Overheating!!! (boil over)

[NavyRescue]

I have done everything i can think of and i am loosing my mind here!!! Any and all please help me brainstorm.

I have a 1983 22r that is boiling over after about 10 to 15 minutes on the highway. I have no idea why, i can put her in idle in the driveway for an hour and she is fine. I am under the impression that it is when the engine is under load that it is doing something to cause this.

I have replaced the following and know all the parts are in good working order:

-4 thermostats, the one thats in now is modified with the 1/16in hole and the air gap burp removed
-new hoses
-3 water pumps, one cheep one, one toyota one, and a remaned one
-super cool water lubericant
-Flushed, power flushed, coolant % is 50/50.
-removed radiator and flushed with a hose(flow is good, and did not back up)

i even jacked up the truck to elevate the motor and ran for 30 min with the cap off to burp the air out!

What is there left to do here?!!! Please help

[brainlessfool]

timing 

[Tyler82toy]

any cracks in rad cap gasket? good seal?

[Fiercefirstgen559]

Try timing or could be head gasket is letting compression in to the coolant when under load. You can remove the spark plug and pressurize the cylinder with the radiator cap off and look for bubbles in the water.

[Fiercefirstgen559]

any cracks in rad cap gasket? good seal?

x2 had a Honda overheating due to bad cap

[emsvitil]

Could still be a clogged up radiator.....

[marktrd4x4]

You could have a hole in the timing cover the chain wears and eats a hole in the water pump outlet.

[NavyRescue]

the Timing is 5 btdc brainlessfool/ it has a TRD cam but still should be at 5btdc.

RAD CAP Gasket Tyler82toy? do you mean the radiator cap? I have put two new ones on, i just forgot to mention that.

How can i tell if its a cloged radiator emsvitil?

And as for the timing cover, it is 25,000 miles old along with the rest of the motor. Its just a daily driver and weekend warrior so its not driven very hard.

WTF??? FML!!!

[NavyRescue]

I was able to drive to work tonight without it boiling over, but i drove slow and never went over 55 along with slow acceleration when entering the highway. I think it has somethng to do with how high my RPM's get! Does that sound wrong? the compression should leak out even at idle right?

[brainlessfool]

the Timing is 5 btdc brainlessfool/ it has a TRD cam but still should be at 5btdc.

ok, some simple ?s do you have the vac. lines on right? are ya sure that when checking you don't have any vac. advance kicking in?

[Wermz84]

When you say boiling over, do you mean coolant actually comes out?  or it is just reading really hot?

sounds like a silly question i know.  just curious.

[NavyRescue]

I don't think anyone has all there vac lines correct. I have a 1983 Toyota pickup specific manual from Toyota and it does not have a clear diagram or picture of how all the lines go. So I would say my lines are as close as I can get them. I just wish there was someone out there with a clear picture with their air cleaner off so I could double check mine.

The term boilover is used when you engine cooling system boils the coolant over from the radiator cap into the reservoir. And my is doing that everyday.

I have tried all different kinds of coolant mixtures with no prevail.

[Quick Draw]

I was having some similar issues.  But I think it had to do with air bubbles that I was having a hell of a time getting out of mine until tonight.

2 Questions for you:
Is your heater working and hot?
When you open the cap, what is the coolant doing?

I have an engine swap in my first gen, so it's a little different setup.  But for mine, it was hard to tell that I had all of my air bubbles out in the summer time until I tried to use my heater.  Then I ran it with the radiator cap off and noticed that the coolant didn't seem to be flowing very quickly.

Here's the method I finally figured out to get it completely burped:
Park on an incline.  Stuff a funnel into the radiator cap opening and seal it with electrical tape.  Fill up the funnel about halfway and run the engine.  Then rev the engine some, get the hell out of the way, and keep filling it up.  Repeat.  I did this for like 15 minutes before it finally quit with the air bubbles.  I originally thought that it would circulate the air bubbles through at idle.  Mine wouldn't.  Revving it up was the key.  Afterward, my heater was nice and hot.  I'll see tomorrow if that cured the overheating.  I have a sneaking suspicion that it did.

That may or may not be any help to you... but I just wanted to tell you my experience.  Good luck!

[Fiercefirstgen559]

I was able to drive to work tonight without it boiling over, but i drove slow and never went over 55 along with slow acceleration when entering the highway. I think it has somethng to do with how high my RPM's get! Does that sound wrong? the compression should leak out even at idle right?

does sound wrong. Under load you will have a lot more pressure on the hg.

[NavyRescue]

Quick Draw!!! I hope your right, i am going to give it a try, i am out of options here besides doing some major engine dismantling. Did you use coolant or just water? I know my mixture is lean right now because coolant is effing expensive when your truck spits it out every day. By the way for all reading this, walmart has the cheepest coolant prices of any place 6$ for 50/50 and coolant is coolant, the only issue is i am in the navy and cant go in there in uniform... total crap if you ask me. So i end up going into napa and spending 11$ and the guy (steve) behind the counter is on a first name basis with me now. And every time i leave i tell him " I hope i never see you again, at least at work"  he laughs and says ill see you in a few days. ahhhhh.....


-Any way, My heater is working but it has never worked too well. I really could not tell you if it is working correctly because i have never even met someone else with a first gen to compare it to.

