Next question.... oil thermostat

[andyt11]

As previously posted, I'm stripping the engine ready for a rebuild. During this time I'll be replacing temp senders and pressure swithes etc, because they are only four or five bucks a piece and are easy to access right now.

Whats the failure rate of the internal thermostat on the 3.2? Its $160. Again, whilst I'm not out to cut corners, I do have better things to spend the money on. (like a nice exhaust or a Steve Wong Chip!)

There is a photo attached, I can a little daylight if I look from the bottom so it is slightly open at around 5 degrees C. Seem normal?

As far as I could tell, last year it was operating normally, takes about 10-15mins of normal driving to get to first line on temp guage in fall / summer warth. I have no reason to suspect it, but if they are notorious for failure I'll switch it for a new one while I can get to it. If not, I'll put a new O ring on it and re-install.

[76-911s]

I have a 76 2.7. I replaced all the seals like you. Put the engine back in, and had problems later with the thermostat. At the time $160 seemed like a lot for not having issues with the temperature, so i opted out.

Needless to say, a couple of weeks later I was having problems. Had to drop the engine to replace it. If i had to do it all over again, I would have replaced it then.

If money is not an issue, i would replace it. just my $.02.

Gary

[Eagledriver]

I haven't heard of many failures on these. I tested mine in boiling water before I reused it. Spray it with WD40 after drying the water to keep it from rusting before you use it again. No reason to believe a new one will fail later than your current one. You should be able to replace this in the car with at most a partial engine drop.

-Andy

[kanadary]

i replaced the green gasket on mine with the engine in, not even partial drop so i would let it ride...

[andyt11]

Thanks, much appreciated. I'll let it ride. It's a bit luck of the draw I know, but unfortunately there is a budget so trying to make a judgment call on a number of items like this without cutting corners.

Tricky. But the experience on this board helps.

[JT]

OK, how did you guys replace that thermostat without an engine drop? If my Mocal thermostate is not bad, i'll be forced to remove the internal one and I've never dropped my engine.

[Eagledriver]

JT, I depends on what car you have. On an early car you can reach the thermostat by just removing the airbox. A Carrera may require more work. The thermostat is on top of the engine so you just remove whatever is in your way.

-Andy

[MH911]

I just did this last month on my Carrera. Just need to remove the air box also. You should have a good size mirror to be able to see everything back there. Lowering the engine a few inches will make the job that much easier also.

[JT]

Andy,

I've got an '81 3.0 in my '74 Targa. That means all the CIS crap is in the way. I'll continue to search the forum for more details, but won't know if I have to tackle this until the testing results of my Mocal thermostat are revealed. I really hope it's bad.

Thanks,

JT

[bell222]

The o-ring is the part that is notorious for failing. The heat makes it brittle and then it leaks. The thermostat usually doesn't fail. I just replaced the o-ring on the thermostat, breather cover gasket, oil pressure switch, and the seals in the main oil cooler in my 84 Targa without an engine drop or a partial engine drop. The thermostat o-ring, oil pressure switch and breather cover takes about 3hr. Figuring out how to raise the plastic cover over the oil cooler to get to the 2 top nuts took longer than anything. It can be done and is worth the effort. Any questions, just send me a message.
Good Luck with your projects.

[MH911]

bell,

The secret to those two top nuts on the oil cooler is to remove the rear right wheel. Lower the engine a few inches and remove the sheet metel that separates the valve covers. Loosen that plastic cover. Then use a very long extension to get a socket under there from the wheel-well.