Water Temp Continually Increasing When Highway Driving Upto 120c

[Luke32]

Did bleed the air out the head. RB26's have a small bolt on the side of the head that you take out when you fill up the radiator on level ground while its running. once the water starts coming out of the hole put the bolt back in. The head is higher then the radiator, so that is the only way to bleed out the air once the radiator is full and make sure you have your heater on.

[GTRNUR]

I live in Cairns and get a hot day or two. Though at the moment when we are actually getting to see a bit of sun the temps on the MFD on my R34 rarely get above 80 degrees. Mostly when crusing at 80km/h or above it sits on 76-78.

I have a PWR radiator now but that was only put in for a little better cooling for track days, and the stock one was looking a little tatty. It still worked plenty well enough to maintain simular temps in this climate though. Even on a 38 degree track day at townsville my water temps never exceeded 100 degrees, and considering that is on a lowish speed sprint track thats pretty impressive.

My suggestions.

Thouraghly bleed the air from the cooling system PROPERLY. Start with a cold engine thats not running... Pull the bottom radiator hose and get rid of all the tap water for a start. Then fill it up with distilled water. Do the same with your overflow bottle. Tap water is full of crap that causes corrosion, which leads to blockages, failed pumps and thermostats.

Then as above (Luke 32 says) loosen the 10mm bolt on the front of the head on the drivers side that has the copper washer under it. Start the car and remove the bolt from the head completely. Water will begin to flow out the bolt hole. Keep topping up the radiator til the water flow is steady and not sputtering out air. Let the water level in the radiator go down enough to allow you to tip in some coolent concentrate and then put the bolt back in.

Tip in a bottle of redline water wetter coolant concentrate (Its what I use) and top up with distilled water.

If this procedure doesnt drasticly help your engine temps, you can go to a paranoia level with bleeding the trapped air... This is worth doing anyway if you live in Darwin as your summers are bloody hot!

Get a coke bottle and cut the bottom out of it and test fit it to see if it screws and seals nicely into your radiator cap hole. Find a steep hill to drive up and park nose up, so the radiator is above the engine (has to be a steep hill). Screw the cut bottle into the radiator cap hole and fill the bottle 1/4 up with distilled water and re-start the car.

Run the engine at idle and the occasional rev until bubbles no longer bubble out of the radiator. Once done, replace the radiator cap and check your overflow level is ok. Only when you have done this can you be 100% sure your cooling system is free of air locks.

If you have done this precicely and it still over heats, only then should you move onto having the radiator pressure-back washed, replacing thermostats and water pumps etc. Looking in the top of the radiator hole you should be able to see coolant movement as well. If you do chances are there is nothing wrong with the water pump. Many R32's on the road would still be using their factory fitted pumps, so your R34 would have had to have been pumping sea water for it to fail at only 100,000k's.

If you want to invest in a radiator, get a 40mm PWR one. ARC and trust radiators also appear for sale randomly on the forum, and i'd jump at one of those too as the quality is excellent. Yes there are $300 radiators, but frankly if thats your budget you cant afford to own the R34. Treat it with some respect and use only good quality parts on it. If your at 100,000km you should have replaced the radiator hoses as well.

Good luck!

[full_stick]

I do live in Darwin so I will do this, just want to know will this drastically reduce engine temps??? When I'm in start stop traffic car is no worries and remains in the 80s which was normal. Just don't want to go through this extensive process again when I can get a pressure test for free according to a local workshop. I do however really don't want to have to replace it now as I just did the clutch twice in 6 months as well as tune and other things so really can't afford new radiator at the moment and I do want a decent PWR or ARC item.

[blind_elk]

To be honest your probably right I don't know how to bleed out the air. So all I did was basically drain all the fluid by removing the bottom hose of radiator, put a hose in the top of the radiator in an attempt to flush shit out while car was idling, reconnected hose, turned car off, filled radiator with coolant, then let idle again and attempted to put more fluid in but thinking that the bubbles would come out once car was idling but this really didn't happen and I couldn't really fit any more fluid in???

So thats what I did. Please tell me what I should have done... I love doing this stuff myself but there's just so much to learn....

Flushing the radiator in this manner is juat a total waste of time. The radiator got blocked trying to push the crap from top to bottom, and the crap got stuck. How is pushing it in the same direction supposed to clear it?

You need to reverse flush the radiator - better if you take it to a radiator place to have it done properly.