Rb25Det Neo Water Pump & Thermostat Replacement

[R1maniac]

My R34 GTT shows moderately high oil temperatures (100+) and bit of steam coming out of the radiator. Water temperature shows normal though. Car cools down in few minutes after I stop but Im not dirving it anymore until I fix the issue.

So Im upgrading the entire cooling system (radiator, pipes, thermostat and water pump). Im looking at a 40mm aluminum radiator from ebay. Replacing the radiator is a kids job.

But how hard is it to get to the thermostat and water pump? I could find topics on RB25DET but not much info on the Neo engines. Any leads on this would be much appreciated.

Thanks guys

[Carbon 34]

My R34 GTT shows moderately high oil temperatures (100+) and bit of steam coming out of the radiator. Water temperature shows normal though. Car cools down in few minutes after I stop but Im not dirving it anymore until I fix the issue.

So Im upgrading the entire cooling system (radiator, pipes, thermostat and water pump). Im looking at a 40mm aluminum radiator from ebay. Replacing the radiator is a kids job.

Flush the system before changing Anything with heater on !! So the heater core can be flushed as well

But how hard is it to get to the thermostat and water pump? I could find topics on RB25DET but not much info on the Neo engines. Any leads on this would be much appreciated.

Thanks guys

Use top coolant , never mix with tap water or another brand ,

Good time to do hoses as well as mentioned

Belts as well

alloy Radiators dont always fit perfect even name brand ones !! if your mounts have sagged on tranny, engine or radiator the shround might hit

Or rub on frame rail

If you havent done water pump and timing belt do it now to save the hassle if needed and $$

replace the radiator cap to 1.3 bar cap , to raise boil temp

Buy redline waterwetter or motul cool and dump in before totally full up , it makes a dramatic difference

Use aviation gasket sealer and factory parts or nismo items , the aviation gasket seals it the first time not tenth time , permatex brand , messy so dont get it on the car or your clothes

the thermo is easy just put it in right side up lol

expect rusty bolts and muck to come out of flush even on a well kept car

Drain air , burp the bottom hose a few times before starting to get air out , , pull overflow out and use non kerosene based cleaner and a baby bottle brush inside to clean it replace hose to it while out as well and prefill to max

it should suck some in the first few hot cold cycles then stablize at full , make sure you have heater on hot !! Or airpockets will fill head and heater core and destroy the head if bad enough !!

buy all new hose clamps as well , makes life easy and on silione hoses the old ones cut in

Check the coolant daily cold For a week then if its all good every fill up of fuel is a good time for a glance at it ?

[Hanaldo]

replace the radiator cap to 1.3 bar cap , to raise boil temp

Don't do this. It might stop the water from boiling but you don't want to get up to standard boiling temperature anyway, you're exponentially increasing the cavitation of your cooling galleries. If your water is getting close to standard boiling temperature then stop driving, don't just raise the boiling point.

[jjman]

Don't do this. It might stop the water from boiling but you don't want to get up to standard boiling temperature anyway, you're exponentially increasing the cavitation of your cooling galleries. If your water is getting close to standard boiling temperature then stop driving, don't just raise the boiling point.

agreed.

+ unless you plan on changing ALL hoses on the motor then puttin a 1.3 bar cap on is quite likely going to start popping these too (iv had so many friends do this). Rememberyou have a car that would be around 15 yrs old now. Those hoses are in good nic anymoe...

[R1maniac]

Thanks guys. I've ordered a 52mm aluminium radiator. It seems to have the right holes for mounting the shroud. Hopefully it will fit.

Apparently the water pump (N1) and thermo was done few months ago by the previous owner. So I'll probably skip those.

I reckon the only reason why my radiator failed was becasue I had low coolant concentration and more water in the system. I was literally flogging it when it failed lol. To add to this, my boost sensor was not plugged in then and the car was running lean. So it probably raised the temperature quickly.

Hopefully the car will back on the road on friday

[Carbon 34]

Don't do this. It might stop the water from boiling but you don't want to get up to standard boiling temperature anyway, you're exponentially increasing the cavitation of your cooling galleries. If your water is getting close to standard boiling temperature then stop driving, don't just raise the boiling point.

Thats not how the cooling system works mate

If you run the .9 factory one you run the risk of boiling over on the track days or super hot days in traffic , it was never designed for australian conditions !!! Which are way more severe then most places on the planet

You can run the factory one but it should be replaced with new radiator anyway ( the radiator comes with a new 1.1 bar cap but horrible quality imo

Most new caps run 1.1 to 1.5 including nismo caps , my nismo cap 1.3 bar and 52mm alloy radiator with n1 style pump and nismo thermostat with redline waterwetter and red heavy load organic coolant runs cool as hell on smoking hot days and the thing actually shows on laptop on the dyno the nismo stat opens sooner to let coolant cycle sooner , 3 blocks and the temp is up

Grounding the coolant also helps oxidation from occuring , most failures are rust or oxidization issues caused by mixing coolant brands, tap water ( hard water) a gauge mount in the hose or a small gauge wire to ground extends the quality long term sounds weird but its documented to help ?

[R1maniac]

Thats not how the cooling system works mate

If you run the .9 factory one you run the risk of boiling over on the track days or super hot days in traffic , it was never designed for australian conditions !!! Which are way more severe then most places on the planet

You can run the factory one but it should be replaced with new radiator anyway ( the radiator comes with a new 1.1 bar cap but horrible quality imo

Most new caps run 1.1 to 1.5 including nismo caps , my nismo cap 1.3 bar and 52mm alloy radiator with n1 style pump and nismo thermostat with redline waterwetter and red heavy load organic coolant runs cool as hell on smoking hot days and the thing actually shows on laptop on the dyno the nismo stat opens sooner to let coolant cycle sooner , 3 blocks and the temp is up

Grounding the coolant also helps oxidation from occuring , most failures are rust or oxidization issues caused by mixing coolant brands, tap water ( hard water) a gauge mount in the hose or a small gauge wire to ground extends the quality long term sounds weird but its documented to help ?

Did the 52mm Radiator fit well mate?