Can't get seal around thermostat (photos included)

[bbb0777]

Crossposted from Heating & Air Conditioning, but I do have this apart right now...

What's up with this? Two different thermostats (one from O'Reilly's, one a NAPA Premium). I have the thermostat housing out of engine, put in thermostat, run tap water through other end - water leaks around thermostat. That's not normal/correct, right?

Photos to show how much water/thermostats/inside of housing:
http://imgur.com/a/phcyF

This 1995 Ford Ranger 2.3L has always had a somewhat cool running engine. The needle doesn't move much past the lower line, and hooking up an OBD2 adapter - just idling, it'll eventually reach 181 after ~18 minutes, but no higher than that. Feeling the upper radiator hose, it heats up gradually, instead of staying cold then suddenly going hot (like it should, right?)

When driving, it'll range from 178-191. The thermostat was a 192 degree one.

So...any idea what's wrong? Months ago I tried a Motocraft thermostat - same relatively-cool running engine. That was before I was faucet-testing anything, though.

Thanks,

 

[ab_slack]

Just a hack here.

I thought thermostats always leaked a little thru intentionally to insure some small amount of flow.

Not really knowledgeable with the 2.3L. Some stuff I read it seems 2.3L running cool is very common.

Hopefully someone who knows more will come by and provide a more authorative answer

 

[Haywire6000]

My dad's 1996 2.3l does the same thing. On really cold days she doesn't see anything about 165-170.

 

[rockwell39]

Same Problem

I have a 1995 Ford Ranger 4 cyl 2.3 that runs cool. My mechanic put in 2 different thermostats 195 degree and they both make the engine run cool.
I have put up with the cold engine for a few years now.
I finally bought a Ford Motorcraft thermostat. However when installed with a new gasket I fill the neck of the thermostat housing up with antifreeze and it just drains right into the motor. (Gasket is not leaking) Basically the thermostat is not sealing at all.
I'm thinking about buying a new housing to see if that helps. Is it possible the housing warped over time? I'd hate to waste the money if it won't help. To many cold winters in MN I need some heat.
I've even installed a grill cover which I don't even open in the summer. It has helped some though barely get above 170 in the winter.
Any ideas would be greatly appreciated.

 

[Big Jim M]

I never install a thermostat without drilling a 1/8" hole in the butterfly first! That little bit of coolant flow doesn't bother the temperature at all. AND it allows air trapped in the system to get out. So any small amount of flow PAST the thermostat would do the same thing. When the coolant gets to 192* the thermostat will open the correct amount to keep the engine at operating temperature.
Big Jim

 

[bbb0777]

I have a 1995 Ford Ranger 4 cyl 2.3 that runs cool. My mechanic put in 2 different thermostats 195 degree and they both make the engine run cool.
I have put up with the cold engine for a few years now.
I finally bought a Ford Motorcraft thermostat. However when installed with a new gasket I fill the neck of the thermostat housing up with antifreeze and it just drains right into the motor. (Gasket is not leaking) Basically the thermostat is not sealing at all.
I'm thinking about buying a new housing to see if that helps. Is it possible the housing warped over time? I'd hate to waste the money if it won't help. To many cold winters in MN I need some heat.
I've even installed a grill cover which I don't even open in the summer. It has helped some though barely get above 170 in the winter.
Any ideas would be greatly appreciated.

I also put in a new housing - it made no difference whatsoever. Same exact situation - fluid ran around the thermostat, etc.

Eventually, I just made my own radiator cover using black (so it's not visible) foamboard from WalMart. I've also seen it at Fred Meyer in slightly smaller (but still larger than the radiator) and thus cheaper, pieces.

I just cut it down to the size of the radiator, cut a hole in the center of it (to allow *some* air through), poked a hole in each corner with a screwdriver, and zip tied it onto the radiator via those holes.

I experimented with how large of a hole to make in the center of the foamboard - it definitely can be more effective than your grill cover. I started with maybe a 2x2 inch hole - and my car almost overheated on a short test drive! Eventually I got to having about half (maybe more?) of the foam board cut away.

I think in winter my engine was at about 195, and now in summer it's closer to 220. I think the highest I've hit was 235 going for a long, long period uphill in the summer. So, it seems like the current % of the radiator I have covered (whatever % that is) is about ideal. But to get there I had to cover the radiator - do a test drive - cut the hole a little bigger - do a test drive - cut the hole a little bigger - etc., until I got what seemed about ideal.

 

[rockwell39]

Big Jim M,
Bleeding the air out of the cooling system with the old thermostat took quite a while before, so your 1/8" hole idea is a good one.

bbb0777,
I noticed that the Ford Motorcraft Thermostat didn't come with a rubber black washer/boot like the after market ones. I couldn't get the Motorcraft T-Stat to fit with the rubber washer/boot in the housing though.

Which T-Stat did you end up using? Did you use the rubber boot?

Is the foam board in the craft section at Wal-Mart? I've never used it before.

Good idea on the foam board I will have to give that a try. I tried waxed cardboard which worked fine until it rained an then it would fall apart.

I bought this truck new in Dec 96 and it had great heat and ran at normal temperature. I didn't run into trouble until the water pump failed after that it never ran at normal operating temperature. My gas mileage takes a hit in the winter, usually around 20 mpg vs 28 in the summer.

Thanks for the response I thought I was the only one with this problem until I stumbled across your post.

 

[bbb0777]

I noticed that the Ford Motorcraft Thermostat didn't come with a rubber black washer/boot like the after market ones. I couldn't get the Motorcraft T-Stat to fit with the rubber washer/boot in the housing though.

Which T-Stat did you end up using? Did you use the rubber boot?

Is the foam board in the craft section at Wal-Mart? I've never used it before.

Good idea on the foam board I will have to give that a try. I tried waxed cardboard which worked fine until it rained an then it would fall apart.

I bought this truck new in Dec 96 and it had great heat and ran at normal temperature. I didn't run into trouble until the water pump failed after that it never ran at normal operating temperature. My gas mileage takes a hit in the winter, usually around 20 mpg vs 28 in the summer.

Thanks for the response I thought I was the only one with this problem until I stumbled across your post.

I think my Motocraft thermostat came with a rubber boot...? But anyway I had tried a new Motocraft thermostate, as well as two different aftermarket ones. None seemed better than the others at allowing a higher operating temperature

I had forgotten to mention - I tried using RTV gasket maker to seal the thermostats in better. It helped some, but really using the foam board was what did it.

The foamboard is in a section near general office and school supplies (e.g. pens, scissors, etc.). I believe places like Office Depot also sell it.

 

[rockwell39]

I was considering RTV as well just wasn't sure if it would hold up to the antifreeze or not.

Thanks again for the quick response I will pick up some foam board just in time for back to school sale.