[PREAST]

My 2006 DTS began to overheat in slow traffic today, defroster on. Reached my location but found that the radiator fans were not working. Anyone know a general cause for this?

 

[Submariner409]

Check the fuses and relays in the underhood fuse box. Your car may have one or two Maxi-Fuses for fan power as well as 3 relays.

With any HVAC function set that calls for A/C compressor operation, fans should run in SLOW all the time. With no such HVAC setting, fans are controlled by the ECT and PCM - they go to SLOW at 224 degrees and FAST at 236.

On your temp gauge - what is your perception of "overheating" - that needle will move in slow/heavy/stopped traffic.

If your gauge is different from this one - but has 9 tick marks - the marks correspond to this picture...............

 

[grullon10]

Also check the bolt of under the hood fuse box they get loose. If they are good you may have a problem with the box. Do you have the check engine light on.

 

[PREAST]

Temp gauge went in the red area (270)while in bumper to bumper pre-Patriots parade/snowstorm traffic in Boston this morning. Check engine light came on as well.

 

[grullon10]

Check it with a scanner for shore it will give a code because it over heat it but it may give you a code for what's wrong with it. You have temperature in the mid 30s turn the ac on by lowering the the isse temp to 60 and see if the fan come on. You very l k pat fan the Seahawks gave you the game.

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Ps as a new yorker dis like everything Noth of Stamford ct but rep the Celtics

 

[bigtone]

Check the fuses and relays in the underhood fuse box. Your car may have one or two Maxi-Fuses for fan power as well as 3 relays.

With any HVAC function set that calls for A/C compressor operation, fans should run in SLOW all the time. With no such HVAC setting, fans are controlled by the ECT and PCM - they go to SLOW at 224 degrees and FAST at 236.=QUOTE]

Beg to differ, but cooling fan operation is different for 06 on up. Fans do not come on when the a/c compressor is running, the pcm controls the fans via coolant temperature and refrigerant pressure. I know this for a fact based on my 06 and 10 DTS's. This is also stated (vaguely) in the factory service manual.

To the original poster, my 06 had a few cooling issues which directed me to look at the fan operation. One thing I did find which may relate to your problem is that the 06 and newer are very sensitive to even a slightly lower coolant level. I didn't prove this, but as mine ran past midscale on a few occasions after ascending or even waiting for a traffic light on a steep incline I suspect air may have worked it's way from the tank to the engine. The tank on these models does not provide much head for the system like the older Devilles do. You must check the coolant level cold. Do this before you do anything else.

 

[Submariner409]

^^^ Good to know. Thanks for the correction.

 

[PREAST]

Bigtone, the issue does seem to be related to the coolant level. I added coolant then the fans came on. I must find out now why my coolant was low. Nothing obvious. Level was just below cold level when fans were not working.

PS: To Grullon10, Pete Carroll couldn't call a good play for the Pats when he coached them, the least he could do was call a good play for the Pats while coaching against them, thanks Pete!

 

[grullon10]

Jjjja . You may be loosing antifreeze behind the water pump housing. Get a flash light and look down the in the area of the brake booster you coukd see the the top of the transmission see if it is wet. That back gasket of the water pump housing leak. And one morw thimg change the surge tank cap they go bad it could be that.