Internal Thermostat Kaput

[Clark Griswald]

My '77 has been running hot and I've concluded that the internal thermostat isn't working. With the car good and hot, I placed my hand on the internal cooler. Warm yes, but 210 like the guage said? No way, not even close.

Anyway it looks like a bear to reach that thermostat with the engine in the car. I have the CIS to get in the way.

Anyone have tips for getting that tstat out with the engine in the car?

I assume I will need to lower the engine, no big deal. I want to avoid having to pull the intake, but it looks like the big peices of the airbox/fuel distributor will have to come out.

[Clark Griswald]

No takers, eh? Well I'll be doing this late this afternoon so I thought I'd give it a bump.

[Early_S_Man]

Chuck,

Loosen and remove the four M12 bolts thru the engine/trans mounts and lower the 'package' about 5" - 6" ... NO LOWER, without removing any fuel, electrical c,onnections or CV's! You should be able to get the thermostat out from the right rear wheel well (with wheel removed, up on jack stands) without disturbing any of the CIS system, but you probably would want to disconnect the battery, and remove the starter!

[Clark Griswald]

Well Warren, that is the hot ticket. Topside access is just about impossible and would require 2-3 elbows in one arm and small hands.

Even from the bottom side with the engine dangling down this is a really big pain. And I am convinced this must be the most greasy spot on the entire car. My oil pressure switch is probably leaking, and I will take the opportunity to replace those seals.

I actually haven't pulled the tstat yet. I opted to degrease the whole area before pulling it out to prevent the crap from dropping inside. Ran out of daylight so I am letting it dry overnight.

I've got new thermostat and oil pressure switch seals on the way from our host.

[KTL]

Originally posted by Clark Griswald
..... My oil pressure switch is probably leaking, and I will take the opportunity to replace those seals.

I actually haven't pulled the tstat yet. I opted to degrease the whole area before pulling it out to prevent the crap from dropping inside. Ran out of daylight so I am letting it dry overnight.

I've got new thermostat and oil pressure switch seals on the way from our host.

I think the upper rear of many folks motors is the number one candidate for biggest oil mess. Mine was. The new oil pressure switch comes with a new seal ring, doesn't it? I couldn't find a part # for the switch's ring, only the case adapter seal ring. Thankfully, the new switch included the seal. Anyway, I put a little RTV around the new crimp joint (per somebody's recommendation), we'll see if it prolongs the future oil leak.

My old T-stat o-ring was one crispy critter. Tried some Dow 112 on the new one. We'll see if that prolongs any leak. I also opted to put a little Curil T around the mating surface of the T-stat to the motor case. Will probably be a bear to get out next time. With my luck the T-stat will take a crapper in the next year or two. Oh well, at least it won't leak there!!

The new thermostat and grime removal should have the green one running as cool as the red one now.

[ginpunk]

Any improvements? Mine is having the same trouble.

[jclc]

Clark,

I have a similar concern on my '74, runs warm. Maybe once you get the Tstat out, you could test it in boiling water (is that done with these?) and let us know if you could tell its bad this way?

Jeff Craddock
Orange, CA
74 911 Coupe