toyota4x4907

It started two weeks ago when I go to take a test drive right after I finish installing my CB radio. My truck suddenly started to overheat like a sticking thermostat, but I had been driving for about 10 minutes already and it was mid-30s. First time in the 10K miles that I have owned it. Okay. So I turn the heat off like you would do when the t-stat is sticking on 22res. Temp goes down. It didnt get but a few mm past the mid mark before I noticed it and did the latter. Then its fine all the rest of the day and the next day. Two days later, it does it again, after about 10 minutes of driving. I think the t-stat is failing. I wait and see a few more days with nothing. Come Saturday(4 days later) when we are getting pallets for a bonfire, the temp spikes, so I turn the heat off and everything, but it won't go down. I slow down and stop but the temp stays at about 5/8 the way to the red zone, just past 1/2. I try speeding up to get more air over the radiator. Nothing. stays there. Finally it goes down and all is okay for about 20 more minutes, then it happens again but cooled down when I turned the heat off. Yesterday I cracked the radiator open and it was low. I put some coolant in and it took nearly 3/4 a gallon. Replaced the t-stat with an OEM one, 88*C. Burped the system. I tested the old one and it was not at fault. After just driving 5 minutes to work, then 4 hours later I go to lunch and look in the radiator and its low again. Put some more coolant in and it takes 1/2 gallon. WHOA!
Everyday it will start to spike after about 5-10 minutes of driving and if I turn off the heat it will cool down.
No leaks on the ground. Spark plugs are worn normal. no wetness on them. No white smoke. No burning coolant smell, even at rest with up to 3/4 throttle. Compression at 160, give or take a few.
I also have lowish, erratic oil pressure.
Help?

toyota4x4907

Also, no coolant in oil, no oil in coolant. Changed the oil last Wednesday.

And about an hour ago when I was doing the compression test, as I was screwing in the gauge, some coolant got pushed into the reservoir....

And and, it still runs and pulls strong with no new miss/skip/twitch.

aviator

I found I had a largish pin hole in the front of my rad below the inlet that was pissing coolant... I put in some bars leaks and it seems to have stopped it though my wrench cringed when I told him he said I should have used 3 egg whites and some pepper as a safer leak stopper... apparently he's had some issues with coolant channels getting clogged by the other stuff...
I've since added about 2 and a half jugs of premix coolant and the fluid levels are solid and it's running well...
I'll have the system power flushed before I install a new rad though...

check your rad for leaks...

toyota4x4907

Made it home all 6 miles from work tonight with the heater on hot and fan on high. Didnt overheat.


There are a few dents with crushed fins, but I'm 99% sure they were there when I bought it. The radiator is dry, other than it spilling when I was burping the system. I have dealt A LOT with 22re radiators since I bought my '93 5 years ago. Its just that it happened THE DAY, FIRST DRIVE after I installed my CB. I'm wondering if maybe I messed something up when I was wiring it in

I tried some stop-leak crap in my '93 two winters ago when I still owned it and the radiator was giving out. It ended up alll in the reservoir 3 days before the radiator burst. I really should have replaced the reservoir when I replaced the radiator, but I didnt know of any junk yards around then. Also, I busted open the radiator after I took it out, it was cloggggggged up with that stop-leak stuff. I dont think I will ever use it again.

abecedarian

Your CB probably is interfering with the hypotenutectic protaganist for the quaternary amplitude inverse modulation inverter. The may be adversely affecting the Lambda modulation circuitry resulting in the improper pulse-width modulation of the whatchahoozits.

toyota4x4907

thats exactly what i was thinking, Abe!

toyota4x4907

Now it seems to be pushing lots of the coolant into the reservoir after I drive it to op temp and park it for a few minutes. Bad radiator cap? or do you think its more along the lines of HG?
Still no mixing of fluids. Both are very healthy looking.

pruney81

you could be leaking exhaust gases into the coolant perhaps?

toyota4x4907

Where are there places that exhaust gas can get into the cooling system?

pruney81

I think through a blown head gasket. If the gasket is blown in a certain place you will leak exhaust gases into the coolant, or maybe your intake is leaking somewhere?

pb4ugotobed

Replace your radiator cap. When it gets too much pressure, it is designed to blow the extra pressure off into the overflow reservoir. When the cap gets old, the springs gets weak, and it will blow off the excess pressure prematurely, say at 9psi instead of 12psi. You could lose a lot of coolant this way fast.

yoder519

when my 22re blew a HG, i didnt notice any coolant in my oil either. but i smelt antifreeze every now and then. it was blew on the first and 4th cylinder. with about 2inches of anitfreeze settin on the pistons,, rusty cylinder walls and pistons

toyota4x4907

yeah, but didnt you have white plumes of smoke, rough idle, and less power? My truck is still pulling like a strong 22re, no white smoke except the usual when warming up since its still below freezing at night, 0-15 usually. It has been just being pushed into the overflow bottle, and I have been putting it back in after each drive. I'm going to get a new radiator cap Saturday day after I wake up and see if that helps.

toyota4x4907

new cap didnt help.

it will NOT overheat as long as I keep the heat control to cold. It doesn't push as much coolant into the overflow when i have the heat off as when its on hot.

Probably the head gasket, eh? Getting funds together for engnbldr o/s valve head with cam, steel t-chain guides, oil pump and water pump.

flyingbrass

Hmm. Turning the heat on should make the engine run cooler because the heater acts as a smaller radiator. I got by doing that once when my radiator was plugged enough to not handle the blistering summer heat.

However, 4crawler wrote about the opposite, which is what you're describing, in his t-stat writeup. His ass-backwardly ran hotter with the heater on. See http://www.4crawler.com/4x4/CheapTri...tml#Thermostat

If I were you I'd try replacing the thermostat. Not with that terribly expensive one because I'm cheap and don't know if it's even the problem, just a decent new one to test. I'd cut out the jiggler valve thingy so some coolant flows through its small hole all the time. See what happens. It won't cost much to try.

Or, just cut the jiggler out of your existing one. If it doesn't have a jiggler, drill a 1/16" hole.

toyota4x4907

I already replaced the t-stat with a new OEM one because that was my initial thought. I had the t-stat sticking problem on my '93 22re when I owned it so I know how that goes. Hasn't helped.

I was thinking I should drill out the jiggle valve when I was installing it, but decided not to to just test it. I still might do that tomorrow, even though Im sure its not going to help.

flyingbrass

What 4crawler describes is different than a malfunctioning sticking thermostat, so maybe losing the jiggler will help. Engines should run cooler with the heater on, not the other way around.

95blackToy

i agree about the radiator cap. my 3.0 had similar problems. you couldn't even tell water was coming out the exhaust except at start up. after a few minutes it would overheat mine was the head gasket though.

91 4Runner

Try checking the lines that goto the rear heater core. if there is a pin hole leak there you won't see any puddles.

toyota4x4907

I did real quick. I'm going to go over all the cooling lines tomorrow.

Earlier when I was driving, testing the new cap to see if the old one was maybe bad, I had the heat on hot and the fan on full but there was no heat. Then I heard a gurgling from the front heater core and got hot air all of a sudden. Usually it will slowly warm up. Not cold, then hot all of a sudden....