Ok yesterday on the way home my 93 5.0 decided to start spewing antifreeze. After the steam cleared and I could open the hood without fear of being burned I see that the bypass hose has a split in it. Being as since these are the stock hoses I thought the hose just had had all it could stand and gave up the ghost. I changed out that hose and filled up the radiator and noticed that the water was not flowing when the truck warmed up and the temp was rising fast. Also large bubbles of air were rising up throught the filler of the radiator. Does this sound like a stuck thermostat or am I looking at mega bucks......

 

Does kind of sound like it could be the t-stat or clogged radiator or line too...try having the engine running with the heater on when your filling up the coolant, you probably got some air in the lines, sometime's take a while for it to come out.

btw SPROCKET is every where!

 

Haven't been here in a while.

 

Air trapped in the line stumped me once too, acts like a stuck t-stat or a bad pump but just air in the system. You could have a stuck thermostat or bad water pump though, unlikely to be a radiator, I think you would see the engine run progressively hotter over a period of time as the radiator went bad. My water pump went out and I put a new one back on today in fact, not a bad job.

 

ford cooling systems and normally better then what is actually needed . the tstat could be stuck , and or the water pump may not be getting enuf suction to move the water . all i could say is maybe do what sprocket said have the truck running when filling . knead the upper hose to , to make sure you dont have any air pockets. ( vapor lock can cause alot of different symptoms) if that doesnt help i would replace the water pump and t stat .

 

Will be changing all the hoses and the t-stat tomorrow and doing a flush of the system. I will let you guys know how it goes.

Thanks
Brett

 

I had that same sort of thing happen after I replaced the water pump on my truck, I test drove it and the temp gauge was showing overheating. It wasn't really overheating though, the air bled out of the system as the coolant was added, and squeezing the upper hose helped loosen the bubbles. Just keep adding coolant til it's full, drive it, and recheck it for the first few days, until the cold fill level is maintained consistently when checked cold.

I think that an air pocket around the coolant temp sender can cause the gauge to show overheat.

Brian

 

Update.. Changed the t-stat and put in new hoses and backflushed the system. Truck was running while backflushing and temp was fine due to the fresh cold water.. After flushing I filled the system and started the truck squeezing the upper hose. The truck was still running hot . Decided that it must be the water pump and got a new one and installed it. Backflushed again. Filled the system with water and and the truck ran 20 min at idle with no overheating . Drained the system again and filled with anitfreeze and water mix ran truck at idle 35 min and could watch the temp gauge rise and fall with the t-stat. Long story short I think I had a bad water pump.

And since I removed the battery cable and reset the computer the surging idle seems to be gone to.

Sorry for the log post

Brett

 

At least its fixed

 

Looks that way for now.. Haven't driven it yet just let it idle for 30 min to see if it was going to over heat. Need to put some mileage in it now..