My 1991 F350 has the 7.5l / 460 gasser. It's running cold and never warms up past the bottom line on the "Normal" range. It does warm up a little if I'm idling for a long time. Little to no heat in the cabin, but it runs perfectly. I'm thinking it's the thermostat.

So what would you say? Aftermarket or Motorcraft thermostat? I've searched a bit on other threads and seen folks say it both ways. What have you used and what's been your experience? I'm not so interested in the why this or that arguments unless you've had personal experience one way or the other.

 

I personially use both OEM and a brand called a "superstat" (not sure if its a brand of a specific store) but you should be able to ask for one for your truck and they are (IIRC) rated for higher spec of OEM and if they fail they are designed to fail in the open position to prevent overheating issues with your vehicle, I had one installed in the Altima when the OEM failed in the closed position and nearly caused the engine to go boom, so we put the super stat in and haven't had an issue since. the truck will be getting one soon (when summer comes around) and any new truck I get will automatically get one also.

 

Stant is an OEM supplier of thermostats. They are the ones who make the SuperStat, mentioned by Jaime. Stant

I should have a new one on my doorstep from Amazon this evening.

 

thanks, forgot that was the name! speaking of installing a Tstat I assume it will be pretty easy on the truck? I couldn't really find a resource about installing a tstat, perhaps we could put one together with pics? I will be ordering one shortly so once the weather gets warmer I can install a new one for the lady of the family

also this one looks like it will fit and is rated for 160*F should I get that one or get one rated for higher temps?

Stant 45356 Thermostat Superstat 160 Degree F Each | eBay

 

I ended up ordering a Ford one off of Amazon: http://amzn.com/B000C5FRUQ
I should have it Friday. Yay for Prime.

Part of the reason I was thinking of an aftermarket was so I could get it done tonight after work (I'd never make it to a dealer before they closed). But I've got a couple of other things I need to do, so I'll take care of the t-stat this weekend sometime.

I'm still curious what other folks might have experienced. I've read where some folks say "only get Motorcraft," where other folks say "OEM ones are junk."

 

I say Motorcraft or Stant T stats are the way to go. I don't care for the cheapo or gimmicky ones like Failsafe. Those are junk.

 

Never had a problem with the stant brand thermostat or rad cap. Available at almost all parts stores or wally world. I think on that truck they are right on the top of the block, follow the upper rad hose.

 

I replaced my entire cooling system about two years ago. My radiator had a pinhole leak and I decided it was cheap enough to do everything. Anyway, I went through three t-stats from the parts store that didn't open, all made in the U.S. I even put the last two of them in a pot of boiling water on the stove so I could see if maybe it was something else. I was stunned. I ended up ordering a racing t-stat from Jegs for about twice the price. I don't know if I got screwed or not, but it has worked as advertised since day one.

Just my $.02.

 

You don't say what engine you have and I didn't see it in your mods thread.

The straight 6 engine is 192 degrees. (I just asked on this forum before buying mine!)

160 degrees is low for any engine I know of.

In general, I think it's a bad idea to arbitrarily go to a different temperature than what is recommended by Ford. All the engine controls are based around that temperature.

The Stant Superstat for my truck was $7 shipped from Amazon with prime.

 

I've had terrible luck with Stant, period! Even Mr. Gasket!

Motorcraft or Mitshimoto is the only 2 t-stats I would recommend. Mitshimoto is $$, but its very well made, and identical to Motorcraft.

I've seen more failures with Stant and other readily available t-stats from the parts store than I can count. 3 out if the box for my 4.9 and 1 on a 2004 Dodge Neon. $12 for junk Stant vs. $30 for Mopar t-stat. It didn't fail afterwards.

 

I had the exact same problem with my 460, I just picked one up from Autozone.

It's been working great for the past 4 months.

 

I have the 5.0 and I haven't added it to my mods list as its something I just remembered I want to do (the current tstat works well but I like to be proactive and replace things before they break and I don't know how long this one has been in there) I have the V8, and I agree I do need to find the temp for my engine tstat now, so I will (once I get the truck back) pull the tstat and see what its rated for then order a comparative one, I will ask the shop I farm large "special" tasks out to for the info and see what they say

 

Replaced the thermostat today. I wonder if the old one wasn't stuck open after all. When I pulled the hose (and neck?) off of the old one, it was kinda stuck in there. I got it out easily enough, but when I did, some coolant rushed up and out. That leads me to think that the old t-stat was closed and holding coolant back.

After putting the new one in, I started the truck and let it idle for a while. Not much difference: kinda warm air, and the needle just got up to the bottom line in Normal.

On the other hand, I've seen other threads where folks have said that this is normal on the 460 engines. Still others seem to have plenty of heat. I dunno. I've got the crew cab, and it still eventually warms up okay. I'm not really worried about all that. The truck runs just fine and all - I just don't want to be killing my mpg any worse than it already is.

As a side note, I did notice that the coolant was VERY orange. I imagine I'll need to flush it. I'm wondering if it's clogged up somewhere or a couple of somewheres.

 

The thermostat was closed, because the engine was not running at up to temp.

I'd definitely flush it with clean water until the rusty colored water is gone.

 

BTW, my truck isn't coming up to temperature and the cab heat is lukewarm, and that's being kind. Truck has a new radiator and a new heater core from the previous owner. Thinking back to the conversation when I bought her last month, I recall he said it had a brand new Failsafe thermostat. That's why I bought a new Stant SuperStat without even opening it up. He also had a brand new, never installed sensor for the coolant temp gauge behind the seat. My guess? No heat, he replaced a bad tstat with a brand new tstat that doesn't work, or maybe he put it in backwards? - that's possible with some engines I've worked on.

Just another reason that I never trust replacement parts until they've proven themselves. Especially when you're replacing parts proactively, like plugs, wires, caps & rotors; if the old ones were ok, keep them until you know the new ones are good. Maybe thermostats can't be trusted either.

I'd be testing this bad thermostat theory today if we weren't getting snow again.