Overheating Issues (1 Viewer)

[CruisinTiger]

Ok I have 86 fj60. Ihave replace the thermostat with an Advanced auto parts t-stat. I just had my radiator boiled and soldered today. They did miss one very small hole in the top, goin to get that fixed. I put in rad fluid and water...one jug with the 50/50, another 1/2 full of rad fluid, and then filled the rest with water about 1-1/2 jugs. So I ran it and the gauge runs in the middle when moving. But let it idle for 10 min or so and it almost went to the red. I had to shut it off cause I had to head out of state for work today. SO here is my question...should I re drain and fill with straight rad fluid - advan and disadvantages of doing so. I also plan on taking off the fan and fan clutch and borrowing a metal fan and testing to see if my fan clutch has gone. If that doesn't help I will replace my water pump. Am I missing anything? When I replaced the t-stat a few months ago I ran it a few days without a t-stat and it ran much cooler than half way, could it be a bad t-stat? I don't think that is the case though.

Thanks, Chuck

 

[chitown40]

Sounds like either a fan clutch or a partially stuck closed thermostat, although I'm leaning towards the fan clutch. Can you see/hear it engage at idle?

 

[CruisinTiger]

No but that's part of my ignorance I guess. I'm not sure what I am supposed to be listening for. Is it kinda like if you turn on your A/C and you hear the compressor engage?

 

[lovetoski]

When the fan clutch engages, it makes a really loud "roaring" noise, almost like a muffled jet engine. A properly working fan clutch will engage on startup, then disengage until the engine gets hot enough to need it. Above the middle of the temp range is hot enough. If you are standing at the front of the engine, with the hood up, with the fan clutch engaged it'll be blowing a lot of air!

If your fan clutch is bad, consensus tends to be to buy an OEM replacement. They are super reliable. Aftermarket ones tend not to last.

 

[flowman]

When the fan clutch engages, it makes a really loud "roaring" noise, almost like a muffled jet engine. A properly working fan clutch will engage on startup, then disengage until the engine gets hot enough to need it. Above the middle of the temp range is hot enough. If you are standing at the front of the engine, with the hood up, with the fan clutch engaged it'll be blowing a lot of air!

If your fan clutch is bad, consensus tends to be to buy an OEM replacement. They are super reliable. Aftermarket ones tend not to last.

Don't mean to jump this thread, but does this mean if the engine isn't too hot the clutch won't engage and the fan won't be turning? I'm thinking my fan clutch is going, (just as easy to turn it by hand when hot as cold, and never hear any roaring), but my fan is always turning.

 

[hodag]

Give your fan a spin by hand after it has reached operating temp (with the engine off of course) It should be pretty hard to spin, if it spins freely, your clutch is bad. I just went through all the same probs as you, and the fan clutch solved it. I know everyone says OEM, but I got a lifetime garantee clutch from Autozone. It was $51 as compared to $176. I can pull it and take it back if it fails. But Im a cheapass. Two other cheap and free things are changing your rad cap and burping the system.

Only run enough antifreeze to keep it from freezing in your area (buy an antifreeze gauge). Water has better cooling properties than antifreeze, but it doesnt lube your waterpump or keep you from freezing up.

Hodag

 

[3pits]

or keep it from rusting,, try a water wetter, it does not change the cooling properties, just the

I just replaced my radiator, and am coooling fine also did the cap, tstat, did the pump and hoses 2 years ago, but have not driven my 62 in a year,,,,,, I had leak issues, not over heating (except when I ran out of water,,,
you can check the tsat in a pot of hot water and a food/meat thermometer

 

[Fourrunner]

Mine had similar issues when I flushed/refilled the system. It turned out I had air in the system and just needed burped. Pulled the truck up on a steep incline (noise facing up) and let it idle with for a few. Think I took the cap off as well. Fixed it.

 

[RoddQLD]

Soon after I bought my HJ61 (12H-T) it overheated on a long trip. Unfortunately I tried to get home hoping that the cooler afternoon and open road might help to keep it cool enough, but no.
The engine got that hot it nearly seized. Fortunatley no long lasting damage was done and it is now at 495,000 km's.
The cause of the problem? A build up of gunk inside the engine that took half a dozen flushes to get out. The top tank also had a slight leak but apparently that is not usually enough to cause major overheating. Only recently I noticed that the water pump was leaking so I immediately replaced that.
The radiator has also been replaced with a new one, because the previous one started to leak at the top tank again.

After the cooling system flush the engine ran quite cool all of the time. In Queensland it gets quite warm in summer and I never have any overheating problems anymore.