After almost 350,000 miles it seems the head gaskets on my '97 are going to need some attention. Initially, I thought the water pump had finally croaked, but when I pulled it, there was a brown varnish coating the inside of the housing and the coolant was a little oily. I replaced the pump anyway as the pressure, assuming from the leaking head gasket, had busted the seal. When the engine is under a load I get air bubbles in the tank.
My question is: Is it worth the time and money to replace the head gaskets and not rebuild the engine?
350K is quite a few miles, but I figure it may be worth a shot. Obviously the motor has been a good one. I am assuming a head change kit and a quick resurface would be the least I could get away with, and even then I am probably going to spend at least $500. There are plenty of used 5.4L engines out there with less miles for under $1K that I could probably swap in. Even then, I will be left with a truck nearing 400K miles on the factory trans build.
In these times, if it was mine, I'd probably try it, with one thing in mind. As with a lot of people now, time is plentiful, so tearing the top half of the engine off isn't the hassle to fit into a schedule it used to be. However, I'd for sure clean the heads, disassemble the valves/springs, check the seats, depending on how the valves/seats look, VERY lightly hand lap the valves, replace the stem seals. Check the heads for straight, cracks, etc. (probably do this first thing after cleaning). Realize the above is just to get a decent set of heads, that will probably outlast the rest of the truck. Best way is to drop them off for a valve job/ reconditioning, but this will cost some $$.
Even doing everything yourself, I can see easily, $400-500 for the basics, like all the gaskets, sealers, fluids, filters, spirits for cleaning, etc.. Of course, either way, redo the top half, or change the whole engine, it'll burn a weekend, and the bottom half won't be much fun with everything rusted/seized. Who knows what else might have to be changed or replaced, after you buy an engine.
The heads do not need surfacing unless the surface is damaged, or the heads are warped (which I have NEVER seen on a modular, BTW). The issue is that there are very few shops that have equipment that can get the finish on the head surface to the correct Ra, and if they attempt to surface the heads without the correct finish, they WILL leak.
IMO-plan on rebuilding or replacing the complete engine, and when you get into it-if the shortblock is good, then there's no reason to replace or rebuild it, and you save money. Judge this yourself when you tear into it and do an inspection of the cylinders.
I think with that many miles on the motor and tranny, I would just buy a used 5.4 with a tranny and put that in. You might spend some more money but your gonna be PO if you do the heads and right after that the motor dies.
Oh ,but the way. Congrats on getting that many miles out of it! That's fantastic.
Yeah,with as many miles I assume that if I am going to go through the trouble of removing the heads I may as well rebuild the bottom end also. I have looked around and found many 5.4L for reasonable prices. Also, I believe later models have the PI heads on them, so that would be a bit of an upgrade, yes?