FJ62's Overheating. Several of us don't know why. (2 Viewers)

[White Stripe]

I believe toyota made a tropical weather or heavy duty fan. Not sure of the pn. Will only help at low speeds though.

 

[MoaByte]

One detail that may be significant is that my cruiser sat idle for a year with the hoses off while I was getting things together. /shrug. I dunno.

Ummm. Anybody else thinking about wasps/ rodents? I had my fuel tank out for a couple weeks and had to drill out all the vent lines because Mud-Daubers packed the lines. If those little bastards did that to a water jacket or two, wouldn't it cause some crazy cooling issues?

 

[Seth S]

So sounds like a new water pump and fan clutch just to be safe, rock auto for less than 100$

I fought this problem way back in nam, ended up being the head gasket. That 2f cost me almost 3k$ to get it running right, which it does now but for that price I could have v8 swapped it

I would spend the $$ and get the OEM water pump. Not sure about the fan clutch but probably good to go OEM on that as well. Two components that you don’t want to have to change often or suffer from poor quality.

 

[rhah]

Ummm. Anybody else thinking about wasps/ rodents? I had my fuel tank out for a couple weeks and had to drill out all the vent lines because Mud-Daubers packed the lines. If those little bastards did that to a water jacket or two, wouldn't it cause some crazy cooling issues?

I wouldn’t count it out at this point.

 

[CruisD64]

Ummm. Anybody else thinking about wasps/ rodents? I had my fuel tank out for a couple weeks and had to drill out all the vent lines because Mud-Daubers packed the lines. If those little bastards did that to a water jacket or two, wouldn't it cause some crazy cooling issues?

I'm not counting anything out at this point. I did order one of those high pressure water and air guns.

Hopefully forcing the water in both directions loosens whatever is in there. I'll be doing that first and then a proper chemical flush.

 

[ChrisD]

Hey all,

I've been troubleshooting my FJ62 that runs quite hot when hitting hills and have tried everything I can think of to mitigate it.

Things I've done:

New Radiator (CSF)
New thermostat (OEM)
New Fan Clutch
New Water Pump (Had to replace anyway)
New AC Condenser (Old was clogged up and AC didn't blow very cold at all)
New Temp sender
Aftermarket gauge to confirm stock gauge readings
Checked the timing. Was originally off by 4 degrees but is now good.
Isolated tranny cooler (stacked plate Derale)
Heater works fine
System was burped
Radiator cap new
Vacuum lines replaced
Head gasket confirmed fine. (Compression is 150-155 across the board with 227k miles on it.

Basically, when driving the car and going up a steep grade if I'm on it for a like 30 seconds it the temps will creep to about 215. Doesn't matter what temp the outside is. Does the same thing in the middle of a Truckee winter. Some people I've spoken to have said that maybe it's normal but I drove my dad's FJ62 for YEARS and the temp always remained steady no matter what the temps were outside. I suppose that car is my baseline.

One thing I noticed today is that the Cold Start Injector sensor is cracked. Like the plastic is physically cracked that the connector fits to. I'm not sure if it's malfunctioning but considering I've tried pretty much everything I wanted to see if maybe that could be the culprit?

Another thing it COULD be is misadjusted valves. This is a new head and I only did the initial adjustment. That being said the valves are quiet in operation. I do plan on doing an adjustment in the next week.

Also, since it's been so hot in Truckee I was thinking of pulling the Tstat entirely and driving it to reno and back to see how high the temps get. I'd put the tstat back in after that. Would this be ill advised?

I'm grasping at straws and would appreciate any ideas, no matter how crazy they might seem.

Thanks!

My 1985 FJ60 had good compression all the way through but overheated constantly as well. After changing everything I could, I took it in To my shop. The head gasket was bad, the head was shaved and valves ground. Runs cool all the time on and off the road. Yuma, AZ. 100+

 

[MoaByte]

My 1985 FJ60 had good compression all the way through but overheated constantly as well. After changing everything I could, I took it in To my shop. The head gasket was bad, the head was shaved and valves ground. Runs cool all the time on and off the road. Yuma, AZ. 100+

So head gasket? Was it blown between cylinders, wasn't installed right? This thread is for posterity. No offense intended. Glad that increasing compression still worked.

 

[CruisD64]

My 1985 FJ60 had good compression all the way through but overheated constantly as well. After changing everything I could, I took it in To my shop. The head gasket was bad, the head was shaved and valves ground. Runs cool all the time on and off the road. Yuma, AZ. 100+

Head gasket should be good. I had a head professionally rebuilt, shaved and installed it myself. Main block checked out fine. The original head was cracked.

