aristo overheating

[avinesh]

hey guys, bought an aristo last sunday and its got an over heating issue.......it doesnt heat up while driving around at 50-60km/h only over heats on the motorway and when ever it comes on boost....have replaced radiator cap and thermostate, over heated even after changing these. The radiator looked really blocked so gave it to a radiator specialist yesterday, picked it up today and they told me only 1/3 of the radiator was working coz it was really badly blocked......will change water pump hopefully over the weekend and see if these things make a difference.....did a compression test and came up to almost 180psi on all 6 cylinders also did a tk head test and it passed that test as well......car has 223,000kms on it and is stock apart from a front mount intercooler and intake...boost is set at 10psi, now the worying thing is the car had bubbles in the radiator with the cap removed and idling but it passed all the test so im confused, maybe it was the blocked radiator or maybe water pump???? will find out when i start the car again i guess after fitting a new water pump....any ideas on whats happening in the mean time?????

[allencr]

...bubbles in the radiator with the cap removed and idling ...fitting a new water pump

Bubbles are normal if its at operating temp. The heads internal temps are well over 100C when the coolant flow is slow at idle.
Why replace the pump? Shaft loose/wobbly, or leaking/seeping/dripping from its weep hole? Noisy? If not, then don't bother unless you don't see any coolant flow when the engine is revved. With the radiator that clogged, coolant should have erupted out when revved up after the thermostat has opened up.

[DFECTED]

...bubbles in the radiator with the cap removed and idling ...fitting a new water pump

Bubbles are normal if its at operating temp. The heads internal temps are well over 100C when the coolant flow is slow at idle.
Why replace the pump? Shaft loose/wobbly, or leaking/seeping/dripping from its weep hole? Noisy? If not, then don't bother unless you don't see any coolant flow when the engine is revved. With the radiator that clogged, coolant should have erupted out when revved up after the thermostat has opened up.

huh?


Sounds like you have a headgasket issue, but only under boost, is it using water? If you do end up doing the headgasket, and you want to keep the car for a while, do it properly and surface the block as well

[BZG Wagon]

So have you fixed or replaced the radiator?

Assuming it's corrosion make sure you clean out (or better - replace) the piping etc around the motor as that will likely have corrosion in it as well.
Also make sure you're using antifreeze - as it stops your motor from corroding and raises the boiling point of the water in your car which prevents overheating.

Bubbling doesn't sound good (usually, but not always, air gets past your head gasket & into water circulation, causing bubbles) but your engine compression sounds good. Did the radiator specialist put anything in there?

IMO sort your radiator and then take it from there. Sounds like you'll probably need to do a heck of a lot more than a radiator flush to bring it all up to scratch.

[edwagon]

JZ engines have metal headgaskets from factory and are pretty tough - they do not often blow.
Bubbles do not sound good, but depends if the system is bled properly etc before you can read too much into them - TK and comp tests are good to have done, and good to have come back negatory
Depends how hot it has got, and how often

Def need to get the radiator sorted obviously - a blocked rad will def cause the issues described.

Even if the water pump is not leaking and has no play, it could still have either lots its fins through corrosion/cavitation, or be spinning on the shaft. So IMHO replacing it is a good step.

Make sure you replace the thermostat too - it could easily be jammed

[Dell'Orto]

In before magn1t - bhg

[CXGPWR]

Possible not enough air flow due to front mount placement. check engine fans are working well etc.

[avinesh]

In before magn1t - bhg

yea i was suspecting blown head gaskit as well but got confused after performing all the tests as they came out showing very good results...better then expected, i dont really wana spend thousands on the head gaskit and see it overheat again, the thing that really confuses me is i have a 420kw plus supra with stock internals and have over heated that many times due to the electric fan not working or the belt coming off the water pump pulley (sorted all that now) and it has never had a bhg even after all that, the aristo on the other hand is an auto and with almost no mods and factory boost.....by the way where can i find an aristo water pump??? tried repco they only seem to have supra water pumps....

[Dell'Orto]

Yeah its probably hasnt, but magn1t likes to diagnose all heating faults as BHG...was just beating him to the punch

[avinesh]

...bubbles in the radiator with the cap removed and idling ...fitting a new water pump

Bubbles are normal if its at operating temp. The heads internal temps are well over 100C when the coolant flow is slow at idle.
Why replace the pump? Shaft loose/wobbly, or leaking/seeping/dripping from its weep hole? Noisy? If not, then don't bother unless you don't see any coolant flow when the engine is revved. With the radiator that clogged, coolant should have erupted out when revved up after the thermostat has opened up.

the coolant did erupt when reved, replacing the pump because it started to leak yesterday....

