Sc300 2jzgte swap. Over Heats when ac is turned on
08-09-17, 05:54 PM
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Sc300 2jzgte swap. Over Heats when ac is turned on
Hi.
I have 1995 Sc300 2jzgte swap. everthing works fine. It's just when I turn the ac on it starts to over heat. Iit has brand new oem water pump , supra fan and fan clutch , supra fan shroud , thermostat and koyo rad radiator. If anyone can help I appreciate it. I have also bled the system a few times
thanks
I have 1995 Sc300 2jzgte swap. everthing works fine. It's just when I turn the ac on it starts to over heat. Iit has brand new oem water pump , supra fan and fan clutch , supra fan shroud , thermostat and koyo rad radiator. If anyone can help I appreciate it. I have also bled the system a few times
thanks
08-10-17, 01:09 AM
#2
Have you hooked up the OEM TT auxiliary electric fan? There is a 93-96 single fan version and a 97-98 twin fan version. The shrouds are different for 93-96 and 97-98 as well. The more common TT shroud is the 93-96 version.
Everything else on your swap's cooling system sounds like it's in order.
Alternative to that you may need to install an small aftermarket electric fan in that same location (lower driver's side of radiator on the engine side) with a relay.
I'm not aware of how others have done this or if they have done this with their 2JZGTE swaps but a factory aux electric fan is how the 2JZGTE was set up in the Supra. I assume this might be your problem but it's hard to determine for sure without seeing the car up close. Also, the Florida heat this summer can certainly make use of the stock (TT) cooling system and GTE engine bays tend to be a little hot regardless.
If you have a Supra TT fan shroud in there already then the best thing would be to source whichever version of the OEM aux electric fan goes into the circular cutout(s). I think they may be available used only now but I'm not sure.
Everything else on your swap's cooling system sounds like it's in order.
Alternative to that you may need to install an small aftermarket electric fan in that same location (lower driver's side of radiator on the engine side) with a relay.
I'm not aware of how others have done this or if they have done this with their 2JZGTE swaps but a factory aux electric fan is how the 2JZGTE was set up in the Supra. I assume this might be your problem but it's hard to determine for sure without seeing the car up close. Also, the Florida heat this summer can certainly make use of the stock (TT) cooling system and GTE engine bays tend to be a little hot regardless.
If you have a Supra TT fan shroud in there already then the best thing would be to source whichever version of the OEM aux electric fan goes into the circular cutout(s). I think they may be available used only now but I'm not sure.
Last edited by KahnBB6; 08-10-17 at 01:15 AM.
08-10-17, 03:35 AM
#4
I have the feeling something else is the problem but tough to guess without seeing the car.
Just for your info and reference , I have a 2jzgte swapped SC making 980rwhp with the GTE fan setup and has no auxiliary fan. Just a hole right there
for the aux fan. To complicate it, it has a 5" thick inter-cooler and in between the condenser/radiator and inter-cooler there are 2" thick transmission coolers and it doesn't overheat even with the AC on.
I also have two 2jzGTE swaps SCs making good power using the SC300 shroud which means no auxilliary fans and do not overheat with AC on.
The stock Supra GTE fan setup is one of the best cooling setup for these cars.
Is it too much heat is introduced on that shroud's auxilliary fan's hole now that you don't have that fan ? Is your fan clutch new or used ? New or used , verify if it is engaging into higher speed when the temperature rises. IF it doesn't then that is your problem.
I assume everything on your Supra GTE Fan setup is all original / stock both parts and how they are installed.
Just for your info and reference , I have a 2jzgte swapped SC making 980rwhp with the GTE fan setup and has no auxiliary fan. Just a hole right there
for the aux fan. To complicate it, it has a 5" thick inter-cooler and in between the condenser/radiator and inter-cooler there are 2" thick transmission coolers and it doesn't overheat even with the AC on.I also have two 2jzGTE swaps SCs making good power using the SC300 shroud which means no auxilliary fans and do not overheat with AC on.
The stock Supra GTE fan setup is one of the best cooling setup for these cars.
Is it too much heat is introduced on that shroud's auxilliary fan's hole now that you don't have that fan ? Is your fan clutch new or used ? New or used , verify if it is engaging into higher speed when the temperature rises. IF it doesn't then that is your problem.
I assume everything on your Supra GTE Fan setup is all original / stock both parts and how they are installed.
Last edited by gerrb; 08-10-17 at 03:49 AM.
