Smokey on start up?

[rockheadrumble]

Hiya all

My 940 has just recently got very smokey on start up. Il list what happens;

Turn the key
engines idles with no smoke for 1.5 mins ish
then the smoke gradually gets worse
it gets really bad and then starts to fade as the engine gets up to temp
when at full temp there is no smoke

If i rev the engine (3500or over) when sitting whilst smokey the smoke goes away. if i get in turn the key wait for a few seconds then start driving there is no smoke or if i rev hard whilst driving there is no smoke. if i drive whilst not up to full temp then stop and idle the smoke comes back intil up to full temp.

The smoke is definatly water, it is white smoke and when the smoke is at its peak water droplets come out the exhaust. And i am losing water.

Im thinking it is the head gasket or turbo seals. More so the head gasket as my car over heated the other day whilst queing, steam cam out the reservoir bottle. i forgot to manually switch my fan on, its on a switch at the mo as i have converted to electric from clutch.

I can understand why there is no smoke when driving or revving hard at idle though?

Any surgestions will be greatly appreciated.

thanks

joe

[AndysR]

If it's steaming out the exhaust to excess, bareing in mind that cars naturally condensate and if I remember correctly from my parent's 760 days these larger older cars due to exhaust length and silencer section configuration do condensate quite a bite during colder weather, then it means that the engine is vapourising the water during the combustion cycle. If it's doing that I would expect an oil and water mix visable on the oil cap and mixing with the engine oil itself and possibly you'd find the engine would run rough and ultimately overheat due to combustion gases overpressurising the coolant system.

[rockheadrumble]

Its definatly not just natural condensation mate, its alot worse than that, and it is only a recent problem that has occured.

I forgot to mention, i did a pressurisation check on the cooling system. i pumped it up to 15psi as instructions then it said to leave for 1 min. I left it for 2 as i nipped to the loo and in that time it had dropped about 0.2psi. if i had only left it for 1min as per instructions then the drop most likely wouldn't of been noticed.

il need to check the cap to look for mayonaise.

could it be the head is slightly warped from overheating so when it gets hot it expands and and seals the gaps?

thanks

joe

[jayeastanglia]

is the car using oil? Am thinking it sounds like oil seals in the turbo starting to leak a bit and the oil sits in the exhaust and once the exhaust heats up a bit the oil is being burnt..what colour smoke is it and if you can video it and post it on u tube and post the link up here

[Jim S70R]

If its using oil then it could be valve stem rubbers or like already said turbo seals are starting leak.

[rockheadrumble]

The smoke is white so im prety certain its water. Also it dissapates quickely after exiting the exhaust.

Does any body know if it was the head/head gasket or the turbo seals they would expand when hot and therefore seal the gap and stop the leak/smoke.? It seams strange that it goes away when revved or hot i would of thought revving it would make it worse.

Thanks for your replies.

joe

[jayeastanglia]

take a video of the smoke from start up till it goes..post it on utube and post the link up here

[andyb1375]

You need to carry out a block test as this will check to see if it is head gasket or block. pop round and i will do it for you.

[rockheadrumble]

You need to carry out a block test as this will check to see if it is head gasket or block. pop round and i will do it for you.

Ah great, thanks mate. Il pop round this week some time after work. What time would be good and which day? i finish at 4.30 but could get away a little earlier if need be.

thanks andy

joe

[andyb1375]

Ah great, thanks mate. Il pop round this week some time after work. What time would be good and which day? i finish at 4.30 but could get away a little earlier if need be.

thanks andy

joe

Joe

will be about tomorrow or any morning next week as working lates

[rockheadrumble]

ok mate, i could come round tuesday about 1030-1200? iv got to go to the hospital at 9.15 so could come round after that?

cheers

joe