

[t walgamuth]

worn but good. no indication of a cylinder down or such. no evidence of a burned valve. 500 miles per quart of oil may not be so bad for a 200k mile engine. what kind of oil are you using? if it is thin you might want to go to a heavier oil. also how many miles on an oil change? if you go too far the oil thins out and in an engine with some miles like yours it may burn out a lot faster after running 3000 miles.

also what kind of plugs are those?

my $.02

tom w

[tivoliman]

Using Quacker State 10W40, change (excpet for adds) 3,000 miles

I'm thinking since #6 has more oil than the other plugs (next to none) the valve covers are in need of replacing - still running with originals.

The #6 thing was posted on another thread.

So - just need to schedule a visit to the mechanic.

Thanks

I needed another set of eyes looking at the plugs. Especially since my preasure gauge for compression is "lost".