Radiator replacement time, agree?

[Jesda]

When I bought my Q there were minor cooling system issues. I replaced the water pump then had the radiator end tanks pulled off to have it cored (they went at it with a pipe cleaner or something). Things were super even in sweltering midwest summers. Then I replaced the thermostat last year. Things have been pretty good.

Recently, a coolant leak developed under the plenum so I used two bottles of liquid aluminum to seal it -- big mistake. I ended up flushing the whole system to get all the crap out, but at least the leak is gone for now.

Replaced radiator caps a few times already and ran a cleaning solvent, but it still ran hot on the highway. Idle with AC is stable. Interstate driving or a few WOT runs get the needle creeping way up.

I've ruled out the fan because the temperature is perfectly stable sitting still at idle, and the clutch doesnt allow it to spin freely with the motor off.

I then decided to flush the heater core (what came out looked pretty clean) and once again flush the radiator (again, quite clean since I've been flushing by dilution for the past couple weeks). We'll see if that takes care of anything, but I'm starting to believe my radiator is finally pooched. Should I have it cored again to get all the crud out or just replace it?

$400 for a new radiator, which is down payment on another more recent car. I might buy Wes's radiator from his 94.

Do you guys agree that my radiator is my problem?

[Jesda]

I should also add that everything was fine (except for the leak) until Liquid Aluminum. Never ran hot, just leaked.

[Q45tech]

Number 1 danger to a Q is owners, then incompetent mechanics, then untrained [on Q] technicans........liquid aluminum? or any stop leak stuff.

Just buy a generic replacement rad for $150, it will surely be better than what you have destroyed.........at least for a few years.

[97Q45t]

A really good radiator won't cost $400 unless you buy it from the dealer. I bought a Koyo radiator for my Y33 at a local radiator store for about $160. Quality and look of the Koyo are exactly the same as OEM radiator except for that it doesn't have a Nissan logo but a Koyo logo. Koyo for G50 is about $270 on eBay ( I checked ) but you might get a better deal from a local radiator shop. I recommend you go with the Koyo instead of a generic aftermarket one. Everything fit right, just like OEM.

[gniknave]

You're having the exact same issue that I'm having with my 240 right now. Have you felt the upper and lower hoses yet? Usually if there's a temperature difference (which there is in my case), it means there may be a blockage in the radiator which may come to surface under a heavy load (uphill and highway driving). Does the problem go away with the heater on full blast?

Hit me up on AIM, I can get you a radiator for WAAAAAY less than $400 - and a high quality one at that. I just need the production date from your car.

[Jesda]

Yep, problem disappears with the heat on. Flushing the heater core apparently made a world of difference. After class today I did some serious WOT flogging and 90mph highway driving with the AC on (I swear, the Q is a salsa dancing partner), and the needle crept up but only to the middle tick mark on the temp gauge.

Radiator coring or replacement will be next, then I think I'll be ready for summer. Evan, I'll check my build date and IM you.

[gniknave]

You may follow the same advice NISTECH gave me and attempt the bleeding procedure one more time before installing another part. Though my arguement was that it may be that time anyway.

You might be able to take some pointers from this thread though it isn't Q related: zerothread?id=112177