1hd-t getting too hot (1 Viewer)

[missipboy]

fj62 with a 1hd-t/h55 3.73 gears and 32x11.50 at's. some armor, but not real heavy. i just replaced the fluid in the fan clutch with 10,000 and i have a new radiator. my shroud could probably use a little work, but other than that everything is in pretty good shape. the 1hz i had in it before also did this, so i think it's an issue with something other than the engine. it starts heating up on the highway when driving over 60mph. never a problem when driving slower than that. today i was driving about 65mph and closely watching the gauge and the temp shot up into the red and then came back down shortly after i let off the pedal. (maybe a bad ground/gauge or something related) do these engines require better than stock cooling? would improper heater hose routing cause this kind of problem? i have a preturbo pyro and egt's have never been above 1100.

 

[Tapage]

Are you sure you can trust in your water temp sensor/gauge ..?

then I will said the factory 60 series rad are not big enohugh compared to the factory 1HD-T rad .. you if your engine it's pushing hard it need more water/cooland in the cooling system ..

I can tell ya my 2H-TI never go EGT in the red zone .. but I need to keep an eye in my water temp always when I'm pushing it hard ..

Edit: are your engine healty .?

 

[missipboy]

Not sure if i can trust my gauge or not. My next move is to install another temp gauge.

If my radiator is too small, what are my options? I see an aluminum one on man-a-fre but big money.

Not sure what you mean by healthy, but it's supposed to have a little over 100,000m if i remember correctly. No problems yet, but i haven't had it long. New beb's and timing belt.

 

[lshobie]

Try the new guage, you could put a 1HZ rad from ENS into it - i think 400cdn - aluminum cored rad. I have a condensor in front of mine, 8274, turbo, an engine bay full of stuff and mine never over heats no matter how hard I punish it. (HZJ79)

 

[1tontoy]

For what its worth and assuming you are still running the stock FJ62 temp guage, my FJ62 used to do the same thing after I swapped in the H55 transmission. The guage would spike when running on the highway at around 65MPH, but would drop if I backed off the throttle...

I haven't investigated, but I wonder if the fact FJ62 originally had auto trans has something to do with the issue....i.e. wiring harness related...

 

[missipboy]

Try the new guage, you could put a 1HZ rad from ENS into it - i think 400cdn - aluminum cored rad. I have a condensor in front of mine, 8274, turbo, an engine bay full of stuff and mine never over heats no matter how hard I punish it. (HZJ79)

is the 70 series radiator the same as 60 series?

 

[Radd Cruisers]

is the 70 series radiator the same as 60 series?

70 series rad is smaller...

I bet you have a blocked rad or a crappy fan clutch - even though you put new fluid in it.


~John

 

[lshobie]

70 series rad is smaller...

I bet you have a blocked rad or a crappy fan clutch - even though you put new fluid in it.


~John

I'm with John, I bet the fan clutch is crap as well.

 

[Volcano cruiser]

I doubt that it is the rad. I'm running a 1HZ in a 40 series and I just had a guy build me a 4 core rad, exactly the same size as the stock 40 rad that it replaced. I just didn't have anymore room in the bay once I left a few centimeters for the condensor for the airconditioner and a small rad for the intercooler(future). It is both my DD and weekend trail warrior and I run it hard in the city (tropical climate) and on the highway, no overheating drama as long as I stay on top of the fluids and regular PM. Replace the water temp sensor first and check along the line from there. Good luck.

 

[Bomar]

Parker,

There is a rad shop in memphis that can custom build you a alum rad cheaper than buying it from MAF.

 

[bigbrowndog]

Are you sure your thermostat is opening when it should? Pull it out and check it. It may be staying closed or partially opening.
When you filled the fan hub was the bi-metal spring working after the rebuild check this with a hair dryer or heat gun. Search the extensive thread in 80 series section. Idaho Doug and ToolsR Us did a lot in this thread with many others.
The radiator may look OK on top but it is common for 30 to 40% of the cores to be blocked in the bottom especially where they are used in cool climates where a moderate portion of the radiator is being used it happens here in hot areas with predominate town/city driving.
I don't really understand fitting a motor like that and relying on s*** Toyota guages we all know are useless. { read in= designed to not frighten the owner as to what is actually going on]

 

[missipboy]

70 series rad is smaller...

