The problems started when I went 4-wheeling. I knocked a radiator line loose. It was repaired and I noticed my coolant was very brown. It was flushed and new stuff added. I changed the oil and filter. My mechanic told me I have an exhaust leak and that I had white smoke coming out of my exhaust. I saw the smoke myself but it doesnt happen all the time. Recently my coolant is brown again, I ran some coolant flush through the system and added pepper to plug a small hole. My engine hasn't lost any power. It runs normal, doesn't burn oil. At least not a really noticeable amout. And there is a misfire in cylinder 8. Any suggestions on what it could be??

 

Sorry it's a 2000 f150 5.4l triton v8

 

If your loosing coolant , i would buy a bottle of BARS copper head gasket sealer for $10 at AUto Zone and put it in the antifreeze and drive around the block a few times... Problem solved.

 

try this link it should help you..good luck Part 1 -Head Gasket Test (4.6L, 5.4L). Blown Head Gasket.

 

I know there isn't coolant in the oil, it isn't white. But the coolat down come out of the radiator cap

 

There is a test kit to test coolant for exhaust.
That should tell you for sure if a cylinder is pushing combustion into the cooling system.
If you know #8 is missfireing, that's a good place to start confirming what cylinder it is.
When it's missfireing, remove the plug and look at the tip for moisture and compair to another cylinder's plug.
The white emmissions is the results of coolant passing through a hot cat.
It does not burn so is not black or grey because coolant is not a hydrocarbon like gas or oil.
There may be a sweet small to it as well.
Min is you will have to replace head gasket.
Good luck.

 

IF you get coolant puke out the overflow tank cap after 5-10 minutes of running, thats a sign of compression in the antifreeze. Cracked head or head gasket leak... thats an easy fix for the Bars Copper sealer.

 

Would it be worth spending a few extra bucks for a gasket seal?

 

The "Applies to " section on the right of that link implies many more years of head gasket problems with the 5.4 L than I've heard. I thought they had that fixed by the end of the 2002 production year by making the gasket sealing surface boss larger?

 

My buddies 04 (new model) 5.4L F150 had a small head gasket leak that was very hard to diagnose. The oil and coolant werent mixing because it was a small leak near the inside of the cylinder wall... thus letting coolant into the combustion chamber but no oil mixing with it. Oil check out fine, as did the coolant... but the biggest give away was misfire on cylinder #3 and the white smoke out the tail pipe that smelled sweet.

If your exhaust is white smoking pretty bad and smells sweet... my money would be on head gasket.

 

I'm going to try the bars copper sealer first and see if that solves the problem, otherwise new head gasket here I come

 

That stuff is total crap. It should be called Bars Copper Engine Screwer. It works by putting small flecks of metal in the cooling system. These flecks will supposedly plug small leaks, which they do ok, but they also plug lots of other things. You can get similar results by adding an egg to your cooling system. Its not good for the cooling system in the least, its intended only to be used as a temporary fix until you can actually get the problem properly repaired. So there is no point in even trying it, your engine WILL need to be fixed, and it is cheaper to get it fixed right, than to add a bottle of junk to your cooling system and then have to fix both the original problem and the new problems the additive caused.

I have used the stuff before, has a slow leak that we couldn't find (eventually did find a rotted out block plug that was behind the PS bracket). It cost me both a radiator and a heater core.

Even in theory, the stuff might work on a small external leak, when the 15psi of cooling system pressure will drive the particles into the leak to form a seal. But against a head gasket you have the 150 psi of cylinder pressure versus the 15 psi cooling system. The combustion pressure will always force the particles out of the hole, clearing it, not sealing it. If the head gasket couldn't hold back the pressure, what makes anyone thing that some small particles will do better.

 

Wow ok, so should I spend $80 for all the gaskets or get it tested more before probably having to do this?

 

I'm getting a gauge to do a compression test this weekend, what should I look out for as a sign of a blown gasket??

 

The older leak stop type stuff from 20 years ago that was aluminim flakes or oily pills was not the best sealer. THe new copper head gasket sealer is amazing. I cant say it works in every situation, and some people may have had additional problems that caused things to happen. I can tell you that i had a manifold gasket blow that caused a bad water leak and overheated similar to you. I changed out the manifold gasket and then noted a small leak , use of antifreeze. It was leaking into the combustion chamber and casuing rough running on startup and then used a cup full a week, etc.. I put the copper sealer in and that was 2 years ago and 40,000 miles and its fine. The new stuff does not attack the radiator or heater core. It plugs holes that have a big pressure drop across it, like a leak to atmosphere or combustion chamber. My cooling system works great, heater is fine, and air conditioner is fine... I was somewhat concerned as the guys mentioned above. I drained it after a year, ran the acid cleaner thru the system to see what would come out. After 2-3 flushes, i had the small gasket leak return. I added new antifreeze, a new bottle of copper sealer, and 15 minutes later, no problelm again.. that was a year ago. 40k miles total on 2 tests.