Temp guage variations?

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BMXPath
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Joined: Fri Oct 19, 2007 7:55 am
Location: Texas!

Temp guage variations?

Postby BMXPath » Tue May 06, 2008 8:54 am

How much variation in temp do you see normally?

As long as I am moving, it stays on the same spot on the guage.
Like this...
Image

Just about anytime I sit at idle it starts to go up pretty quickly... like in a drive thru or stuck in some stop and go traffic.
It has never overheated, but it has gone high enuff to shut off the A/C a couple of times. I put it in neutral and take the RPM's to about 2500 and it goes down almost immediately.

My Pfinder has been this way since I bought it. Of course, it is only a problem in warmer weather. Gotta worry about it a bit more with a hot Texas summer approaching.


boogyman
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Postby boogyman » Tue May 06, 2008 9:24 am

It shouldn't go that high. Do you have air in the lines and is it topped off? Ours never climbs that high that I've seen. If you hear the air bubbles running through then you need to get it bled out and that should keep it more constant.

When the truck is cold and off. Fill the radiator if not full. Then start the truck with the radiator cap off. When you see the water flowing, put the cap back on and check where the temp gauge is at. That should be your normal operating temp. It should be around 180F according to the manual. It shouldn't get much above that even sitting still. Of course lack of flow during low rpm idling time does raise it up a bit.

Gray
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Postby Gray » Tue May 06, 2008 10:26 am

When this engine gets to operating temperature it's at about what the gauge photo shows and stays there without moving. If your radiator isn't totally plugged with bugs then probably an engine flush is needed but maybe something else is messed up such the clutch fan, thermostat, coolant pump. Even a loose fan belt will cause some vehicles to run hot or overheat but I don't recall if the VQ40 coolant pump is belt driven or direct from the engine.

I don't know at what temperature it happens but another thing that engine overheating does is the temp sensor tells the injection system to inject more fuel to try to cool the engine down, so your FE might not be doing so good.

Has this being happening for awhile or did it just start BMX?

.

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BMXPath
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Postby BMXPath » Tue May 06, 2008 12:35 pm

Grey,

It has been happening as long as I have owned my Pfinder, which is a little over a year and a half. It doesnt happen all the time. I had the radiator flushed at about 40K. It was the same before and after.

boogy,

I am gonna try yoursuggestion about the cap.

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BMXPath
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Postby BMXPath » Wed May 07, 2008 3:55 pm

boogyman wrote:When the truck is cold and off. Fill the radiator if not full. Then start the truck with the radiator cap off. When you see the water flowing, put the cap back on and check where the temp gauge is at. That should be your normal operating temp. It should be around 180F according to the manual. It shouldn't get much above that even sitting still. Of course lack of flow during low rpm idling time does raise it up a bit.
boogyman,
I did what you suggested. Seems to have worked, so far... Although I havent sat thru any drive thru lanes on a hot day yet. :wink:

boogyman
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Postby boogyman » Thu May 08, 2008 5:20 am

Glad to hear it, hope it stays that way.

amr40509
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Postby amr40509 » Thu May 08, 2008 7:45 am

Greybrick wrote:When this engine gets to operating temperature it's at about what the gauge photo shows and stays there without moving.
.
Mine does the same thing. Winter/Summer/Summer towing the boat/sitting/moving -- it doesn't matter, once up to temp it stays right where it is in the photo, no real movement.


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