I bet you have a blocked rad or a crappy fan clutch - even though you put new fluid in it.


~John

I'm with John, I bet the fan clutch is crap as well.

thanks everyone. i bought an aftermarket temp gauge and i'm going to replace the clutch and check the thermostat.

 

[ukaviator]

If the fan clutch was bad then wouldnt it over heat around town?

He said it was overheating on the highway above 60mph - at that speed the fan clutch isnt doing anything to cool the engine its the volume of air hitting the rad thats doing the cooling.
Worth replacing if its leaking, but I dont know if that will fix your problem.
I had the same kind of issue with my 3B. Drained the rad and it was as brown as mud.
Flushed the rad and block with Prestone Flush, and continued to flush with water until all the crud was out and now its fine.
Just my .02

 

[missipboy]

hmmmm...radiator is new.

 

[ukaviator]

The rad may be new but the block could be gunked up. Worth doing a flush just to check, its not expensive.

How is your water pump? Is it leaking around the housing at all?
Are you having to keep topping the rad off with coolant at all?
Could be the thermostat like bigbrowndog said.
Check those things and replace the thermostat as planned and report back what you find out

On a side note, i have an aftermarket gauge as well as the stock, and every now and then the stock water temp will spike into the red for no reason and the settle back down, but the aftermarket gauge stays steady. I have a bad ground on the stock somewhere but just havent been bothered to chase it down

Oh and im so jealous of your 1HD-T .... just thought you should know

 

[ukaviator]

Couple more things I just thought of .... are you running A/C and is the turbo a recent addition?
Both those things will make your engine work harder, and as a result create more heat

 

[Dave 2000]

Air trapped in the heater can causing localised overheating.

I would beg, steal or borrow a heat gun, just point it various places and read off the temp, a particular place to check is right next to gauge sender and also the top and bottom hoses to check heat loss across the matrix. If it happened with the old engine and you have a new rad and you have done the fan mod then I would be looking for a false reading from the gauge

regards

Dave

 

[missipboy]

i have yet to get the second temp gauge hooked up, but i did get it up to temp, popped the hood and shut the engine down. the fan just kept spinning, so i tried ordering a new clutch from napa, but the one i got was too short. my clutch fan mounting surface height is 77mm and the one for an fj62 is 67mm. does anybody know where i should look for the correct clutch?

 

[Radd Cruisers]

If the fan clutch was bad then wouldnt it over heat around town?

He said it was overheating on the highway above 60mph - at that speed the fan clutch isnt doing anything to cool the engine its the volume of air hitting the rad thats doing the cooling.

This is commonly mentioned as a repair factoid - but it is wrong.

The reality of the situation is, that when a poorly working fan clutch is replaced, overheating issues (given that the rad and t'stat are okay) usually go away.

I've been down this very same road a few times over the past couple of weeks, and the fan clutch needs to be working properly even at highway speeds.

~John

 

[Dave 2000]

This is commonly mentioned as a repair factoid - but it is wrong.

The reality of the situation is, that when a poorly working fan clutch is replaced, overheating issues (given that the rad and t'stat are okay) usually go away.

I've been down this very same road a few times over the past couple of weeks, and the fan clutch needs to be working properly even at highway speeds.

~John

I have to agree with this, my Discovery had an electric fan fitted with a warning light and this would come on if driving hard on the motorway in particular up long steep hills even at speed........well at the pace my Discovery could muster

It is to do with air literaly 'bouncing' off the matrix at speed where suction from the fan is more important, this does not happen on all vehicles and there are a lot of factors to influence this.

regards

Dave