I have a 2002 with the 4.2L engine. The truck has ~280,000 miles on it. No complaints there. However, I recently began having issues with the engine.

1. It seems to "use" coolant. It had been pretty minor for awhile.
2. It threw a couple of codes. Misfire detected on startup, first 1000 revolutions. coupled with a misfire in cylinder #x (can't remember which cyl)
3. On startup occasionally during the last couple of months, it would run very poorly, then smooth out.
4. Saturday, I started it after it had sat for three weeks, and it poured out pretty strong white smoke. It got better, but never really stopped. (I ran it about 1 minute total)
5. I checked the coolant overflow tank, it was empty. I had filled it recently.
6. Oil level was indicating about 1 quart high. I had filled it to "full" last time I started and run it.

So, I am thinking bad intake gasket? Maybe head gasket? Is there a way to figure out what may be the culprit before the teardown?

My main question is this. With the mileage on the engine, should I replace the gaskets (whichever are bad) and put in new plugs, wires, change the oil, etc. or should I look for a lower mileage engine from a junkyard?

I don't mind doing the work, but I hate to spend the time and money to replace everything on this engine if it likely won't last very long.

Thanks!

 

I would start with a spark plug reading to see which ones appear to be burning coolant. While they are out, do a compression test and look for uniformity. This may help you determine whether the heads have to come off or not. If they do, I'd probably look for another engine. If not and all you need to do is intake gaskets, I'd probably do that, along with front cover gaskets.

 

I pulled the plugs and did a compression test.

1. 180
2. 190
3. 175
4. 185
5. 180
6. 190

When I turned the engine over before I did the compression check, I looked for coolant coming out of the cylinders, and didn't see any from either side.

I cannot tell (others probably could) by looking at the plugs if it looks like any have had coolant in the cylinder. Although, there is one (#5) that is really shot. They all are ready for a change.

What should I be looking for as a sign of coolant?

I can take some pics if someone can give some guidance.

Thanks!
Steve

 

Did you drain the oil? What does the dipstick look like?

 

I have not drained the oil yet. I have bought the gaskets, plan to clean the engine tonight, and then get started on taking the intake off this weekend.
As far as the dipstick, it looks overfull. I did not take the time to look real close and inspect it, I just checked the level. However, I did take the oil fill cap off, and the oil that I could see in the top part of the engine looked milky.

 

Drain the oil first and get back to us.

 

Ok. What will I be looking for in particular? Oil/water mix and/or separation?

 

OK. So the oil is a rust brown color. Not nearly as dark as it usually is when the oil is changed. And, it is much easier to slosh around in the drain pan. I drained it into a 12 quart pan, and there is probably close to 7-1/2 to 8 quarts in the pan.

 

4.2 engine, yellowish foam on inside of oil cap, had the intake gaskets change a few years ago. has ~300,000 miles, I not sure how to change the head gaskets but would like to do the work my self if possible. what would be the best option?

 

Starting your own thread instead of hijacking someone else's.

Yellow crap inside the oil cap is normal in cold weather, it's condensation that isn't burning off. If it's not using coolant you don't have a problem.

 

Sounds like its time to pull the intake off and begin replacing stuff

 

Well, Its all back together, and running smooth & quiet. A quick run to the gas station, and all was well. No leaks, odd noises, or parts left over.

 

Did you find evidence of leaky gaskets?

 

It appears that the driver side gasket, cylinder nearest the firewall was the culprit. I appreciate the help and advice from the folks on this site. The pictures and description of the teardown and replacement were a huge help.

 

when in doubt, pull an oil sample, Blackstone labs will analyze it for you. an oil sample will tell you many things about your motor, long before you see physical signs