How to Replace the Head Gaskets on a 1990 F150, 5.0 Engine.
So we here at Light Outdoors just changed the head gaskets on my son’s 1990 F150 with a 5.0 engine.
This job is a freaking nightmare, especially if you are working on this thing out in the sun.
Yeah the Lightoutdoors garage is packed full of junk and needs to be cleaned out again.
Basically you have to remove almost everything on the front of the engine and everything on the top of the engine as well. Thankfully Carparts.com had all the parts we needed and made getting them a lot easier. Fast shipping and great parts at great prices.
To get started we had to diagnose the issue.
We knew we had water in the oil and steam coming from the exhaust pipe so that leaves four options.
1. Intake manifold leaking.
2. Head gasket leaking.
3. Cracked head.
4. Cracked block.
We started by going to Carparts.com and ordering a gasket set. I figured if it was the intake, since I had to go through all the trouble to remove it, I might as well replace the head gaskets.
So to start, I pulled the hoses from the air filter, radiator and heater.
I removed the fan and fan shroud to give me room to work.
Then I began removing all the peripheral parts, Alternator, Smog Pump, A/C Compressor, Tensioner and their mounting brackets.
Next I removed the throttle cables, and throttle body.
Next I removed the plenum. This is a pain because there is one T40 torx head screw on the inside that you have to get to through a slot in the plenum itself.
Then I marked the distributor with a paint pen, on the engine and base of the distributor itself, and marked the location of the rotor in the distributor. I also marked the plug wires so that I wouldn’t have to sort through them and hunt up the firing order and all that mess.
Next I removed the wiring harness and fuel rails. I left the injectors in place, then removed the intake manifold. Saw the gasket for it was fine so I went to the next step.
Removing the valve covers and pushrods. I made a piece out of Styrofoam to hold the push rods in the order in which they were taken out and taped them all down so they would not get mixed up. If I had been putting in new pushrods I wouldn’t have done this.
Then I removed the bolts for the exhaust manifolds and moved them out of the way. Had to replace the passenger side one as it was broke in half and came off in two pieces.
Next I removed the head bolts and the heads. Problem found!
The driver side head gasket came off in four pieces.
The passenger side one was in good shape (I did replace it also just in case you were wondering).
Then after three days of cussing, jumping up and down and having multiple conniptions(sp?) I was ready to start cleaning everything up and reinstalling.
I cleaned the heads, the block, all the associated parts, blew everything out with an air hose, and cleaned up after that with a shop vac and was ready to reassemble.
That was done in the reverse order of taking it apart.
Torqued everything down, changed the oil, flushed the engine both oil and coolant, then started it up let it run for about twenty minutes, changed the oil again, and flushed out the coolant system again.
Fired it up let it run for about an hour just idling to keep check on the temp and if there were any leaks, and everything is back to normal.
I left out the part about it started raining the day after I got everything took apart so I was held up for a few days waiting on that to quit. However I did spray everything that was exposed with a heavy coat of wd40 each day in the morning and in the evening. When I got read to reassemble I just wiped it down, sprayed it all off with Carburetor cleaner, let that evaporate and put it all together.
So far it’s been three weeks and the truck is doing great.
Since I am trying to keep this a family website I left out the specifics of the language I used during the conniptions. So check out Carparts.com for all your parts.
The links here on Lightoutdoors and all the pages of lightoutdoors.com are mostly affiliate links.
Clicking them doesn’t cost you anything more and it helps keep my site afloat. So any and all clicks are appreciated.