coolant temp update

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May 31, 2003
Just got back to civilization and Internet world and want to update my high coolant temp situation from last month. After experiencing Chernobl-type coolant temps while towing a 5000 lb load in the Az desert and mexico, we did a trip to Palm Springs with no towing. With the OBDII scanner hooked up and climbing a pretty steep (but not radical) grade, the coolant temp shot up to 128F. Slowed down to get the temp down.

On the mexico trip, some of you suggested cooling system problems. I found the fan clutch was suspect but didn't have time to get it replaced before Palm Springs. Some of you thought I could have radiator sludge clogging problems, but since I had recently had a complete cooling system flush and service, I assumed that the radiator was OK.

Well, you were all right. When I took it in for the clutch, I asked the service mgr to chech the radiator. He said it should be OK because it was recently serviced. WRONG. It was full of sludge and had several cold areas!!

I politely suggested that should have been discovered when the service was performed. he backpedalled and said that since I didn't mention any problems, they just hooked it up and flushed it.

So after a new radiator and fan clutch, I put it to the test on a hot (100F) day up the Tejon pass on I5. Got in the left lane, floored it and held it there all the way up. With intake air temp of 159 degrees the max coolant temp was (suspense building?)........199 degrees!

Man, what a difference a fully functional cooling system makes. Most of this last week, I've been beating the crap out of this truck - climbing very steep hills on dirt roads - hardly ever out of low gear... and the temp gauge needle never moves up.

When I get back home to So. Cal in another week or so, I'm going to hook up the boat and find some grades to climb and see what happens. It should clearly be a better (cooler) experience.

What is/was the coolant you had in the radiator? Silicate free or orange stuff?
I am sure glad the PO replace the radiator :)

I bought the 80 in Oct and had the service done in Dec. I wasn't as informed then as I am now -thanks to the forum - so I didn't even look to see what was in it pre-flush. The dealer put Toyota red in it then and now.


Which radiator did you get?
CDan, you bring up a good point. I went with the alum spec'd for the 96. Did that because I took it to the dealer on Thursday, expecting only the fan clutch replacement and had a trip planned to start on Sunday. Since it was nearing the cut-off for orders to be delivered the next day (Fri) I just decided to be conventional.

If I had more time, I would have further investigated the earlier brass 3 row job. I also would have talked to a radiator builder about a custom build. There seems to be room between the stock radiator and the fan for a fatter radiator. If it hadn't been for the urgent need, I think a custom radiator would have been my choice.

The dealer offered an aftermarket for $180 less than the Toyota, but I haven't had the best luck with aftermarket in the past. Put one on the FJ55 and it ran hotter than stock.

Ed...I'm glad to hear you found the problem. There is not a better feeling than when you solve one like this.
landandsea- you said
"With the OBDII scanner hooked up  and climbing a pretty steep (but not radical) grade, the coolant temp shot up to 128F. Slowed down to get the temp down."

Am I correct in assuming this was a typo and you meant 228F?
[quote author=alaskacruiser link=board=2;threadid=4063;start=0#msg30336 date=1060036699]
landandsea- you said

Am I correct in assuming this was a typo and you meant 228F?


Just what I was wondering. Glad you are back in buisness, landandsea.
That was 128C...Just kidding.....Have to start proof-reading my posts. 228F it was.

We are in the second week of a 2 week trip and without the new rad and fan clutch, I think we would not be having as much fun.


I found the site. Thanks for the tip. Great wedding wasn't it.

Hey guys, we have a new member. Welcome to the forum, Steve.

He has a very nice '97 - with lockers.

[quote author=landandsea link=board=2;threadid=4063;start=0#msg30020 date=1059845521]

The dealer offered an aftermarket for $180 less than the Toyota, but I haven't had the best luck with aftermarket in the past. Put one on the FJ55 and it ran hotter than stock.


By any chance was this a CSF brand radiator? I had a CSF 2-row core replace the 2-row core in my mini-truck. Even with the OEM radiator 60% clogged (because of the junky orange prestone "extended life"), I was able to go uphill to Mt Shasta in 104F w/ a full load in back (no towing, just full of cargo)...temp gauge stayed cool. In cooler temps (maybe 95F max, flat ground) in So. CA w/ the CSF 2-row core, the gauge would get hot, about 60% of the way up from the cold mark. This was so bothersome that I felt reluctant to use the A/C when it was 95F outside! I replaced that w/ a Modine 3-row core...seems pretty decent, but I bet the Denso OEM 3-row core (made for the turbo mini-truck) is far better, but the dealer says you can't get the Denso unless you go to Japan and buy it.

I can't remember the brand, but he did say it was made here in So. Cal.

After reading your experience with CSF, I'm forever going to tell myself that it was in fact a CSF that he offered so that I can feel like the extra $180 was well spent.

Where in so. cal did you have your cruiser worked on? I have been experiencing similar problems.

Since I figured that picking a dealer to use was a crapshoot anyway, I started with the one closest to my house - Toyota of Long Beach. For the most part, I'm happy with them. They even did my OME springs and Edelbrock shocks, even though I bought the parts and took them in.

The service advisor I deal with is Wayne. He understands my objectives and works with me to get them done right.

Where in SoCal are you?

Today I had a chance to hook up the boat and do some comparisons with my like-new, expensive cooling system.

Without boat - flat road - 55mph - no A/C = temp 185F

With Boat, same road, same speed = temp 190F.

Then got on the freeway and drove some hills that gave me a problem last time....

This time: speeds 55 - 63 mph: A/C on = 190F - 204F.

Last time(before cooling system repairs) - same hills; 35 mph; A/C off = temps of 222F -228F.

My conclusions...If you want to tow 5000# with a FZJ80, you can do it IF you replace your radiator, fan clutch, thermostat, belts. In other words, bring your cooling system back to as-new performance. Don't expect 6 to 10 year old parts to still do the job.

As always, we pay for our thrills.


WOW, That is an eye opener. :eek: . The Wulf and I just went to Lake Powell and I had some temp issues I have not had in the past, even with a new fan clutch. When we got back I ran a bunch of high pressure water through the radiator and that seemed to make a difference. I have yet to hitch up the boat and attack a couple of the hills near by, but I can say that my original fan clutch was less than perfect. Clearly a properly operating cooling system makes a HUGE difference, particularly when you can double your speed AND have the A/C running on the same hill AND drop the coolant temp 20+ degrees. EXCELENT testing sir :D
Thanks again for the post and all the info. I'm pretty confident that I'm having some of the same issues.

I live in Hermosa and get service done at the Manhattan Beach dealership. I'll have my advisor call your advisor when i bring it in.

We should go wheelin some time. Next weekend we are talking about a day trip to Big Bear.
Ed & Silvercruiser

Great information! I'm also experiencing similar cooling issues, flushed by dealership, and I know its clogged / below par. Ordering a new radiator, and fan clutch while I'm in their replacing the rad.

Were you able to monitor / watch the change / constant readings from that scantool?

I'm in Sierra Madre, San Gabriel Foothills, and we should all get together for some wheeling! What BB Trails are you considering?


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