white exhaust smoke on startup

Hey all,
The jeep has been running well since I fixed the broken exhaust valve. I have a little issue with white exhaust smoke on startup. Most threads on this topic claim the head gasket and the white is burning the coolant. I followed a bunch of the suggestions posted in those, and need a little advice on where to go from here.

1) There is NO coolant in the oil.
2) There is NO milkshake junk under the valve covers
3) There is NO detectable loss of coolant from the radiator.
4) The exhaust does NOT smell sweet or like antifreeze at all. I don't have daul exhaust so I cannot narrow it down to one side. The exhaust smells like gas if anything.
5) Compression is very good. The dry numbers are 155, 155, 150, 160, 155, 160.
6) Plugs were a little blacker than ideal, but they were pretty good. Passenger bank ones were a little wet.
7) Retorqued bolts but they were good and tight.
8) Temperature (gauge) is spot on where it was previously, however it is a little less stable then it was before. Seems to jump around +- 5 degrees now, where before it wouldn't budge.

My questions are
1) Should some smoke be expected being that I have only put ~25-35 miles on it since replacing the heads? Possibly just residual coolant from that work?
2) I am running MMO in my oil and gas...could this have something to do with it? I thought running rich would lead to black smoke.
3) If I had a coolant leak, would the radiator be pressurized when I pull the cap after running it?
4) Have I missed anything? I REALLY don't want to pull the head again.

Sorry for being so long winded...I just think better answers come about when everyone has all the info...

thanks
jim

 

aren't the bad/weak valve seals associated with blue smoke? Is the white vs blue smoke color hard to distinguish? To me, the exhaust smoke is clearly white. However, from the "seals" response it sounds like I have covered my bases as far as a coolant leak and should look into buring oil issues...

 

Sounds like a valve seal to me.

 

you could pressurize the cooling system and watch for pressure loss; a radiator shop could do this.
are you sure no coolant is inside the exhaust system ? if so, it can take a while to burn off depending on how much.
you could try a can of Bars Leaks on the chance you have a weeping head gasket or intake gasket or some other abnormailty in the block/head surface.
the V6 from the factory doesn't use valve guide seals

 

Does it still smoke after the engine is warmed up?

 

the smoking has been minimal, if anything, over the last few days. I am wondering if I just had some coolant burning off from when I pulled the heads.

 

ok, so I am getting confused and frustrated and hoping for some advice on the motor. I want to take it out on some trails, long drives, but I am afraid to b/c I am not comfortable with her yet.

Some history, I had a bad exhaust valve and had it repaired. Reinstalled the heads and the engine seems to run very strong. No backfiring, plenty of power, no hesitation. It will cruise at 60-65mph, 180* and 45 psi of oil pressure. I am very happy with that part. The compression on all cyls is good (see above). I have put ~50-60 miles on it since the heads were reinstalled.
For a while, I had some white smoke on start up that'd go away once the engine was warm. It went away for a few days, but now it is back and worse. Everything from above (compression/no loss of coolant) is the same. New things include:

1) I can see a pool of water/oil on the tip of the exhaust pipe on startup that blows off as it warms up. Seems to be water/oil mix. It is mostly clear, with some specs of oil.

2) I have small oil leak(s) that amount to a teaspoon of oil on the ground after I drive it. I had low idle oil pressure (5 psi), topped of the oil (1/2 qt), and it went to about 20 psi at idle. This was on a warm engine.

I am just not sure what to do. I am really getting tired of fighting to find these little leaks and the smoke. Could the coolant/oil from pulling the heads take a while to burn off? Head gasket jumps to mind, but I am not loosing coolant. I had one response that the problem was seals, but another was that there were no seals on the engine. I am seriously considering pulling it and rebuilding it b/c I would just like to do it once.

thanks, jim

 

the advice I've given you is sound.

Have you been to a radiator shop and presuure tested the cooling system ?
You can do this yourself, but the Stant brand tester or any of the others are more than you may want to spend.

