I've had my 1J in my car for at least 4 years if not more, no major problems
Doesn't overheat while driving or boosting on the freeway.
It has had electric fans from day one, never had a problem, even on a stock radiator. Then one day it started.

I did blow the upper hose, but i was using the same one that came on the engine. Lower was the stock sc one.

Now it has a larger radiator, the driftmotion oil cooler kit, a FMIC.
440 injectors, SAFC, Blitz Boost controller and upgraded 1j turbos @ 14 psi.

It does leak some coolant (whit smoke) or something into the exhaust when it gets hot
Thermo has been replaced. Heatercore bypassed. No cat

No BHG (no mixing oil/coolant), Exhaust gases in coolant test done..

Can't figure it out, unless the turbos are cracked...

Anyone have the same problem or ideas?

 

Have you ever replaced the water pump?

Do you have all your ducting in place?

 

+1 on water pump. It should actually cool down in boost because the engine is higher rpm and water pump should be pumping faster

 

No on the water pump, I'll replace that next week. How often to they fail? Usually don't they leak first?

 

It's hard to say how often they fail. These 1J motors are 20+ years old, and that is one of the first things that people usually do when they do the swap is throw a new pump on. Yes, typically they do leak or squeal first, but to me it sounds like that may be the only thing left. If your thermo is new, radiator is new, and heater core bypassed, then the only thing really left to consider is the pump itself. And it is probably a good idea to change it anyway

 

I have a NAT sc300. My car runs on the warmer side, fresh coolant flush, new water pump, new oe lower hose. Little bit older upper hose. Tstat is a little older, that's next on my list along with silicone hoses.
I made a front vent or some say grill. But I mail did it for venting to the radiator. When cruising at 40mph my stock temp gauges has dropped one full 1/5th or a full notch on the cluster. Has shocked me and I'm so glad I did it. This pic is from when I just got done with it. I still need to do some more trimming, but my gf and I just had a little girl 2 days ago so work on the car is on hold for a couple weeks!

But I would say change the tstat, are you sure your gauge is reading correctly?

 

Cancel that I meant water pump not tstat!! I'd do a water pump and timing belt while your that far in it. And check back

 

New coolant temp sensor and all new sheet metal ducting as well. Temp when idling or cruising is the notch below half (since there is no 1/2 way notch).. It won't even over heat when idiling and the fan's arent on. Only while drifting.

The only thing that hasn't been replaced was the water pump.

Would cracked turbos cause overheating? I know it could cause the white smoke..


if doesn't go away after this, i'll 1.5jz it with my h1c, although i'll miss winding it out to 7k

 

is your intercooler ducted properly to allow air to pass through to the radiator properly? do you have an oil cooler? what are your oil temps like?

 

Custom sheet metal ductwork, replaces the OE plastic. Also a gt500 hood vent. No problems when driving normal, just drifting. Doesn't even seem to budge in temp when hard fwy pulls , etc. No oil temp gauge, but its a 8x11" oil cooler . it had the same problem before the cooler, I added it hoping it would cure the problem, but it didn't. Same with the hood vent. The turbos are custom built with the ebay 1jz stainless dp.

 

Remove the electric fans and put back in the factory fan with clutch......

This is why I would never chance a used JDM engine.....at a minimum should do new oil pump and water pump

 

I ran for 4 years on a dual electric fan setup, never an issue. Primary a 2100 CFM, secondary secondary a 800 cfm. I think the stock one is about 3500 cfm. It's close, but these pull that at idle (or off), which is more than a stock one. Air flow when driving is greater than that since it's being pushed into the radiator.

As i said, i used to tell people about ditching their electric setup in favor of stock, but i've never had a problem in 4 years, even while drifting at small and large tracks. I went to Irwindale in the summer, and even ran my A/C while waiting for my turn. I've never had a problem with these fans.

 

Blocked radiator?

 

negative- i used the stock radiator for years, then it started over heating, thought it was the rad, replaced with a cx racing supra radiator, has a 2" core.

 

When I supercharged my SC400, I had a massive overheating problem.

I had a Koyo Supra Radiator, Water wetter, with distilled water, Ford Taurus electric fan (man that thing was a beast), and it still overheated, especially on the highway.

It ended up being my lower splash shield/under guard thing.

Put that back on, and it was good to go.