Running a bit hot - GT-R Register - Official Nissan Skyline and GTR Owners Club forum

Marky_GTSt · 4th August 2006, 06:20 PM

Anyone else having heat problems with this weather or is it just me ?

Problem: When driven quick ish with the aircon on it gets allmost to the top of the temp guage, it also does this when driven fast for more than 10 miles or so. If I run the heater full blast it keeps it in check a bit better.

I have checked the waterpump, Changed the thermostat and viscous coupling, checked the system for blockages (all looks clean) there is no real water loss (about a litre a month if that) pressure cap is a new 1.2 bar nissan one, Electric fan is working, Belt to water pump is newish and tensioned ok, there is no air in the system.

Anyone have any ideas what else to check ? Am I missing something ?
Is there any way to check the viscous coupling I have fitted is working ok ? It doesnt seem much better than the old one from what I can tell, Coupled with the fact that the temp goes down with the heater suggest the radiator or fan to me.....

Also, The turbo pipe to the intercooler was restricted a bit, so I have altered that to see if the turbo working to hard was causing the problem, It seems to have helped a little.

Turning off the aircon and driving steady brings the temp back down, but very slowly.

Might pop to my MOT place and have the probe in the rad to see if the head gasket is on the way....

Any suggestions welcome...

whoflungdung · 4th August 2006, 06:37 PM

Check for an air lock.....

When you stop next time it does this, pop the bonnet

Listen for any bubbling sounds, if it sounds like a kettle boiling under the bonnet you have an air lock

To fix this, remove the radiator cap(be very carful when doing this)

Then leave the car running, check the water in the rad

And top up as you go, until it is full again(takes around 10 mins)

Once full the water will stay at the top of the rad, put cap back on

It may not be this, but it is a possibility

Good luck!

Marky_GTSt · 4th August 2006, 06:52 PM

It does do the boiling sound, but only if I switch off while its really hot, So I figured it was just the water boiling, It doesnt do it if I let it cool down first.

Thanks for the suggestion I will give it a go, Might set up a header tank too and see if I can clear it that way...

whoflungdung · 4th August 2006, 06:57 PM

Quote:

Originally Posted by Marky_GTSt

It does do the boiling sound, but only if I switch off while its really hot, So I figured it was just the water boiling, It doesnt do it if I let it cool down first.

Thanks for the suggestion I will give it a go, Might set up a header tank too and see if I can clear it that way...

From my small amount of experience, thats an air lock

And a very easy and cheap thing to sort out...thankfully

NikWilson · 4th August 2006, 07:16 PM

There is a coolant bleed screw by the fuel rail on the RB26 engine, not sure about the GTSt.

This is the high point in the engine and a good place to bleed the system also.

Nik

Marky_GTSt · 4th August 2006, 07:24 PM

Its there on the GTSt too, I have bled through this but got no air out..... So if there is any it must be trapped elsewhere.

Fuggles · 5th August 2006, 07:34 PM

Have you got a bigger rad and an oil cooler? Might pay you to fit these as well if you haven't already

NigelR32 · 5th August 2006, 08:55 PM

You say you use a litre of Water a Month...................that's not right!! It sound to me like you have a semi blocked rad, a dodgy Rad Cap, or a weepy Head Gasket. Remember, if your Gasket leaks from water jacket to cylinder, you wont get a water oil mix.

When she's at normal temp, try and squeeze the top hose, it should compress fairly easily. If it feels solid, the system is becomong pressurised.

Regards

Marky_GTSt · 11th August 2006, 05:56 PM

The system doesnt pressurise I have allready had a squeeze round, And I get no bubbling from the rad with the cap off and the engine running, But I also know that this doesnt allways mean the head gasket is good, i dont mind if its gone as I was going to upgrade anyways.

I thought about an oil cooler (which im going to get) but the car was fine and now its not, so somethings gone wrong and before I start cranking up the power I think I need to find out what, else this will come back to haunt me later

Should get time this weekend to have a look, But my guess is head gasket. Though Im still not convinced the viscous coupling is any good (no whooshing sound from the fan and im sure it used to be quite loud) Could do with borrowing a known good one as im not bothered about buying another one just in case.

