jameslc9

Hello,
I have a 94 pickup with 3vze engine. I thought I had a blown head gasket from running poorly and low compression in #5 cylinder. After removing the heads I found that the intake valve was hanging open on #5, and had little or no intake valve clearance on the remaining cylinders. The machine shop found that my intake valves were bad, instead of angled where they contact the seat they were curved, making the valve travel deeper into the head and eliminate the valve clearance. They replaced the valves, and did a valve on the heads. I replaced the timing belt, radiator, rad hoses and thermostat. And checked the water pump, it was fine. Now that I have it back together it overheats with the thermostat installed. I've tried two different thermostats, my old radiator. Still overheats after running for 30 minutes. I removed the thermostat, and it runs fine, just cool. I checked the cam timing again and the ignition timing also. I think I have a couple valves with too much lash, could that cause overheating? I'm out of ideas. Thanks for your help.

rattlewagon

Sounds like you need to bleed your cooling system. Use the search feature here, there are plenty of threads explaning how to do this.

Also, you posted this in the wrong section, thats why no one has answered you yet. There was no 3vze untill 88, so maybe try posting this in the 86-95 section. or have a mod move it over there.

Good Luck and welcome to YT!

jameslc9

Thank you. I didn't realize I posted it in the wrong spot. I have read many of the bleeding instructions here in the forum as a guest, then got off my but and joined. Lol.
I think I bleed it pretty well but it still overheats.

rokblok

iTrader: (1)

I would try and put the thermostats in a pot of hot water. Then increase the heat a bit, watch with a thermometer and verify that the thermostat opens at the close to the designated(on the thermostat) temp. I have had head jobs that I have had to replace 5 thermostats cause they wouldnt open. Cheap parts tend to do that...

93toyrunner2

Either purchase a Toyota thermostat with a jiggle valve, or drill a hole in the one you have and place the hole at 12oclock to allow the coolant to flow through and push out the air in the system. Bleed the system once again several times, and keep an eye on your coolant level for a few days, and you will be fine.
There are several write-ups on this site about this process, and it seems to be the only thing that will work. I had the exact same problem, and the drilled hole fixed mine.

jameslc9

Thank you all.
I will try your sugestions and let you know how I made out.
Jim

vital22re

iTrader: (2)

where the head gaskets oem? and if not... were they installed upside down?

93toyrunner2

Hmmm. If they were installed incorrectly, then it would not run cool after he removed the thermostat.

vital22re

iTrader: (2)

didn't overheat before right? what changed? new head gaskets and heads rebuilt. There is a thread about problems with aftermarket head gaskets being made wrong. Could be blocking coolant flow to the heads.

skypilot

iTrader: (1)

This was actually my first thought. But just thinking that sure does suck; I do hate doing a job twice.

betelnut

My first thought too.

Also, maybe a dumb question but I do dumb things consistently, you installed the thermostat with the springs facing the cylinder block, right?

Liveforocks

actually it would. I went through a year and a half of this because the p/o installed mine backwards. feel on the passenger side just below th number 5 cylinder. if there is like 3/4 excess gasket sticking out then they are on backwards.

5runner

deff check in to the after market head gasket being bad cuz i got a cheap one and it blew in like 6 months. also i know i had an over heating problem for a little wile and it was just cuz i did not put my fan shroud back on so make sure urs is on and the fan is working properly

jameslc9

the gaskets are aftermarket. I hope I didn't install them upside down. Damn. I also changed the timing belt, but the timing marks line up correctly when engine is on #1 tdc at 0 degrees on the damper. I tested the thermostat and it works correctly. Well if I have to tear it down again, it's just what I have to do. I'll check for overhang at #5 cylinder. Thanks for all of your responses.

jameslc9

A late update. It was the %&#$ head gaskets. They were blocking a large coolant passage on the passenger side. I bought a set from toyota, installed them and it's been running fine ever since. No more ebay gaskets for me. Thanks for all of your suggestions and help.