2JZ over heating problems help please??

[trd-drifting]

Any ideas apprecitated

Ok I have a overheating problem with my stock 2JZ-GTE that has taken me 2 months and i cannot sort out. had a few mechanics and the tunners do not know why either.

Motor was sposed to be a runner ended up having a blown head gasket do not know the history of it. Importer was a wanker and send me a head gasket and bolts and told me to fix myself. It is stock besides the usuals exhaust fmic g3 link wide band o2 sensor etc.. It can be driven around town and on the open road and not overheatd with a 52mm 3 core radiator. The standard radiator gets up to 95degrees in these conditions.
under boost 10psi the temp sky rockets and you have to back off and let it cool down takes about 2minutes to get it to 100-110degrees with the big radiator in, had two huge fans (tuners fans) on the dyno and could only do two power runs then we took it off.

Before dyno only drove 3kms and didnt get to warm i had the head crack tested checked for straightness machined etc.. i overhauld it on top of that as well while it was off. The block was straight replaced headgasket and no more water in the oil. So far ive driven it about 1000kms

What ive checked....

Headgasket was identical and had all holes pressed out etc...
Does not loose water
It does not blow water into the overflow when getting hot etc... (shouldnt be exhaust gasses in the coolent)
Radiator is not blocked
It is not leaning out
Do not think it is a air lock driven the car nearly 1000kms now and it bubbled out over flow a little bit as i did not bleed cooling system properly first time, when it first got warm then stooped. Then took it for a drive
Pretty sure it not radiator cap tried 3.
Pressure tested cooling system
Brand new Thermostate and it does open at 84 Degrees
What pump genuine toyota 5000kms old off my 1JZ bearings are good and impellor has not rubbed etc.. pretty sure it cannot move back to lose efficiency
Compression around 180 each cylinder
The timing is correct, and doesnt miss or anything stupid. all new belt etc..
Prettys sure it not ecu temp sensor as water temp gauge reads same and fluke thermography gun reads within a degree of the temp in radiator.
No cylinders as best i can see with gun are hotter than others.
1huge Fan on front and small on back both on and running in right directions.
Heater core is not blocked and the non return works. Turnning on the heater does not drop temp mind you mkiii supra heaters are shit. Heater plumed in or by passed doesn't change anything
All the coolent lines are clean around block as checked when i put on.
No kinked lines
Using coolent not water as well

I have flushed out the cooling system as i noticted it had a bit of sludge in it after changing the head gasket was blown, drove it only 3km didnt even get hot at that stage (didnt thrash it) heaps of brown merky water came out, and water was discusting and left the hose running through it for a hour ( I know this will not remove sludge if there is some at bottom of the water galleries) Used nulon cooling system flush as well cheap but heaps brown merky water came out. Still each time i drain the coolent it comes out brownish/greenish been 4 times now.

I havn't removed the thermostate was going to do it this w.e as i have pulled it down again to check everything for a third time so cambelt etc.. water pump off etc...
Also have not done a link down test

Posted this on a few fourms
Sorry this is so long but i think this is everything any help very frustrated and just want to go to the track again :s help

Josh

[sik_gt_starly]

Is the radiator very accesable?

When its overheating touch radiator with hand and feel for cold spots, you will know if there is.

If there are cold spots when its overheating radiator is blocked.

[Jason T]

Presure test the radiator system and find the leak

Allen key bolts in centre of head and water pipe o ring from water pump to head are both places 2JZ leak from

Removing thermosat will only mask problem dont do it.

Find the leak.

[matt dunn]

Removing thermosat will only mask problem dont do it.

Find the leak.

Pretty sure that the thermostat's are double acting,
well the 2JZ one's I have dealt with were,

so if you take the thermostat out it makes it overheat more.

[matt dunn]

does it have a water cooled oil cooler?

What oil do you run?

[strx7]

the big fan that is infront of the radiator? does it fit on the back of the rad? if so, loose it off the front, mount it on the back. At highway speeds it WILL be impeading air flow thru the radiator.

How do you know the radiator is not blocked? have you had the tanks off it? if not, then you cant say with certainty that it isn't blocked.

to me it sounds like either a) air lock or b) crook radiator

[85AW20v]

Or an upside down, back to front, round the wrong way head gasket. Just a thought as I haven't seen one of these apart to know if it can be put on wrong.

