Temp gauge acting strange..

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Sep 28, 2006 | 11:23 AM

aguylookingforadvice

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Temp gauge acting strange..

I have an 89 4.9L I6 w/M5OD. About a week ago I noticed the temp gauge creeping up between the M and A on NORMAL. I can see steam coming out from under the hood. Popped the hood and noticed that the radiator had a small hole where the antifreeze was leaking out. It looks like the radiator pushed back into the fan and created a circle pattern from the fan. This must have occurred with the previous owner? Anyways, I replaced the radiator with a new one last night. Filled up the radiator with a 50/50 antifreeze-water solution and test drove it. Guess what? The temp gauge is still creeping up to M and A on NORMAL?? I checked the oil and there is no sign of antifreeze or water? Any suggestions? Faulty temp sending unit?

Thanks in advance,

Sep 28, 2006 | 12:15 PM

94broncoxl

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Joined: Aug 2006

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From: St. Paul, MN

I wouldn't worry too much unless it goe up to or past the L. FRom what your describing it is still in the normal range.

Sep 28, 2006 | 01:25 PM

GWall

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Also check to make sure your radiator is completely full of coolant. Sometimes an air bubble gets trapped that prevents it from filling up all the way.

Sep 28, 2006 | 03:01 PM

Rusty90

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From: Woodinville, WA

You have to be careful with those pinhole coolant leaks. What is the Ford cooling system pressurized at when it is in the normal range, 12-13psi? That is why the 92-93 RX7 twin turbos burned to the ground, there would be pinhole leaks in the cooling system, which is pressurized to 21psi, it would spray at the turbo (when in vapor form) and would ignite, burning the car to the ground...

Sep 28, 2006 | 03:53 PM

aguylookingforadvice

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Thanks for your replies..

What's strange is that the temp needle will go from N to MA in one straight shot. It's not gradual like you would expect to see when an engine warms up. It'll go from the MA (NORMAL) back to N and then swing back to MA off and on?

I checked the radiator it's completely full. Any other ideas?

Sep 28, 2006 | 03:58 PM

phoneman91

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Joined: Jun 2002

Posts: 2,033

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From: Aurora,Colorado

Quote:

Originally Posted by aguylookingforadvice

If you are sure that there isnt air in the cooling system--and you have a rapid movement of the needle--I would suggest that you have a defective temperature sending unit or a bad connection in the wiring involving the temperature sending unit.