that might just be the head gasket starting to leak into the cooling jacket then, 70 is just past optimal cooling enough that anything out of wack can build a little temp, but the exhaust coming in at high rpm builds up really quick at those rpm. still try the thermo and flush first.
i woudl replace the thermostat.. and then drain the oil.... i would be willing to bet that when the stat stuck closed or patially open, the engine got so hot that the head swelled a little and allowed some oil to get in the water, or the head gasket blew and then let the oil and water mix... it only takes a little.. but the4 water in the oil is one of the worse things to have.. since there is nothing to stop the internal parts from corroding.. they are completely bare metal.. and any little bit of water will rust over night
Also water will not compress......but it will freeze.....Here at the Rock,thatis a bad thing if it is the head gasket. For your sake Jamie,I hope it isn't.
sometimes you can take off your radiator cap and rev it up a lil (or alot) to check for the head gasket. the compresion can blow coolant 2 or 3 feet high. just dont forget about the mess. a little spill is ok but if it blows out, bad gasket.
I let it run for about 20 minutes with the radiator cap off when I got home the other day, nothing came out. I've put about 230 miles on the car since I made this post and so far the temp hasn't gone back above 175. I just got done changeing the oil and it looked like oil with 3,500 miles on it usually does, black. For some reason the brown color has disappeared out of the coolant. I just went and got a new thermostat and I will be putting that in later tonight. The head gasket is a Fel-Pro and only has about 14,000 miles on it from when I rebuilt the head this time last year. Matter of fact I think I put the head back on exactly a year ago today. I have a hard time believing it's blown already. I can change the head gasket in about 3 hours, so I'm not really too worried about it if that is the problem.
Do you have a spring in the lower radiator hose? At high RPM's the water pump can draw hard enough to collapse the hose ....
Jamie; as Dan says, replace the hoses, and try to flush out the block and rad. Could be some rust had settled in the t'stat, and jammed it open/closed. Hope this works out ok for you. Take care,
Just put in the new 'stat and flushed the entire cooling system. It's definately rust in the water. It's still getting warmer then I would like, but I'll live with it for now. It had a 192 thermostat in it and I replaced it with a 180. It holds about a steady 170 at 70 mph. At 75 it climbs up to 180, and at 80 it climbs to 190. At 85 mph it starts climbing and dosen't stop till 225 degrees. I rarely do over 75 mph so I'll just leave it be for now. I took the spring out of the lower hose back in June of last year when I had the engine out of the '74 for the first time. It was rusty and I could break it apart, so I figgured I better get it out before it breaks and gets sucked into the water pump. I don't have the money to replace the hoses right now, maybe in a few weeks. The old thermostat didn't look too bad to me, but what do I know. My dad has a brand new 195 thermostat out in the garage, what do you guys think that would do? Thanks for the help.
You need to get a new lower hose with a spring in it so it does not collapse on you. That doesn't mean you don't have other issues, but that will choke off your water circulation bad.
Since you asked, I would spend a couple of bucks and try a 160^ T'stat. I just don't see the need to get the engine up to 195 all the time. From what I'm told, newer Ford EFI engines run a hotter Tstat (180^) ONLY to work in unison with the computer. Personally, I would do a radiator flush and put a 160^ thermostat in it. BUT, please don't go on my limited experience with what engine temps should be. Good luck.
