Smoke From Exhaust

[itshimdazza]

Guys i know there is a bit of smoke from your exhaust when yo go WOT, but color should it be?

I have noticed that i leave a trail of lightish blue smoke (oil?) should it be of a black color?

I am hoping it not my rings or maybe head gasket?

so what color should it be and what should the cylinder pressure be if i do a pressure test on each cylinder be?

Dazza

[TiTAN]

you may get a puff of carbon (black) when you got WOT, blue smoke is not good.

[RB25PWR]

It'll be either the rings or the valve stems. Either way it means your engine is in a bad way and it also means spending $. Black is fine, that normally happens when you boot it. White is also OK, but blue spells trouble.

[The Dan]

What you need to do is confirm the exact colour.

Accelerate really fast, then quickly u turn and have a look. Report back ASAP

Seriously though, if you're at WOT you are not going to be able to tell the difference between fuel smoke and oil smoke unless there is a MAJOR issue with the engine.

Do a compression test...if the results are low, do a leak down test and find out where it's going

[NZM.031]

just cut some hoops bro.. do some fully hectic skids and check the different colour smoke... you could lots of different smokes though, clutch smoke, tyre smoke, fuel burning smoke, unburnt fuel smoke, burnt oil smoke, unburnt oil smoke, coolant smoke/steam, etc... so yo'll have to do lots of hoops to figure out what it is... you can tell by smelling aswell.. so you have to straddle the door and be half in half out or have the door open. if you get blue smoke.. dont worry about a compression test or anything, just hit it with a hammer till it goes away, if that doesnt work, use a bigger hammer.. if that doesnt work, youve got an electrical problem.

hope that helps...

Linton

[snozzle]

+1 for compression test + leakdown

if that comes up ok, could also be your turbo oil seals starting to fail

[itshimdazza]

Thanks guys but your starting to worry me.....

Ok so have you guys got any idea what the compression should be? and if thats fine is it the turbo?

and how does the oil get to the turbo anyhow (yeah i know dumbass question but i am new to turbos) I know its a standard turbo supposedly highflowed but i cant tell whether this is true or not?

actually how do you test the turbo for oil leaks/burns?

& last but not least.

If its rings/valve stem seals &/or turbo fcan you guys possibly give me an idea as to cost (ball park figure) of those things (individually) to get repaired!!!!!

Dazza

(nooby)

Edited October 15, 2009 by itshimdazza

[talky]

yeah my car did the same thing.it was valve stem seals

[NZM.031]

if it blows smoke on WOT, its usually rings (oil coming past the rings).. if it does it at idle, its usually valve stem seals (vacuum sucking it through the seals).

a genuine nissan VRS kit - Valve Regrind Service - which is all gaskets from the head up, can be found from a few sources for around $250.. this comes with everything you need to strip a head right down.. but replacing the valve stem seals is done from the top side of the head.... take the cams out, get a valve spring compressor and remove the springs, then you can get to the seals real easy... do the seals, put the springs back in, the cams back in, the covers back on, and your done. possibly take you or your mechanic half a day at a leisurely pace.

if its piston rings, its going to be a bit more.. obviously the engine has to come out.. sump off, head off, pistons out.. the problem here is... once you pay for/do all the work to get to this stage.. you mayswell do the bearings at the same time.. which is around $250 for ACL rod bearings and the same for mains i think.. and you dont want to put them in and have it be out of spec... so you send your bits n pieces away to be checked and machined..

at this point, it wont be much more to get a bit of lightening and balancing done.. now youve got a nice block, all machined up, and new bearings and rings.. and you think, well... nows a good time to put some forgies in it, while its all out, then ill have a really nice engine... throw in some RB26 rods which are a bit stronger than 25 items.. bolt it all up and you'll have a rock solid bottom end... good for 300+kw. but overall it cost you a shite load more than you wanted.. and more than dropping in a good 2nd hand engine.

while all your engine work is being done, you sit down with your head and do a little bit of work with the ol die grinder... just clean it up a little, get the valve seats re done, do the manifolds to match the ports.. and before you know it... youve got a nice tidy head, to go on a bulletproof bottom end, that will last you for many many years at a decent power level.

thats how rebuilds go haywire and cars are off the road for a year or two... and why big turbos end up on previously sedate cars... people just cant stop when rebuilding, and the engine is good for nice power, so they throw on a nice turbo... which then comes all the other stuff... fuel system, clutch, ecu, etc. etc.

but honestly... apart from the machine work... there is nothing on an engine that cant be done by you, at home... its all just bolts.. read the service manual and follow the destructions and you can put your engine together with a bit of patience, a few normal tools and a few special ones for measuring and tightening.. its nothing spectactular.

cheers

Linton