Well here is my problem ..... First I was overheatiing with an old t-stat (192) Had the guage reading at the l of Normal. So I changed the t-stat to a 180 now the guage barely comes off cold?? Any ideas??? 1985 6.9L E350.. Thanks for any help ...

 

That thermostat is tricky to get into position. If it got moved to the side or slipped out during assembly, no more t-stat action.

With the engine cold start the truck and check for pressure in the top hose (you want none). It should be easy to pinch off by hand, if the t-stat is closed (as it should be). Once the truck gets up to normal operating temperature the stat should open and allow pressurized cooled to travel back to the radiator through the top hose. The hose will then be much harder to pinch off.

Anything other than that operation will require you to open-up the system again and check your t-stat position or get another-one that works.

FYI. I had the wrong idea for a number of years, but this is the way water flows through your engine.

The water pump pulls coolant from the bottom of the radiator and pushes it into the block. When the thermostat is closed the only travel that takes place is through the heater core. It goes into the core from the block connection below the passenger side exhaust manifold, through the core and back to water pump via the fitting atop the pump (this is helpful if you get your heater hoses switched). Once the thermostat opens at 180F or whatever, the coolant then has 2 paths, through the heater and through the top radiator hose back into the radiator.

Hope this is helpful..................Zorrro

 

well I know that it never does actually get up to 180 the radiator is barely warm.I took it out this afternoon and drove about 75 miles and never did the guage even go into the normal range. Guess I need to pull it back out and see whats going on ... Should I go with a 180 or 192 ???

 

I don't know what temperature is best. I have put in two of them and both times, asked the parts people for the stock temperature range. If memory serves me well (fat chance), I believe they both were 192's. I run at the "O" in normal on my gauge.

 

I've read someplace, "only use the Ford T-stat". Why the aftermarket ones don't work I don't know. But you might try a search and see what you come up with. I may have seen that on another forum also!

Mine runs at about the "0" also. Don't know what temp. the thermostat is though.

 

You know, that brings up a very funny story. A 335 series gasser requires a different t-stat than any other gasser. The Cleveland t-stat has a collar that fits down near the restrictor plate, and without this, it overheats. We tried running a 160* t-stat, and when the temp guage said 225* all the time, we saw the local Ford master. He pointed out this mstake and gave us the correct 180* Cleveland t-stat, and in 6 years, it hasn't gone over 210*.

 

Most aftermarket t-stats have a by-pass feature built into them,so does your truck,the little steel ball in the t-stat housing,so therefore you will have 2 by-pass systems,NOT a good way to run.Go to your ford or IH dealer and get the correct t-stat.

 

Oh so thats what that is!!!!!! LOLOLOLOLOL I kinda figured that one.. Will go to a ford dealer and get the right Tsat. Thanks for all the help!!!!

 

This type of engine has a internal bypass .When closed coolant flows internally through a passage in the block.Factory t-stats have a rubber sleeve around the lower portion of the t-stat that provides a positive seal. Factory t-stats are 192 degrees.