Hi. Nice to find so many F150 enthusiasts!

I have an 89 Lariat. straight 6. For the past two years or so, I've been having trouble with the truck stalling, within about 30 minutes driving. I don't drive it much so it hasn't been too much trouble to deal with. It will start again after waiting 10-15 minutes and since I don't take it far, I can (usually) get it back home. I took it to a local mechanic who wasn't helpful. Didn't seen very good at troubleshooting. Anyway, I just tuned it up, plugs, dist cap and rotor, wires, and replaced the thermostat. I have the fuel filter but didn't install it yet. While I was flushing the rad after installing the thermostat (I cracked the thermostat housing in the process Doh!), the truck stalled again, and the engine is pretty hot after just 15 minutes of idling. I also noticed that there is no heat now from the heater in the vehicle, whereas prior to the thermostat replacement, I had heat!

Anyone have any experience with this issue(s)? I searched the forums and found some similar things, but wanted to post about this since my issue seems to be a combination of stalling and "overheating". Thanks for your assistance.

John

PS Over the past 7 years I've owned the truck, I've replaced the radiator and a fuel tank sending unit and fuel pump. The second tank needs to be replaced now as it's rusting at the top. Lots of other routine maintenance done over the years. Too numerous to list here.

 

First be sure you did not install the stat upside down.Or you may have air traped in the heater core a easy why to fix to is put the front wheels up on ramps block the wheels and remove the radiator cap ( cold engine).In park set the idle at about 1200 RPM as the coolant drops add more to just about 2inches below the top.When you start getting heat add coolant to the radiator install the cap tight and restore the idle to spec fill the over flow tank about 2inches above the cold fill line. Most times this fixes the problem.

 

John,

Have you pulled the codes? If so what are they? Replacing the fuel filter is a very good thing. It might have somethig to do with the stalling issue. As far no heat from the heater, I believe you lost a lot of coolant and the heater core is now full of air. When you replaced the thermostat did you put the spring side down? That is the way it should go. Replace the thermostat cover and fill the cooling system up but wait until the engine is cool.

 

I almost forgot about your stalling.A common problem ford had with the control module would overheat and stalling would happen till it cooled.This is the module at most times was mounted on the inner fender it was silver type color about 7inches square with two connectors.An easy test you can do is get a small bag of ice and strap it on top of the module so it does not fall off while driving. Now drive the truck and see if it does not stall or goes a lot longer before stalling if so the module is at fault replace it.

 

Don't have a jumper wire to pull the KOEO or continuous codes. I'll pick one up at NAPA when I pick up the replacement thermostat housing this afternoon and post them here along with an update about control module update after trying the bag of ice diagnostic. :-) Thanks for the fast help. MUCH appreciated!