How's water getting into my exhaust?

[GTVeloce]

So, car is running well. The TS has been installed into the GTV and kept all original except exhaust (2" SS) after standard exhaust manifold.

On a club run yesterday, the guy behind me says that at the end of a blast I'm puffing a little white smoke. So little I can't see it in the mirror. Possibly it is happening during gear changes? Today I did a test and with the engine at operating temp, I placed a board behind the car and blipped the throttle. Sure enough, water splots appear on the board. Definately water (not coolant) and I'm not losing any fluids.

So, where is this water coming from? Is my exhaust running too cool cos I don't have a cat? I do run a lambda sensor but I'm not sure how much it does as I run it in open loop.

[Neil Choi]

Head gasket?  Water leaking into cylinder and blowing out the exhaust?

[Neil Choi]

Probably wrong as you said water, not coolant.

[Stuart Thomson]

So, car is running well. The TS has been installed into the GTV and kept all original except exhaust (2" SS) after standard exhaust manifold.

On a club run yesterday, the guy behind me says that at the end of a blast I'm puffing a little white smoke. So little I can't see it in the mirror. Possibly it is happening during gear changes? Today I did a test and with the engine at operating temp, I placed a board behind the car and blipped the throttle. Sure enough, water splots appear on the board. Definately water (not coolant) and I'm not losing any fluids.

So, where is this water coming from? Is my exhaust running too cool cos I don't have a cat? I do run a lambda sensor but I'm not sure how much it does as I run it in open loop.

OK, water is a natural product of the combustion of hydrocarbons, if you had only just started the car and it was still cold, then this is normal.

White smoke after a run will not be water, the exhaust gases are too hot to allow the steam to condense.  I suspect you may have a leaking diaphragm in your brake booster, the vacuum assistance draws brake fluid laced air into the intake system, where it is burnt to produce a white smoke.  Or it is coolant and you have a head gasket problem, coolant also burns to produce a white smoke.  Check compression on cylinders and keep an eye on brake fluid level.

Cheers
Stuart

[Cool Jesus]

I'm sure you know what to look for with a coolant leak, having performed an engine swap. Any bubbles in the expansion tank? Coolant, oil discolour?
New exhaust will condensate the air trapped in the baffles.
You don't mention any coloured smoke when you tested, could the puff have had a tinge of blue indicating a little oil past the valve stems off throttle?
With no engine performance symptoms, just watch your coolant and oil, but it feels like your new exhaust jûst needs to burn in.

[GTVeloce]

I asked the guy behind me if there was any blue to the smoke and he said no, he thought it was just white.

I do sometimes get bubbles in the coolant reservoir just after I switch the engine off. I have never noticed any while the engine is running.

The test was done at operating temp but I had just idled the car to that point so maybe the engine was warm but the exhaust not. I will retest after a good run.

The brake fluid is an interesting one I hadn't considered. I have a small leak from the reservoir past the rubber that seals the fluid level sender. Meaning it is hard to know if I am burning any as I am losing it out the top! Makes a lovely smell when it dribbles on the exhaust... I have another reservoir so I just need to accept the mess I'm going to make and do the job so that I can keep an eye on fluid level.

Definitely a compression test is on the cards now. Has anybody got a gauge they are willing to lend me in the Melbourne area? Happy to come to you.

Thanks

[Cool Jesus]

Hmmm, still not seeing any real symptoms of a blown head gasket mate, fingers crossed 

I certainly don't consider myself a mechanics back side, just a back yarder with a quickly increasing knowledge base on all things mechanical. Especially since coming into the Alfa fold.

No point regurgitating head gasket diagnosis, there's a multitude of threads on the net. Just find one that seems fair dinkum, rather than some idiots like myself gas bagging away.

Even so, the bubble check occurs during engine running, leaving the expansion tank cap off while you warm it up. Once warm, a couple of blips of the throttle will produce/introduce combustion chamber gas into the coolant system via the leak. Conversely, whilst driving, on deceleration or after a squirt on the throttle, the combustion chamber is quickly sucking hard as it throttles down. As such it sucks coolant into the chamber, hence a puff of white smoke after decel.

Either way, you will definitely notice power loss from the engine. Believe me, I've been through 2 head gaskets, and it only needs a nanomicron of a pin prick to screw up the combustion process. Then from that nanomicron to fully blown doesn't take a lot of driving around town, parking the car at the shops pondering whether the car was running OK. Come back 15 mins later and when you start it up on only half the cylinders you arrived on, there's a fog machine spewing out the rear end. Awesome...

During the very quick research I did on a point in my last post, before I posted, I did notice a post mentioned that a compression test isn't conclusive. My thoughts are if a noticeable compression reading is made, you'd have my fog machine from above. On this point, are you getting any odd puffs of smoke when you start up cold or hard start scenario? That would be water settling in the cylinder from the leak?

[Al Campbell]

... a compression test isn't conclusive...

Just trawling through my mental archives of half-ars*d automotive knowledge but I think a leak-down test is more definitve.

[Cool Jesus]

a leak-down test is more definitve.

Yes Al, thats it, couldn't think of what it was when I was typing away before.

[brook308]

The 1st thing I would do is have a look at your spark plugs, if water is entering a cylinder/s then you'll find a very clean plug and piston crown. Water may only be entering the cylinder/s during overrun vacuum conditions and may be ok under load, hence the white smoke on deceleration or during a gear change.