Oil T-stat...

[JeffW]

My external oil thermostat isn't working any more. It looks like these are rebuildable but I was wondering if I should switch to an aftermarket unit I need to install a radiator style oil cooler also so I'm going to try and do it all in one shot ( one oil change).

Also is there any reason I should prefer the factory oil cooler over a Mocal kit? The factory kit just seems so much more expensive for the same thing.

Thanks,
Jeff

[JeffW]

You guys are joking right? Nobody has ever changed one of these?

[Chuck Moreland]

I would advise against a tstat change. You can rebuild cheaper than you can buy a new aftermarket item. Hell you can buy a used factory tstat for about $125.

If you go with a mocal tstat you will have to get fitting adapters at something like $50 each since mocal has AN type connections. And you will have to replace at least some of your oil lines with Flex since the mocal has different fitting placement. Or you may replace all your oil lines with AN and hose (even bigger bucks, not factory and not as effective).

Plus the mocal doesn't have a pressure bypass.

The Troutman tstat is available with factory-type fittings but I believe will require at least some flex hose due to differing placement of connectors.

Again you are much cheaper to rebuild or buy a used factory tstat. And your car will be worth more at resale with a factory tstat setup.

As for the cooler, the factory carrera is spendy. Sometimes you can find them at a good price, even new. A good aftermarket item can be a more cost effective choice. Again you just need adapters for the fittings.

[Dana_Drury]

If you wish to save yourself pain, just replace the Thermostat. Seeing as it has probably lasted for 20 plus years thats pretty good service.

Please double check that it is your external thermostat and not crushed lines. I spoke to a gentleman recently who was adimant that his t-stat had died, I recommended that he double checked his lines, lo-and-behold, his external lines had been crushed to the front cooler.

He didn't equated a recent tire change and the increased heat.

(This is just to save yourself spending several hundred or whatever and then finding out that you still have a heating problem.)

[Rouxzy]

Jeff,
I rebuilt mine myself. Was pretty easy. Bought the parts thru Pelican. Sealing ring - $3.75, and Pressure piston for side ( this is acutually the thermostat) - $61.24. I also found a new oem carrerra oil cooler to replace my trombone for about $200.00 on ebay. Had to buy two hoses to connect new cooler that cost $25.00 each. Look under oil circulation in the Pelican online cat. and you'll see illustrations of it all. You will also need to get mounting hardware and very much advised stone guard. I am fortunate to have a friend who is a tin knocker who was able to make all of this for me from titanium, my cost was a bottle of Yukon Jack. Very strong and light.
Good Luck
Tom

[RJM3]

How did you check to see if was not working? Did you use a pyrometer? Did you check at the frt fender mt cooler? regards jer

[Rouxzy]

To check to see if mine was working or not I waited until the engine temp was around 200. I grabbed the front oil cooler and it was still cold.

[RJM3]

Had you checked along the way going and coming to the t stat housing? I mean about every 12 inches ?...just curious regards jer

[Rouxzy]

I did check along the piping but you have to be carefull because you will have heat transfer on the metal piping itself. You might think the oil is hot but it is just heat transfer on the metal. That is close to the thermostat area.

[JeffW]

Mine was warm, from the heat transfer but not 200 + degrees like it should have been. I'm wondering if the internal cooler is working. My car used to stay around 180 all the time now it hits 240 almost everyday. Thats why I decided I needed to check.

[davis911s]

Jeff my t-stat wasn't working so I took it out. And cleaned the parts. Then re-assembled it. Of course when I put it together I jimmied it so that is ALWAYS open. But I have heard that just taking the thermostat apart and cleaning will sometimes free up the components.

Worth a try.

Shawn

[JeffW]

Does the oil drain if you pull the t-stat? Just wondering I'm due for an oil change but I only want to have to do one...

Also - Did you guys need the caps or just internals?

[Axeman]

This is kind of related to the same subject. I just bought a set of oil lines and thermostat housing for my 75 so I can install an external cooler. Before I install these, I want to make sure that there are no metal shavings or anything inside these long lines and the t-stat housing. I need your recommendation on how to flush the inside of these parts.

Thanks,
--Michael

[Axeman]

Bump.

Help...anyone?

[emcon5]

Originally posted by davis911s
I jimmied it so that is ALWAYS open.

I remember reading somewhere that this is a bad idea. I think it had to do with cold thick oil under pressure rupturing oil coolers.

Anyone else hear of this?

As to how to checking used parts for debris, I would take apart the thermostat and clean everything with something like brake cleaner. For the hard lines, only thing that comes to mind is to break out the garden hose.

Tom

[J P Stein]

Nope, never heard of such a thing.........well, once maybe

[Axeman]

Tom thanks! I guess I'll brake out the garden hose or my Karcher tonight...

--Michael

[Jim Sims]

Here's what I did to clean up used lines and thermostat. After removing the end caps and taking out the internals replace the end caps using the old metal sealing rings and applying "never seize" to the threads. I would recommend having the thermostat housing mounted in a soft jaw vise and using a well fitted bar in the end cap "screwdriver" slots to remove the caps. Do not attempt to use a normal screwdriver for this. If possible leave the hard oil line attached if the themostat housing is still hanging on the end of the hard oil line. You should know that even while taking care there is high likelihood of the thermostat housing becoming damaged when you take off the end caps. If the threads are corroded even the aluminum to aluminum pieces can "weld" together. Next, plug one end of the lines and all but one of the thermostat ports. Pour in some Berryman's B12 Chemtool and slosh it up and down the lines and through the empty thermostat housing for a few minutes. Do this in a well ventilated area with no open flames around. Pour out the Chemtool into a suitable metal container (do not use a plastic container as it will dissolve the plastic) for disposal; note if anything (dirt, metal shavings, etc.) comes out with the Chemtool. Repeat with mineral spirits and continue rinsing/sloshing until the mineral spirits come out clear. Properly dispose of the used Chemtool and mineral spirits. Then use dry compressed air to blow out the lines and housing and for good measure let them sit for a few days (if you can) with paper towels secured over the ends and ports. While you have the thermostat out you can check it for proper operation; do a search on this topic. I would carefully clean the internals with a rag wetted with mineral spirits, dry and apply a coating of clean oil and store in a plastic bag until reinstallation. Finally, reinstall the internals in the housing using new metal sealing rings and never seize on the endcap threads. Also, use never seize on all the line fitting threads but not on the sealing faces of the fittings. Good luck, Jim

[Axeman]

Thanks Jim for all the info..looks like I got my work cut out for me this week!

--Michael

[davis911s]

I remember reading somewhere that this is a bad idea. I think it had to do with cold thick oil under pressure rupturing oil coolers.

Tom, I heard this too, but I only have a loop cooler so there is nothing to rupture. I wouldn't do it with a carrera cooler type setup either.

Shawn