Overheating problems F150 4.9

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Jun 3, 2013 | 03:46 PM

Sbroom

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Overheating problems F150 4.9

So My dang truck keeps overheating. No leaks; new waterpump and hoses. Old thermostat. I am planning to replace the thermostat in case the spring is worn out but then I thought, do I really need the thermostat at all? I figure the thermostat controls how much coolant circulates in the engine by opening more as the coolant gets hotter... Any reason not to just take it out so the maximum coolant circulates all the time? is this idea stupid?

Jun 3, 2013 | 05:14 PM

jdan1993150

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Yes it is a bad idea. This will drastically reduce your fuel economy as well as the performance of your engine. You can change the temp. of the thermostat you put it, but even that is just covering up a problem somewhere else. Vehicles don't just overheat if there are truly no issues.

Find your leak or restriction and fix it, that will solve your problem.

Jun 3, 2013 | 06:08 PM

Nathan Plemons

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Contrary to popular belief, thermostats control the MINIMUM operating temperature of your engine, not the maximum. A thermostat that is stuck open or missing altogether will allow the engine to run way too cold. Too cold means increased cylinder wear, increased emissions, and as has been mentioned, abysmal fuel economy.

A thermostat is certainly cheap and easy, but that may not be the issue. You mentioned new hoses and water pump, have you checked to make sure your radiator isn't clogged up?

Jun 3, 2013 | 06:14 PM

Sbroom

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Thanks for the reponses. I'll put a thermostat in. How do you check for clogs in the cooling system?

Jun 3, 2013 | 07:15 PM

jdan1993150

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Simple answer, run your engine until hot and the thermostat should be open all the way and feel both radiator hoses. If there is a bad clog you'll feel a noticeable temp difference.

More complex version involves pressure testing etc, which you might want to do anyway to see if your system has any leaks.

Also since the water pump is new, did the issue start after you installed the new pump? It could have a bad impeller causing low flow, or maybe the belt is loose after reinstall? Have you heard any squeaking?

Jun 3, 2013 | 08:32 PM

Sbroom

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Long story short, it overheated before I replaced the water pump, and coolant was busting out of the pump. I replaced the pump, the two main hoses, and the thermostat housing (which I had cracked while I was replacing the water pump.) There are no leaks now, but the temperature seems to jump up and dive down a bit erratically while driving. It usually doesn't pass halfway. Last night while I was driving up a big hill, the temp spiked almost outside of the normal boundaries and the reservoir was boiling coolant. I had to stop and open the hood for 30 minutes. Any ideas?