'99 Tacoma Overheating

[joeped]

I've had a recurring problem with my '99 Tacoma with the truck overheating. I've replaced the thermostat, radiator, and most recently the head gasket and exhaust manifold. The same symptoms are happening though. My antifreeze resevior goes bone dry within a couple days of filling it, it starts up rough in the morning, and its kicking out thick smoke from the exhaust. Any ideas as to what this could be?

[TcmaBoy]

What color is the smoke? What does it smell like? Have you done a compression test? When was the last time the radiator cap was replaced? When the head gasket was replaced were the heads machined and checked for cracks?

[joeped]

The only time that its smoking is in the morning. It's a thick, white color. The smoke has a very strong odor to it, most likely antifreeze. The radiator cap was replaced when I replace the radiator about a year ago. The head gasket was machined but I cannot say for certain if it was checked for cracks. My mechanic is usually pretty good and thorough so I assumed that it was. I checked a couple of things with it this morning that a mechanic from a Toyota dealership told me to check:

First, I checked the oil to see if there was any antifreeze in it. No issue.
Second, I started the car without the radiotor cap on and let it run for about 10 minutes to check for bubbles. Again, no issues.

However, its still kicking out that thick smoke from the exhaust.

[TcmaBoy]

Does it only do it when it is cold outsied, or does it also do it when it is warm out?

[XRobber]

If it only does it when you first start it, it could be the valve seals...

[Flash75]

Bad valve seals will not cause a coolant leak. You probably have coolant leaking into a combustion chamber. A Combustion Leak Detector Kit is used to to determine if there are exhaust gases in the coolant. I think the test will show a leak. The leak can be caused by a head gasket, cracked head or block. There may be some other possible causes. It shows at start up because when you turn a hot engine off the cooling system has pressure and will leak until the pressure drops. This fills the combustion with enough coolant to cause smoke. After the engine starts there isn't time between cylinder firing to allow enough leakage to smoke.

See information about the leak detection kit here.
http://www.amazon.com/Lisle-LIS75500.../dp/B0002SQXSI
For information on testing cooling systems read this article.
http://www.troubleshooters.com/tlitthypothesis.htm

Clifton

[XRobber]

Originally Posted by Flash75

Bad valve seals will not cause a coolant leak. You probably have coolant leaking into a combustion chamber. A Combustion Leak Detector Kit is used to to determine if there are exhaust gases in the coolant. I think the test will show a leak. The leak can be caused by a head gasket, cracked head or block. There may be some other possible causes. It shows at start up because when you turn a hot engine off the cooling system has pressure and will leak until the pressure drops. This fills the combustion with enough coolant to cause smoke. After the engine starts there isn't time between cylinder firing to allow enough leakage to smoke.

See information about the leak detection kit here.
http://www.amazon.com/Lisle-LIS75500.../dp/B0002SQXSI
For information on testing cooling systems read this article.
http://www.troubleshooters.com/tlitthypothesis.htm

Clifton

im not saying anything about coolant. I am saying white smoke when the vehicle is first started up, could be valve seals.

[joeped]

It has only been happening when its been cold, and only in the moring. Even after it sits all day in a parking lot, it doesn't smoke at all. The only thing I could think of was that there was something wrong with block, considering the gasket was replaced and the head was machined last week. Thanks for the advice, I will look into the exhaust test.

[TcmaBoy]

If it only does it in the morning, and only when it is cold out what you have is called condensation. With the swithch from MBTE to ethanol in gasoline there is more water in the fuel, as a result in the mornings when it is cold out you get more condensation out of the tail pipe. This is perfectly normal.

[joeped]

I'm no mechanic but this is not condensation. I don't see other cars smoking like this and mine only has 80K on it. This is a very thick, white smoke with a very stong odor to it. There has still got to be a connection between that, the loss of antifreeze, the overheating, and the rough start up.

[TcmaBoy]

Originally Posted by joeped

I'm no mechanic but this is not condensation. I don't see other cars smoking like this and mine only has 80K on it. This is a very thick, white smoke with a very stong odor to it. There has still got to be a connection between that, the loss of antifreeze, the overheating, and the rough start up.

Burning oil will smell like something burning. Coolant in the exaust will smell sweet. If it has a fuel or solvent like smell to it then it is probably just condensation and unburned fuel due to the rich start up mix. Oh yeah, and once agian have you checked compression?

[Flash75]

A combustion leak test as I mentioned will tell you if there is combustion leak in the cooling system. It will not tell you which component is causing the problem. You can also have a cooling system pressure test performed to see if the cooling system holds pressure. To find the exact problem the engine will have to be opened and inspected and the parts inspected/tested.

FWIW: Bad valve seals leak oil, oil smoke is usually blue, fuel smoke is usually black and coolant/water smoke is usually white.

Clifton

[joeped]

well I think we found the problem to this ongoing issue. There was a pin sized hole in the head that apparently was overlooked when it was machined. Thus, the cause of the loss and burning of antifreeze. The head is currently being machined so hopefully when I get it back I won't have these issues again. Thanks for everyone's advise.

JP

[Flash75]

I hope it works, thanks for posting.

Clifton