Engine heat on hills with the H55F (1 Viewer)

[GLTHFJ60]

The root of the issue is simple. The cooling system is not operating efficiently. The h55 would generate less heat in 4th than the a440 transmission given the same hill, that much is a given.

I worked on a 60 a couple of years ago that had severe cooling system corrosion, and would overheat in all situations, even idling in the driveway. Investigation found that the coolant was so old all of the aluminum components effectively dissolved.

New thermo housing and thermostat, and water pump later, and the truck still had issues. I had the radiator hot tanked, and flushed the block with a mild muratic acid solution, and it was perfect after that.

 

[Randy88FJ62]

He's running 33's with stock 4.11 gearing. That's not helping.

I'd try and borrow a set of 31's and drive for a bit. The truck mayneed to be regeared?

I am not a H55 manual specialist so maybe someone else has 33's and can chime in?

 

[SteveH]

Sounds like you did your homework on the electric fan - thanks for your reply. As you noted, many electric fan conversions are tragically done with no shroud. One look under the hood, and you KNOW why the truck won't stay cool.

 

[GLTHFJ60]

He's running 33's with stock 4.11 gearing. That's not helping.

I'd try and borrow a set of 31's and drive for a bit. The truck mayneed to be regeared?

I am not a H55 manual specialist so maybe someone else has 33's and can chime in?

I had a h42 with 33s and 4.11s for a long time. 4th gear in the H42 is the same as 4th in the h55. I then had 4.11s with 35s for an even longer time. Never any issues with overheating.

The issue is the cooling system.

 

[Randy88FJ62]

@NLXTACY had his FJ60 on 35's and stock H42 and his wife blew the motor IIRC years ago?

So regearing may actually be apart of this issue? The contour electric fans add another layer of ambiguity to the problem.

 

[Godwin]

I had a h42 with 33s and 4.11s for a long time. 4th gear in the H42 is the same as 4th in the h55. I then had 4.11s with 35s for an even longer time. Never any issues with overheating.

The issue is the cooling system.

I agree with this, the issue is with the cooling system. I've been driving a 3FE + manual transmission FJ60 for > 20 years and have never had a cooling issue with the stock set up. Have driven it in summer heat all across the southern US.

It's the cooling system.

 

[NLXTACY]

On my 60, blew a motor?

 

[Spook50]

He's running 33's with stock 4.11 gearing. That's not helping.

I'd try and borrow a set of 31's and drive for a bit. The truck mayneed to be regeared?

I am not a H55 manual specialist so maybe someone else has 33's and can chime in?

I drove it across the state on the 31s I had before, and it heated up going over Stevens Pass on those as well (also in 4th gear holding about 55-60).

 

[Spook50]

The root of the issue is simple. The cooling system is not operating efficiently. The h55 would generate less heat in 4th than the a440 transmission given the same hill, that much is a given.

I worked on a 60 a couple of years ago that had severe cooling system corrosion, and would overheat in all situations, even idling in the driveway. Investigation found that the coolant was so old all of the aluminum components effectively dissolved.

New thermo housing and thermostat, and water pump later, and the truck still had issues. I had the radiator hot tanked, and flushed the block with a mild muratic acid solution, and it was perfect after that.

It's been over 100K miles since my water pump was replaced (which sucked. Original seized halfway across WA state on my way home on leave after my first deployment and I'd like to avoid that asspain again), so I'm suspecting you're right on both a coolant flush and water pump replacement. I think a good flush like you recommended might be in order. The front heater core and the clock & cylinder head would probably benefit from it. I could take the chance to replace some coolant hoses and clamps while I'm in there too so that would be a good thing to do before it heats up too much for the summer. Looks like it's time to start collecting parts and looking into the best way to flush a 3FE.....

 

[RockDoc]

Before you dig too deep.... is the "air" side of radiator happy? I've had a few times where the fins have become choked off enough from wheeling mud or plant debris (driving through standing crop, tall grass, cattails) that air flow through the rad can't keep up. A quick look with a light shining through from the other side of the rad should tell you if this is an issue or not.

 

[GLTHFJ60]

Before you dig too deep.... is the "air" side of radiator happy? I've had a few times where the fins have become choked off enough from wheeling mud or plant debris (driving through standing crop, tall grass, cattails) that air flow through the rad can't keep up. A quick look with a light shining through from the other side of the rad should tell you if this is an issue or not.

