why do i have blue smoke on overun??

[theflyingbrick]

hello boys and girls not posted for a while as ive been busy sorting my life life out lol anyways my attention has turned back to my beloved brick and ive carried out some lovely little mods and well needed repairs....however....ive got plumes of bluey smoke bellowing out back after boosting up and lifting off!! now if i drive "normally" and dont boost up its fine its only really after moderate to flat out acceleration,at first i thought piston rings but wouldnt it smoke all the time?? i was also advised that it could be the pcv,so ive removed and replaced it but no difference,in fact i still have the dipstick smoke symptoms,ive now read that it could be the oil return blocked at some point!! im not sure so thought id turn to only people i trust to give good sound advice


oh just to add the turbo was rebuilt some weeks ago and the problem came later so dont think its that!!

[Harvey]

Sounds like turbo or valve stem seals.
If you leave it ticking over for 15-20 mins then rev up do you get a puff of smoke,or does it give a puff first thing from cold ?.

[theflyingbrick]

nope no smoke on idle or after 10/15 mins only after ive boosted up and shut off whilst driving!! and as far as im aware the smoke from stem seals or turbo seals would be white,this is blue

[oblark]

Mine has started doing the same as yours and I`m putting down to the valve stem seals.

[Kingsford G]

Check your compression 1st

[theflyingbrick]

Mine has started doing the same as yours and I`m putting down to the valve stem seals.

oh bummer ��

[stribo]

It could still be the PCV, check out Matthew's site, has something to do with the pipe from the PCV to the inlet pipe not being big enough
I'd give you the link, but I'm posting from my phone.

[t5 pete]

If it doesn't do it on first start up or after idling ide put my money on the turbo normally with valve stems it will kick a puff out when first started as oil seeps down and same with idling

[merc85]

Leave it ticking over 15 mins, blip the throttle. it will be quite obvious if the valve stems are leaking, sounds to me tho turbo seals, was the impellor shaft nice a straight, they are easy to bend when doing the nut up

[t5 pete]

It could still be the PCV, check out Matthew's site, has something to do with the pipe from the PCV to the inlet pipe not being big enough
I'd give you the link, but I'm posting from my phone.

Heres the main problem with the pcv pipe work

[Ettienne]

I said turbo to Oblark earlier, as his engine is a genuine Volvo replacement unit about 5 years old and 50-60k miles on it. I doubt the valve seals have gone in that time and the rubber will be fairly new.

[Ettienne]

Pct nipple thing

[t5 pete]

I said turbo to Oblark earlier, as his engine is a genuine Volvo replacement unit about 5 years old and 50-60k miles on it. I doubt the valve seals have gone in that time and the rubber will be fairly new.

Great minds think alike

[mike 850]

I had the same and it was a blocked pcv, ended up stripping the system and putting a bigger pipe and getting rid of the tiny ptc valve

[theflyingbrick]

I had the same and it was a blocked pcv, ended up stripping the system and putting a bigger pipe and getting rid of the tiny ptc valve

ive just replaced the pcv but didnt change the pct nipple so ill have a look at that tomorrow im also gonna drop the sump so i can fully clean all the ports connected to the pcv,if not ill rebuild the turbo again and see whats what

[theflyingbrick]

Heres the main problem with the pcv pipe work

is the one on the right blocked? or is the one on the left opened up? either way do you what the outcome was after works carried out?

[theflyingbrick]

I had the same and it was a blocked pcv, ended up stripping the system and putting a bigger pipe and getting rid of the tiny ptc valve

did you still use the ptc nipple but just with bigger pipework?? might be because its moddified now it needs bigger passage ways to breath??

[t5 pete]

The one on the right is how they originally are very very restrictive and easily block up the one on the left is one that I've modded and bored out to the same bore as the pipe work

[oblark]

Mine has only started blowing clouds of blue smoke on WOT today, so that rules out the turbo as I`ve been running the turbo for at least a month now.

My catch tank is vented to the turbo - maf pipe so if I get time tomorrow I`ll vent the catch tank to atmosphere and see what effect that has

[960kg]

nope no smoke on idle or after 10/15 mins only after ive boosted up and shut off whilst driving!! and as far as im aware the smoke from stem seals or turbo seals would be white,this is blue

What makes you say white smoke?...

White smoke = water vapour burning, condensation in exhaust , HG failure
Blue Smoke = oil burning, rings worn, pcv blocked, HG failure between water jacket and oilways. turbo seals, valve stems
Black Smoke = petrol burning, rich

It could still be the PCV, check out Matthew's site, has something to do with the pipe from the PCV to the inlet pipe not being big enough
I'd give you the link, but I'm posting from my phone.

Americans always go dramatic for attention.......the normal size hole is designed that size as the crankcase pressure works on slightly negative and i do believe if you make the hole larger you should in theory make the negative pressure situation worse `cos it needs more vacuum to pull out the fumes!.........smoke at the dipstick is normal to a point as the fumes decide to take the easiest route as you have removed the dipstick....logic really!....the time to be concerned is when the dipstick shoots out and oil follows.

I changed my PCV at 160,000 what the book says and replaced with all Volvo normal parts, no problem at all.

Mine has only started blowing clouds of blue smoke on WOT today, so that rules out the turbo as I`ve been running the turbo for at least a month now.

My catch tank is vented to the turbo - maf pipe so if I get time tomorrow I`ll vent the catch tank to atmosphere and see what effect that has

It won`t be valve stem seals on WOT as there is no vacuum in the head........it should be pistons or rings too sloppy in the bores or wrongly gapped.......you only get slight negative pressure in the crankcase in a good engine as the engine is only a pump and when some pistons go up some come down to negate the pressure.......being a 5 cylinder the pressure is not equal like in a 4 cylinder two go up two go down, but when knackered the old Ford crankcase tube at the side of the block would chuff like a steam engine when going uphill.

I do believe the flyingbrick is at the early stages of valve stems seals as usually it will smoke from a cold startup as the oil has drained past the inlet valves but he says it doesn`t also worn turbo seals will give smoke mainly on idle and especially after a hot 10 min idle, but it doesn`t .......it smokes when WOT and then lift the throttle which means he has caused a larger vacuum because of the revs. so then the vacuum in the inlet manifold will suck oil past the valve stems and give blue smoke out the back. The only other thing i can think of is if he replaced the turbo was the intercooler cleaned of oil?

The other good test is a trailing closed throttle on a steepish hill in 2nd gear when a high vacuum is caused and due to worn seals it will smoke slightly but at the bottom of the hill when you open the throttle whoosh lots of smoke.

Only my opinion!