How hot is too hot for water temp in mid-90's ambient stop n' go? (1 Viewer)

[lasoundguy]

Having a bit of a heat wave here in SoCal and I'm still getting used to my (new to me) FJZ80. I did some cooling system work just after I got it last month (HCV, PHH, radiator hoses, coolant drain/fill w/ new) and it's been running great, averaging 180-190º on the highway and 190-200º F in town with ambient temps in the 70's and 80's.

However yesterday with ambient temps in the low 90's my intake temps were about 170º and the truck got up to 210º (saw 212º briefly fighting my way through rush hour in Hollywood but once I hit about 15mph it dropped down to 205º.)

I'm on the original head gasket (I think) and at 210K miles so trying to be conservative. Are these temps normal or indications I should do more on the cooling front? The previous owner replaced the fan clutch but I don't think it's modded/blue (still searching around and figuring out what those mean tbh.) I unfortunately deal with a lot of bad gridlock so considering an aux electric fan kit too (hoping for when I need it for trails not traffic.)

I have been searching and getting a lot of good info but figured I'd ask the group as well. Thanks!

 

[Tools R Us]

What radiator and clutch? Mine runs mid to high 180s, maybe 192-194 in total gridlock.

 

[mudgudgeon]

Do you here the fan roar as the clutch engages?
If you don't hear the fan cycling on and off the fan clutch is not doing all it should

 

[lasoundguy]

I do hear the fan go--I'll go check but to my knowledge the PO just had the standard OEM clutch put in. Is the fan clutch where you think I should focus my effort to diagnose? Let me search for how best to validate functionality. Thanks.

 

[Kernal]

New OEM Thermostat, or unknown?

 

[lasoundguy]

New thermostat about a year ago, but think it's aftermarket.

 

[1911garand]

Just for reference, my coolant temp maxed out @ 199f when towing 18' walleye boat, fully loaded at highway speeds @ 85F. Heavy load, no over-drive used, 35" tires, stock gearing.

New Koyo radiator and blue fan clutch, no fan clutch mods.

 

[jaymar]

Also in LA. You wanna see temps in the 180s, maybe 190s even if it’s 100+ outside. Find @NLXTACY ‘s overheating thread for complete OCD guide to addressing every possible cause of overheating. I recently had a blown fan clutch, hit 215 in ten minutes. Replaced with Wit’s End blue hub, dropped 20 degrees even with no foam around fan shroud.

 

[lasoundguy]

Great info, thanks all. I believe the radiator is OEM original. Comparing to 1911garand and jaymar's temps I have some investigation to do.

I did some digging and based on these part numbers from the receipt (from PO) it looks like OEM parts, but it was four years ago (longer than I thought.)

 

[1911garand]

When I replaced the radiator, I found the condenser packed with 21 years worth of bugs, seeds, dirt, etc.....

I have this tool left over from when I was an auto tech and blasted the condenser clean using water: (the bad reviews are from people that dont know what they are doing)

Amazon product ASIN B002ZN08LG
Perhaps check to see if you are plugged up - just a hose and sprayer works too.

 

[jaymar]

I do hear the fan go--I'll go check but to my knowledge the PO just had the standard OEM clutch put in. Is the fan clutch where you think I should focus my effort to diagnose? Let me search for how best to validate functionality. Thanks.

Open hood start engine. Turn off key. Someone else immediately grabs a fan blade with their fingers. If they can stop the fan with no problem, the clutch is dead. I’m told it’s hard to lose fingers this way, but I make no guarantees. You can’t do it yourself because by the time you get out of the car to the fan it’s already stopped.

 

[mudgudgeon]

Is the fan clutch where you think I should focus my effort to diagnose?

Yep.
I would do the following as essential items if you're trying to solve overheating
Thermostat, flush system, fresh coolant and hoses, fresh radiator cap, fan clutch.

Beyond that, if general tune and engine condition is good, and you still have overheating issues you're looking at a blocked radiator (internal passages, or external fins) or head gasket

 

[ppc]

Never stick your hand in near the fan. That's is just plain dangerous. You could use a rolled up newspaper to try and stop the fan but I prefer to stop the motor when hot and then rotate the fan manually to check the amount of resistance.

 

[jaymar]

Never stick your hand in near the fan. That's is just plain dangerous. You could use a rolled up newspaper to try and stop the fan but I prefer to stop the motor when hot and then rotate the fan manually to check the amount of resistance.

Or have someone else do it.

 

[rolliges]

Those temps are similar to mine in east coast humid 90+ and stop&go.

My system is in very good condition; added an AUX fan for stop&go and beach driving.

 

[lasoundguy]

Thanks @rolliges. I honestly thought I had sorted cooling until yesterday, was quite surprised to see numbers over 200ºF again. (Last time had been prior to maintenance on cooling system.)

Seems like I'll probably end up trying a new fan clutch from Wit's End (@NLXTACY ) but first I need to finish the knuckle rebuild I started on today. Seems my brake lines need some love.

 

[jaymar]

@NLXTACY ‘s ultimate overheating thread.

I'm at my absolute wits end- truck still overheating despite best efforts

I have been plagued with overheating issues for half a dozen years now. The truck has always been on the higher side of comfortable. I have now done everything under the sun to try and mitigate the issue to no avail!!!!! Today was the straw. Its currently 110º outside my house here in West...

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