[W126 Coupe] My 500 SEC smoke when car down a inclined street

[Robin Jones]

Could be the head gasket. I had the same symptom some years back and the 
cause was a leaky head gasket -- the leak was mainly at the back of the 
head. Mostly, the leaking head gasket fluids would burn off without me 
noticing, but on nose-first inclines I think the leak increased and let more 
material through that showed up as white/grey smoke.

Robin Jones
'89 560SEC

----- Original Message ----- 
From: "nom" <cbcad at free.fr>
To: "Dick Spellman" <spell.yy at verizon.net>; <mbcoupes at mbcoupes.com>
Sent: Monday, May 08, 2006 9:27 AM
Subject: RE: [W126 Coupe] My 500 SEC smoke when car down a inclined street


> Hello Dick,
> Thank you for your answer.
> IF my car have a piston rings problem or a valve problem, it must smoke
> every time, no ?
> Why it smoke only when front is down and rear up ? It's amazing isn't it ?
> It doesn't consume oil or water, nothing. It starts without smoke and 
> turns
> very well.
> Oil is 15W40 and change every 5000km or 1 year because it doesn't drive a
> lot per year. With MErcedes filter only.
> When it smokes, the color is light blue, nearly white and it smells burnt
> oil. You drive the car 1 or 2 km and it stop to smoke until next downing
> road.
> I must do the next change of oil and filter, I do it and try to take a
> little bottle to do analyse it by a petrol compagny.
> REgards
> Christophe
>
>
>
> -----Message d'origine-----
> De : Dick Spellman [mailto:spell.yy at verizon.net]
> Envoyé : lundi 8 mai 2006 15:21
> À : Mercedes Coupes Mailing Lists; cbcad at free.fr
> Objet : Re: [W126 Coupe] My 500 SEC smoke when car down a inclined
> street
>
>
> Christophe Welcome!
>
> If you can, check the compression wet and dry on all 8 cylinders to
> confirm what is most likely worn valve seals and/or valve guides.  It
> would seem unlikely that the oil rings on the pistons would be the
> problem on your engine.  Much more likely that it is the valve
> seals/guides.  A less accurate method of assessing what is going on with
> the engine would be to answer these few questions.
> What grade/viscosity oil are you using?
> What is the oil/filter change interval you are using?
> What color is the smoke?
> Are you consuming oil?
> Are you consuming anti-freeze?
>
> Regards,
>
> Dick
>
> cbcad at free.fr wrote:
>
>>Hello to mbcoupe,
>>I'm Christophe from France and I own a 1987 500SEC in France. This car 
>>runs
>>great but since some month when I drive it on a inclined road (when car
> goes
>>down), some oil is burned in exhaust system and it smokes a lot of at rear
>>exhaust pipe ! When you drive it on a horizontal road, all is good. It's
> the
>>same thing if the car is parked with front down when I start it, it smoke 
>>a
> lot
>>for few minutes.
>>All engine runs good but I don't know if oil goes directly to exhaust
> manifold,
>>or intake manifold and is burned as gas, or maybe a valve problem, or 
>>maybe
> a
>>anti-pollution system fault, etc....
>>Someone can help me because I'm very sorry to see my MB coupe like that.
>>I hope it's not a big problem, next week I'll change oil and oil filter to
> see
>>if it change something.
>>Please can you advise me.
>>Sincerely
>>Christophe
>>
>>PS: How can I join the members's car list ?
>>
>>The MB Coupes Website!
>>W126 SEC Mailing List
>>Postings remain property of MB Coupes, L.L.C.
>>
>>
>>
>
> The MB Coupes Website!
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> Postings remain property of MB Coupes, L.L.C.