That being said, I noticed something interesting today. I was driving into Reno from Truckee to pick up my new AC lines and the HOTTEST the motor got was 201 degrees which is unusually low. Some of those hills I'd hit 220 easily in cooler temps even. Ambient temps were 102. Not sure why so low but I'll take it. The only things I've done were throw in a 180F tstat a few days ago and added Seafoam to both the oil and the gas today. Maybe it was carbon buildup? Dirty injectors? I haven't pulled the plugs yet and won't have a chance until next week. I'm leaving town to go work on my boat. I also noticed the seafoam got rid of a minor stumble the engine had. It may just be a fluke.

I do still plan on performing a full flush and swapping the rad with a Mishimoto (2 CSF's have been failing due to leaks for me so I'm done with them). I'll post every detail of what I do.

I'll also be recharging the AC myself. We'll see how that goes!

 

[Spook50]

So head gasket? Was it blown between cylinders, wasn't installed right? This thread is for posterity. No offense intended. Glad that increasing compression still worked.

I'm curious too.

 

[CruisD64]

Anyone ever try Ford VC-9 flushing solution? Sounds like its good stuff but I'm unsure how safe it is on the 3FE.

 

[Seth S]

Anyone ever try Ford VC-9 flushing solution? Sounds like its good stuff but I'm unsure how safe it is on the 3FE.

don’t know what VC9 is…but a 3fe is cast iron block and head. Odds are good that the 3fe is made of tougher materials than the more modern for engines. Rubber hoses and radiators have changed little in the last decades.

 

[Michael Hanson]

Hi, Check bottom radiator hose for collapsing, fuel pump wearing out causing a lean engine mix,timing retarded,radiator clogged again because engine sat awhile and crud went into new radiator.. Flash build up on engine coolant passages, really tough to get out. Mike

 

[CruisD64]

Hi, Check bottom radiator hose for collapsing, fuel pump wearing out causing a lean engine mix,timing retarded,radiator clogged again because engine sat awhile and crud went into new radiator.. Flash build up on engine coolant passages, really tough to get out. Mike

Great suggestions! Though I'm sure if I had a lean condition I would not have passed CA emissions... though that was 1.5 years ago. Crud sounds like a possibility. I got one of those high pressure water and air gun setups which I will try. I will remove the tstat and shoot through the tstat housing and from the lower radiator hose as well. That way it'll flush bidirectionally. I will also be doing a proper flush. I'm going to work on this next week.

 

[Michael Hanson]

How old is the cat converter, are you running with your skid plates on to deflect air into the radiator? Mike

 

[Gretsch]

So was a simple pressure test ever done on the cooling system to check for leaks? I didn't see it in the thread anywhere. The answer typically is "nothing leaking that I can see". Visual inspection is not real helpful with the miles of plumbing on these rigs. You'll likely never see the leaks just from driving the truck around. A laundry list of cooling system work was done on this truck potentially revealing many new avenues for leaks to develop. Get a pressure tester on here and find/correct them. I replaced a similar list of parts on mine. I 'didn't' have any leaks on mine either. Then I pressure tested it and magically there were 4. HTH.

 

[ChrisD]

So head gasket? Was it blown between cylinders, wasn't installed right? This thread is for posterity. No offense intended. Glad that increasing compression still worked.

Sorry, yes I believe it was between cylinders. As far as I know, it was the original gasket. It was determined to be blown by the chemistry of the radiator coolant. I don’t remember all of the details. Thanks

 

[studawg]

I don't think you can But no, orientation is correct with the rubber ring gasket on top as well.

If its anything like the thermostat in the 1FZ, you definitely can. I didn't know that and that simple thing caused my a lot of headaches and scratching my head trying to figure out why I kept overheating. Because if its not installed with the vent holes in the right spot, it wont vent the air bubbles out, and it would sometimes run hot, and then NOT run hot, which it sounds like it just did. Maybe you put it in correctly this last time, which is why it ran cooler temps this last trip?

 

[Seth S]

If its anything like the thermostat in the 1FZ, you definitely can. I didn't know that and that simple thing caused my a lot of headaches and scratching my head trying to figure out why I kept overheating. Because if its not installed with the vent holes in the right spot, it wont vent the air bubbles out, and it would sometimes run hot, and then NOT run hot, which it sounds like it just did. Maybe you put it in correctly this last time, which is why it ran cooler temps this last trip?

Yep. You can install the 60 and probably 62 t stat upside down.

 

[CruisD64]

Ah. I didn't think so but I've had it installed correctly every time. fat part on top with the round rubber gasket against the top of the tstat housing.

 

[CruisD64]

I also picked up a couple of these. Thermocure

Going to run it with distilled water for a few days as well as the prestone stuff (not at the same time). Seems promising.

EDIT: Some of the reviews for the Thermocure are scary!!! Eep!! Anyone ever use this stuff?