Smokin'....- burst radiator hose and other cooling issues (2JZ)

[gwumpkus]

my Mk3 has a 2JZ in it from the aristo, and initially the mighty 2JZ presented some problems with overheating, which has since been resolved with a larger aluminiium radiator and 2 electric fans in it.

yesterday i thought i' wake up turbo no 2 (its still runing on the stock twins), and pushed past 4500rpm.. right then i smelt something strange in the cabin, and moments later, smoke streamed out from the left side of the engine..

i figured one of the hoses must have burst or something. wonder if anyone's experienced this before? this is the 2nd time that coolant's leaked out due to (exscessive?) pressure? the first time it was the lower Rad hose, bound by a stock clip.. u know, the kind that expands when u use pliers to clamp on the ends? i replaced that clip with a standard hose clip/band that is screw tightened, and the prob went away.

i'll jack up the car tomorrow to check for the burst hose.. i'll prob replace ALL rubber hoses in the engine bay with Samco silicone ons... this leaking cooling system is driving me nuts... its making even daily drive a very suspicious affair... sheesh...

any thoughts friends and gurus?

 

[gwumpkus]

i've just taken off the intake manifold to access the lower engine block to check. seems that the only coolant related stuff down there that might bow/leak are the bypass hoses for the oil filter. again this is held by the stock clips. i'm going to replace these wth regular band-on type of clips.. has anyone thought of, or has actually replaced ALL these with the band-on types?

 

[IBoughtASupra]

These are all the coolant hoses your motor will have. Toyota, along with other manufactures, use constant tension clamps. This is the one you are describing that will need to be squeezed with a pliers to be removed.

I have never seen them go bad, if anything, just give them a squeeze on its side and it good again as long it's not oval shaped.

Please get rid of your electric fans, get a GTE clutch and a GE fan blade and use it. Trust me, you will be happy with that setup than your current electric fans.

You can buy new constant tension clamps. Just Google it.

Upper radiator hose
Lower radiator hose
Oil cooler to block hose
Oil cooler to metal pipe
Coolant feed and return lines for the twins
Heater hose at the rear of the head in the center
ISCV coolant lines
Throttle body coolant lines
Heater valve barb on the metal pipe

 

[ifyouaint1sturlast]

You mention upgrading your radiator due to cooling issues..

You have some kind of hidden issue if you needed to do that. The stock radiator with clutch fan on a stock Aristo 2JZ-GTE will work just fine. If you were overheating then there was some underlying problem to begin with.

 

[NecroCyde]

Hmmmm....Still running the Aristo Hydrofan waterpump? Did any of the Boost/vacumn related hoses get hooked up wrong to the coolant lines? Thermostat fucked? bad coolant? Blockage in one of the water necks? For that much coolant to be leaking out and you smelling it in the cab along with overheating constantly... Something very very amiss here, did the coolant lines that run through the ISC Valve and the throttle body get hooked up right?

From what we have seen, cant say this is a common issue at all. Coolant/vacumn hoses get crossed alot on a 1jz, but normally not causing symptoms of this size.

 

[gwumpkus]

thanx for all your responses. to start with, i think the clutch fan was suspect, so the shop basically junked it, and fitted in 2 x 12" fans. ive read repeated that the stock fluid coupled fan is best, but what do u guys do about the SHROUD? considering that i have a rad thats for the 7M, coupled with the 2JZ...

initially it ran on the stock 7MGE radiator, which wouldnt allow me to go beyong 90km/h.. hilarious man.. that got upgraded to an aluminium radiator (2-row, 52mm overall thickness).. and its been ok since.

to be clear, its overheated on 3 occasions:

once, when the relays for the fans died..

then, one of the constant-tension clips (now i know what they're called! thanx!) somehow wasnt holding properly, and coolant leaked out of it. i then replaced that with a band-on tyupe clip, and it stopped leaking!

this third time prompted me to inititiate this post. i've just replaced all the clips below the manifold.. just to be sure.. and guess what.. once i topped up the rad and started the engine, coolant started trickling again, and i traced it to ... (dammit!) a cracked rubber bung/plug right at the REAR of the spark plug galley!! i guess that was the return point for the coolant that would have been circulated to the heater, which was sensibly deleted (heat is what we have in abundance where i live!).. i looked around and realised that these little caps appear in several places! imma buy a whole bunch of these to replace them..... now i wonder if Samco makes these as well...

 

[gwumpkus]

necrocyde: is there a difference in the water pumps between the 2 versions? i've always eondered about that, cos as i said earlier, my hydro-fan got deleted .. how do you guys who've used the aristo 2JZ get around this?

Hmmmm....Still running the Aristo Hydrofan waterpump? Did any of the Boost/vacumn related hoses get hooked up wrong to the coolant lines? Thermostat fucked? bad coolant? Blockage in one of the water necks? For that much coolant to be leaking out and you smelling it in the cab along with overheating constantly... Something very very amiss here, did the coolant lines that run through the ISC Valve and the throttle body get hooked up right?

From what we have seen, cant say this is a common issue at all. Coolant/vacumn hoses get crossed alot on a 1jz, but normally not causing symptoms of this size.