X2, good call @RockDoc . Easy thing to check too, worst case scenario the Ac condenser needs to be unbolted and shifted to take a peak.

 

[Spook50]

Before you dig too deep.... is the "air" side of radiator happy? I've had a few times where the fins have become choked off enough from wheeling mud or plant debris (driving through standing crop, tall grass, cattails) that air flow through the rad can't keep up. A quick look with a light shining through from the other side of the rad should tell you if this is an issue or not.

Was thinking the same thing the first time it happened so I took a look. Clean as a whistle and no fin damage at all. Nearly a brand new radiator so I expected that. My A/C condensor does have some fin damage (nothing severe) so I'm considering changing it out since I suspect (from a different issue) it may have a bit of corrosion in it anyway.

It's not getting to the overheat point (yet) but it is enough for me to pay attention. The highest the needle has gotten is just a hair below the top white mark, when normally it hovers right above the second white mark down. Hasn't crossed the top white or hit the red yet.

 

[Dunbar]

I agree with this, the issue is with the cooling system. I've been driving a 3FE + manual transmission FJ60 for > 20 years and have never had a cooling issue with the stock set up. Have driven it in summer heat all across the southern US.

It's the cooling system.

I have been running the H55F with my 3FE and 33's for 16 years in the Texas heat and have never overheated. Not pulling a grade with a 3000lb trailer, never. I got a lower seam leak in my radiator 11 years ago and replaced it with a Performance radiator which is pretty much identical to the OEM radiator. I run the stock fan and fan clutch and see no benefit of an electric fan.

 

[HemiAlex]

How much hotter does it run? I noticed temps while climbing grades would rise 5-10* but they always came back down. Both with the h42 and 55.

 

[Spook50]

I have been running the H55F with my 3FE and 33's for 16 years in the Texas heat and have never overheated. Not pulling a grade with a 3000lb trailer, never. I got a lower seam leak in my radiator 11 years ago and replaced it with a Performance radiator which is pretty much identical to the OEM radiator. I run the stock fan and fan clutch and see no benefit of an electric fan.
View attachment 2334223

I would argue the point of no benefit to an electric fan, depending on what you're arguing. For cooling, probably no benefit, but if installed right they can cool just as well as a clutch driven fan. For freeing up engine performance, there is definitely a big benefit. The clutch driven fans take a lot of oomph to get spinning, and you definitely feel it on a 6 cyl engine. I am certain now though that I'm in need of a system flush, especially given that my front heater isn't performing the way it should, so that has me wondering if there's buildup in the water jackets in my block and cylinder head too.

 

[HemiAlex]

Also, you can swap to an 80 series 3FE fan clutch. Meant for a heavier auto trans truck, it will be an upgrade for a 60.

The times that I’ve had the worst issues with temperatures spiking it was as simple as the cooling system not holding pressure and lowering the boiling point of the coolant. Either by a leaking radiator cap or a pinhole leak. Also, using a radiator cap fill jug and thoroughly bleeding the cooling system really help avoid grief on a 60.

 

[John McVicker]

I agree with what @HemiAlex said regarding the 80 series fan clutch...FCT 049. Far superior to the 60 fan clutch.

 

[HemiAlex]

I’m going to try it shortly. I have issues with the AC in the 100* heat. It works but the lack of airflow really makes the system struggle. I think the fan clutch would get it as close to optimal as possible.

The truck will idle at 199* in the sun with the ac going all day long. I can hand throttle it at 1200 rpm and it runs at 187*

 

[Dunbar]

Does the 80 Series 3FE fan clutch bolt right up on a FJ62? Is the fan the same? If this is an upgrade path if I ever need to replace the fan clutch again I'll keep that in my pocket.

 

[Godwin]

I agree with what @HemiAlex said regarding the 80 series fan clutch...FCT 049. Far superior to the 60 fan clutch.

Does the 80 Series 3FE fan clutch bolt right up on a FJ62? Is the fan the same? If this is an upgrade path if I ever need to replace the fan clutch again I'll keep that in my pocket.

I'm going to give this an 80% yes (crusty memory detracts 20%) I think that I'm using this FJ80 fan clutch on my 2F and think it would work on a 3FE.