Ran into a guy today at a mechanic's shop who noticed my truck (5.0 V8) and said that he loved those old trucks and then asked if I had any over-heating issues. I haven't really, maybe just once or twice with a trailer on, but then again I'm skeptical of my temp gauge in the dash... But he said that to avoid that problem I needed to get like a 160* thermostat instead of the stock one (which I don't really know what it is either) and that I would be a lot happier if I did. Is there any truth to this? Or was that just the usual bull-stuff that people like to say? I know that on some other older trucks a lot of farmer-types would just delete the thermostat entirely, but I've only seen that done on trucks from the 70s and before.

TL;DR: Is the stock thermostat restrictive?

 

The problem with going with a 160 tstat on a computer controlled engine is on average days the truck never reaches operating themp and the computer wants to add extra fuel because it thinks it is still cold. The computer wants a 195 tstat so that is what I would stick with. If you are experiencing over heating issues with a stock t-stat there is something else wrog or yo are working the snot out of it and need more cooling capacity, i.e. bigger radiator.

If your truck were carbed with no computer then yes a colder thermostat would help it

just mu $.02

Matt

 

What norfolknova said! If you have cooling problems, then pressure test the system, check the rad. cap.
A heavy duty radiator makes a big difference. I put one on my truck (didn't need a heavy duty) because the dealio I got off ebay was better than an oem spec. one.

 

Yep, what they said ..."it's not nice to fool mother computer, she'll give your truck gas pains" Dave

 

Well that's sort of what I figured. And the stock thermostat for a 5.0 is 195, correct? And you also say the truck should not really ever get that high? What is a good average temperature for highway cruising then? (this is why I'm wondering about the in-dash temp gauge--It never seems to move; regardless of puttering around town during winter or hauling a trailer during 100deg weather)

 

Red, you are correct 195* is it ... as per the computer !!! Going down the highway ... except on a really hot day, it should run around 180* or so!!! That is why I installed electric fans... and here in the Vegas area it's always a hot day. As for the factory in dash temp gauge, mine works real well, but I here of a LOT of guys that have changed to aftermarket units and I probably will also when.. not if ... it dies. Things like that are on a list of "get-er-done's" some day soon !!! Best of luck !!! Dave

 

Not to start an argument, but the computer will go to closed loop operation after a few minutes of running, regardless of temperature. Closed loop is where it adjusts fuel trim based on the feedback from the oxygen sensor. The picture above shows engine coolant temp at 116 degrees (upper right value, 116°FWT) and under that it shows CLSD LP (closed loop) fuel mode. This was maybe 5 minutes after startup, while stopped at a stop sign. Coolant nowhere near 195°F yet lol. Mine never gets there, usually runs around 175. Like I said, not starting a war, just putting information I believe to be correct out there.

 

Well I am not a mechanic or even a real gear-head, but these 'new' computer driven cars always confuse me. At least with old carbed vehicles I know what should be going on and how most everything works. Add an out-dated computer into the mix and I'm just about helpless...
But it would seem to me that the best thing is to leave well enough alone with the thermostat. And mongo, I've read through several write ups about the electric fan swaps, but I think that's a little bit more than I'm up for. I'm sure if you wanted to squeeze every last bit of power or gas economy out of your truck then it's ideal, but I'm already dealing with over-sized tires, so I'm not going to win any efficiency awards. BUT! I am sort of interested in having more space under the hood. I'm not sure if you're familiar, but on farm trucks the hay-unrolling bale beds have become quite popular. I've seen models run off the battery to an electric hydraulic motor, but I have also seen some that use a belt on the front of the engine to provide the power. If you removed the old fan clutch and that section of belt it might free up room to add one of these rigs to your old farm truck (much to the confusion on mechanics everywhere that can't understand why a truck will run without that belt up front being on..)