Tractor Forum banner
1 - 20 of 28 Posts

·
Premium Member
Joined
·
3,786 Posts
Discussion Starter · #1 ·
Well, my 4runner is coming down with some problems now. It has been a SUPER reliable and well-built truck. It is a 95 model but now reaching 170K miles, it is getting just a little bit more tempermental. Problem now is an overheating problem. Feels like good circulation through the block (can feel the upper hose and can feel the flow) - eventually after a while of idling, the radiator starts dumping overflow out like crazy into the overflow resevior, then massive steam starts coming out of the overflow container not the block nor the radiator. Very strange. Does this sound like a thermostat or stuck cap? Or something more sinister? It sounds like it is losing pressure and therefore allowing the fluid to vaporize in the block, causing the steam blowout to the overflow box. Could it be as simple as a thermostat or radiator cap?

Thanks so much!
Andy
 

·
EX Super Mod
Joined
·
5,317 Posts
Could be both they both went out on mine. Frist the thermostat but it just ran hot then later the cap went bad and it was doing what yours is. My bet would be the cap but if you havent change the thermostat i would do that to just to be on the safe side.
Jody
 

·
Registered
Joined
·
8,567 Posts
I think Jody hit the nail on the head. May as well drain and flush the system while you are at it if you have not done it any time in the last few years.
 

·
Registered
Joined
·
361 Posts
:smoking: Hate to suggest this but it could be a blown head-gasket also. I would try Jody & Chiefs ideas first and go from there if that dont solve the problem.

Reason I say this is because I had the same problem on a 350-Chevy and it was a bad gasket.
 

·
Registered
Joined
·
8,567 Posts
I had this idea in mind in the event course of action A did not work. Just didn't want to spoil your good mood this morning. ;) :D
 

·
Premium Member
Joined
·
3,693 Posts
Probably not the cap, but heck they are cheap. I would put in a T stat also. Could be a problem, and also cheap. My fears is it could be a head gasket though. What motor is in the truck? 4, or v6? My brother works at a toyota dealer, and I can ask if anything is common.
 

·
Premium Member
Joined
·
3,693 Posts
something else for you. Some of the Toyota's had the T stat in the LOWER hose. May want to check the lower hose to see if you have flow. Also any smells coming out the tail pipe?
 

·
Registered
Joined
·
361 Posts
:flamedevi

Paul are you suggesting that Andy should sniff for burnt rice?. Just kidding about the chop-stick test.LOLL
 

·
Premium Member
Joined
·
3,786 Posts
Discussion Starter · #10 ·
It is the V6 3.0L 4RUNNER 4WD LTD version of the truck series.
I check for antifreeze in the oil and vice-versa and no dice there.
Everything looks clean and happy. I am thinking (hoping) it is simply the cap or t-stat.

Thanks for the info!!! :D

Andy
 

·
Premium Member
Joined
·
3,693 Posts
see eaven with the cap OFF, it should not blow out like that just running. I would think the Tstat first. Oh and BTW, I would get an OEM tstat. Some of the aftermarket stuff out there just does not work in the Asian cars. Take it from a guy in the biz.
 

·
Registered
Joined
·
275 Posts
Before you go wasting your time and money on buying anything, pull your thermostat and test it on your stove in a pot of hot water and a meat thermometer.
It sound like the coolant is overheating in a localized area, vaporizing and then venting itself through the overflow. If the water was getting somewhere it didn't belong, it would be leaking somewhere else, mixing with oil or getting blown out the exhaust.
Does this happen every time you run the engine? Do you top off the coolent after each event? Do you notice any leaks on the garage floor?
If this only happens every week or so, you could have a slow leak that lowers your coolent and then manifests itself into overheating. If that's the case, I would pressure test the system and looks for leaks.
I have more questions then answers. I would definitely not start replacing parts and flushing coolant at this point without understanding whats going on. It might make you feel like you are accomplishing something but that's about it.
 

·
Premium Member
Joined
·
3,786 Posts
Discussion Starter · #15 ·
Naah. Been too busy lately, but I am working on it very soon!

Thanks for asking!
Andy
 

·
Premium Member
Joined
·
3,786 Posts
Discussion Starter · #19 ·
Still not fixed ---- Man I feel really bad about my long time 4WD friend sitting there in agony. The t-stat is mounted inside right by the water pump behind the front plastic timing cover. I was going to try to see if I could manage to get to it or if I need to take it in to a shop for the repairs. It needs some work but I truly think that the truck is worth it. Any ideas? Dont think I could drive it there with the overheat problem obviously --- Maybe I should go ahead and see exactly what is involved with the work and try to get it done myself. Man o Man -----

Andy
:eek:mg:
 
1 - 20 of 28 Posts
Top