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A low temp thermostat won't cool a hot motor. When the thermostat is closed little cooling takes place. When it is open it makes no difference what kind of thermostat it is. Apparently the purpose of a low temp thermostat is to promote more even warming up of the engine. It won't solve any overheating problems but it will get your heater working more quickly in winter.

Fair enough but i dont agree that the it will get the heater working faster.

In my car with an oil cooler and a low temp thermostat it runs at 75 degrees on the dyno.

I do agree with a blocked radiator it wont cool correctly as u guys have said. But i would still get a nismo low temp and put it in. If the thermostat opens earlier than the coolant can be kept cooler from 62ish degrees instead of reaching 72 degrees and then slowly open and by the time the coolant has cooled and circulated through the motor the temp is up to 80+.

If it starts cooling at 62ish then its got a better chance of being kept lower.

Yavuz has noticed alot of Interferance with CAS signals on skylines lately. . Do u have a pic of the dyno sheet to show what he means

One more thing you can added after you have done the radiator flush is add motul mocool, its a coolant aditive that help's to reduce eng temps a few deg's.

Im currently using it in my 32 up in darwin, and have noticed a 10deg drop (or thier abouts) results are similer for the guys that use it up here. it's only $30 too.

Eh? ive ran a low temp thermostat before and it does exactly that - it holds the coolant temperature lower than a standard one does but its not a good idea for a street car, especially if its not tuned to operate at those lower temps (65-75 degrees of the top of my head)

I just went for a 20 min drive, come back home, and heard a couple of bubble noises from the radiator area. The resoiver was down on coolant and i only topped it up yesterday. This sounds like a blown head gasket..

Im not getting any white smoke from exhaust but my bad idle tells me their could be coolant leaking in the block and making the car miss. What do you think? Anyway to test the head without Taking it apart? Cheers

Edited by Aleckr33

if it was a head gasket you could be getting oil in your coolant or some exhaust gas contamination... most mechanics can do a test on the coolant system to monitor what gases are mixed in there...

I just went for a 20 min drive, come back home, and heard a couple of bubble noises from the radiator area. The resoiver was down on coolant and i only topped it up yesterday. This sounds like a blown head gasket..

Im not getting any white smoke from exhaust but my bad idle also leads me their could be coolant leaking in the block and making the car miss. What do you think? Anyway to test the head without Taking it apart? Cheers

Compression/leakdown test.

Did u bleed the cooling system? I reckon its just the engine sucking up some more coolant from the overflow.

When the engines cold,undo the coolant

airbleed bolt and see if any air comes out. Top up the radiator till coolant comes out this bleeder then put

the bolt bak in and tighten. Then take off radiator cap and run the engine with the heater on and fan on 1, this should remove the air From the cooling system, top up reservior now too. Then fit the radiator cap and take it for a drive monitoring the temp

Check the colour of your plugs, greenish tinge on one or more will obviously indicate Coolant....

Had similar problems/symptoms as you on an RB30ET making good power...we pulled the plugs and #6 was green and moist all around the electrode, car would randomly misfire once it got up in the high rpm, temperature would creep around, run slightly warmer than normal...we changed the plugs for fresh ones and the misfire went away briefly...until the plug got wet again after a few squirts, then it came back!

I'd say from what youve described and as you mentioned, youve got a head gasket issue, take it for a good drive then pull plugs and check their colour.

Edited by NSNPWR

Ok gone for another drive today.. Water temp seems to be stable at 80 - 85 Deg, no bubbling or coolant loss after driving, Iv checked oil cap, dipstick, radiator cap and reservoir and i couldn't see any discolouring. No unusual smell at all from those areas.

The idling issue is still there on start up but is gone after the car is warmed up, but when the car is hot it definately sounds like its missing, very noticeable, but not so much at cold starts.

I haven't touched the IAC as im not too confident undoing it/putting it back together.. so i might just leave it to Unigroup.

Johnnilicte you have pm.

Cheers guys for the help :)

Edited by Aleckr33

Flush the coolant system a few times should fix the overheating.

With the AAC take it off and soak it in petrol and then clean it with compressed air, they manage to get an amazing amount of oil and crap gummed up inside them over 20 years.

Where is the AAC situated on the RB25ET ? Every now & then i have a hunting problem , but didn't know how to fix it . Is it a easy job to pull off & clean it ? :thanks:

back of the intake manifold.

i also rolled a Q tip around the spring and shaft in mine. got even more gunk out.

but there is a whole thread for the AAC......sry off topic...kinda

he seems good at what he does...why not get the guy at Unigroup to fix all these issues while he was installing lotsa money worth of go fast bits anyways??

Edited by boiracer

Yeah i will get Unigroup to fix all these issues, i just wanted peoples thoughts/opinions on them, If i can do something myself to save some coin.

Guys should i look at getting a aftermarket alloy radiator Yavuz has suggested? or should i just replace my noisy clutch fan and keep the standard radiator?

i would start with replacing the clutch fan and flushing out the radiator you have. most of the cheap chinese radiators on the market look shiny and that's about it. they are super heavy and most of them perform worse than standard. I have seen many cars with no temp problems swap to a chinese alloy rad 'for safety' only to find their car starts running much hotter than it did before and end up going back to standard. if you really want to upgrade the radiator look for a quality upgraded core with standard type tanks. it can be done for $400 or so, maybe even $300. that's for a quality core of maybe 30mm or so.

  • 2 weeks later...

Update.

Yavuz called me today and said the CAS is now fixed, Idle control valve is fixed and the car seems to be running ok temperature since iv done the radiator flush. He said the car is currently making 250rwkw but is restricted. He thinks it could be the cat? ... the thing is i just purchased this high flow catco cat from Just jap a week before i gave the car to Unigroup... im not really keen on changing this because it's brand new obviously and thought it would be sufficient for the 250rwkw - 300rwkw mark.

Anyone else have any issues with a Catco cat? What power are you making if you have one?

Cheers

Edited by Aleckr33

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