Idle Steam - please help

[dugums]

I have searched, but have not found an answer. If someone can help, or point me to a useful thread that would be great!

I have a fair amount of steam at idle. It has no real smell, (other than exhaust) it is not blue or grey, just a light, white steam.

I understand it has gotten cold out, but this is more steam than normal. I only have the steam at idle, no visible exhaust any other time.

The car is running really well - ~15 AFR's at idle and cruise, ~11.5 WOT. Boost is strong, etc, idle stable.

Here is what has been done:

Checked turbo for shaft play - none
Compression Test - solid, within spec
Block Test - negative
I'm not losing any coolant or oil

If anybody has any ideas for what I can check next, I would appreciate it!

Some of what was done recently

New composite HG with ARP bolts @ 75 ft/lbs
Rebuilt 57 trim turbo
Head redone - new valve seals/etc
3" DP, Cat, Cat-Back
New IC and hardpipes
New Radiator
AFPR
Walbro pump
Cleaned/flowtested injectors
NEO AFC
Charcoal Canister removed (awaiting a new one)

 

[ms07s]

If your not overheating/leaking/mixing fluids/smelling of fluids/or running bad, I would have to guess it to be condensation and that your are as paranoid about your supra as I am about mine.:naughty:

So it only does it at idle and not under throttle... How cold is it there? When its under 55 or so here you always get a little smoke/steam out the exhaust when it is sitting. Very good question.....hopefully someone else will chime in...(hint hint)

 

[thelonerider]

Engine get wet or washed lately?
Did you replace the small PITA coolant hoses at the back when you did your head? These like to split and pin hole leak.
Where is the steam located?
:dunno:

 

[dugums]

Again, nothing is leaking/mixing. If I did not make it clear, the steam is coming out of the tailpipe. This is not an underhood leak problem.

Engine has not been cleaned (it was just rebuilt, so it is clean).

I thought I was being paranoid for a little while, but the steam is excessive - not to the point of fogging out the neighborhood, but enough that it looks like something is amiss.

Are there any other addressable conditions that would cause steam?

I cannot think of any other tests to run and was hoping that maybe somebody could give me some guidance.

 

[james_9876]

I'm having the same problem and have found nothing yet!! >.<

Weather: 30~60F Been cloudy latly. Just paranoia I guess. I am using a little bit of oil though.

 

[hellraiser456]

i bit of extra steam when the engine is cold is completely normal....combustion produces water...or at least from my understanding. and i believe cats will produce more....i could be wrong though.

you have gone threw the BHG test so i wouldn't worry about it...unless its a ton. every car i have seen smokes white a bit when it is cold.

 

[dugums]

i bit of extra steam when the engine is cold is completely normal....combustion produces water...or at least from my understanding. and i believe cats will produce more....i could be wrong though.

you have gone threw the BHG test so i wouldn't worry about it...unless its a ton. every car i have seen smokes white a bit when it is cold.

I wouldn't have bothered anybody if it was just a tiny bit out of the ordinary. I'll have to find a buddy with a video camera to capture what's going on.

I'm not that worried about it, I just have spent quite a bit of time and money getting this thing running perfectly - I'm not going to stop until I know there is nothing I can do about it.:icon_razz

Anyway, maybe if I can find a camera, I can capture my first few high speed passes, the motor/turbo is about broken in:naughty:

 

[Supraholics]

Does it stop or reduces once the car is warm?

 

[GrimJack]

Keep an eye on the coolant level in your overflow - if that starts to drop, it's time to worry. You'll need to heat cycle it a lot to make that happen, if there is a problem.

 

[dugums]

Does it stop or reduces once the car is warm?

I would say there is a slight reduction in the amount of steam - still over a normal amount.

 

[dugums]

Keep an eye on the coolant level in your overflow - if that starts to drop, it's time to worry. You'll need to heat cycle it a lot to make that happen, if there is a problem.

Coolant level has been dead solid.

Like I said - it's running really well. Other than the fact that I used a composite gasket, the build was done with utmost attention to detail.

I've been driving it quite a bit, so it's gone through a good number of heat cycles. Now that it's broken in a bit, I have been pushing it harder in an effort to magnify the problem (smart, lol) - to no avail.

