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Blue Smoke From Exhaust When Sitting At Lights

bnr#@

By bnr#@,
in Engines & Forced Induction

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bnr#@ Mentor

bnr#@

Posted
Posted

Was sitting at the lights today and sudenly noticed a fairly large cloud of blue smoke coming up behind the car, well past the spoiler...

This is the first time its happened, cant reproduce it again. Also there is some oil on the no 5 spark plug every time its been changed.

Car is 32GTR. Engine has been built, pistons are tomei, clearances are 2 thou. Head has been recondisioned and has JUN bronze valve guides and new nissan valve stem seals. Turbos are stock that have been rebuilt with steel wheels and new seals by Slide. The whole package has done 11000K's so far and is running on Motul Chrono V 10w40 oil.

Compression has been done and was 175psi in all cylinders except 5 which had 180psi (and a bit of oil on the plug)

Ideas of what it can be?

d-brodgtst Apprentice

d-brodgtst

Posted
Posted
oil in your exhuast from turbo seal? but I geuss then it would happen ever time it's hot..... dunno but I wanna know what the go is with the oil on the plug i get that sometimes.

is it using oil??as in low in the sump?

andygtr93 Contributor

andygtr93

Posted
Posted

Is the oil on the electrode of the spark plug or the ceramic?

Oil on the electrode side of the spark plug and blowing blue (oil) smoke would indicate to me that your valve stem seals are leaking. If your compression is fine then it won't be rings.

Does it blow blue smoke when you first start it? The metal valve stem seals would expand slightly when it heats up with engine temperature which, in theory, should mean it would leak more on cold start, then when the engine is at operating temperature

d-brodgtst Apprentice

d-brodgtst

Posted
Posted
Is the oil on the electrode of the spark plug or the ceramic?

Oil on the electrode side of the spark plug and blowing blue (oil) smoke would indicate to me that your valve stem seals are leaking. If your compression is fine then it won't be rings.

Does it blow blue smoke when you first start it? The metal valve stem seals would expand slightly when it heats up with engine temperature which, in theory, should mean it would leak more on cold start, then when the engine is at operating temperature

agreed, where is the oil on the plug,this is true most engines wont blow smoke when at NOT,more info plz

andygtr93 Contributor

andygtr93

Posted
Posted

The oil has to be getting into the cylinder from somewhere then. If its isolated to a single cylinder, that means it wouldnt be from the turbos because then it would go into all 6 cylinders and there would be oil on all the plugs. Seeing as how you have had the valve stem seals replaced thats the first place Id be checking... How much smoke is coming out and how closelely can you monitor the oil level... like if it only slightly drops over a few days it might be cheaper to just live with it and check your oil regularly

d-brodgtst Apprentice

d-brodgtst

Posted
Posted

my bad,slow on the reply,

i see oil on the thread of the plug on plenty of cars,at least 1 a day,culd be oil leaking from rocker seals,it doesnt normally come from the chamber,oil in the chamber normally ends up in the exhaust,id be inclined to agree with the valve stem seal comment,check them,could be leaking which is why you may have gotten the slightly higher comp reading on 5,

andygtr93 Contributor

andygtr93

Posted
Posted

Id just be monitoring the oil level and how much its blowing when you start it first thing in the morning... just MAKE SURE you check the oil level regularly, the last thing anyone wants is a GTR with a popped engine, as Ive just experienced, even parts are expensive and if you're not a mechanic, the labour charge would be painful

Best of luck with it

d-brodgtst Apprentice

d-brodgtst

Posted
Posted
head off thats a start lol

srry but im agreeing with andy on this,monitor it every day,when it starts consuming a lot of oil ie it burns 1/2 to a full litre in say a wk then id worry bout pullin the head off,i suggest you start saving some money...the heads comin off at some point...

andygtr93 Contributor

andygtr93

Posted
Posted (edited)

To replace valve stem seals...

exhaust and inlet manifolds off, which means turbos off, from my experience it would have to be near impossible to get the inlet manifold off with the engine in the car, possibly new head bolts depending if the ones used are stretch bolts, then getting the old seals out, the price of new seals, and then the reassembly. depending on labour rates, parts availability, and condition of everything else internally... could be a costly fix

Hence the reason I'd be recommending to monitor the engine oil every few days.

Or you could join the ever expanding club of GTR owners who spend all their money on their cars and get the head port matched to the manifold while everything is off the car

As usual its a case of how big your wallet is

Edited by andygtr93
d-brodgtst Apprentice

d-brodgtst

Posted
Posted
Thats a bit annoying as I just paid someone a fair chunk of money to recon the head while everything was apart.... may have to have a chat to them

could be worth a chat,it all depends on if they have warranty on the work they performed,otherwise your pretty much up that creek,

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