[avinesh]

...bubbles in the radiator with the cap removed and idling ...fitting a new water pump

Bubbles are normal if its at operating temp. The heads internal temps are well over 100C when the coolant flow is slow at idle.
Why replace the pump? Shaft loose/wobbly, or leaking/seeping/dripping from its weep hole? Noisy? If not, then don't bother unless you don't see any coolant flow when the engine is revved. With the radiator that clogged, coolant should have erupted out when revved up after the thermostat has opened up.

huh?


Sounds like you have a headgasket issue, but only under boost, is it using water? If you do end up doing the headgasket, and you want to keep the car for a while, do it properly and surface the block as well

yea it did use water two or three times but that was when we pulled over to the side of the road coz the heat was almost at 3/4 and it over flowed out of resevor so thats how it lost water, it over heated a couple of times to over half when giving it a bit of stick but then went back to normal when i drove it slowly, i checked the water level after it had overheated and it had coolant right to that max so it overheated with full coolant present so basically it only overheats when on boost or goin up hills or just over 100km/h not while driving normal and also it overheats with coolant present....

[rollaholic]

get a genuine pump, highly affordable.

check the sponsors section, and hit up mark

[the fallen303]

which model aristo is it? 147 or 161? i'm unsure on the 2jz vvti engines in the 161, but the pump in the 147's has the hydraulic pump for the fan built into it, and is HELL expensive to replace. if you're replacing anyway, change to the supra pump (just have to find a supra pulley, as they're hard to find, or buy an after market one) and run electric fans.

converting to supra setup costs bout half, if not less, of a new aristo one...

[avinesh]

which model aristo is it? 147 or 161? i'm unsure on the 2jz vvti engines in the 161, but the pump in the 147's has the hydraulic pump for the fan built into it, and is HELL expensive to replace. if you're replacing anyway, change to the supra pump (just have to find a supra pulley, as they're hard to find, or buy an after market one) and run electric fans.

converting to supra setup costs bout half, if not less, of a new aristo one...

do i have to buy the rear housing of the water pump to convert to supra system???? also how much em i looking at to replace to orginal aristo water pump compared to the supra system?? will the pulley from a 1jz soarer fit????

[the fallen303]

i'm not sure to be honest as i haven't actually done the change myself, i'll talk to my mate that has done it and get back to you.

the pulley from the soarer should work.

sign up on jzs147.co.au forums, they're an awesome bunch over there, and really helpful.

[DFECTED]

Just thinking aout it, i have seen engines getting hot due to auto gearboxes overheating because the trans cooler is in the bottom of the radiator, pull the auto dipstick out and smell it to tell if its burnt.

Off topic, myself and grotty (aka import enhancements) have joined forces to become Custom Works Automotive, we have a full engine reconditioning workshop and also do fabrication, general mechanics and wiring so stop in if you are in the area. Cambridge trce, behind cambridge automotive and next to bunnings 5674374

[avinesh]

Just thinking aout it, i have seen engines getting hot due to auto gearboxes overheating because the trans cooler is in the bottom of the radiator, pull the auto dipstick out and smell it to tell if its burnt.

Off topic, myself and grotty (aka import enhancements) have joined forces to become Custom Works Automotive, we have a full engine reconditioning workshop and also do fabrication, general mechanics and wiring so stop in if you are in the area. Cambridge trce, behind cambridge automotive and next to bunnings 5674374

its got an aftermarket trans cooler so it doesnt go through the radiator......im goin to have to swap to a supra/soarer water pump setup.....does anyone have the rear water pump housing off a soarer 1jz turbo or mk4 supra turbo????

[avinesh]

i installed an electric fan on the front of the radiator because the viscous fan pretty much covers only one side of the radiator so just to help the viscous fan out i installed a 14 inch electric fan, now the thing is how do i make the fan come on??? i have managed to install everything except the switch wire of the fan because i have no idea how to make it all work, i dont want to run it full time as i heard it burns them out

[YeMs]

you need to get a temp switch and put it on the top side of your thermostat. wire it through that

[avinesh]

ok car started to overheat again...looked into the radiator and it looks blocked like before again, symptoms are the car overheats if reved past 5 grand while standing still for about 40secs. after fitting soarer radiator which looked to be in better condition compared to the aristo one the car didnt over heat even though i reved it past 5 thousand rpm for about 2mins but if i reved to over 6 grand it would start to climb slowly after about a minute of reving.........with the soarer radiator however im only running one viscous fan without a shroud where as on the aristo radiator i was running the viscous fan and 14inch electric fan together and the viscous fan had a shroud, so the conclusion is the smaller soarer radiator seems to be holding the temp much better with only one fan which is without a shroud (makes it not so usefull) also the test was done with and without the heater on with the soarer radiator and heat on with aristo one. what do you guys suggest???