t-stat rebuild revisited...

JeffW · 08-07-2002, 01:12 PM

Well I had my external oil thermostat rebuilt and still no oil flowing in the tubes. Now I have to change the one on the internal oil cooler. Anyone done this? Looks like an engine drop to get this one done.

Early_S_Man · 08-07-2002, 01:21 PM

Jeff,

If you paid a shop for the rebuild, take the car back and demonstrate to them that no hot oil is flowing to the front! The work wasn't properly done ... and it has nothing to do with the engine-mounted thermostat, as it isn't in the scavenge circuit!

Get the external thermostat wotrking BEFORE chasing your tail about the engine thermostat!

JeffW · 08-07-2002, 01:27 PM

really? they told me that it goes though the intenal first and if it doesn't pass oil then the external won't either... Odd..

Jim Sims · 08-07-2002, 01:30 PM

I'd check the lines and front turnaround/"radiator" for blockage. I don't have the oil flow diagram in front of me but I recall that the scavenge side of the engine driven oil pump feeds directly into the external oil cooler thermostat. Then the oil either went forward to be cooled or back to the oil tank. I doubt the internal oil thermostat is the source of the problem. Then there is also the chance something went wrong in the external thermostat rebuild. Yes, one usually has to do a partial engine drop to access the engine mounted thermostat. In the case of a stock '76 CIS there are a lot of "air lines and such" immediately above the thermostat the impede access. I took off my airbox/induction system (I did a full engine drop and removal) rather than fight it. Good luck, Jim

Chuck Moreland · 08-07-2002, 01:50 PM

Ditto what Warren said. That internal tstat is not in the circuit.

Either your rebuilt xtstat is not working or you have a blockage in the oil cooler circuit.

Did you test the xtstat before installing? Put in a pot of boiling water (or oil if you like) and you should see it open. If it doesn't open on the stove, it won't open in the car.

If that is working you need to find the blockage in the cooler circuit. Disconnect the parts. Run your garden hose through the lines. Blow air through the cooler.

JeffW · 08-07-2002, 03:42 PM

He says my internal one is shot too. I don't know how you test something like that but my car shouldn't overheat with just the external one not functioning. It should get hot though. just a few months ago it was staying around 180 -200. never over that. It will get up to and past 250 now and I know the external cooler isn't working and after their rebuild it still isn't working. I'll let him eat it if it doesn't fix it. I called him on it and told him it wasn't in the circuit and he said the last one he did this to fixed it. I mentioned that he may want to check the look and he said something clogging to look was almost impossible unless the engine threw some metal out. I'm going to junk the car...

dean · 08-07-2002, 03:53 PM

I just had the same problem. In really hot weather and driving hard my oil temp went to the red. My lines to the front where cold. I replaced my oil thermo in the fender and it now works good. The thermo cost $250 and the only leak I had is the large plug that the factory should have tightened. Sheesh for $250 I would thing the plugs would be tight. I sure am glad I didn't rebuild mine. Those big plugs look like a bear to remove

dean · 08-07-2002, 03:54 PM

Oh yea thanks Chuck