New Guy with an LJ78W (1 Viewer)

[mech9er]

Hello! this is my intro.
I purchased a 1994 LJ78W with 1KZTE.
Currently desperately trying everything to keep the engine cool.
Any help on that front is appreciated!

It has a new 76 degree tstat
new aluminum rad
new water pump
new belts
new viscous fan
new head and gasket
toyota red antifreeze

She still keeps getting hot!

 

[Houser]

By hot do you mean boiling over or just running hot at the temp gage.
If it loosing coolant then getting hot you may have a cracked head. Also
lj78s usually come with 2.4 liter 2lte engine. Lj78s with 2ltes are usually sold with cracked heads.

 

[jmylie]

Get some Water Wetter or a simialr product:

Amazon product ASIN B000CPI5ZK
Definately helps my 2LT

 

[Black94Prado]

Digital gauge or factory? I thought the factory gauge didn't even work and now with 340k km's on the 1kzte and dealing with a few issues within the fuel delivery system the truck is running hot as well. Into the red until the rad was rebuilt a few weeks ago but with temperatures sitting around 40C /104F here in central America plus about 800+LBS in the truck and 33" MT's combined with the mountainous terrain... She's still getting hot. I won't let her get into the red but I can moderate with driving style. I'm using an EGT gauge tapped pre-turbo into the exhaust manifold blanking plate after deleting the EGT and it seems the temps are tough to keep as cool as I'd like in this weather, especially with altitude.

Truth is before the overheating the water temp gauge never moved so a cracked head is likely despite no other symptoms at all, no bubbling, clean oil and coolant, no smoke. I'd say you might have a hairline crack as well. Big thing is your driving style at this point man, if you see she's getting hot just drop O/D off or even throw it into second. It's hard driving so slow but damage control is necessary until you figure it out.

If you don't want to tackle the head yet I would 100% do the standard 1kz safety measures if you have the $$ (I don't).

3" Exhaust - at least downpipe
Intercooler
Manual boost controller - turn it up to 14PSI
Delete EGR (if you can - I know legality is iffy)

Also I would really really recommend some good gauges, I wish I had done that sooner, would have saved me a LOT of headache... These trucks are old and slow you can't just bomb mountains brainlessly in hot weather when they're stock.

 

[mech9er]

Digital gauge or factory? I thought the factory gauge didn't even work and now with 340k km's on the 1kzte and dealing with a few issues within the fuel delivery system the truck is running hot as well. Into the red until the rad was rebuilt a few weeks ago but with temperatures sitting around 40C /104F here in central America plus about 800+LBS in the truck and 33" MT's combined with the mountainous terrain... She's still getting hot. I won't let her get into the red but I can moderate with driving style. I'm using an EGT gauge tapped pre-turbo into the exhaust manifold blanking plate after deleting the EGT and it seems the temps are tough to keep as cool as I'd like in this weather, especially with altitude.

Truth is before the overheating the water temp gauge never moved so a cracked head is likely despite no other symptoms at all, no bubbling, clean oil and coolant, no smoke. I'd say you might have a hairline crack as well. Big thing is your driving style at this point man, if you see she's getting hot just drop O/D off or even throw it into second. It's hard driving so slow but damage control is necessary until you figure it out.

If you don't want to tackle the head yet I would 100% do the standard 1kz safety measures if you have the $$ (I don't).

3" Exhaust - at least downpipe
Intercooler
Manual boost controller - turn it up to 14PSI
Delete EGR (if you can - I know legality is iffy)

Also I would really really recommend some good gauges, I wish I had done that sooner, would have saved me a LOT of headache... These trucks are old and slow you can't just bomb mountains brainlessly in hot weather when they're stock.

Appreciate it!
Yes I have an aftermarket water gauge. It’s on the coolant outlet house.
Highest it’s ever gotten was 110C
I do understand you can’t drive them like crazy but others seem to do crazier things with theirs and don’t have the issue.

It just got a new head and gasket a few months ago so I don’t think that’s the issue.

No coolant loss. Coolant is clean.

2.5” straight pipe from the flex pipe back.
I do have a 2.5” dump pipe I’m planning on installing also.

EGR delete and egt temp gauge will be here tomorrow.

Intercooler is in the plans also.