Jump to content
SAU Community

Recommended Posts

Hey forum I am having an issue with my car overheating and was wondering if anyone can give theories why. I never had heating issues with my normal radiator with clutch fan, but I took it out to install an aluminum dual core I got on a deal. Now the car overheats during normal driving in the daytime. It overheats to the point where hot water bubbles out of the overflow bottle and the stock temp gauge is right below the mark before the H on the gauge.. I have driven it extremely hard in the night time and it didn't overheat, or I just have not driven it long enough, but I think I did as it was driven hard. It just seems to overheat in the daytime under normal driving conditions. I have a 16" electric fan attached to the radiator for cooling without shroud. Can anyone give suggestions as to why it is overheating now with a bigger radiator installed?

Link to comment
https://www.sau.com.au/forums/topic/281403-overheating-heating-issue-r33/
Share on other sites

You may have a air lock in the system.... Just a thought does happen if they are not filled correctly...

Try this:

Start your engine, but leave the radiator cap off so the pressure doesn't build up.

Let the engine run until it reaches its operating temperature.

Turn on your heater and set the temperature control to hot. This will circulate the coolant and any air in the heater lines and core.

Check the level of the coolant. You may find that the level has gone down some. How did that happen? The air trapped in the radiator kept the level artificially high; when this air was released, it opened up more space in the radiator, and allowed more antifreeze into the system. Add more water and antifreeze, in the same 50/50 ratio, to fill the space left by the bled-out air.

As the air bleeds out, the coolant may bubble and spit from the opening on top of the radiator. Use caution--that coolant is hot.

If this does not work check thermostat but i would say thats ur problem.

  • 2 weeks later...

depending on the front mount (if you have one) you could have it restricting flow to the radiator, some aftermarket ones due tend to create a host of cooling problems especially on the track, but go through the basics first, check coolant level and look for leaks/blockages within the radiator...

I have a 16" electric fan attached to the radiator for cooling without shroud.

:O

Just had my dual core installed, retained the stock shroud and my temps are about 13-15 degrees lower at all times...

:(

end thread.

Edited by gunmetalgrey

gunmetalgrey was the first person to pic up the problem. without the shroud the fan isn't work properly. it is probably only working at 50%, if that. most of the cooling comes from the ends of the fan blades as they are traveling faster then the centre of the fan (same rpm, but at a faster speed). without a proper shroud the fan can just suck air from around the outside of the radiator. personally i, and many others, think that the stock clutch fan works better than most thermos.

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now


  • Similar Content

  • Latest Posts

    • Harness is for a s1 Rb25det, and it is engine and lower harness.  the old harness had broken off plugs and was in very rough condition/exposed wires and splices etc. it is not able to be put back on the car, I could visually inspect to see if they had rewired any pins on the ecu plug. The fuel pump definitly isn’t turning off it’s an external pump and very loud you can hear it. Will look at the other harness tonight, am also going to pull the fuel rail and watch the injectors spray, will update here with what I find. Pretty sure at this point it has to be something to do with injectors because car will fire up on starting fluid and cas is clicking the Injectors. Fuel pressure is steady 43psi 
    • Check the injectors flow evenly, and are actually flowing what you and the ECU think they should be flowing. If it's starting up on starter fluid, you have a fuel issue. Is it possible under cranking your fuel pump is turning off?   The harness you replaced, is that the whole engine harness? Do yourself a test, and drop the old harness on and plug it into the Z32 ECU. It's possible they've wired things different. From memory S1 to S2 is different in RB25 and you may have a wrong loom
    • I haven’t pulled the injectors to watch them spray yet but they are clicking from the cas and all of the spark plugs are wet with fuel. I’ve thought the cylinders were being flooded from the beginning and was hoping fuel pressure would fix it. Tonight I am going to pull the rail and watch the injectors spray. Don’t know how to test/diagnose if the plugs are firing in correct sequence but that should be a timing thing and as far as timing goes my car still has the half moon for the cas can only install it 1 way. And my mechanical timing is 100% correct I posted photos above. Confirmed with the balancer on and off. 
    • I checked spark on all cylinders and they all visually have spark with the plug pulled and grounded, but plug 1 is the only one that fouled. This was a running swap that blew up and was rebuilt by a machine shop, put a new wiring specialties harness and did all gaskets, studs, and bolts while it was out.  compression is 135-150 across all cylinders. Aside from that from my understanding with the z32 ecu and maf the car should start regardless. The wiring for TPS and the dual 02 sensor/ dual knock sensor stuff shouldn’t actually stop the car from starting or even running well, (just slightly rich)  they just give fault codes. Car supposedly is supposed to start as long as you have z32 afm and ecu with the nistune base map and that’s info coming from a well known and trusted tuner who does a lot with SR/RB (Rsenthalpy). After more trouble shooting today where I’m at right now is that the cas is sending signal to the injectors they click while spinning the rotor, Fuel pressure is now set at 43psi, all cylinders have good compression and all of the plugs looked great (just wet with fuel) except for cylinder 1 which was very black (cylinder 1 has 150psi compression). all of the coils generate spark if pulled out and grounded out on the head. On the fuel pump car just pops into the exhaust. On starting fluid car will fire off. Hard to tell if all cylinders are firing off but definitley a couple. sounds like all of them but it’s only for 3-5 seconds hard to tell. 
×
×
  • Create New...