Running hot, please help

This happened to my old 22re on the way back from a camping trip in very hot weather, highway driving. Shot right up, pulled over expectign to see coolant puked everywhere, but no obvious sings of any problem or leak. I let it cool and started off again (I was headed down a mountain) and had the heater blasting and had to play with my speed to keep it cool enough to get home, about 50-55 for a couple hundred miles on a Sunday night in the boonies.

It turned out to be a weak hose that was collapsing. Have you ever replaced your main radiator hoses?

Also, for the fan clutch, I seem to recall hearing about a dental floss test. Tie a piece around a blade and tie it off to something fixed to stop it from freewheeling when the clutch is not engaged. Go drive it. If the clutch is working properly, it will engange and break the dental floss. If you do a test drive and the floss is not broken, the fan clutch is not working.

Someone correct me if I didn't get this right.

 

No i havent, no one in town had them so I ordered them and havent received them yet.

 

Spewing coolant when you take the cap off hot is normal. The cap holds a certain pressure rating 15-20 psi usually. What I was trying to say is that if you are building pressure before you have any significant heat in the engine, then you may have a gasket problem. Definitely not a diagnosis in itself, but it would make me want to look closer at the headgasket.

15 year old radiator with 200k is suspect for sure. One other thing I have thought of: rev the motor up in neutral and look to see if the lower hose is collapsing. I've never actually seen it happen, but they can get soft and then the water pump can suck it flat. At that point, the truck will overheat.

My 86 toyota 4x4 had a bad radiator when I got it. It ran fine in town, but got hot on the freeway when the ambient temp was over 85F. It would overheat especially fast on any type of hill in the hot weather. If you are doing this all yourself, radiator is relatively cheap. Even if you end up doing a headgasket later, I think it would be worth changing the radiator now. It would suck to do a headgasket, then have the radiator fail and blow the new gasket. Pretty simple to change the radiator out on a first gen truck.

 

I agree about the pressure, just i have pulled lots of hot caps and never had this kinda pressure. I have already pulled the radiator and cleaned inside and out, of course i know you cant reall ever know if the inside is clean or not.

 

Do radiator shop disassemble radiators and rod out the tubes now days or is it less expensive to just replace the radiator?
Can you borrow a ScanguageII to actually see the way the water temp changes?

 

Get a non-contact thermometer, check for cold spots on the radiator.
Pull the plugs. If one is steam cleaned, it's leaking coolant into the cylinder.
Get bugs out of ac condenser and straighten the fins. If light can't pass straight through, neither can air.
It sounds like you have lost some cooling capacity. Radiator is the most likely culprit, don't forget to check for coolant leaks. It may only cause overheating now, but you'll score the cylinder walls and kill the rings. Coolant will wash oil out of the cylinder. Another indicator is white smoke on start up. After running at operating temp for a while, shut down and wait 20 min. Start up and check for a puff of white smoke. White smoke=coolant, blueish smoke=oil.
Hope you find the cause soon!

 

I dont know right now im lost.

 

I am having the same problem only the problem has been getting worse and worse. Now I cannot even run the a/c at night when I am on the highway. On a hot day I can't drive any faster than 50mph before the temp climbs. I have replaced the main top hose because of collapsing and I have flushed the hell out of the radiator. I am now going to replace the radiator and bottom hose and hope I am cured.

Another possible problem that has not been brought up could be clogged up catalytic converters. If the exhaust is clogged up you can have heat back up into the engine at higher rpms. However this is probably over thinking the situation


Does anyone have radiator suggestions. I am tempted to go for a new but dirt cheap rad with a lifetime warranty. Anyone have experience with the cheapos?
http://compare.ebay.com/like/280503...fee624b&itemid=280503325147&ff4=263602_263632

 

Hey you guys with the hot running Tacos, please post your fixes when you finally resolve the problem.
Thanks

 

You might try a temporary fix by just replacing the cat with a cat test pipe to see if that solves the problem. There are some on Ebay if you can't rig up one of your own.
Although I would expect severe performance problems with a clogged cat.
http://cgi.ebay.com/ebaymotors/95-9...22cQQitemZ390194967084QQptZRaceQ5fCarQ5fParts

That Ebay radiator might be a good thing to try. My experience with Ebay vendors has been very good. Those guyz have over 5000 sales with a 99% rating.

 

I was in cincinnati for a baseball game over the weekend. while in traffic for over 10 minutes, the gauge would start to creep up towards the red line. i have replaced the thermostat, as well as the radiator coolant. it has no leaks. it only overheats when idling and when it is pretty hot outside (i.e 80's). could this be a cracked head, bad water pump or something else?
thanks
p.s., you can smell the engine (i'm assuming) burn when this happens

 

Could be a bad fan clutch if it only happens in traffic

 

Yeah, rabbits problem sounds like fan clutch.

 

i'm gonna look into a new fan clutch. i appreciate the help. i'll let everyone know if this fixes the problem.
thanks

 

Update
Did the block test today and checked good. Put on new radiator and will let u know if it fixes problem. Again thanks for all the help.

 

New update. New radiator appears to have fixed the prob, thanks again.