4th August 2006, 06:20 PM	#1 (permalink)
Marky_GTSt New Users Join Date: Dec 2005 Location: Near Sheffield Posts: 3,048	Running a bit hot Anyone else having heat problems with this weather or is it just me ? Problem: When driven quick ish with the aircon on it gets allmost to the top of the temp guage, it also does this when driven fast for more than 10 miles or so. If I run the heater full blast it keeps it in check a bit better. I have checked the waterpump, Changed the thermostat and viscous coupling, checked the system for blockages (all looks clean) there is no real water loss (about a litre a month if that) pressure cap is a new 1.2 bar nissan one, Electric fan is working, Belt to water pump is newish and tensioned ok, there is no air in the system. Anyone have any ideas what else to check ? Am I missing something ? Is there any way to check the viscous coupling I have fitted is working ok ? It doesnt seem much better than the old one from what I can tell, Coupled with the fact that the temp goes down with the heater suggest the radiator or fan to me..... Also, The turbo pipe to the intercooler was restricted a bit, so I have altered that to see if the turbo working to hard was causing the problem, It seems to have helped a little. Turning off the aircon and driving steady brings the temp back down, but very slowly. Might pop to my MOT place and have the probe in the rad to see if the head gasket is on the way.... Any suggestions welcome...

5th August 2006, 07:34 PM	#7 (permalink)
Fuggles GTROC Chairman Join Date: Jul 2001 Location: UK Posts: 16,942	Have you got a bigger rad and an oil cooler? Might pay you to fit these as well if you haven't already __________________ . GTROC chairman Please feel free to contact me with any GTROC questions send an email to info@gtr.co.uk or send a PM

5th August 2006, 08:55 PM	#8 (permalink)
NigelR32 GTR Register Member Join Date: Jul 2002 Location: RB26ville Posts: 916	You say you use a litre of Water a Month...................that's not right!! It sound to me like you have a semi blocked rad, a dodgy Rad Cap, or a weepy Head Gasket. Remember, if your Gasket leaks from water jacket to cylinder, you wont get a water oil mix. When she's at normal temp, try and squeeze the top hose, it should compress fairly easily. If it feels solid, the system is becomong pressurised. Regards __________________ Nigel...........GTROC Member Now on '32GTR No.3

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4th August 2006, 06:37 PM	#2 (permalink)
whoflungdung GTR Register Member Join Date: May 2005 Location: NW England Posts: 1,989	Check for an air lock..... When you stop next time it does this, pop the bonnet Listen for any bubbling sounds, if it sounds like a kettle boiling under the bonnet you have an air lock To fix this, remove the radiator cap(be very carful when doing this) Then leave the car running, check the water in the rad And top up as you go, until it is full again(takes around 10 mins) Once full the water will stay at the top of the rad, put cap back on It may not be this, but it is a possibility Good luck!

4th August 2006, 06:52 PM	#3 (permalink)
Marky_GTSt New Users Join Date: Dec 2005 Location: Near Sheffield Posts: 3,048	It does do the boiling sound, but only if I switch off while its really hot, So I figured it was just the water boiling, It doesnt do it if I let it cool down first. Thanks for the suggestion I will give it a go, Might set up a header tank too and see if I can clear it that way...

4th August 2006, 07:16 PM	#5 (permalink)
NikWilson GTR Register Member Join Date: Oct 2002 Location: East Dereham, Norfolk. UK Posts: 933	There is a coolant bleed screw by the fuel rail on the RB26 engine, not sure about the GTSt. This is the high point in the engine and a good place to bleed the system also. Nik

4th August 2006, 07:24 PM	#6 (permalink)
Marky_GTSt New Users Join Date: Dec 2005 Location: Near Sheffield Posts: 3,048	Its there on the GTSt too, I have bled through this but got no air out..... So if there is any it must be trapped elsewhere.

11th August 2006, 05:56 PM	#9 (permalink)
Marky_GTSt New Users Join Date: Dec 2005 Location: Near Sheffield Posts: 3,048	The system doesnt pressurise I have allready had a squeeze round, And I get no bubbling from the rad with the cap off and the engine running, But I also know that this doesnt allways mean the head gasket is good, i dont mind if its gone as I was going to upgrade anyways. I thought about an oil cooler (which im going to get) but the car was fine and now its not, so somethings gone wrong and before I start cranking up the power I think I need to find out what, else this will come back to haunt me later Should get time this weekend to have a look, But my guess is head gasket. Though Im still not convinced the viscous coupling is any good (no whooshing sound from the fan and im sure it used to be quite loud) Could do with borrowing a known good one as im not bothered about buying another one just in case.