Smoke and noises

[BenBaron]

So, here comes my next problem just as Im getting ready for my SVA,
started it up on Sat morning (quite cold I might add) and loads of white smoke comming from both exhausts, now then what could that be I wonder, doesnt look like oil burning as there is no blueish tinge to it so I hope its cause it was cold but if I reved it the smoke went away until the revs dropped again. It didnt use to do this only this weekend, so anybody know what that is? could it be something (hopefully) to do with my mixture or something? Im useless at tuning an by the way...

On the second front Im getting loads of tapping from the left bank of pistons hoping its just the lifters and I need to tighten up but could it be something else and could this be causing the smoke?

cheers
Ben

[dingocooke]

Probably stating the obvious here Ben; you did get it really nice and warm didnt you?
If not it could be condensation now that the ambient temp has dropped, and that is visble more at tickover and is white...Apologies in advance...

[BenBaron]

Hi Steve,

no appologies nessacarry, Im a novice when it comes to engines, so condensation would be luvly if thats what it is, it just worried cause I didnt knwo what it was, I'll warm it up tonight and see if thats the one, should it dissapear or just be a little bit?

Whats the SVA ruling on this, how do they check if its pollution or just cold engine if the test is just visual?

cheers
Ben

[dingocooke]

Hi Ben,

If you run the engine for about 5 minutes or so, it should get up to temp, but anything over about 80C engine water temp should see the condensation (if thats what it is) disappear gradually.

Not sure what age your engine is, but the older engines at SVA are tested for 'no visible smoke', ie no emiissions figures to comply to.
Im sure some of the SVA knowledgeable on here will help you on this one.

[BenBaron]

So is this condensation in the bores then? is that where its comming from? or have you a good explaination of where all this nasty smoke/steam is comming from. I assume then the smoke test will need to be done with a nice hot engine then

:thumb:

[wilf]

Oh Ben, Ben Ben.

Where to start?

An engine started from cold is just that - cold. The exhaust gasses always contain a fair amount of water vapour, and so, especially when ambient temps are low, and the engine is cold, you will see white "smoke" coming from the exhausts. So long as this condensation goes away once the engine (and the exhaust pipes) are warm, no problem. If it persists, even with a toasty hot engine, you may have cylinder head gasket problems. (doubtful, so don't panic).

Condensation tends to "disappear" or fade away as it blows away from the exhaust pipe, smoke doesn't.

SVA emissions tests are done with a hot engine, at it's normal operating temperature (they normally wait till the cooling fan cuts in to tell them the engine is up to temp, so make sure that is adjusted right).

[dingocooke]

bless him..

[tony]

Ben

As Wilf says:thumb: .

Both my AK`s beltched out white smoke from a cold start for about 2 mins until the pipes warmed up and it evaporated, nothing to worry about:thumb: .

Your engine will be well warmed by time the sva man tests it, mine had been running for 15 mins , just make sure they allow you to "purge" the engine ie. run it at 2-3000 rpm for a few seconds just before the emissions test.

[wilf]

Oh - we forgot about the tapping noise.

Let the engine run up to full operating temp before you get too worried. Then, if the tapping is still there, go look at the rocker clearances. What cam do you have? If you have hydraulic cam followers (tappets) it should self adjust unless you have got the preload wrong. You did set the preload, didn't you? I seem to recall you asking here about it, so it should be OK.

Often, these things sound like a bag of bolts until they have warmed through. (mine doesn't of course, it knows better than to do that to me )

Be aware that small exhaust manifold gasket leaks can also sound like mechanical tapping, and you may have to re-torque the header bolts more than once as the engine heat cycles for the first few times.

[Clive]

Hi Ben, as a rule of thumb, white smoke = water vapour (condensation)
Blue/black smoke = oil/fuel (Mixture too rich, or oil in cylinders from worn valve guides)