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

[Dick Spellman]

Christophe:

I remarked <> below in your last message.

Dick

nom wrote:

>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 ?  <Not necessarily, is this occurring while you are going down a steep grade with the engine helping with the braking.  Do you live in hilly terrain where this is often the case?>
>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.  <If you are not seeing oil consumption by checking the dipstick before an oil change then I would leave the car alone and enjoy it.>
>Oil is 15W40 and change every 5000km or 1 year because it doesn't drive a
>lot per year. With MErcedes filter only.  <Good.>
>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.  <Again, where you are not seeing oil consumption at the dipstick, I think perhaps you are seeing a build-up of raw fuel (cold start) and or moisture in the exhaust and do not drive the car on long trips, just short ones in which case the car is fine with a bit of smoke expected at cold start and the first few minutes of driving.>
>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
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>
>>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
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>the
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>>same thing if the car is parked with front down when I start it, it smoke a
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>lot
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>>for few minutes.
>>All engine runs good but I don't know if oil goes directly to exhaust
>>    
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>manifold,
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>>or intake manifold and is burned as gas, or maybe a valve problem, or maybe
>>    
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>a
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>>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
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>
>>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.
>>
>>
>>
>>    
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>
>The MB Coupes Website!
>W126 SEC Mailing List
>Postings remain property of MB Coupes, L.L.C.
>
>  
>