I bought a 180* Stant 35818 thermostat only to find out it doesn't fit in all the way which blocks the cap from closing. I compare it to the old one and notice the rubber o-ring is missing on the old one, that is probably the cause of my temperature being high. All night I used a metal spunge and tried removing all the rust. Even used cloth to block the passages and sprayed pb blaster on the trouble areas. The thermostat still doesn't fit in all the way.

Any help anyone please? Hopefully it won't come to it but I'll probably cut the rubber ring off the new one tomorrow morning, I guess it's better than running no thermostat.

That's covered in the cave (saved Ogre having to say that). Basically says to lube the thermostat O-ring with silicon grease before installation.

The java applet from Ogre's Cave freezes my computer, but thanks for telling me what it says to do.

i used a round wire brush on my drill to zip out the rust deposits.

------------------
'84 2m4 se, a work in progress http://www.mtsu.edu/~mkr2c/fiero.htm

Here's the Cave text for the Java challenged computers:

Thermostats

Installation

How hard is that? You just shove it down the hole... They should all be this easy.

One small thing people over look... When installing Fiero or similar thermostats, coat the O-ring on it with a film of petroleum jelly or better yet, silicone oil/grease. Dielectric compound and brake grease are both good. You only need enough to leave a film on the ring.

If you don't lube the O-ring, the coolant usually isn't slick enough and the thermostat won't want to seat or you tear the O-ring. I suspect this is how many thermostats end up bent.

You have to use firm pressure, and sometimes a little wiggling helps, but you shouldn't have to force them down the hole. When it's fully seated, the frame will not obstruct the cap. If a lubed thermostat won't seat, suck out some coolant and inspect the neck. Look for corrosion or dents in the seating area. Push in the thermostat and see if the neck is out of round.

You'll also find it easier to install the cap if you put a film of lubricant on the rim of the thermostat neck. That will let the rubber slide easier and help prevent corrosion.

If the rim is corroded, clean it with fine sand paper and coat all the cleaned area with silicone grease. (Dielectric or Brake grease) The silicone won't easily rinse away like most petroleum products and it won't react with the coolant or the cap. Paint could actually bond the cap on. You should probably replace the cap. A corroded rim often damages the seal.

If it is that rusted I would just toss it and put in another thermostat housing.

You do know that the low temp thermostat will not change anything if the car is overheating don't you? If the car is running 220 degrees plus both the 180 and the correct 195 will be wide open.

Hey thanks to those pointing me to Ogre's Cave, I can't view his site due to the java applet.

I put the grease on the o-ring and easily it slipped in. Now the temp isn't as hot. I can't believe I went to three Autozone/Kragen and talked to two car guys (one from the forums here) and none of them knew this.

[This message has been edited by Pontiac Boi (edited 09-30-2003).]

If you get a new one or clean-up the old, coat the inside with Magic Lube. It's a teflon based gel sold at swimming pool supply stores. Use it on the rubber gaskets and cap seals too. Works like magic!