When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Was going down the highway the other day doing about 70 and all of a sudden the truck overheated. Pulled over and let it cool down, turned the heat on and drove home with no issues. has approached overheating several times since but I have turned off the engine before it did. It's a 2000 Ford excursion V10 with 145,000 miles on it. I flushed the system and changed the thermostat. Had a sniffer test done and the heads seem to be fine. not sure if the water pump and radiator are original. upper radiator hose gets extremely hot, but lower radiator hose and degasser lukewarm at best. If I let it idle without the heat on, it will overflow due to pressure, not heat. The two mechanics at the garage are not sure what the next step is, any help or advice would be appreciated.
My neighbors 5.4 Expedition had a failed water pump that exhibited similar symptoms. Once we removed the pump from the block the impeller blades were almost completely corroded off, thus not providing any flow. Took a thermostat and a few coolant flushes to figure out that problem.
May not be your issue but a new water pump is cheap.
I'm also thinking possible clogged radiator, what was the condition of the old coolant when you did the flush? Was there a lot of scale and solids in the old when drained? Was it very dirty looking? Does the lower radiator hose get hot when its overheating or on the verge of overheat?
The coolant was in good shape. Lower hose has been lukewarm each time. That's why I feel it's not circulating correctly. I love this truck, but I cannot afford a head gasket job. I have over $7000 into the lift, wheels, tires and paint job and that was affordable prior to my marital separation. The motor went on my 07 expedition a few months ago, so this is the only vehicle I have left.
You could drain and capture the new coolant and try to do a large volume surge test through the radiator. Disconnect the upper hose from the T-stat housing and remove the lower hose from the radiator. Then with the aid of a large funnel hit the upper hose with as large of a shot as quickly as possible, like a 5 gallon bucket and observe the lower outlet flow, it should drain out nearly as quickly as what you can dump into the top hose. If you hit it pretty hard with a lot of water and the outlet is slow to drain you are looking at a clogged radiator.
So it's not a clogged radiator from what I can tell. Equal stream of water out of both hoses and no debris came out. so is the verdict a new water pump do you think?
Could some of the tubes be partially blocked and causing this problem in the rad? Some flow is happening, but not enough? Any suggestions about a good rad cleaner or I have read even vinegar. Want to try a few more things before I dump money into a new rad and water pump. Thanks.
OK, I really need somebody's help. Replaced the radiator today which was partially clogged, but the truck still overheats unless I turn the heat on. Then it operates normal temperature. Without that, it red lines and pukes. Even with the new rad, the lower rad hose is still lukewarm at best. my understanding is it should only be about a 20 to 30 degree difference from the top rad hose. Ran a therm gun to verify that. I'm not losing any fluid in the truck runs great, except for having the heat on which is not great in the summertime.
Both. Running the heat is the only way to stop it from overheating. How high does the front end need to be to definitely purge the system? With the rear heat unit, i'm wondering if there are still air bubbles. I don't have ramps, but I'm sure I could find a very steep hill and try purging some more.