head gasket/ head crack

[dinosore]

I've got a 1992 3.0l and have had white smoke and moisture from the exhaust. My coolant level hasn't dropped from the overflow tank but I haven't driven far as I use truck to go camping/ rock climbing...it is not a daily driver. Im pretty sure my heads are cracked or need new head gaskets. Today I ran the engine for about 5 minutes and still got white smoke and condensation, when given gas the exhaust shoots water, and it is 70 degrees today, so not condensation by any means. I can't comment on loss of power since I did notice a loss of power when I went from stock 14's to 15's with 235/75's with stock 3.45 gears. Now i havent checked compression or anything but any other possibilities? If so should I just look into an engine swap ( one that would still allow me to pass CA smog) or is it worth while to tear it down and rebuild from the heads up?


This image is what was left on the ground after idleing for 5 minutes from a cold start in 70 degrees at 4pm today.

 

[RonD]

There is a quick, simple, and best of all free test you can do.

The cooling system is a sealed system.
A cold cooling system has no internal pressure.
A cylinder generates 600psi when it fires, 170psi with starter motor

So the "Glove test"
Cold engine
Unplug coil, you want a no start
remove rad cap
remove overflow hose and plug that opening, vacuum cap from engine works or ??
Place a latex glove over rad cap opening and seal it with rubber band, balloon will work and so will a condom, lol.

So now system is sealed again
Crank engine
if glove bounces or starts to inflate you have a gasket or crack leaking cylinder pressure into cooling system, 100% accurate test

If glove never moves you do not.

If glove does bounce then you can ID which cylinder has the leak by removing 1 spark plug at a time and then crank engine, when glove stops bouncing the last spark plug removed is the leaking cylinder, replace spark plug to confirm.


All exhaust systems drip water, when you mix air and gasoline then ignite it, one by-product is H2O(water), plus any humidity in the outside air can add to that, this is why exhaust systems rust from the inside out.

 

[dinosore]

so the engine just cranks but doesnt turn over and I watch for the glove to bounce? A friend also said you could check by opening radiator cap and letting the engine come up to temp if you see bubbling but the coolant level doesnt drop its cause the heads. is that reliable?

 

[Andy D]

Ron's method is more precise. Also in an overheat situation you don't want to cause any more damage.

 

[RonD]

so the engine just cranks but doesnt turn over and I watch for the glove to bounce? A friend also said you could check by opening radiator cap and letting the engine come up to temp if you see bubbling but the coolant level doesnt drop its cause the heads. is that reliable?

Yes, engine cranks but doesn't start because coil is disconnected.

You are using each cylinder as an air pump, which is what it is, if there is a leak, the 170psi of pressure on compression stroke will force air into cooling system, since it is a sealed system any extra pressure will be seen as movement of the glove.
Cold engine is also better since metal is not expanded from heat yet so leak tends to be easier to ID.

Bubbles with engine running is not as definitive, but can be a sign.
Problem with that test is that if you have a small leak in the cooling system, when you last turned off the engine warm, the coolant cools and shrinks in volume, this normally pulls back coolant from overflow tank, but if there is a leak then air is pulled in from that leak point.
Next time you start engine you would see bubbles as that air is purged at rad cap.
So could be a gasket/crack issue or leak in a hose, not definitive enough IMO.

 

[dinosore]

okay. the truck has not overheated once on me (thank god) . But white smoke and water from exhaust is new to me and im pretty sure this truck unless i never noticed it. Thanks for the input. I got a meeting at a vet clinic I will bring home a glove and test for the head crack and report back. Thanks again.

 

[dinosore]

Got busy with the old ladies car trying to pass ca smog then this storm but did the glove test. Used a rubber cap from a bolt head to cap overflow spot. It was a pita to get on and off so I'm sure it sealed it. The glove was put on with a stretched out hairband looped as tight as possible. Saw no movement in the glove ... no head gasket leak or head cracks i guess. Any other ideas as to why i got white puffs when idling and larger white puffs upon acceleration?

 

[enjr44]

In my opinion (for what its worth) is that if you don't drive it much and don't get it hot (like ten miles at speed) you will not get the exhaust system hot enough to dry it out. While I was rebuilding a old truck, it would get started and idle run for say ten minutes while I did this or that. After a month or so of doing this the white smoke would not stop at all because there was so much water in the system and the exhaust was not getting hot enough to dry out.

Since you said it does not over heat, take it out and drive it for say ten miles on the highway at like 60 mph. See it the white smoke stops. IF it does, there you go!!

Ed

 

[RonD]

Got busy with the old ladies car trying to pass ca smog then this storm but did the glove test. Used a rubber cap from a bolt head to cap overflow spot. It was a pita to get on and off so I'm sure it sealed it. The glove was put on with a stretched out hairband looped as tight as possible. Saw no movement in the glove ... no head gasket leak or head cracks i guess. Any other ideas as to why i got white puffs when idling and larger white puffs upon acceleration?

Great news about no head gasket leak

When you mix outside air(O) and gasoline(H) then ignite it, one of the normal by-products is H2O(water) plus any H2O in the air(humidity).

So there is always water in the exhaust, no way to avoid it, and this is why exhaust systems, from day one, have always rusted from the inside out, lol, and this is why they use stainless steel on some exhaust systems.

What you may be noticing this time of year is the condensation point of the water vapor coming out the exhaust, as soon as it hits the cooler air it starts to condense, you see that as a white vapor, in warmer air it doesn't condense as fast so no vapor.
In the winter there is usually higher humidity as well, so more water is coming into the intake and water doesn't burn, it just changes to a vapor and goes out the exhaust pipe.

And as enjr44 said, you really need to run an engine for 20min each time you start it to get most of the water vapor out of the exhaust system and out of the oil as well.
If you open the oil filler cap or pull out the PCV Valve and see a white residue, that is water vapor mixed with oil, and it is a sign that the engine is not being warmed up each time it is driven.

 

[Rearanger]

But white smoke and water from exhaust is new to me

If it were antifreeze the white smoke would be thick and hang in the air. It would also smell sweet.

 

[dinosore]

Thanks all for the responses. I'm taking the truck or this week to the desert for some camping and climbing. Before i turn the truck off ill hop out and check the exhaust. Hopefully no white smoke or water after the two hour drive.

 

[RonD]

Well there will always be a bit of water out the exhaust, gas + air w/ ignition = H2O