I've got a two-speed Subaru electric fan installed on my Samurai, behind a new OE radiator. Since I did that, the car runs really cool, even during heavy use on sand dunes. However, when cruising on highways, the temperature guage goes up.
Since I did the vitara 5.125:1 vitara ring and pinion swap, the problem became much worse because of the higher RPM. During highway cruising, the temperature really goes up, and I can only control it by keeping the RPM below 3000 RPM. The results are identical between the 1.3L engine, and the 1.6L engine which I swapped in a couple of weeks ago.
What is the best solution to this problem? I'm thinking of putting back a stock transfer case instead of the 6.5:1 crawler gears, to increase the gearing ratio a bit and get it closer to the stock ratio with stock tires. Or to get an aluminum radiator from Hawk.
My question is: will the Aluminum radiator completely solve the problem? And which approach would you advise me to take?
The new Aluminum radiator will help to cool it down better than a stock component, but I don't think it will solve your problem.
There has to be a good reason why it is heating up so much. You probably already know to check the thermostat. When I was young, I was told to throw the thermostat away... i found out the hard way how important a good, working thermostat helps to slow the flow enough to cool the motor.
in old El Paso...
First things I would check would be the thermostat, water-pump and make sure the fan is blowing in the correct direction. I know it sounds crazy, but given the symptoms, it sounds like the fan is not blowing in the correct direction. If a push fan, it should be mounted on the front of the radiator and blow towards the rear of the vehicle. If a pull fan, it should be mounted on the rear of the radiator and pull the air through, blowing towards the rear of the vehicle. It's worth checking!
Thanks guys. I know for certain that the thermostat is ok and working fine, cuz I recently baught a new one, and that the fan is blowing in the right direction. The car remains really cool while idling. The problem is exactly the same with both engines, which tells me it is not the water pump, as the pump has been changed with the engine. Another thing, I sold my old engine to a friend, and he says he has absolutely no overheating.
The problem really only started to show up after I did the vitara diffs. When the engine revs high at the highway, it starts heating up. Could it be the diffs' R/P were not balanced properly, and causing the engine to exert more effort to push the car at high speed?
Is it actually running hot, or is it just the gauge?
The following has been seen before;
(high rpm = higher alternator output = higher battery volt = higher gauge readings) ??
The radiator is practically new, I replaced it a year ago and haven't used the car that much since. So I really don't think it is blocked.
It is not just the guage, because when the temp guage goes up, I feel the heat from inside the cabin and the AC cooling becomes very poor, which otherwise cools very nicely.
Another idea occurred to me: what about putting a different thermostat that has different temperature valving? I will probably try that and see how it goes. Heared the Nissan thermostat opens at lower temperature than the Suzuki, so maybe that will help?
Last edited by alternator; 07-23-2010 at 06:08 AM.
tripple check the fan direction. if it's cooling at low speed, it could still be pushing air forward through the radiator without a problem, where at high speed the ram air would counter a pusher fan blowing forward through the radiator causing the air to just stall.
At freeway speeds, the air blowing against the front of the vehicle should be enough to cool the radiator without a fan at all. I used to run my rig on the highway going 55 in 3rd gear with 33" tires on it as I climbed the mountain passes to Temecula. Never had the gauge go into the hot area, and I must have been pulling well over 5K RPM's with an outside air temp of 98+
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