[MAGN1T]

The headghasket is probably still leaking because the block wasn't "decked".

Pretty common on JZs if you talk to an engine reconditioner.

Steve

[FLAWLES]

The headghasket is probably still leaking because the block wasn't "decked".

Pretty common on JZs if you talk to an engine reconditioner.

Steve

say what?
jz is not an M series engine steve

[FLAWLES]

im with strx7
either air lock/cooling system not bleed up correctly

or dodgy rad

are you not running the factory jza70 rad? (assuming thats the car? )

[MAGN1T]

The headghasket is probably still leaking because the block wasn't "decked".

Pretty common on JZs if you talk to an engine reconditioner.

Steve

say what?
jz is not an M series engine steve

It's an engine, iron block, alloy head. The result is rust on the top of the block.That's when you put water into it.

There's only one way to do a pressure test on a cooling system. That's to hook up a pressure gauge to the cooling system (somehow) and then take it for a drive, watching the pressure increase with the load.

All that sludge that you washed out used to be block and head before it rotted.

Steve

[RS13]

The headghasket is probably still leaking because the block wasn't "decked".

Pretty common on JZs if you talk to an engine reconditioner.

Steve

I highly doubt this. Even pressure across all cylinders, no water loss and he has pressure tested the cooling system.

I'm putting my money on a blocked radiator. How did you check it? A blocked radiator may still allow water to run through it.. I had a similar problem with a C33, would run fine when cruising around, but show it any decent revs and the temp would max out within 30 seconds. Turned out to be a partially blocked radiator, I had ruled it out because it flushed fine, water even came out clean!

Maybe try another radiator?

[2jayzgte]

Do you still have all the factory shrouding around the Radiator???

I've seen a friend of mine who ran a big PWR radiator that used to overheat also as all the air was'nt being trapped by that factory shrouding.

I would try and get some sought of shrouding built to trap there air with the bigger radiator go with a high pressure cap 1.3 bar and also add a TRD thermostat that opens at 71 degree's instead of the factory one that should open at 82 degrees and see how you go with that.

[trd-drifting]

Cheers for all the responces,

Is the radiator very accesable?
When its overheating touch radiator with hand and feel for cold spots, you will know if there is.
If there are cold spots when its overheating radiator is blocked.

Not that i have felt and with the thermography gun the radiator was pretty much the same within reason due to the cooling while the car was warm at idel. The Radiator is brand new (chinese) keeps the car a lot colder then the old standard radiator that use to run fine with the 1jz as i have used both of them. The radiator shop said they can't pull the header tank off to clean as they welded on with the aluminumn 3 core but i have cleaned it with caustic soda from work.

Presure test the radiator system and find the leak
Allen key bolts in centre of head and water pipe o ring from water pump to head are both places 2JZ leak from
Removing thermosat will only mask problem dont do it.
Find the leak.

I have had the pressure tested the cooling system one of the first things i did with the truck mechanics at work and they said it was fine. If it was a leak or is wish i could find it, the o rings have been replaced and they are not pinched or anything. If it is a leak any other way to find it??

[trd-drifting]

does it have a water cooled oil cooler?
What oil do you run?

Yes pressure tested that before i pulled head to make sure it wasnt that leaking water in the oil but that was fine same as turbos etc...
I use Castrol GTX 15w 140 the black bottle never had any problems before with it.

the big fan that is infront of the radiator? does it fit on the back of the rad? if so, loose it off the front, mount it on the back. At highway speeds it WILL be impeading air flow thru the radiator.
How do you know the radiator is not blocked? have you had the tanks off it? if not, then you cant say with certainty that it isn't blocked.

to me it sounds like either a) air lock or b) crook radiator

Yes the big fan is huge and blows like no tomorrow and is in the front as well as you have the mkiii bumper which is shocking for air flow. It doesnt fit at the back now due to the larger radiator. Yeah it will be but the intercooler is in front of that and would be doing the same, but i have never had a overheating problem like this with a smaller radiator and my 1JZ when thrashing it etc.. I cannot say radiator is clean but it was brand new for this motor and then i cleaned it with caustic soda as the tops can not be removed easily according to the guy at our radiator shop as it a aluminumn radiator and the old ma70 one ive tried as well which about half as thick and it heats up 10 times faster with that in but ran all day long when i had my 1jz.

