FJ62 - Runs Hot on Freeway - But Not When Wheel'n

[accasbel]

My FJ62's temperature is erratic. When I do freeway speeds, it will be alright for awhile, steady about midway up the gauge. But eventfully it will climb up dangerously close to the red. Until the water temp gets really high, the oil temp looks OK. And this is with the tach at about 2000 RPM, cruise’n down the road.

Funny thing is, when wheel’n, tach going back and forth from idle to 2000 RPM, the temperature stays midway, unless I go up a long, steep uphill grade.

The garage mechanics think that the cooling system checks OK, but something is amiss. Belt tension appears OK, fluids appear OK, fan clutch appears OK. What’s left? Are these symptoms of a restricted radiator, or maybe faulty thermostat? Probably best to replace the thermostat and have the radiator serviced, but a sanity check for other possibilities seemed the thing to do.

Thanks, Lee

 

[Gumby]

Plugged radiator would be my guess. The fan would have nothing to do with it.

 

[toy60]

Do you have a electric fan in front of the Radiator as well as the engine fan. If u have turn it off and see what happens. One may be interfearing with the other.

Or its just blocked and it cannot circulate the water fast enough at 2500 rpm

Good luck

 

[bull]

Fan Clutch? Does your engine get loud sometimes? Like a cessna taking off?

http://slowspeed.com/repair/fanclutch.html

 

[Rice]

High heat at freeway speeds is usually an indication of radiator not being able to cool the water enough. I'd suggest having it boiled out.

 

[Jman]

Also, your lower radiator hose might be collapsing a bit at high rpm, check to see if it has the spring inside the hose.

 

[Landpimp]

the OEM hoses have no spring in them.

But it sounds like a rad that needs a cleaning/recoring or replacement.

Fan clutch will not effect the highway cooling.

If you havn't already I would check the t-stat, it prolly needs replacement anyway. But I suspect the big problem is the rad itself.

[quote author=Jman link=board=1;threadid=13994;start=msg130257#msg130257 date=1080747651]
Also, your lower radiator hose might be collapsing a bit at high rpm, check to see if it has the spring inside the hose.
[/quote]

 

[Jman]

[quote author=Landpimp link=board=1;threadid=13994;start=msg130272#msg130272 date=1080748805]
the OEM hoses have no spring in them.

[/quote]

They don't? Whaddya know! I had a few spares from the p.o., they were aftermarket and had the springs in them, didn't know that OEM has no spring.

Anyway, he might not have an OEM hose on there, spring might be missing or maybe corroded. The hose that was on my truck when I bought it was pretty supple, especially when hot, didn't take much pressure with the fingers to flatten it.

 

[lowtideride]

my 60 runs at 1/4 while driving thru town and on the trails but it runs at 1/2 when im on the freeway doing about 65 ( with stock gearing and 35s) sound about right??? or am i heading for the same problem???

 

[bull]

I had the same symptoms on my 62. I fixed my fan clutch and the temp problem was gone. Also you may want to look at the seams top and bottom. Is there a white/gray residue by them? If so you could have a high pressure seam leak....

 

[OldFJ62]

I had the same symptoms on my 62. I fixed my fan clutch and the temp problem was gone. Also you may want to look at the seams top and bottom. Is there a white/gray residue by them? If so you could have a high pressure seam leak....

I had a similar problem where the fan clutch would stay engaged the whole time I was on the highway . I swapped the thermostat a long time ago with one from the local auto parts store and it did not hangs anything. I had the radiator serviced and still no change. I even swapped the water pump with still the same results. I had the radiator serviced a second time and was still in the same boat. I swapped the fan clutch and still no change. I switched to purple ice and it seemed like it helped but still was experiencing the fan clutch being engaged the majority of the timd. I did a blue devil deep clean flush which included dang near two bottles of blue devil radiator cleaner with fresh water and a six hour drive. I went ahead and upgrade to an x-line mishimotor all aluminum radiator. All in all still was not satisfied because I kept hearing the fan clutched engaged on the highway. The temp gauge showed a lower value which was a good sign. It was not until I swapped out the thermostat with an OEM one that I felt like I cracked the case. It turns out that the oem opens fully at 100c and partially at 88c. The over the counter thermostat from the local parts dealer opens wide at 80c. Since it was wide open at a lower temperature it did not allow the radiator to cool the coolant since it was circulating at a high speed throughout the components while driving on the highway. Only took me about $1,000.00 and 5 years to figure it out. Feel free to send any donations via chase quick pay or a thank you if my findings help you at gabrielvela1@aim.com

 

[erse]

I had a similar problem where the fan clutch would stay engaged the whole time I was on the highway . I swapped the thermostat a long time ago with one from the local auto parts store and it did not hangs anything. I had the radiator serviced and still no change. I even swapped the water pump with still the same results. I had the radiator serviced a second time and was still in the same boat. I swapped the fan clutch and still no change. I switched to purple ice and it seemed like it helped but still was experiencing the fan clutch being engaged the majority of the timd. I did a blue devil deep clean flush which included dang near two bottles of blue devil radiator cleaner with fresh water and a six hour drive. I went ahead and upgrade to an x-line mishimotor all aluminum radiator. All in all still was not satisfied because I kept hearing the fan clutched engaged on the highway. The temp gauge showed a lower value which was a good sign. It was not until I swapped out the thermostat with an OEM one that I felt like I cracked the case. It turns out that the oem opens fully at 100c and partially at 88c. The over the counter thermostat from the local parts dealer opens wide at 80c. Since it was wide open at a lower temperature it did not allow the radiator to cool the coolant since it was circulating at a high speed throughout the components while driving on the highway. Only took me about $1,000.00 and 5 years to figure it out. Feel free to send any donations via chase quick pay or a thank you if my findings help you at gabrielvela1@aim.com

As this thread is from 2004 I am going to guess the OP and others figured out the problem long ago. You could have probably saved some of your thousand dollars by coming to mud sooner...

Feel free to reimburse me at wedontchargemoneyformudadviceitsacommunity.com....

 

[LAMBCRUSHER]

When mechanics start tossing parts in to see what's wrong, they should be paying you for their becoming educated( if any of them remember what is was that they changed on the last car that made the light go out...)

 

[IBFJ62]

Ok, long shot, but I had the same crap on my old '83 Hilux 4x. After much frustration, it was broken bottom brackets on the radiator. At low speed, air flowed through no problem, ran cool. At highway speed, I figure the bottom of the radiator pushed rearward and the air flowed over and down, not through. Might be worth a look, grab the bottom of the radiator and tug..

 

[roadstr6]

Last time I had this problem on a 2F (Hot at speed and cool sitting or creeping) it turned out to be a stopped up radiator. I did the Muriatic acid flush and a ton of crap came out...then it sprung a leak. I ended up replacing the radiator and have had no problems since.