-and when i open the cap i see coolant moving but only for a short period then the thermostat closes and it stops and sits full in the radiator. What should it be doing, i seem to remember my bronco moving coolant like moses parting the red sea. I have never had a cooling problem before and i am learning as i go, if it were anything else i would be OK but i am just out of my element here.

Thanks for all the help to those who have provided it

[Wermz84]

The term boilover is used when you engine cooling system boils the coolant over from the radiator cap into the reservoir. And my is doing that everyday.

I have tried all different kinds of coolant mixtures with no prevail.

Yup just making sure you were using it the same as me.  So my idea is out.

[David]

You might check to see if the fan is working at highway speed.

[NavyRescue]

David, how do you check the fan on the highway? or at highway speed as you say...

[Fiercefirstgen559]

Inop cooling fan would cause overheat at low speeds

[HIvoltgeToy]

I went to the Toyota dealer gave them my VIN # and they printed an exact vacuum diagram. It helped me out a ton. Now with the over heating, do you have a winch? Or bumper blocking air flow? Your fan is ineffective at highway speeds, so if your radiator is blocked it could cause the over heating. Just a thought.

[David]

Just work the throttle by hand and bring the rpm up to 1500 or higher and see if the fan clutch is engaged and fan turns strong.
I don't agree that the fan is ineffectual at highway speeds, air movement is key to cooling, a non working fan will windmill and do nothing or simply block air flow. My 2 cents.

[NavyRescue]

ok so i spent about 30 minutes working the throttle and burping the motor, the bubbles never stoped... i think my head gasket is done! i feel like there is a leak in the cooling chamber and some how letting in air or exhuast gasses. the fan clutch is engaging fine and i have a stock bumper with no obstructions. I just dont see how i can pull the throtle until the rpm's are about 3000 and every time i let off air bubbles come to the neck of the radiator unless i have a bad gasket or cracked head.

Any thoughts here? am i founded in my thoughts or should i just pull out the 45 and put her down:(

and again thanks for all the help everyone has provided.

[Snowtoy]

No need to put her down, you haven't diagnosed what is wrong yet.

During all of this what has the temp gauge been doing?

You can eliminate the head gasket by testing the coolant for exhaust gasses.  Autozone rents for free a lot of tools, they might have a test kit, if not NAPA sells sells their Leak Detector kit for about $43.

What psi rad cap did you get?  Even though the rad cap is new, that doesn't mean it is good, you cam rent a free  radiator test kit at Autozone, or they might just check it for you.

From the looks of it you have replaced everything except the radiator.  Even though it flowed when you flushed it, that wouldn't mean it was good, it could still be corroded or partially clogged, causing the coolant to boil.  You could pull the rad and have it inspected and rebuilt, but it might be just as cheap to buy a new one from radiatorbarn.com, radiator.com, or a local shop/store if you don't mind one with plastic tanks.

[83yota]

my 83s heater was AWESOME. I could run around in the middle of winter with my windows open and still have to turn the heater down. if it is your head gasket they are easy to change. no more than a day with little to no experence. I can do one in about 4 hrs now but i have done ALOT. If it is your head gasket, be sure to buy a new head or the cheaper way is to get it palined at a mach shop. If you buy a new head make sure it is not a cheap knock off (thus the reason I have changed so many HG) good luck

[NavyRescue]

thanks snowtoy I am just fed up. I have never had a problem that i have not been able to fix on my own. and now i feel like my truck is pissed off at me, hahaha. anyway... I have bought two 13 pound rad caps and they are good plus i have used the original toyota cap too, and same result. I will head to autozone and see if they have a test kit available, and see what happens. But do you recommend buying a radiator over checking the head gasket first?

[Wermz84]

Have you tried testing for flow with the radiator in the vehicle?

leave the cap off and start it up, when the engine warms up and the thermostat pops open you should be able to see the coolant flowing through the fill neck.

Don't know if that was up there or not.  hopefully it can help.

[Snowtoy]

......... do you recommend buying a radiator over checking the head gasket first?

No, I would go the cheapest route first, and test the for head gasket leak or cracked head.  If the HG and head checks out fine, then move onto the radiator or possibly the fan clutch.  Do you ever here the fan kick on while driving?  It will always be spinning, but the clutch wont always be engaged, and it should be quieter when it is off. 

[emsvitil]

Run without the thermostat and see what happens.

[NavyRescue]

Copy, I am taking a week of leave here next week to tinker with my baby. I am planning on checking the timing and getting it running smooth again. I am also going to rebuild the carb. It has been about 3 years now since i rebuilt the carb with an off the shelf rebuild kit so i am installing an asian kit so i know everything is the way it should be.

I am also going to Harbor freight to pick up a compression tester, they have one for 15$ for the inside track club members so i cant pass that up.

I jacked up the truck 2 days ago and ran it for about 30 minutes filling it up with sthright water from the hose. She has been running great! i dont understand, i have had two days of good use with no overheating or boilover. so... i just think it is because i am driving it so slow but i am going to go offroad here today and see if the radiator decides to boilover.

As for the clutch fan, its new! and it works great. it pulls air with hurricane force and the radiator core is cool to the touch.

but with the cap off i dont really see coolant flowing like a river, but it is flowing.

[bknaus]

Sounds like the friends I know who have had head gasket leaks/cracks. One was obvious cause his oil looked like chocolate milk (have you checked yours?) but the other was less obvious and he could drive for about 25 minutes and then he had to let it cool because he was boiling over like you were talking about. I'd definitely look in that direction...