08-10-17, 04:26 PM
#6
Kind of a long shot here but ended up being the issue on my car. I put a new radiator, water pump, belts gaskets everything in the front of the motor started it up and it started over heating. Turns out the brand new thermostat would get stuck intermittently. Maybe check that out. See if theres hot water running through both hoses. One of mine was cool to the touch.
08-10-17, 05:34 PM
#7
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I replaced the thermostat thinking the same thing with a Toyota Supra oem one and still the same problem. It actually overheats with the ac off also. The only thing used on my swap is my Koyo radiator. Thinking about changing it out next.
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08-11-17, 05:41 AM
#8
Unless it is defective in some way (I cannot imagine how other than a leak) the Koyo race radiator (aluminum) is a good product. Koyo also makes an OEM-like Supra radiator but most go for the aluminum version. All of their radiators are manual transmission types so if you happen to have an automatic you have to use a separate transmission cooler.
Checking the thermostat was a good idea. It's the same thermostat for the 2JZ-GE and 2JZ-GTE btw. I have had a fairly new one get stuck on me after not very many thousands of miles. This was with an OEM Toyota thermostat. It can happen sometimes even though it is not a very common failure with a new one.
Did you rebuild this engine or is it a JDM swap? Is there anything you can think of that might cause a cooling system obstruction? What about your heater core and heater control valve connections or the health of your HCV?
^^ I think checking the surface temperature of your radiator hoses is also a good idea.
Does it overheat with the heater at the highest setting and on full blast and with the A/C compressor turned off or does this make no difference?
You said you did bleed the cooling system of bubbles several times. Something that can help with SC's and Supras is to (carefully!) jack the car's nose up to rest the front lift points on jack stands (and use some wheel chucks on the rear of course). Sometimes after a full system flush you will still have air pockets trapped in the engine. I have found that sometimes the best way to get all the air pockets out is to go to a dealer or a trusted oil change place or mechanic's and have a vacuum coolant refill done. It's not cheap and I can't guarantee that will solve your problem but if indeed there are any air pockets left in the system and any of those are in the cylinder head that could cause an issue.
Though I don't want to suggest trying many tests one after another at the risk of truly overheating your engine and causing harm.
Checking the thermostat was a good idea. It's the same thermostat for the 2JZ-GE and 2JZ-GTE btw. I have had a fairly new one get stuck on me after not very many thousands of miles. This was with an OEM Toyota thermostat. It can happen sometimes even though it is not a very common failure with a new one.
Did you rebuild this engine or is it a JDM swap? Is there anything you can think of that might cause a cooling system obstruction? What about your heater core and heater control valve connections or the health of your HCV?
^^ I think checking the surface temperature of your radiator hoses is also a good idea.
Does it overheat with the heater at the highest setting and on full blast and with the A/C compressor turned off or does this make no difference?
You said you did bleed the cooling system of bubbles several times. Something that can help with SC's and Supras is to (carefully!) jack the car's nose up to rest the front lift points on jack stands (and use some wheel chucks on the rear of course). Sometimes after a full system flush you will still have air pockets trapped in the engine. I have found that sometimes the best way to get all the air pockets out is to go to a dealer or a trusted oil change place or mechanic's and have a vacuum coolant refill done. It's not cheap and I can't guarantee that will solve your problem but if indeed there are any air pockets left in the system and any of those are in the cylinder head that could cause an issue.
Though I don't want to suggest trying many tests one after another at the risk of truly overheating your engine and causing harm.
Last edited by KahnBB6; 08-11-17 at 05:49 AM.
08-11-17, 07:15 AM
#9
Sounds like your radiator might be full of rust and/or oxidation. Try flushing your coolant system with some kind of cleaner. If it doesn't help, then you might have to replace the radiator. Also, probably not a huge deal...but...don't forget to use the Toyota "red stuff" coolant. I was told this is proprietary formula from Toyota and outperforms almost all coolant/antifreeze formulas out there. Again, probably not the issue, but while your at it...
08-11-17, 08:14 AM
#10
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The engine is a Jdm swap but it was completely resealed and the head was sent to a head shop and was rebuilt as well. The heater core is bypassed. I was wrong about the car , It only over heats when the ac is turned on. I just drove it for 20 mins with no ac and it ran perfect. I have only used oem parts ( Toyota coolant ) thanks for your help
09-13-17, 08:22 AM
#12
Some say bypassing the HCV and letting coolant recirculate at all times in the heater core will eventually clean out or "flush" the core, but I haven't seen any hard evidence of that yet.
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