Have you tried a can of Bars Leaks ? This will seal any problem area around the head or head gaskets; this costs only a couple bucks at most. This is not a permament fix, but could help in finding the problem area.

Short of those two ideas, yank the heads, magna flux and check for cracks and replace the gaskets.

Since the problem is new since you removed the heads, logic would dictate that is the problem area.

 

Jim, I forgot that part. I pressurized the coolant system and had the air coming out the overfill line. It would kinda "pop" if i plugged it so I assumed the coolant was staying where it should. I didn't try bars leaks b/c of that test. sorry about that...I thought I hit everything! I fear I need to pull the heads again, but I am wondering why I had this intermitent smoke/no smoke/smoke. Plus, the sudden burning/leaking of oil.

could I still have coolant/oil in the exhaus since the reinstall of the heads? Maybe it needs more time on it to really burn off? I do need to find the oil leak(s) though.

 

the pressure tester takes the place of the radiator cap; kinda like a radiator cap connected to a tire pump.
you pump the system up to 16 lbs or whatever your system/cap is rated at.
leave it on for an hour or so and watch to see if the pressure drops; if so, you have a leak; internally or externally, assuming the tester is sealing properly.



http://www.amazon.com/Stant-12270-Cooling-System-Pressure/dp/B0002SRGWU

 

OK...
I added the Bars Leak and ran the engine for ~25 minutes. The temperature, which is normally 170 spiked to about 215-220 and I shut it down. Not sure what is up with that. Clog?

I started it this morning and it was smoking worse than ever. I took it in and they did a compression check on the coolant system and found that it has a leak. I am fairly certain that this smoke is coolant leaking into the exhaust due to a head gasket. The shop wants to keep it overnight to see the smoke/water out the tailpipe in the am, but I am a little hesitant. Any thoughts???

Sounds like a head gasket to me.

EDIT: I forgot to mention that they did the hydrocarbon test and it passed, so there is no gas in the coolant. Head gasket leaking into the exhaust.

 

I can empathize with you. It sounds similar to the situation I had earlier this summer.

http://www.earlycj5.com/forums/showthread.php?t=57318


Let's hope it's just the head gasket.

Eric

 

yep...i read that thread once or twice. I am 99% sure it has to be the head gasket leaking into the exhaust. There is like a little pool of water at the tailpipe in the morning after I start it. It sprays out if you rev the engine. I just don't see the need for the shop to keep it.

No coolant in oil
No hydrocarbons in coolant
No oil in coolant

Coolant in exhaust.

 

Re: white exhaust smoke on startup - normal

I just wanted to close this up.

The shop called back this morning and the tech concluded I was seeing normal condesation with a slightly rich fuel mixture burn off on cold startup. They could not detect any loss of coolant, the coolant system hydrocarbon test passed, and a tailpipe test also verified a closed system. I am confused, that the radiator pressure test indicated an internal leak, but I am not sure what to make of it. All other signs point to a sealed system, so perhaps it was a faulty test. I feel much better, especially after finding out the tech owns a '47 and his father a '46.

thanks again for all the help/advice.

 

What is your choke set at? Air cleaner element clean?

Don't forget you are at sea level or real close to it. And the humidity in Seattle is always high.
That will cause condensation in the exhaust tail pipe as it cools.

Run up the 522 to Monroe and back. That will warm it up pretty good and burn off all the condensation that has formed.
:hurrican:

 

yeah, it goes away once it is warm, but my concern was the little pool of water, which has black flakes in it. I thought it was oil, but I think it was just carbon build up coming off the tailpipe. I didn't want a little leak in the driveway to turn into a real headache on the trail. I am glad the shop tested the coolant and the tailpipe. just the piece of mind, being that this was the first time I had ever done any engine work (putting the head on initially).

thanks again...i am sure this won't be the last issue i have...

 

Yea I had the same problem...getting all worked up over nothing. I am sure I have a few threads up about when i saw water spraying from my tail pipe. It's typical condensation. happens every morning to every car. Especially if the grass is moist. If it goes away after 5 min's, your A ok.