Even if I can't get a video camera, I'll just take some photos so you can see the amount of steam I'm talking about. I have had a few Supras, and even though every car is different, I just feel this is a touch abnormal.

The change to colder weather (when I started noticing the excessive steam) also happened to coincide with when I installed a Walbro pump and Aeromotive AFPR - just to add something to the timing of this event.

I appreciate all the help guys!

 

[dugums]

I am wondering if you guys can address this question in a little different way.

As hard as it is, let's forget about the 7M's problems with BHG's -- we can do this because I know the symptoms and have/will continue to test for this until I can resolve (or give up on) this problem.

Let's also assume the integrity of the build is good. We can do this because if this is not true, I am going to get more severe (easier to identify) symptoms in the near future.

The Walbro is pumping fuel and the AFPR is working as well - so let's forget those. (not that I know how these would cause it anyway).

So the question is - if we assume there is excessive water (not from the coolant system) coming out of the tailpipe, what conditions are possible to cause this?

I'm sorry to phrase the question like this - or ask you to not think about some of the classic diagnoses for this vehicle, but I guess I've already learned the common answers through research, so I am looking for some less common causes.

I wanted to also throw this out there - is there any way this could be caused by bad gasoline or the ~< 1/8 tank of gas that was sitting in the tank for four months? (it wasn't run until it was filled a full tank of premium)?

Again, I am at a loss -so any suggestions are welcome!

 

[eman2289]

The only thing i could think of would be condensation.

Paging IJ! lol

 

[NewGen]

Your gas could possibly have water in it. But most gas has aleast alittle. You could try draining it and getting different gas to try in it. It could also be a combination of both condinsation and water in your gasoline.

 

[jetjock]

The major byproducts of combustion (at least good combustion) are CO2 and water vapor. Toss in colder ambient temps and it all sounds normal to me.

 

[IJ.]

^ What he said

Sounds like it's actually running right, exhaust pipe temps might be a little hotter than normal turning the water into steam but when mines running right it gets a bit of a dribble from the pipes.

 

[dugums]

^ You know, I don't think I was analyzing this the right way. There are a couple things that I did differently on this car compared to the other Supras (and other models) that I have had.

I almost certainly have hotter exhaust temps coming out of the tailpipe: The exhaust manifold, turbo exhaust housing, and downpipe have all been coated and should be flowing significantly more than my other systems. It has also been leaned out a smidge over the range of engine speeds; so, in general, the system is going to stay hotter overall when in operation.

Based on your responses, now I am thinking that what I consider an excessive amount of steam is actually a result of moving the heat more effectively through the system?

Well, thanks for the input - it would be very nice if my problem is a non-issue. I will update this thread if anything else comes of this - I hate finding all these similar threads that never post a conclusion.

 

[dugums]

I thought I would put an update on this in case anybody else has the same "problem".

I don't know if it's a meaningful test at all, but I put a large metal plate behind the tailpipe to see what accumulated on it.

Sure enough, it was water - a lot of water. It also does not smell like anything out of the ordinary - just normal exhaust. I also put my hand behind the tailpipe to see if it was filmy or oily - and it was not - sort of just a warm mist.

I also noticed that it's much worse when the car is cold - meaning when it warms up there is still a great deal of steam - but a tad better.

I am still convinced that there is some reason I am getting so much steam - but I guess I'll just have to deal with it now.

I will update this thread if anything comes of it.

 

[7msupradude]

After reading your mods, acknowledging that you are running a cat, your car is just fine. Having a free flowing exhaust will increase exhaust flow (obviously) and that cat turns the majority of hydrocarbons into H2O, water. (read your catalitic converter box, it will explain that) Just remember that you are driving a high performance car with a free flowing exhaust & Cat... it is naturally going to produce more condensation/ "steam" in the cold weather than the average car in front of you.

 

[theprodigy79]

I agree with the post above; ever since I installed the DDP and 3" high-flow cat I've been getting a lot more condensation blowing out in the cold as well... I was a bit nervous about it at first, but all else is fine so I'm guessing it's just the free flowing exhaust.