Greetings:

I am a new owner of an 1988 MB560 SEL. It is an awesome road car, wish I had gotten one earlier. In any event, when I come to a stop from say 90 km, there is a lot of blue smoke that comes from the exhaust. The car has lots of power and there is no blue smoke any other time. I have reviewed information on this Forum re this issue. The car has recently had the heads overhauled including new valve guides and valve stem oil seals, which seems to be a common cause of this problem. If I put the transmission in neutral and coast to a stop, no blue smoke, so it seems it is happening when the engine is doing some braking.
Anyone have any ideas on what may be causing this problem?

Thanks, Timberock

Check out what Steve Brotherton had to say in this thread. The color is different and the condition occurred going downhill, but in this case and yours, engine braking comes into play - higher manifold pressure.

How confident are you that the valve guide/stem seal work was properly done?

Lots of white smoke when going downhill

How many miles are on it? My first thought would be that the rings/cylinders may be getting a little age on them. It can run like this for years as long as you keep your oil topped off.

I am under the impression that if you rebuild a cylinder head high mileage engine then you increase the load on the bottom end and just make these types of issues show up a little better.

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Jim

I am going to be talking to the mechanic who did the heads and then I will have more information as to exactly what he did. I am assuming he knows what he is doing, but...

The 560 has 242,000 km. What you say makes sense, for engines are really nothing more than pumps, so that if one part becomes stronger (heads), pressures will seek the next weaker link. So does that mean that when decelerating, an engine is actually "sucking" oil out of the crankcase past the oil ring if they are not sealing properly?

Surprise, for some reason today, the car has stopped the blue smoke thing.
The car had been sitting for a long while, so maybe the recent driving has "woken" something up, I don't know, but for whatever reason, no more blue smoke.
Thanks to all for your suggestions.
Timberock

Timberock

Do you park your car on any sort of an hill or incline?

What is the cold oil level? (oil level checked after sitting over night)

What is the level or your ATF after fully warmed (after at least 15 miles of driving-dipstick is hot to the touch)?

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'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

I would have your mechanic check 2 things. Have him check the trans modulator for ATF on the wrong side of the diaphragm, and I would have him pull the valve covers and check the tightness of the cam oiler tube holders.

Peter

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Auto Zentral Ltd.

I lied, the smoke is back. Seems if I go for a big run, smoke disappears, perhaps engine is burning it faster than it can accumulate.

In any event, all the good stuff has been done in the past, so I am going to pull the Valve Covers and see if anything is amiss!!

Thanks, Timberock

Black smoke mean an overly rich mixture. Has it been using more fuel than usual?

__________________
'03 E320 Wagon-Sold
'95 E320 Wagon-Went to Ex
'93 190E 2.6-Wrecked
'91 300E-Went to Ex
'65 911 Coupe (#302580)

Blue smoke still happening but seems it is only if I am going downhill and come to a stop or slow down at the bottom of the hill and make the turn. When I step on the gas, I do the "James Bond" smoke screen thing.

Is there somewhere than "loose oil" is being allowed to say, run into the fuel system and then gets burned, but can't do this when the car is on the level??

Appreciate any thoughts on this

Timberock

Oil smoke under deceleration or after long periods of idling (and at initial startup) is diagnositic for worn valve guides and seals.

Something I have discovered about MBs is that they run much tighter valve guide clearance than american cars and trucks. If the mech that did the work reamed the guides to "typical" standards, they are too loose and leaking, and under high vacuum conditions are pulling oil down the intake valve stems. Will cause you to use about a quart in 1000 miles extra oil. Will usually result in a puff of blue smoke when you start first thing in the morning, too.

Bad seals, or seals that were not correctly installed will do the same thing.

Leaking rings usually cause blue smoke under high load, when the blowby overwhelms the recovery systems and dumps oil in the intake.

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!

Hey Timberock,
You know, my 190E had a similar problem no to long ago. I had intermittent blue smoke on acceleration/ deceleration, and some pinging. Everything checked out fine, oil leaks, compression, head gasket. Only one thing was out of whack. My ATF fluid was being used at an alarming rate, about a quart every two weeks. Even though no signs of an external leak, I found that my vacuum modulator diaphragm was leaking and ATF was being sucked into the intake manifold. Replacing the modulator fixed the problem and not a hint of blue smoke since. Check your ATF fluid level, you might have the same problem as I did. Good luck.
Randal

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1991 190E 2.3 SOLD
1972 911t 2.4 owned since 4/80 300,000+ miles SOLD
1999 C43
Merlin XLM, All Ti, 17.5lbs.