20k in blue hub & still hot

[freshspecbluegt]

Doesn't sound like you are really running that hot. Maybe the high side of normal but you are not anywhere near the A/C cutoff of 226. I don't know if there is a specified operating range in the FSM but CDan posted a few years ago that A/C will come back on line around 217 if the truck overheats so by that logic the engineers felt that 217 and below is an acceptable operating temp.

Plenty of guys see high 190s to low 200's in the heat
https://forum.ih8mud.com/80-series-tech/400234-summer-desert-temp-readings.html

I usually stay around 196-198 on 100 degree days, but heat soak sitting for lights or in traffic will bring the temp up to 205 regularly.

 

[Buckru]

Doesn't sound like you are really running that hot. Maybe the high side of normal but you are not anywhere near the A/C cutoff of 226. I don't know if there is a specified operating range in the FSM but CDan posted a few years ago that A/C will come back on line around 217 if the truck overheats so by that logic the engineers felt that 217 and below is an acceptable operating temp.

Plenty of guys see high 190s to low 200's in the heat
https://forum.ih8mud.com/80-series-tech/400234-summer-desert-temp-readings.html

I usually stay around 196-198 on 100 degree days, but heat soak sitting for lights or in traffic will bring the temp up to 205 regularly.

Are you running the same temps at night? That's what has me a bit puzzled. Without the heat of the day, I would think I would be running much cooler.

Thanks,

Buck

 

[94SRUNNER]

I am not sure if you touched on this. But how is the tenson on your main drive belts? And did you check your engine timing?

 

[cary]

A couple of thoughts.

1) Have you done a good cleaning of the radiator and evaporator fins? If you are off roading a lot, there is a good chance you have mud/dirt in there that is reducing the radiator efficiency.

2) Possibly a partial radiator blockage? While you have the handy IR reader, try and scan multiple places on the radiator to see if there are any cold spots.

Also, don't forget you are carrying a bit of extra weight. If you have lamps on your bullbar, they do affect airflow and seem to increase the running temp by as much as 10f.

 

[TJ96TLC]

Have you replaced the radiator? The flushes could have dislodged a ton of silt and debri that clogged the radiator.

 

[Buckru]

Radiator changed to 3 row brass.
Timing has been checked. It was off a hair, just enough that when adjusted helped smooth out my idle.
I recently soaked the condensor and radiator with simple green and hosed her off. I did this with the fan cluch out.
Belts are snug. I tightened them a bit at first thinking the 20k in the blue hub was causing them to slip. I will back em off a bit.

Damn Cary, now my wife will get to hear how I need another tool.


Keep it coming.

Buck

 

[freshspecbluegt]

My temps seem to be pretty stable across a wide range, the lowest operating temps I have seen in weather below 40F (skiing in Mammoth) are mid to high 180's and going up long grades in 90F+ weather I routinely see 205-206. In the more moderate temps that I usually run around in 65-80F I'm usually mid to high 190's. So I wouldn't really be surprised that a 20-30F drop in temp at night doesn't really have an effect on your operating temps.

I've spent quite a bit of time looking through the threads on cooling and scangauge temps and my best guess is that the 95-97's run somewhere between the low to mid 180's right up to the low 200's depending on ambient air temp. I would love to know if some one has an actual Toyota spec for the operating temp.

 

[inkpot]

Howdy! After replacing the radiator, did you go back and re-seal all the air gaps around the radiator and condenser so the fan will have the max airflow thru them? John

 

[94SRUNNER]

inkpot(and others)....how much would a damaged fan shroud alter temps and air flow? Mine is mostly intact, but cracked pretty good at the very top.

 

[inkpot]

inkpot(and others)....how much would a damaged fan shroud alter temps and air flow? Mine is mostly intact, but cracked pretty good at the very top.

I would not think it would make much difference at all, as long as it is still holding it's original shape. If it doesn't have big gaps that loose a lot of air flow, don't sweat it. Maybe a little duct tape will make it last a bit longer. If it is bad enough to contact the tip of the fan, then you have a real problem. Maybe a pic of the damage would help diagnose the situation. John

 

[Buckru]

The foam around the rad is in great shape.

I read where someone with a scanguage reprted decreasing temps 2-4* by "foaming" the fan shroud. At some point, I'll do this. A degree or two reduction here and there adds up in the long run.

Buck

 

[94SRUNNER]

How does one "foam" the fan shroud? If anyone could shead some light on this that would be great.

 

[Buckru]

How does one "foam" the fan shroud? If anyone could shead some light on this that would be great.

