Overheat problem

[KIRK343]

I have never had an issue with overheating with my 03 MM until recently. I have 4:10, K&N cold air, and recently installed UDP. I have taken a 3 hour interstate trip and a 3 hour trip back with no problems. However this past weekend I took another similar trip and my temp gauge fluctuated from 3/4 to all the way hot. This is running at approx. 80 mph with cruise control. I had to put close a gallon of coolant in after the trip. I can't see any leaks at all. I put a new thermostat on approx. 6 months ago. has anyone else ran into this issue?

[03Merc]

Did You change the waterpump?


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[martyo]

Does your oil look milky?

Have you tested your coolant for exhaust?

[Blackmobile]

It could be the heater core gone bad, so I'd say get the cooling system pressure tested.

[KIRK343]

I have not changed the water pump and the oil looks clean. No steam from the exhaust either.

Probably a dumb question but how or where do I get the pressure test?

[fastblackmerc]

Most auto shops can pressure test the system.

Try burping the system after you check for any leaks.

Burp procedure is in the link below. You might want to take it to whatever shop you have doing the work as can almost guaranty they don't know anything about the burp procedure.

http://www.mercurymarauder.net/forums/showthread.php?t=98532

[ByronRACE]

I have never had an issue with overheating with my 03 MM until recently. I have 4:10, K&N cold air, and recently installed UDP. I have taken a 3 hour interstate trip and a 3 hour trip back with no problems. However this past weekend I took another similar trip and my temp gauge fluctuated from 3/4 to all the way hot. This is running at approx. 80 mph with cruise control. I had to put close a gallon of coolant in after the trip. I can't see any leaks at all. I put a new thermostat on approx. 6 months ago. has anyone else ran into this issue?
Mine started doing this at 180K. The water pump bearing was going out and causing excessive belt slip due to increased load. It would do it completely at random and would sometimes correlate with the AC compressor load because it altered belt tension. I fiddled around for weeks trying to diagnose it...then took the belt off and checked it by hand. It had a ton of side play and turned rough like the bearing was full of grit.

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[Hauser717]

Mine started doing this at 180K. The water pump bearing was going out and causing excessive belt slip due to increased load. It would do it completely at random and would sometimes correlate with the AC compressor load because it altered belt tension. I fiddled around for weeks trying to diagnose it...then took the belt off and checked it by hand. It had a ton of side play and turned rough like the bearing was full of grit.

My '04 MM has started getting overly hot when sitting and idling. She won't overheat, but will get all the way to the top of 'normal'. Usually a minute into a drive will bring her back down where the temp is supposed to be, but it is still causing me concern.

This didn't start happening until after the oil filter adapter was replaced. I don't know if this is just a coincidence or not but thought I'd ask first to see if she just needs 'burped' or if there is something else I need to start investigating.

[justbob]

My '04 MM has started getting overly hot when sitting and idling. She won't overheat, but will get all the way to the top of 'normal'. Usually a minute into a drive will bring her back down where the temp is supposed to be, but it is still causing me concern.



This didn't start happening until after the oil filter adapter was replaced. I don't know if this is just a coincidence or not but thought I'd ask first to see if she just needs 'burped' or if there is something else I need to start investigating.


You answered your own question. [emoji6]


Builder Of Badassery

[RF Overlord]

^^^what justbob said^^^

When the oil filter adapter was replaced, air was introduced into the system.

[eric jones]

I had similar issue a year ago and it turned out to be that thermostat went bad. Sometimes the temp was fine and then I'd glance at the gauge and would be hot while driving. Just a thought!

[Hauser717]

When the oil filter adapter was replaced, air was introduced into the system.

That's the part I wasn't sure about. As in, I'm not sure why there would be coolant running through the oil filter adapter. But I digress...

I'll get out my burp cloth and hope I can hold her on my shoulder long enough for her to get the air out of her system.

[justbob]

There is coolant passages built into the oil filter adaptor.


Builder Of Badassery

[RF Overlord]

Open the hood. Look down at the oil filter. See the coolant hose right next to it?