"Over" Heating Problem

[TBigLug]

First, some backstory. My temp gauge always runs between the O and R of NORMAL. Sometimes not even getting over the N. I drove out to Ann Arbor today to pick up some groceries at Meijers. Everything worked fine. Got in and started heading to Dexter to pick up Heather looked down and my temp is running between the M and A. Weird, maybe the T-stat hasn't opened up yet. So I keep driving. Get to a stop sign. Sit for 20 seconds or so to let some of the traffic clear. Get back on the gas to go and the needle shoots up to past L and heading for THE LINE! I turn the heat on hot and ful blast fan and as I keep moving it drops back down to between M and A. Goes on like this all the way to Dexter (10 miles) and all the way home (25 miles). Just as I pulled into the driveway, strange, needle goes back down to between N and O. I thought the motor was making more noise while the gauge read hot but it could have been all in my head. Other than that, didn't notice any difference. If it wasn't for the gauge reading hot I'da never known.

My first instinct is water pump. Maybe while idling it's not moving enough coolant to keep the temp in check but when up to speed it's using the extra air flow and rpm's to keep things almost in check. I checked and all the belts were still there. Everything's too wet (1.5 inches of rain today) to see if there was coolant leaking out of it. Do Ford water pumps have a weep hole like Chevy's do?

Any other ideas?

 

[sootman73]

doesn't really sound like overheating to me. sounds like you are running kinda low on coolant and had a hot air pocket at the thermostat. my chevy did that all the time when it was low on coolant. the air temp needs to be a lot hotter to open the t-stat than coolant does. and therefore can read higher. was the heat out of the vents really really hot or did it just seem normal?

 

[Wanderer-rrorc]

air pocket...mine did that a few times..she was about a gallon low..

 

[TBigLug]

Once it cools I'll check the coolant level but it was fine last time I checked it. Bout a week ago. Air from the vents was hot. Not hot enough to burn but really hot. That was normal though, I always get good hot air form my truck anyway. I'll post back once I check the level. Would low oil cause overheating? The oil pressure was reading good (strange since it normally reads low) but I thought maybe that couldbe another problem. Either way, I'll run out and check both since it shouldbe close to cooled down now.

 

[TBigLug]

Just checked the coolant level. Still right up to the bottm of he cap. Oil's a little over two quarts low but it's been worse and I'm about to do an oil change tomorrow anyway.

Next idea... (of course it can't be that easy for me lol)

 

[Darrin Tosh]

How is the Fan Clutch,...?

 

[TBigLug]

It has one. lol What kind of test can I do on it?

 

[duaneboggs]

Perhaps moisture on the connector or a bad ground? I recently had an issue with my oil pressure gauge and it only acted up when raining. I pulled the plug off and cleaned and crimped it a bit and now my gauge works normally again.

Duane

 

[TBigLug]

I'll give that one a check in the morning. It was a torrential downpour so maybe that's it. I'm waiting to b sclded for no having a mechanical temp gauge! lol But, no matter how many of those I've tried to put in my trucks (2), I've never got one to work.

 

[gatorman21218]

Ill second the fan clutch with the t-stat bearing in mind. Without a real gauge (I aint scolding, its Ford's fault for having poor gauges) its impossible to know what numbers your running but if my truck is sitting there idling it'll creep up to 220 degrees (norMal) and then the fan will engage and it'll back down to 200 (nOrmal).

When this all happened did the Warning light come on?

 

[MR.T]

Quick thermostat check

Start the engine and hold the throttle open a bit so it warms up fast. Keep your hand on the upper radiator hose. When/if the thermostat opens you'll feel the hose get hot instantly. If the engine warms up and the hose doesn't, the thermostat has failed closed.

The viscous fan drive is harder to test, and it needs to be warm outside. Do the same thing as above, holding the throttle at about 2K RPM. About 15 minutes after the thermostat opens and the coolant gets hot, the fan should start to roar and the airflow will about triple. The air will be so hot that it will get uncomfortable to keep holding the throttle. In a minute the air going through the radiator will cool down and the fan should slow down.

 

[TBigLug]

Gator- No warning light. Thanks for the temp readings. Gives me a general overview of where it's running.

mr. T- I'll have to do some testing ASAP.

 

[gatorman21218]

FYI My probe is in the "overheat warning" spot on the engine. its the hottest the coolant will get. The factory temp gauge spot will run a tad cooler than that, although again with no number its hard to compare.

 

[Logroller]

WOW yall's trucks really run that hot ,,, holy cow ,, mine only runs at 175 and that is factory temp gauge from international ,, if your running that hot then there is something wrong ,, from what i have known read and seen from my books it that they arent supposed to run that hot ...

 

[gatorman21218]

What have you read? The thermostat opens at 192 degrees. So either you have a bad t-stat or a bad gauge.