Up it goes again

[lenkeit1234]

I have a 1998 4.5l petrol/gas patrol, I am having trouble keeping water in the radiator, overheating blows water in the overflow bottle and overflows it. Have a new aluminium 3 core radiator, thermo fan cuts in and out at around 85 deg, cold thermostat opens at around 70 deg. I can sit it idling for hours the fan cuts in and out fine temperature gauge sits below half. Temp is fine around town. Went on a short trip 3hrs fine, when we got into town temp went up to nearly high turned the heater on temp went down. Stoped for a couple of hours added 2 litres of water headed home, on the way home turned off the air con for a bit may be 10k’s turned it back on up goes the temp again high not ¾ a bit more then plummets down to just over half watched this for a bit then turned the heater on again temp came down to “normal” left the heater on for about 30sec turned the A/C back on all was good until we got back into town up it goes again. Got home added another 2-3 litres again. Any thoughts would it have anything to do with the A/C radiator in front (it does get quite hot)

[Bigrig]

Praying for you it's not the head mate - is there noticeable signs of water on the engine when you've stopped (did you check?). Was there water leaking from anywhere noticeable (I know that sounds stupid, coz you'd already know I guess where it's coming from, but I'm just asking the obvious).

If not, it could be anything from a leaking pipe to a cracked head and anywhere in between, but either way, you need to suss it out quick.

Good luck with it mate, and hopefully others will have input also.

[lenkeit1234]

you had to say it didn't ya. I hope its not the head too??????????????

[Sir Roofy]

what about pools of water underneath while parked up in the front or at the back
might be water pump
orwelsh plugs if not the head

[lenkeit1234]

Unfortunately there is no water leaking from any other place, no pools of fluid, I emptied the reservoir and there have been no leeks except the condensation from the air-conditioner, haven’t checked the reservoir since

[NissanGQ4.2]

what sort of thermo setup are you running and do you have a manual override switch???

Are the thermo's enclosed by a shroud???

[lenkeit1234]

The thermo fan is 14in it has an auto thermostatic controlled switch no manual override switch and yes it has a shroud

[jc58nc]

Get the engine hot and CAREFULLY remove the radiator cap, top up the coolant and run the engine.
See if there are any bubbles coming up in to the coolant.
This is a test to see if the head gasket is blown or a cracked head.
Good Luck.
Jeff

[lenkeit1234]

Thanks for the tip Jeff have tried this and no bubbles?
once again there doesn't seem to be anything wrong around town or on the highway just after a long drive??????????????????????
i will get a new radiator cap tomorrow thought the new one that came with the radiator might be a cheapy???????????????????????????
?????????????????????????

[Killametre]

If that fan is the only one I would not be surprised if it overheats, there would not be a 14" electric fan on the market that would have enough flow to do the job that I am aware of. I tried a high performance 16" one with a shroud once on a land cruiser ute and it could not keep up on the open road. The only success I have seen with electric fans is when people adapt an oem setup (like a late model falcon etc) to their car, generally the universal fans are inadequate.

Cheers Andrew


The thermo fan is 14in it has an auto thermostatic controlled switch no manual override switch and yes it has a shroud

[lenkeit1234]

Stop worrying the heads off and there the start of the issue busted gasket on my way the head doc tomorrow morning to find the rest of the issues

As for the fan???????????? A vehicle shouldn’t need a fan on the open road not even on a hot day. Actually if a thermo fan is setup correctly and the radiator and cooling system is in good condition the fan should only come when you stop at the lights or the drive through ETC. Please correct me if I’m wrong. And I shall see how good thermo fans work when the head has no issues. i will keep you'll posted

[Killametre]

Good to hear you are onto the problem

As for your theory about not needing a fan on the open road this may have been true in the old days when radiators were large and had an unobstructed path for the air to flow and there was no other competition for the cooling air like a/c,tranny and eng oil coolers etc but these days (at least the last 25yrs) most manufacturers have designed cars that will require some degree cooling fan performance at hyway speeds from my experience. This theory of mine is based on experience from 20yrs on the tools, I am sure there are exceptions but I could easily compile a long list of vehicles I know of that will run hot and overheat on the Hyway if their OEM cooling fan is not functioning.

As for yours I hope you dont find your setup not up to the task by overheating your engine once its repaired, I would get a professional opinion of your setup before you motor off


Stop worrying the heads off and there the start of the issue busted gasket on my way the head doc tomorrow morning to find the rest of the issues

As for the fan???????????? A vehicle shouldn’t need a fan on the open road not even on a hot day. Actually if a thermo fan is setup correctly and the radiator and cooling system is in good condition the fan should only come when you stop at the lights or the drive through ETC. Please correct me if I’m wrong. And I shall see how good thermo fans work when the head has no issues. i will keep you'll posted