How can i make sure i deffintly have no air locks i jacked the car up at the front removed the raditor cap, made sure the car got up reasonbly warm can not finday bleed screws on this motor??

[matt dunn]

How much space between the radiator and the intercooler.

have seen at least 3 cars in person that overheated due to the intercooler not flowing enough through it to the radiator and not enough air gap between them to allow the radiator to get a good air flow.

And 2 of them were 2JZGTE powered.

not a big thick cored IC is it?

Matt

[trd-drifting]

Or an upside down, back to front, round the wrong way head gasket. Just a thought as I haven't seen one of these apart to know if it can be put on wrong

From memory you can't get the headgasket around the wrong way as all the holes dont line up and it has a arrow on it as well, was just a acl steel race series not that means anything special.

It's an engine, iron block, alloy head. The result is rust on the top of the block.That's when you put water into it.
There's only one way to do a pressure test on a cooling system. That's to hook up a pressure gauge to the cooling system (somehow) and then take it for a drive, watching the pressure increase with the load.
All that sludge that you washed out used to be block and head before it rotted.

Might try that later this week or if i dont get a chance in the coming weekend. As cambelt water pump theromstat all off again. Where should i t in the pressure gauge make up somthing or put it in where the temp sender is for the gauge? But what should the pressure read as if it goes above 1.3bar you would expect it go out the reilief valve and in to the overflow. And it doesnt do this when the car heats up. Is this a worth while test?

I highly doubt this. Even pressure across all cylinders, no water loss and he has pressure tested the cooling system.

I'm putting my money on a blocked radiator. How did you check it? A blocked radiator may still allow water to run through it.. I had a similar problem with a C33, would run fine when cruising around, but show it any decent revs and the temp would max out within 30 seconds. Turned out to be a partially blocked radiator, I had ruled it out because it flushed fine, water even came out clean! Maybe try another radiator?

Yes i know that why i am really confused as you would expect somthing to be wrong. Yeah the radiator does flush fine but you still don't know how free the core is even though it is brand new, heard horror storys about slave and master cylinders with swarf still in them, so maybe could be somthing inside from factory as it a chinnese one.

I would try and get some sought of shrouding built to trap there air with the bigger radiator go with a high pressure cap 1.3 bar and also add a TRD thermostat that opens at 71 degree's instead of the factory one that should open at 82 degrees and see how you go with that.

It is a 1.3 bar cap and i have a standard 0.9bar cap i think as well as the one that came with the radiator and none of them seem to make a change at all. Will price up the Thermostate tommorow, but wouldnt this just mask the problem and since it is a pretty much standard motor with a few bolt ons and ecu you shouldnt need that i wouldnt of thought, but no harm in getting one.

[trd-drifting]

How much space between the radiator and the intercooler.

have seen at least 3 cars in person that overheated due to the intercooler not flowing enough through it to the radiator and not enough air gap between them to allow the radiator to get a good air flow.

And 2 of them were 2JZGTE powered.

not a big thick cored IC is it?

Umm yeah it is a 75mm intercooler and 600 by 300 i think, but air flow is not a problem i do not think to cause this as at the dyno we had one fan blowing where the intercooler goes and they usually only use the one and then a 2nd one pointing straight down at the radiator and he could only do 2 power runs and it would get to hot and Brent said they never get a car hot with just the one fan going let alone two.

But never had big problems with overheating, due to airflow unless it a bloody hot day on the track after quite a few laps and that was with the smaller 7m radiator with the 1JZ and ran that for 3years. I know i need a new bumper for better air flow but want to sort this out first then that next on the list.

I have a 3rd mechanic coming around after work this week sometime but if anyone thinks of more ideas let me know or anyway of checking somthing please let me know.

Josh

[trd-drifting]

How can i make sure there is no air locks or bleed it correctly? wouldnt 500kms of normal driving force the airlock out due to the coolent expanding?

Also what rpm does standard 2JZ turbos kick in as it seems a lot laggier than my 1JZ. I have removed all the little valves and solonoids and the butterfly valve in the intercooler piping so both turbos spool at the same time. Full boost (12psi) took till 3600rpm according to the dyno charts and im sure my 1jz was like 2800rpm.

Josh

[Girvs]

I may have read this wrong, but are you saying you're running the waterpump from a 1JZ on 2JZ?