I got my 4Runner in December. It was running fine, however, when I shut the her off, I can hear coolent boiling in the overflow bottle. I have replaced the thermostat and the hoses. I have switched the ele. fan over to a manual switch so I have it running all the time while I'm driving. Also I have changed the coolent about 3 times now. It still is boiling even if the fan is on all the time. Any ideas? Should I get a new rad? the rad. fins are a bit banged up. I'm starting to think that you all need to buy stock in coolent companies, because I'm spending so much.

Next the heater only pumps out hot air when the car is moving. I have been told that it could be air in the coolent lines. How do you blead the air out of the lines? Could the air in the lines cause the truck to boil?

 

I was having the same problem due to the electric fan not turning on as expected. I bought this product at the auto parts store called Tow-Kool from a company called CRC? I think. I was actually looking for one called Redline Water Wetter, but the Tow Kool works just fine. I just had to remove the upper radiator hose and drain some coolant, pour the stuff -16 ounces- into the radiator and then I replaced the removed coolant in the overflow bottle.

 

Have you checked your head gasket? When my headgasket went in my 3.0 V6 it started heating up real fast. It is worth having it checked out.

Good luck

 

If your radiator is pretty banged up, I bet that is the culprit of your problems.

There is a way to check and see if you have any blocked lines in your radiator. Let the vehicle warm up. Then place your hand over different spots on the radiator. Be careful, it will be hot. If you find a cool spot on your radiator, then the isn't any coolant running through that spot.

What does your temp gauge say when you hear the coolant boiling?

Can you tell when the thermost opens? I know you have said that you replaced it, but I've had problems with thermostats in other vehicles.

If the fins are a little banged up that shouldn't make a difference.

I don't think there is a way to bleed the air out of your lines, but I could be wrong. I think the air just eventually goes away after you drive it a while. I also don't think air in your lines will cause it to boil, maybe bubble a little, but not boil.

If your entire radiator is flowing properly, then it has to be because all the fins are banged up. You have quite a few miles, so I'm sure its time for a radiator. I would go ahead and replace it.

Good Luck!

 

I would suspect you waterpump is shot and not flowing the proper amount of coolant. I am going to assume, your headgasket is working properly.. Try running it with the rad. cap off and see if the coolant moves once the thermostat opens up.. It could also be the thermostat..

 

it could be a number of things.

Banged radiator
blown head gasket
cracked or warped head


are you losing fluid fast?


we need more info

 

I'm loseing fluid fairly fast, i have to put a gal. in it about every 3-4 days. I went to NAPA and they will sell me a rad for $234!!!!

Is there a cheeper rad out there?

 

Try car radiator direct:
http://www.carradiatordirect.com/

Here's what a quick search turned up for you car.....


1990 TOYOTA 4RUNNER RADIATOR
4cyl; 2.4L; 144c.i.
Our Price: $150.95
Retail Price: $467.59
Part Number
P1430

OEM#
1640035520

$150 is a bit better than $234

Where is the fluid going? do you have a puddle waiting for you every day?

 

Thanks for the info. There is NEVER a puttle wating for me. It just boils over in the over flow bottle. I don't know what to do, I'm about ready to take it to the dealer. I think I might need to replace the rad. Thanks for the info.

 

I just finished having some radiator problems myself. After I filled it level full, I would let it heat up and it would be fine. but as soon as i drove it for about 10 minutes, I would once again have overheating troubles. All I had to do was check it immediately after it started to overheat and then add lots more water and all would be better. Could it be that simple for you was well?

 

I had some rad problems last summer on a road trip into the interior of BC (britsh columbia, canada) every hill I'd go up my temp gauge would start to climb near red(and red for the big hills) and level off and decrease as I peak the hill. The first hill I stopped off to check the rad and overflow and nothing no boiling over or anything out of the ordinary. When I got home I found out that there was a blockage in my core and only half was working properly so I replaced the rad. I could've re-cored it but my mechanic informed me that recoring doesn't always work and itwould be better for me to replace the rad.

 

You might wanna check your radiator cap. The whole purpose of this is to raise the pressure of your cooling system thus raising the boiling point of the coolant. If the cap isn't any good or possibly the wrong pressure rating that could cause it to boil over.

Good luck

 

Look at the underside of the oil filler cap. Is there white jelly goop in it? If so, your getting water in the crankcase. Does it just dump into the overflow bottle, or does it dump so much in there that even it overflows? Im questioning why get a radiator if the water is not leaking to the outside?

 

its probally a blown head gasket or a cracked head..... get that checked out right away. i havent had my truck for a month because im stupid.... it will be fixed saturday though

 

There is one other thing to check. When the engine is at operating temp., see if you can spin the fan while the engine is off. If it spins around 2-3 times the fan clutch is bad.