Possible Overheating (1 Viewer)

[iRoughNeck]

Hello,

I just got into my first FZJ80 last week. I noticed that temperature gauge indicated that I was running closer to the hotter side of things (never in the red but more than 2/3 of the way from lowest temperature marking). Would someone be tell me if that is normal, or if I should be worried about a gasket perhaps? Radiator is brand new so I doubt that is the culprit. I did not see the milky-way when I did an oil-cap check so perhaps I am at the beginning of bad head-gasket.

 

[pandathrust]

This whole 80 head gasket thing has people going crazy. Get an ultragage/scan gauge and use that as a temp gauge. The stock one does absolutely nothing but take up space. I doubt you are even having issues

 

[-Spike-]

The gauges are notoriously inaccurate in that they rarely move from the center of the range unless the engine is way over nominal temp- anything over halfway usually indicates overheating. Don't head straight for the head gasket though- often it's just the old radiator to blame, or a missing shroud and/or foam seals. There are lots of things to check before popping the head.

 

[Marco Lau]

stock gauge sits a hair below half mark from 160 -215 F....so your needle at 2/3 is right around 220-230 F zone. Is this during heavy traffic or in highway speed? Is your AC running? and No....this is not NORMAL! BTW..you mentioned new radiator? Can you show us a pic? aftermarket? OEM??

 

[iRoughNeck]

Radiator is definitely after-market. I am attaching a picture. I am also attaching a picture of the temperature gauge. That is where it typically sits when idle. When driving it will be at or above 2/3. I am thinking of taking it to the stealer for diagnosis, at least.

 

[iRoughNeck]

 

[MoJ]

Did this start immediately following the radiator install?

 

[BigAxeJack]

That black fan clutch could be stock and the source of your issue. Research "blue fan clutch mod" or something similar. I think that Landtank was the OG of that mod. Changing the fluid in mine reduced my summer temps by 10-15*F.

Or it could be an air bubble from the radiator install.

If you're handy with electronics check out the Raventai mod.

 

[BigAxeJack]

Oh yeah, Welcome!

 

[-Spike-]

Sorry, I must have skipped over the part where you have a new rad. Still, blaming the head gasket is a long shot. How's the fan clutch? Does the fan roar on cold startup, or intermittently when running at temp, or constantly when the temp is high? Coolant level? Thermostat condition/age? More details about the symptoms would help- outside temp, speed, highway/city, grade, etc.

 

[iRoughNeck]

Did this start immediately following the radiator install?

No, it was getting hot before the radiator was replaced. It was replaced because it was assumed to be the culprit. All this was done by the previous owner. Like I said, I purchased this not too long ago. Fan seems to be always on. I am in South-East Texas, but it is not super hot yet, ambient is around 90 F this afternoon. Happens at all speeds, city or highway regardless of gradient. Coolant level seems steady at max, but I have only gauged it over a week, so a slow drop would have yet to register. I think the the thermostat is original. Thank you for your help!

 

[iRoughNeck]

That black fan clutch could be stock and the source of your issue. Research "blue fan clutch mod" or something similar. I think that Landtank was the OG of that mod. Changing the fluid in mine reduced my summer temps by 10-15*F.

Or it could be an air bubble from the radiator install.

If you're handy with electronics check out the Raventai mod.

Thanks chief! I will look into that.

 

[Marco Lau]

how about the overflow level?

 

[iRoughNeck]

Oh yeah, Welcome!

Your advice sir, is much appreciated!

 

[iRoughNeck]

how about the overflow level?

Seems relatively stable at MAX.

 

[-Spike-]

No, it was getting hot before the radiator was replaced. It was replaced because it was assumed to be the culprit. All this was done by the previous owner. Like I said, I purchased this not too long ago. Fan seems to be always on. I am in South-East Texas, but it is not super hot yet, ambient is around 90 F this afternoon. Happens at all speeds, city or highway regardless of gradient. Coolant level seems steady at max, but I have only gauged it over a week, so a slow drop would have yet to register. I think the the thermostat is original. Thank you for your help!

If you want to throw parts at it, the thermostat is a lot cheaper than a head gasket, and can cause what you're seeing. On the fan clutch- when you start the engine cold, the fan should roar for a bit and then get quiet. When it's not cool outside, it should also roar when the engine is overly hot, and under normal circumstances that would cool the engine and it would get quiet for a bit, cycling as needed.

 

[iRoughNeck]

If you want to throw parts at it, the thermostat is a lot cheaper than a head gasket, and can cause what you're seeing. On the fan clutch- when you start the engine cold, the fan should roar for a bit and then get quiet. When it's not cool outside, it should also roar when the engine is overly hot, and under normal circumstances that would cool the engine and it would get quiet for a bit, cycling as needed.

I’ll give that a shot. There is definitely no “roar” from the fan at start-up. That being said, it seems to be constantly on, perhaps it is not operating normally. Thanks,

 

[BILT4ME]

1) Looking under the oil cap for milky stuff tells you absolutely NOTHING about the head gasket condition. Period.
2) What is the level of coolant in the RADIATOR? (not the overflow tank)
3) I'll third the aspect of the fan clutch being the most likely culprit, other than not having enough coolant in it to begin with.
4) You may want to consider getting a TOYOTA radiator cap. I have seen MANY radiator caps that SUCK with quality and have had lots of issues because of it. Not to say the Toyota caps are not 100% problem-free, but they do seem to have better overall quality and longevity.
5) The fan is "always on" because it is driven mechanically. It is whether or not the internal clutch engages and makes it ock up together to match the pulley speeds, hence the term "fan clutch")

 

[Marco Lau]

My bet is on fan clutch.

 

[jpoole]

If your truck is a later FZ with ODBII then you should get the following setup so that you can actually see what your coolant temps are:

Any odb2 bluetooth sender that is compatible with your smartphone. I got a similar unit for a similar price that works great:

Amazon product ASIN B00PJPHEBO
Any App on your phone that will read the output from that ODB2 sender. I purchased and installed "Torque" on my Android phone and it works great. You can then watch your temps and know what's actually going on.

If your's is odb1 then the easiest option may be a cheap Infrared temp gun though those are harder to use and can vary based on where you shoot etc.

Beyond knowing the actual engine temps another clue on overheating is that if you hit a high enough temp your 80s AC will shut off. Often this is an early/first clue that the engine is getting too hot. If your AC has been shutting down when your engine temps are up then this could be a big clue that you are actually running warm. Read up on this forum for info about what temp the AC cutoff happens at.

If your rad is fairly clean and the truck runs well overall but is running warm I'd be looking closely at the fan clutch.