Question about Equus 2008 Pontiac Montana Obd2 Can Code Reader For Vehicles Built After 199

1 Answer

Heating system cools when sitting idle

Heater works fine but cools when speed drops and when stop for lights

Posted by on


1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Master
  • 1,669 Answers

That's somewhat normal, it should cool a little, but if it cools alot it means that there is something blocking the water circulating from the engine to the heater core in the car. First check to see if the thermostat valve is opening and closing fully when you move the heater temperature on the dash back and forth. THere is a valve on one of the hoses that goes through the firewall into the heater core. Have someone move it back and forth while you watch the valve. Adjust as necessary. Next, check that you have the antifreeze/water mixture up to the top in the radiator and to the full line in the resevoir. Low fluid gives poor circulation to the heater core. Last, is the worst...a possible blockage in the heater lines...THat is a cleaning out the hoses problem...

Posted on Jan 02, 2013


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017


Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Heater has loss of heat when Idles

Check for a clogged or defective radiator. The inner parts you can't see could be the source of the problem.

Oct 02, 2014 | Cars & Trucks

1 Answer

Why does the a/c work fine at an idle and stopped but will stop cooling after 2 miles of driving?

Have the system serviced as it sounds like it is low on freon. You have enough to make the system work at idle but when run at higher rpm the low side pressure may drop and the pressure switch will shut off the compressor.

Sep 12, 2014 | 2004 Toyota Sienna

1 Answer

2003 kia sedona ex heat not working

If the engine temp rise while sitting at lights then you have an air flow through radiator problem. Electric fans not working or viscous fan hub is faulty. high heat except at speed may indicate an air lock in the cooling system or coolant level in the radiator. Check at radiator cap not the reservoir.

Nov 30, 2013 | Cars & Trucks

1 Answer

Heat goes cold at stop signs

Have cooling system flushed properly which should improve circulation through heater core at idle, or low rpms. I usually flush heater core with C.L.R. (calcium, lime, rust remover) from hardware store before re-filling cooling system by removing hoses to core at firewall, and hook up to a small drill driven pump (also available at hardware store for approx$10). I use that to circulate it through core, and reverse hoses and pump it through in both directions, then let it sit in core overnight if at all possible, just for better cleaning. Drain it next day after circulating a little more, and re-fill cooling system. Be sure to leave rad cap off and heater turned on when re-filling coolant, and allow rad fan to come on and off 2 or 3 times before topping up and putting rd cap back on to be sure all air out of system. Should see improved heat at idle.

Nov 24, 2013 | Plymouth Acclaim Cars & Trucks

1 Answer

Heater issues

Change engine cooling system thermostat.

Oct 30, 2012 | Cars & Trucks

2 Answers

Dded anti freeze, seemed ok for a day,started over heating again when moving but pull over at idle temp drops

Welcome to Fixya

Sounds like you have a problem with the cooling system. First thing you need to check first if the auxillary fans are working from the time you are the engine is overheating. If the auxillary fans is not working then the problem would be the aux fan itself or relays. if Fan is working then you might have a poblem with the water pump.

Thank you for using Fixya!

If you need further help, reach me via phone at

Oct 02, 2011 | 2003 Mitsubishi Outlander

1 Answer

Thermostate ranges from overheating to just fine while driving.

is the fan working? if the fan isnt working it will overheat when idling, as it wont be sucking cold air through the radiator. a quick way to diagnose that your cooling system is fine is when stuck in traffic, turn your heaters onto hot, if the engine temp gauge shows that the engine is cooling down, the cooling system will be fine 9/10 times.

hope this helps.

Mar 18, 2009 | 1996 Buick Regal Olympic Gold

1 Answer

Rough idling and poor fuel economy on 92ford f-150

This whole problem is most likey due to a sludged up intake and idle speed control valve, do the following procedure and it should take care of the problems, also run a couple of cans of LUCUS brand fuel injector cleaner through, I know u will see it is more expensive than other brands, but the thing is it works!
Here is the most common cause of surges and stalls at stops and low erratic idle speed and rough idle, it is the idle speed control air-bypass valve and throttle valve (IAC for short), they get full of gunk over the miles and cause idle issues (stalls, low idle) like yours, Get a can of intake cleaner from any local parts store, not carb spray, intake cleaner, it is made by a company called CRC, remove the air intake hose to the engine, hold the idle high so the engine won't stall, then spray the can of cleaner into the intake while keeping the engine running, use at least 1/2 the can, shut down the engine and disconnect the battery for 5 minutes, then restart and complete a number of mixed driving cycles, town, freeway, stop and go etc., after a few days the problem will go away as the system will relearn to the clean intake

Mar 13, 2009 | 1992 Ford F150 SuperCab

Not finding what you are looking for?
Equus 2008 Pontiac Montana Obd2 Can Code Reader For Vehicles Built After 199 Logo

40 people viewed this question

Ask a Question

Usually answered in minutes!

Top Equus Office Equipment & Supplies Experts


Level 3 Expert

80637 Answers

Brad Brown

Level 3 Expert

17328 Answers

Andrew Taylor
Andrew Taylor

Level 3 Expert

21002 Answers

Are you an Equus Office Equipment and Supply Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides