Over heating issues on my FJ80 (1 Viewer)

[Jamno93]

I recently had the head and head gasket replaced on my 80 series and after I got it back it was still having some overheating issues. I took it back to the shop and they went in and replaced the thermostat, clutch fan, radiator cap, temperature sensor, along with the entire cooling system being flushed twice. And it’s still running warm. The temperature gauge is reading around 3/4 on the dash and when I was sitting in traffic it started creeping up (pictured below) until the A/C eventually cut off so there is still an issue with it. Does anyone have any suggestions on what to do from here? I’m going to get the water pump checked today but other than that I don’t really know what else could be causing the issue.

 

[77mustard40]

Let's start with some information like the year of the truck. BTW the dash temp gauge is useless for 1FZ-FE's, it has a huge dead spot so once it moves you're likely already overheating.

 

[Jamno93]

Let's start with some information like the year of the truck. BTW the dash temp gauge is useless for 1FZ-FE's, it has a huge dead spot so once it moves you're likely already overheating.

It’s 1996 with the 4.5 L 6-cylinder. It ran at the normal temp for about 25 minutes and then jumped up to 3/4 on the gauge but the A/C never stoped running so I kept driving it. Them about 25 minutes later it jumped higher than 3/4 the A/C cut off and it was obviously still having issues. I went from a 170F thermostat to a 190F thermostat so I was expecting it to run a bit hotter but not that hot.

 

[Fj80oregon]

What’s up with your oil pressure? Was that picture taken with the truck off?
What fan clutch did they use?

 

[mudgudgeon]

1st Install the standard thermostat

Also 1st, install an OEM blue hub fan clutch. (Assuming they didn't use oem??)

There's really nothing to go wrong with water pump. It either pumps or it doesn't.
Or it leaks.
If it wasn't pumping, you'd know in much less than 25 minutes.

2nd, if the radiator is blocked, flushing it may not be adequate solution.

 

[mudgudgeon]

What’s up with your oil pressure? Was that picture taken with the truck off?
What fan clutch did they use?

Looks normal for zero RPM

 

[mudgudgeon]

A scangauge, or other obd11 reader that lets you monitor actual coolant temps is a good idea.
As mentioned above, the factory gauge is vague, and IF you see it move, its probably too late already.

 

[Jamno93]

1st Install the standard thermostat

Also 1st, install an OEM blue hub fan clutch. (Assuming they didn't use oem??)

There's really nothing to go wrong with water pump. It either pumps or it doesn't.
Or it leaks.
If it wasn't pumping, you'd know in much less than 25 minutes.

2nd, if the radiator is blocked, flushing it may not be adequate solution.

They put the oem blue hub fan clutch in it.

 

[Jamno93]

What’s up with your oil pressure? Was that picture taken with the truck off?
What fan clutch did they use?

The truck was off and they put an oem fan clutch in it.

 

[77mustard40]

I see you are in ATX and it’s been really hot this week. I’ve got a little over a year on the HG in my 97 and took a couple pics two days ago during my afternoon commute in 109. Toyota cooling components with a modified Bluehub fan clutch and I ran 186 - 190 when moving and it ramps up to near 200 when I hit stop and go. If all your cooling components are in good working order you should be fine. They key for me was modifying the Bluehub clutch.

Were TEQ components used on your truck, or was it aftermarket?

As mentioned invest in a ScanGuage so you have real data, the dash gauge is useless.

Edited; to add 2nd Pic of full speed readings in 109 degree air temp

 

[Marco Lau]

110F ambient heat, plus AC plus sitting in traffic, not surprising. Your fan clutch probably weak and you might still have legacy issues with the cooling system.

 

[greentruck]

Assuming your radiator is either original or was replaced long ago, it;s the most liokely culprit considering the other work you've had done. The radiators get clogged, not all over, but in various spots. Either by feel (engine off ) or with a remote-reading temp gauge ($25 or so at Harbor Freight) there will be obvious cold and hot areas in the radiator to confirm this is the issue.

Solution is a new radiator. Lots of discussion about what is best here on the forum, but I rercommend AL over brass.

 

[Fj80oregon]

Looks normal for zero RPM

Good eyes

 

[77mustard40]

I'd highly recommend modifying the new blue hub clutch, it makes a huge difference in this heat. We are talking and hour and a half of your time and a trip to Hobby Lobby for some 20K CST. You will want to do so even if you determine that you need a radiator. The end result is that your temps will stay within about 8-10 degrees from one another under easy cooler conditions and hot stressful conditions. I have touched 200 maybe two or three times since I did so and it was really hot here every day last summer.

Attached is a how to and another good tread on what to expect afterwards.

Blue fan clutch mod...Thread has gone to hell, read at your own risk

History: On my first drive this summer after replacing my transmission I was having an overheat condition with the truck. On the following weekend while towing a camper it was real severe in the 230* range. After returning I was able to confirm that my Blue hubbed fan clutch was to blame...

forum.ih8mud.com

Landtank Modified Fan Clutch

1997 LX450. 4" IronMan lift, 315 Duratracs, 4.88, lots of armor. I installed the modified OEM blue hub fan clutch from Wits End/Landtank about a week ago and I thought I’d post a bit of feedback regarding engine temps as monitored by my Ultra Gauge. I have been doing weekly trips between Jersey...

forum.ih8mud.com

 

[Darkstar909]

I would say something is up with the fan clutch. Coolant temp gauge is pretty useless but the fact that your AC cuts off is not good. Its definitely getting hot. I had the same issue after replacing HG and pretty much the whole cooling system. The fan clutch looked fine and even passed the newspaper test. However, when I opened it up it was dry and I put some fluid in it. Problem solved. its been running fine every since. Does it still run hot while youre moving? Sounds like its not drawing enough air to keep it cool while sitting idle.

 

[LTrain]

Any chance they didn't properly "burp" the cooling system after the coolant change to remove any air pockets?

 

[azusa]

Fan shroud in good shape? Air in the cooling system? Air flow being blocked ie lights/winch or mud?

 

[Broski]

There’s s lot of little stuff on these old rig to check.
Is there foam present around the radiator?
Is the rubber skirting present at the bottom of the inner fenderwells?
How about the Sheet metal plate below the radiator and above the steering stabilizer ?
All these pieces contribute to the cooling system, keeping the air moving through the radiator and over the motor.