66 Sat
Well-Known Member
Hi guys, I have an odd temperature issue with my 318 poly. The engine has been completely rebuilt, bored, decked etc, new crank, pistons, cam pretty much everything. New waterpump, original 22" radiator recored, with a fixed 4 blade fan, no shroud, 16 lbs cap. I originally had a 160° thermostat in it. When running it in, the temps were too cold, showing about 150° on the new electric Autometer temp gauge. I swapped in a new Mr Gasket 180° thermostat and everything was sweet, running at dead on 180° in traffic or on highway. It would warm up to over the 180 mark, then come back down to 180 and stay there. During this time it puked a bit of coolant a few times, especially if I'd been running it hard shortly before shutdown, so I assumed it had found it's own level.
Last week it started running hotter, like 210° hot. This coincided with it being pretty hot and humid here, say 95°F, but then it's always warm, even in winter it's 75°F. This seemed to happen overnight - one day 180, next day 210.
It runs at 210° regardless of whether in traffic or on highway at 70mph. I've drained a bit of the radiator and the tubes seem clear. It also run at 210 a few days later when the temps were cooler (about 85°F).
I was thinking waterpump or stuck thermostat but wouldn't it keep getting hotter and not stay at 210°? Could the gauge be dodgy? I've also noticed the waterpump has a slight movement in it when I grab the fan and rock it fore/aft which is a concern for new pump.
Also, I topped the coolant up with 900ml of water (nearly 2 pints) and while that didn't make a difference to the temperature it didn't puke it out, which I thought it definitely would at the hotter running temp.
I done a fair bit of research on this and realise ignition timing, fan shroud etc all might help, but nothing has changed on the car recently except the temp it runs at. Any ideas?
Last week it started running hotter, like 210° hot. This coincided with it being pretty hot and humid here, say 95°F, but then it's always warm, even in winter it's 75°F. This seemed to happen overnight - one day 180, next day 210.
It runs at 210° regardless of whether in traffic or on highway at 70mph. I've drained a bit of the radiator and the tubes seem clear. It also run at 210 a few days later when the temps were cooler (about 85°F).
I was thinking waterpump or stuck thermostat but wouldn't it keep getting hotter and not stay at 210°? Could the gauge be dodgy? I've also noticed the waterpump has a slight movement in it when I grab the fan and rock it fore/aft which is a concern for new pump.
Also, I topped the coolant up with 900ml of water (nearly 2 pints) and while that didn't make a difference to the temperature it didn't puke it out, which I thought it definitely would at the hotter running temp.
I done a fair bit of research on this and realise ignition timing, fan shroud etc all might help, but nothing has changed on the car recently except the temp it runs at. Any ideas?