excessive heat from the engine (1 Viewer)

[mondo45]

my friend just bought a '78 hardtop hj-40, 4 cyl., from a friend whose father had originally purchased from the dealer and was well maintained (lucky punk!). his only complaint is that the engine gives off a lot of heat and that it gets uncomfortably hot, even to the point that the heat comes if opening the footwell vents.

i've a 6 cyl. fj-45 and it's never felt excessively hot even when it used to have a cooling problem (build up had been clogging the coolant's flow) and it used to overheat.

question: are diesels that hot? i would doubt it because i drove one that i'd considered purchasing, also factory 4-cyl. diesel, and it did not feel hot at all while driving it off road and pavement. so now i turn to the experts.

thanks.

 

[Conex]

Mine is always hot inside. I put insulation under the floor mats and over the tranny hump and it helped a little. Need to figure out how to do the same thing to the firewall as it still gets really warm. When I open my kick vents I get a warm flow of air also, I personally think its because the engine compartment side vents are almost directly upstream of the kick vents. I will say that where I live is hot ALL the time and it would be nice to cool it off a little somehow other than when it rains, then the windows fog up

 

[Stone]

I guess you're talking about a BJ40? I don't know what those old 40s are like, but I'm guessing they have a lot less insulation than my BJ74. What does the temp gauge say? How's the lfuid levels in thne tranny and t-case? Does it have an aftermarket/custom exhaust that might cause the excessive heat? I doubt that our little diesels get that hot normally.

 

[Diescipel]

I guess you're talking about a BJ40? I don't know what those old 40s are like, but I'm guessing they have a lot less insulation than my BJ74. What does the temp gauge say? How's the lfuid levels in thne tranny and t-case? Does it have an aftermarket/custom exhaust that might cause the excessive heat? I doubt that our little diesels get that hot normally.

Yeah, I really never notice a heat problem on mine, even when climbing out of Death Valley, for example. I would do some diagnosing as Stone suggests.

A fantastic insulation option is aluminized/foil bubblewrap insulation for water heaters. Reflects heat very well and cuts down on the noise to boot. Thanks again Wayne for the suggestion 18 mos. ago.

hth
B

 

[mondo45]

he currently has it in the same type of weather conex, so it might just be normal. stone, if a bj-40 is the fj but with diesel, yes that's what i meant. all the fluids, temp., everything is fine. the car was barely used for over 20 years with only small trips around town. everything is stock on it. diescipel, might you have a link to where that insulation can be purchased?
as you say, they should not get too hot--uncomfortably hot. nothing seems to be causing it, so maybe it is a lack of insulation.
thanks fellas.

 

[Diescipel]

As a general rule, IIRC diesels run cooler than their gas brethren---you might check and see if a gas 40 in the same area is doing similar things. Stone also alluded to exhaust--one thing that can happen is if the exhaust is too restrictive, it can lead to excessive EGTs, bad for reasons beyond an oven in the cab.

The insulation can be found at any home improvement type store.

hth
B

 

[green diesel machine]

Never had a problem with heat so far with my 3B!

 

[s79bj40]

yep, my little b radiates a lot less heat than the 2f in the troopy. Having said that though, the exhaust leak from the b gives me toasty feet in winter. who ever designed 2 bolt manifolds anyway.

 

[Diescipel]

yep, my little b radiates a lot less heat than the 2f in the troopy. Having said that though, the exhaust leak from the b gives me toasty feet in winter. who ever designed 2 bolt manifolds anyway.

Aha?

 

[Dogsled]

vents in hood?

I've seen a very interesting solution to this on a friend's rig - he had louver vents cut into the hood of his turbo'd HJ-60. He also installed those fj60 fender vents that Toyota must have figured diesel rigs didn't need. It looks great, and you can really feel the heat rise. Didn't ask him if it helped with defrosting in the winter...

 

[mallred]

As a general rule, IIRC diesels run cooler than their gas brethren---you might check and see if a gas 40 in the same area is doing similar things. Stone also alluded to exhaust--one thing that can happen is if the exhaust is too restrictive, it can lead to excessive EGTs, bad for reasons beyond an oven in the cab.

The insulation can be found at any home improvement type store.

hth
B

Is this installed in the cab or below the floorboards, I always worry about mosture in the floorboards.

 

[Diescipel]

Is this installed in the cab or below the floorboards, I always worry about mosture in the floorboards.

x2

The great thing about the alu foil insulation is that it doesn't absorb moisture like standard auto insulation. It's essentially bubble wrap with a foil backing--as you can imagine a good choice for water heaters.

I installed it underneath against the tub (Aqualu for me) and cowl, beneath the OEM plastic mat, beneath CostCo mud catchers in the footwells. Works great for me.

 

[mondo45]

i went off-roading with my friend today and told him what you all had said. however, i didn't realize you had also mentioned a possible exhaust leak or restrictive exhaust. i'm pretty sure you should not uncomfortable driving because of the heat. there might be some exhaust issue. i'll see if he can get a picture of it so i can post it. i've some of my fj45 but its a gas I6.

 

[seapotato]

couple things that work , exhaust wrap on the first couple feet of exhaust after the manifold, ( where it runs right past the lines for the heater core ) and a gate valve to turn off the water to the heater core properly..having the heater leaking heat in the summer doesn't help much at all...
I don't think those stock valves ever really shut off.

that being said, you could cook bacon on my tranny hump in the summer....