Thermostats

[Saskredneck]

Yes a thread about thermostats... It's time to replace the one in my 2wd daily driver, enough heat blowing out to keep the window defrosted sorta but having to wear a parka and gloves to drive to work 50km one way to work is getting old. I have heard a lot of mixed things about just hitting NAPA up on the way home so I can avoid going into the city and make a 10 min stop in town. But a lot of people seem to say ford/international is the only one to put in? What are your guy's opinions? I can get an international one sent to my workplace if I buy it through our parts dept, but probably would be Monday before I would have it, small town NAPA has one in stock if aftermarket are ok. I have seen some cummins at work not heat up enough if aftermarket t-stats are used instead of OEM but I've also seen a lot of faulty new t-stats both OEM and aftermarket so I'm torn in who to believe right now

 

[franklin2]

On a cold start up, pull the radiator cap first. Start it up and then go out and look down in the radiator. If you see coolant flowing past in the radiator, you do need a new thermostat. If not, your thermostat is ok.

Welcome to the world of driving a diesel. They are more efficient than a gas engine, and they do not build heat very fast. If your thermostat is good, your best course of action is to cover the radiator. I have a 1/4" thick piece of OSB that I slip down in front of the radiator behind the radiator support. I kept trimming the size till I got it just right, which ended up covering about 1/3 of the radiator. It warms up much faster without overheating in the winter. Mine would never get above 160 in this cold weather without covering the radiator.

 

[79jasper]

Also you heater core could be getting clogged.

Sent from my USCC-C6721 using Tapatalk

 

[Saskredneck]

Heater core is good, I've replaced everything in my heating system this winter trying to get some heat, I know its the t-stat everything else has been done, just wanted to hear some opinions if its best to stick with OEM or if aftermarket (NAPA) will do. Oh and it has a thick leather/cloth cover on the front and cardboard in front of the rad so that shouldn't be the issue.

 

[ToughOldFord]

This is one part you want to get factory, the aftermarket replacements don't even look like the correct one.
My '85 never put out much heat since i bought it, hardly ever got up to temp. Finally went to replace the thermostat to find it had an aftermarket in it, that was physically broken open.

More recently I bought an '86, tore the top end down due to a blown head gasket. Pulled the t-stat housing and surprise, surprise, aftermarket thermostat broken in exactly the same way as the one in my other truck.

 

[chris142]

Sometimes they can fail and open too soon or too late. Usually too late so it overheats. But i just had to replace the one in my jeep last night as it was running 137f and threw a po128 code,

 

[ToughOldFord]

Here's a pic of the one out of my '86:

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[icanfixall]

Thats the chinaese aftermarket pos that fails all the time in our engines. The correct thermostat can be gotten at the Ford or the International dealer. They are the same and they open at 192 degrees and are fully open at 212 degrees. The part numbers are in the parts bin forum too.

 

[ToughOldFord]

True that, I think it even said "China" on it, lol.

IIRC I might have gotten my Motorcraft replacement off of eBay. Or maybe Rock Auto, it's been a little while. I just looked up RA and they have the Motorcraft, $16.58. They also show a Stant for $1.10. What are the chances that one's made in China?

 

[finitetime]

I have the same problem when it gets real cold. There's a door that is vacuum controlled which closes and seals air flow from the ac side that can let to much cold air in. Mechanic told me that was my problem but it doesn't get that cold most of the time here in Georgia for me to pay him to fix it and it hasn't got to the top of my to-do list. Especially after the engine and auto trans heats up. I was literally running around with the ac on in mid December to get cooler air coming in.

Maybe someone with first hand experience can give you some better detail.

 

[Saskredneck]

Looks like I will be ordering an international one through work don't want to buy something that won't work right. And no vacuum controlled damper doors, all cable controlled and has all been taken apart, checked over, broken parts replaced and reassembled.

 

[chris142]

I wonder why the chinese one failed like that? Does it need to be a little thicker there? Add a strengthening ridge? We use and install tons of the ones made in israel in gassers and rarely have one go bad. Like 2 in 10+ yrs.

 

[Can30Diesel]

I ran an aftermarket one in my truck at first, it was a stant which normally work great for everything. Never had a problem with them until this time. It even worked great this time, until I started pulling up hills in the summer. It wasn't opening all the way and my truck got nice and hot.

I put the OEM one in and I have yet to have a problem.

 

[ToughOldFord]

I wonder why the chinese one failed like that? Does it need to be a little thicker there? Add a strengthening ridge? We use and install tons of the ones made in israel in gassers and rarely have one go bad. Like 2 in 10+ yrs.

The problem seems to be specific to these engines. I've also used plenty of cheap-os in gassers that work fine. The IDI needs a HD t-stat apparently.

 

[icanfixall]

Our thermostats open and when they do this they plug off the bypass port under the copper pill. When you look into the block as the stat is removed see the machined hole. Thats where the coolant flows when the engine is cool enough for the stat to stay closed. When it opens that hole is plugged off. I have no proof of this and I'm sure the passage is not completely plugged off either. That would need to be a seat type seal and there is never any wear from the copper pill closing against this cast iron hole. Might be a job for Al to look into this passage being closed off when the thermostat opens.