Cooling Flap T-stat Question
 

I tested my cooling flap t-stat as described in the Haynes manual. When heated the bellows expanded to the minimum length of 46mm. When cool, they contracted to approx 41-42mm, a difference of only 4-5mm. Is this enough change to adequately operate the cooling flaps or do I need a new t-stat?
Thanks!

I can't tell you the exact specs, but yours sounds marginal. Take the cable and pull it completely and measure movement with a piece of tape marking the starting piont. You need the T-stat to move at least as much as the cable will allow. What ever you do, make sure that flaps (cable) are fully relaxed at temp. The only way to adjust the cable is when the engine is hot. But, I guess the manual tells you that already.

The Haynes manual states "Heat a pan of water to 65-70 deg C" The thermostat I received from Pelican was stamped 85-90 dec C.

When I used the cooler temps stated in the Haynes book, I didn't get much thermal expansion. Everything worked to spec when I bumped up the temps stamped on the thermostat.

It's been awhile, but I think I had more expansion than what you state. The thermostat was nice and tight when cold. Just like the photo 4.1 in the Haynes book.

I just made the same repair on my car.

The original thermostat only moved 4-5mm in boiling water. The replacement thermostat is quite a bit shorter than the original. The original was not contracting all the way. Looked to be worn out from 30 years of expanding & contracting.

I bought the replacement from PP. Make sure you buy the replacement cable & coupler w/ it. The new thermostat has a larger thread for the coupler. I didn't order a new cable & coupler & had to drill & tap the old coupler. The replacement thermostat PP sells is 20 degrees hotter than my original.

The car warms-up faster now & the heater works better. I can now see the tab the cable mounts to rotate after about 10 minutes of idling.

Mark
73 2.0

Thanks to all. I decided my T-stat was probably worn out and ordered new one from PP today along with the cable. Thanks for the suggestion Mark!