Our 1987 300SDL (Alfred) has developed a serious valve tap. When first started in the morning the car idles rough with an intermittent miss and smokes gray and white. It misses and smokes until about 2000 rpm where it smooths out and stops. Once the engine is warmed up it has a valve tap that is loud enough it almost sounds like a rod knocking. Again when revved up to 2000 rpm the valve noise and miss go away and the car runs flawlessly.

The car is in stunning condition and I would like to have it running as well as our 1987 300TD. We are new to Houston and need a good mechanic we can trust. After all I drive these cars because they are cheap to own and operate, not to put my mechanics kids through college.


Anyone have any ideas??? Help!!! I want my car running right with minimal smoke!

This type of engine noise may be from the lifters. MB has modified the lifters on this engine several times. REPLACEMENT is the only cure if this is the problem.

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I don't like the gray/white smoke part. You could have a cracked/warped head (problem with this engine) or a bad head gasket. Any oil in your coolant or vice versa?

Yeah, tapping noises are common with this engine and are harmless, other than perhaps to your sanity. If noise was the only symptom, I'd recommend running a can of diesel purge to clean the injectors - they can make this kind of noise. Then switch to synthetic oil - it can quiet down noise lifters.

But the part about the smoke bothers me. White smoke generally means steam, and that means coolant in the combustion chamber. I suspect you have either a blown head gasket and/or a cracked head. How is the coolant level in this car? Dropping?

- Jim

Greg,

Sad to say, but I agree with the others. These are classic symptoms of a head/head gasket problem - I know from experience one year ago. Fortunately, my head was perfect and the new updated head gasket solved the problem. Have it checked out by a competent mechanic who knows the OM603.x engine.

Regarding the lifters, though I suspect this is not your issue, I know a guy who has had his replaced by a VERY reputable mechanic THREE times. . . still tapping. Synthetic oil DOES help. Good luck.

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Chris

'04 ML500 - 53k, Inspiration Edition, Desert Silver
'11 Audi A4 Avant - Brilliant Black
'87 300SDL sold
'99 C280 Sport sold
'85 190E 2.3 sold

Go buy the two little o-rings that fit on the end of the oil filter cap shaft. Pull the cap and replace them -- the ones on there are rock hard and leaking, and the oil leaks down out of the tappets overnight.

The o-rings and synthetic oil cured the lifter noise on my 87 300D.

White smoke on startup is unburned fuel, in this case probably from flat intake tappets and hence "late and low lift" valve conditions. Goes away when the engine is reved up since the tappets fill.

White smoke at idle hot is water/coolant -- cracked head/blown gasket.

I assume the oil pressure is normal -- about 2 bar at idle?

If good oil and the new o-rings don't fix the noise, replace the tappets, they won't get any better by themselves.

Check out my posting on rough idle, too!

Peter

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1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Wow, thanx for all the responses.

First the white smoke only appears when you start the car cold. It stops blowing the white/grey smoke and goes to normal soot color with almost no smoke the instant it starts to warm up. It has the intermittent miss, which you can tell is on just one cylinder until it warms up and then the idle is smooth. But that is when the loud valve tap begins.

No coolant loss, no oil usage, oil pressure is fine.

Once the engine warms up the only time it misses is when you first start to accelerate and it stutters and smokes black heavily briefly and then smooths out and takes off.

Hey all,

I just test drove a 87 300 SDL with similar symptoms. Very rough idle when cold (had been sitting outside overnight at 30 degrees, glowed it about 4 times). Once warmed up, a single louder tick then the regular engine noise that goes away at about 2000 rpm. Car runs, accelerates, shifts, perfectly, turbo is good, maybe needs some cleaning.

The car has 232k on it and they want $3000 rock bottom price. Driver's rear door has decent sized rust on it, rest of the car is ok. Interior just needs seat springs and some Leatherique love, but otherwise everything work on it (has heated seats too!).

What do you guys think about this car? What's the average cost of a lifter replacement and/or valve job? I'd certainly be up for doing the diesel purge and running synthetic, etc, if it might help.

Thanks for any info!

-m

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Now:
2018 Tesla Model X
1999 S500 Grand Edition 164k
1992 300D 2.5 Turbo 287k
2005 E320 4MATIC wagon
1991 Alfa Romeo 164L 99k (sleeping for a while)

Then: 96 Lincoln TC, 93 Lincoln TC, 87 560 SEL, 87 300 SDL, 80 300D, 89 560 SEC

Lifters aren't too serious, just a pain. Rought idle cold that goes away quickly can be bad glow plugs or worn injectors, and at 200,000 plus miles, worn injectors aren't a shock.

Invisk:

Not a bad price at all, considering my brother just paid 12,500 for an similar car last year, although that one is in pristine condition -- still had the trap oxidizer until last week!

Peter

__________________
1972 220D ?? miles
1988 300E 200,012
1987 300D Turbo killed 9/25/07, 275,000 miles
1985 Volvo 740 GLE Turobodiesel 218,000
1972 280 SE 4.5 165, 000 - It runs!

Definately go for it! I paid the same for mine last year with 220K miles. The transmission bowden cable fell off and they thought the motor was dead because it was so slow, thats why it went cheap. I wish mine had heated seats! Mine starts up in 1 crank in 5deg. weather and it will have a rough idle when first started but a few revvs clears its throat and it idles perfectly. I have the same lifter noise too, I think all these engines do.

John