Just picked up a 1999 F150 with the 4.2...standard cab, long bed, with a manual transmission. I got it from the original owner for $1000...it's in great shape....but it has a blown head gasket!

I'm going to use it as a 2nd vehicle/work truck and I'm trying to decide what route to take here. It's got 175k highway miles on it, and has been maintained well, never used for towing or heavy hauling. The bed looks like there has never been anything in it.

From what I've read on here, with the exception of the head gasket and intake manifold gasket on the 97's...the 4.2 seems to be a fairly reliable engine. I can get crazy when I get into something like this and go all gang busters...but I'm trying to decide if I just throw a new HG on it, and replace all the other obvious things...water pump, timing chain gasket, etc and be safe for a while...Or if I should pull the engine and do an overhaul..bearings, rings, etc and be done with it.

Decisions, decisions...but for those of you who have experience with this engine...how are the bottom ends of these engines...pretty strong?

 

The bottom end is almost bulletproof as long as it doesn't hydrolock.

I'd do a top end rebuild - the bearings/rings etc. should be fine. You will know more when you get the heads off and see what the pistons and cylinder walls look like.

 

Sounds like you've got a little project to work on.

Anyhow, just out of curiosity, if you even happen to know... do you/did the original owner know what caused the head gasket failure? Are you sure it's the head gasket? if it overheated for example, I'd be looking at a majority of other items. Such as any scoring on the cylinder walls, burnt/melted valves, etc.

Gives you a good place to start when you know how it happened.

Does the thing even start?

Since it's not a '97 or '98, then I wouldn't be too concerned with hydrolock, but depending on what's leaking, and where it's leaking, I'd be concerned with starting it until you look down each plug hole.

At 175k, I'd say get a new clutch too and a slave cylinder.

 

Original owner said it did not overheat, and I believed him. He noticed it started running rough and some steam from the exhaust. The seller was mechanically inclined and advertised it as either a HG or an intake gasket. He partially tore the engine down and said there is coolant in at least one of the cylinders. For 1k, I figured even if I had to put a long block in it, I would still be ahead considering the excellent condition of the truck....but I would much rather just do a top end rebuild.

I had considered the clutch/slave and a new flywheel, it's on the original. I think I will pull the heads sometime this week and start investigating.

 

Ah, ok. I'd say intake gasket. As long as it hasn't tried being started, then the bottom end should be ok.

Hmm... just out of curiosity, do you know what color coolant it has in it?

The reason I ask, is I am wondering if there was a different type of coolant and they switched and added a different type. I know that some coolants react differently and some turn into a caustic acid that eats aluminum and gaskets. I know in my '99 I had the orange coolant, which was I think was the one you weren't suppose to put regular green Prestone in.

 

From what I can tell, it's got green coolant. But he had drained everything already. When it went up on the tow truck, it dripped a little and that was green. But who knows if that is what it came with, or if he had added/flushed at some point.

 

Sounds like he shut it down just in time to prevent a hydrolock.

 

I've got a 2000 4.2 with a manual trans. and I love it. I haven't had any problems with the engine since I've had it (about 2.5 years now). Only work I've had to do on it was the original alternator just went bad last week. I'd say that's pretty good for 13 years and 150k miles.