2003 Mitsubishi Montero Possible Faulty Temperature Guage

#1
My 2003 monty temperature gauge suddenly started fluctuating form halfway to almost to the red and then goes down to half and back up. Ive read about the issues with the faulty temperature guage which requires some soldering to fix.

Does this sound like the common faulty temp guage or something else?

EDIT:so based on the obd2 scanner, it's getting up to 194f, maybe I'll start with replacing the thermostat

Thanks
 
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#3
I would also check for a coolant leak in the valley behind the water pump.
Will do, I know there isn't any coolant leak on the floor as I checked this morning.

Today on the way home the temperature stayed at a consistent 190.2f.

EDIT: so I'm wondering if this is the famous temperature guage malfunction...today in highway driving and stop and go the temp stayed at a consistent 190.4-194,even though the guage was fluctuating up and down. I checked for coolant leaks by h20 pump but couldn't find anything.
 
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#4
Yes. You have a faulty trace in your gauge cluster. Easy fix with a soldering iron and solder.

There are some videos and or tutorials that show exactly where to repair.... On mobile or I would link to one for you.

Sent from my LG-H932 using Tapatalk
 
#7
Do you have an OEM thermostat? It is fully opened at 212*.
I have no clue, I would assume it's oem

I monitored the temps for a few days in multiple driving situations and again temps were consistently around 192-194F. Are these normal coolant temps?


Thanks for all the replies guys, I'll have a look at the soldering fix
 
#8
I have no clue, I would assume it's oem
I monitored the temps for a few days in multiple driving situations and again temps were consistently around 192-194F. Are these normal coolant temps?
Those temps. are well within the operating temperature range of an oem thermostat.
If it's an oem thermo., it would not even be fully open at those temps.
 
#9
Hmmm anyone have a picture or video of the work being done/finished? Just want to make sure mine looks the way it's supposed to when I've finished doing this. First time to Solder...
 
#12
Well, I have a coolant leak coming from somewhere in that area, it's leaking down the front side passenger area and has progressively gotten worse. I took it to my local mechanic who couldn't find where the leak was coming from...he suggested I take it to mitsubishi stealership :(

Another note, I'm kicking myself HARD for not using the aisin water pump or at the very least a gates when I did the timing belt 10k ago. I used a GMB...i have a feeling here comes a $1500 bill
 
#13
In that picture, 15 is also a common failure o-ring. It is suggested to replace this with the timing/water pump service, but gets ignored. It goes into the back of the water pump housing and is a known leakage point in the 3.5/3.8 engines. Part is $8, but it takes some time to get to the pipe. Follow the FSM and get some new intake manifold gaskets while you are down there. I also should have done the valve cover gaskets while the intake was off.
 
#14
o-ring gasket, could be #9 or #15 or anything else like #13 hose

I should clarify - there are 2(two) #9 o-ring gaskets, both ends of that pipe. I was referring to the one on the left, not in red circle. I took that picture from somewhere else, already edited like that
 
#15
Thanks for the helpful replies...im thinking it's one of those water inlet o rings.

Side question, to replace those o rings, at the very least it looks like the upper and lower intake need to be removed...does the front end, down to the timing belt need removal as well?
 
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