It is nothing more than pulling the shroud and lining the edge with a high temp foam/weatherstripping stuff.

Buck

 

[Grench]

New oem 3 row brass rad and t-stat installed at 194k
She now sits at 226k and has been well maintained

I have been watching my temps creep up lately to the point of running about in the middle and a little higher sometimes with viscosity of 7k in the blue hub.

I would concentrate around the thermostat with 32K miles on it.
1. Was it originally an OEM one? (Rad was per above. Was the t-stat OEM too?)
2. Was it installed with the jiggle valve properly oriented?
3. They're $20 + coolant to change out - put in a new OEM t-stat.
4. With 32K miles it is a bit early, but not necessarily out of line. If it were anything but an FZJ80 we'd be all over the t-stat's miles.

Don't buy an aftermarket part for this - I did a NAPA t-stat once and was changing it again in under 15,000 miles.

When you change the t-stat, take a picture of the old one and new one together. These have changed somewhat over the years.
https://forum.ih8mud.com/80-series-tech/29463-have-thermostats-recently-been-redesigned.html

There is a picture in this thread of at least 2 types of OEM thermostats. The non-OEM I had (for a short time) was visibly junk by comparison.
https://forum.ih8mud.com/80-series-tech/107438-coolant-flush-process-verification.html

 

[Buckru]

T-stat is oem. As cheap insurance, I threw one in this past weekend. No difference.

 

[Tools R Us]

Buck, are you sure you aren't chasing a ghost, your numbers don't sound much if any out of line?

 

[Tyler93]

Buck, are you sure you aren't chasing a ghost, your numbers don't sound much if any out of line?

X2
Is your RT temp gauge mod perhaps hyper-sensitive/need re-calibrated. There may be some positives to the factory dampened gauge?

 

[Buckru]

Kevin,

I do appreciate the question. I don't feel I am. This temp issue has been slowly creeping up. I have owned this particular LX for a little over 4 years now and my previous 80 for 3 years and the temps, with either, have never been as high as they are now. Yesterday, going to the t-ball game, my temp guage read 1.5 needle widths below red line. At this point, this was the absolute worst I have felt the ac perform, ever. Probably due to the high engine temps Heck it seems to have gotten worse after filling the blue hub with 20k. Some might question whether I properly filled the clutch but I had even worse temps with the Eaton and I followed the proceedures for both to a T. As an example, running 15 miles down the beach in very soft sand two years ago the modded temp guage never rose above dead even or 199* in Summer temps of 92*. Last summer the temp guage reached the middle at max.

I am about as mechanically minded as a monkey, some might say less, but I know it's not cooling properly. Nothing in the history of this rig under my care or the po's has had any temps like this (Tarbe was the previous owner if any of yall remember him).

When I refilled with coolant recently, I mixed it 50/50. Before I was 60% water 40% antifreeze. Don't know if this helps with info but better tto much than not enough.

Buck

 

[Tools R Us]

I think you just need to wheel it, driving on the beach doesn't count! I keep showing up at Cruise Moab, looking around, no Buck!

... Yesterday, going to the t-ball game, my temp guage read 1.5 needle widths below red line. At this point, this was the absolute worst I have felt the ac perform, ever.

Temp and A/C at the same time does sound like airflow. When it does it, check the fan airflow.

Probably due to the high engine temps Heck it seems to have gotten worse after filling the blue hub with 20k.

I believe that something is going on with the late blue hub that we are missing? Under some stress conditions, they appear to temporarily loose power, when checked later look/feel good?

Some might question whether I properly filled the clutch but I had even worse temps with the Eaton and I followed the proceedures for both to a T. ...

How did you drain the Eaton? There is a "new" wrinkle, they have an anti drain back, so the valve needs to be propped open and drained with the valve down. If not the reservoir will not drain, mixing old with new will net less performance.

... When I refilled with coolant recently, I mixed it 50/50. Before I was 60% water 40% antifreeze. Don't know if this helps with info but better tto much than not enough.

Buck

More antifreeze will make for slightly higher running temp, but only fractionally and shouldn't significantly affect A/C.

 

[Grench]

I don't suppose the fact that it's a real hot summer in Texas makes any difference to it?

The next step is going to be looking at factors to make the engine run harder or less efficient I think...
Air filter - clean? Clogged might cause it to run rich?
Catalytic converter flowing freely?
Oil filter - is it a 'good' one?
Timing good?

Radiator fins straight or many folded over/bent?

Is it pushing coolant into the overflow? Color?

And the *shudder* suggestion: Have a Blackstone test done on the oil to check for coolant. Has the head gasket been done?