Jeep does not blow hot air when throttle isn't pressed

laredo2006

New member
Hello, the heating in my 2006 Jeep Grand Cherokee 4.7 Laredo is acting a bit weird lately, it takes longer to start and blows cold air if I’m not pressing on gas. Could this be a thermostat problem?

Also, the steering wheel does a half inch turn to the right when I’m driving slowly, as I can feel the tires turning and bumping over something slowly, like it’s trying to pull to the right. Could it need an alignment?
 

As for the cold air, sounds like a vacuum leak, either near the engine or in the dash at the HVAC controls.

For the pulling to the right I would suspect either a bad axle ujoint or CV joint, whichever your Grand Cherokee is equipped with. Look at the joint at each end of the front axle, where the steering knuckle connects to the inner C.
 
As for the heating issue. I'd check belt tension, coolant level may be low, or possibly the system needs to be flushed.
 

hyvac vaccum controls - cause to stop heater blowing? good question. since ive removed the heater, I will look into it. "old men don't like cold jeeps"
 
Coolant level at max. Coolant was changed 35000 miles ago.

What should I tell the local chain garage to look for in both cases so they think I know what I'm talking about? Thanks
 
Coolant level at max. Coolant was changed 35000 miles ago. What should I tell the local chain garage to look for in both cases so they think I know what I'm talking about? Thanks

So 35000 that's thirty five THOUSAND correct? If so it might be time for a super flush and heater core flush. I'd do this myself as oil change centers are more likely doing a drain and fill with no flush.

Where did you check the level?

Another possibilities are:

1.) vacuum leak - take wd40 or carb cleaner and with the engine running spray around the TB, intake at each cylinder and at each vac line. When the engine sputters or RPMs change you hit the leak. Some lines go to a box under the battery and then to possibly the transmission ...

2.) air in the heater core. If this was it once you got heat from stepping on the gas it would continue.

3.) loose belt or slow or frozen pulley. Rev the engine at the TB wile watching the belt. Make sure it continues with the rpm and does not slow or stop.

4.) blocked heater core. With engine up to temp feel both hoses of the heater core one should be hot and one cooler. If both are about the same temp then it is likely blocked

5.) failing water pump - either the impeller is loosing its fins or is spinning on the pulley. With higher RPMs the initial and little contact to the shaft the impeller will turn if it were loose from the shaft. The impellers have been known to rot off.

6.) does this have a flow valve? Most jeeps don't. But the valve may be stuck.
 

As far as pulling to the right I think Bounty Hunter has it right. Axel u joint is bad. Real bad and moving around a lot. At some point it may bind and damage the axel.

Check the axel joint by crawling under the front end (engine off) and turn the axel by hand back and fourth and look for slop in the u joint. There should be none. You could jack the tires off the ground onto jack stands (safety) crawl under and have someone roll the wheels forward and back quickly while you look for slop. Here is a video.
 
Hey there. It was a tire seperation so I found a used toyo geo2 plus and changed it. Thanks. For the heating issue, coolant was changed 35000 miles ago. Garage said it's probably thermostat. Wants $130 to replace it. Water pump was changed 3 years ago also.
 
Hey there. It was a tire seperation so I found a used toyo geo2 plus and changed it. Thanks. For the heating issue, coolant was changed 35000 miles ago. Garage said it's probably thermostat. Wants $130 to replace it. Water pump was changed 3 years ago also.
OMG stay away from that garage!!! $130 for a thermo? I dont think so. DIY 15 -20 bucks tops.

Plus that is not likely your issue. A bad thermo would cause the engine to take a longer to reach temp or you would overheat.

35000 may be time to change fluid. Plus if types were mixed sludge firms and clogs the system.



 
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New developments:

Driving to work this morning I got a check gauges alert and noticed the engine temp was at maximum. I opened the heating and it dropped by a quarter. I was at a red light when all this was happening. Cold air started coming out even though I'd already driven 10 miles. When the light turned to green and I pressed on the gaz the temp dropped by another quarter to half before climbing back up to 3/4's.

Maybe I had put too much water in the coolant mix last year? Guy at garage did tell me thermostat looked like it had leaked some coolant. I did a coolant flush 30000 miles ago. Should I do another one and change the thermostat as well?

Guy at the garage said he would start with that. Should I have them check the water pump or something else? Or is there any test I can do to know what the real problem is?

Thanks.
 
So 35000 that's thirty five THOUSAND correct? If so it might be time for a super flush and heater core flush. I'd do this myself as oil change centers are more likely doing a drain and fill with no flush.

Where did you check the level?

Another possibilities are:

1.) vacuum leak - take wd40 or carb cleaner and with the engine running spray around the TB, intake at each cylinder and at each vac line. When the engine sputters or RPMs change you hit the leak. Some lines go to a box under the battery and then to possibly the transmission ...

2.) air in the heater core. If this was it once you got heat from stepping on the gas it would continue.

3.) loose belt or slow or frozen pulley. Rev the engine at the TB wile watching the belt. Make sure it continues with the rpm and does not slow or stop.

4.) blocked heater core. With engine up to temp feel both hoses of the heater core one should be hot and one cooler. If both are about the same temp then it is likely blocked

5.) failing water pump - either the impeller is loosing its fins or is spinning on the pulley. With higher RPMs the initial and little contact to the shaft the impeller will turn if it were loose from the shaft. The impellers have been known to rot off.

6.) does this have a flow valve? Most jeeps don't. But the valve may be stuck.

I will check all these tonight as well with the mechanic! Thx
 
It wouldn't hurt to do a flush (like the video) after 30,000 mi. If the thermo housing is leaking replacing the thermo while replacing the gasket is not s bad idea. Do use a 190 deg thermo with a bleeder hole up top. DO NOT use a fail safe type or lower temp thermo.

You could look at the water pump from underneath to see if the weep hole is wet or dripping. If it is replace the pump. Do this after a heavy flush.
To verify pump operation.with the engine cold. Remove the radiator cap. Start the engine and when it reaches operating temp the thermo will open. At this point you should see the fluid moving in the radiator.

If you see a constant stream of tiny bubbles there is another issue.

Top off fluid and close the cap. Then shut the engine off.

You need to fix this or you will face bigger issues.
 
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Hi. Read all your advice and thanks. We checked a few things and changed the thermostat and flushed and replaced the coolant and everything seems fine now. There was a bit of gunk in the coolant and mechanic said if it happens again will need a new head gasket...like 850$ US. ..

What ****es me off is that they used a non hoat I believe light green type of coolant when I checked. I will call the manager tomorrow. Manual says to use hoat. Why the hell would these clowns use prestone non hoat???
 
Hi. Read all your advice and thanks. We checked a few things and changed the thermostat and flushed and replaced the coolant and everything seems fine now. There was a bit of gunk in the coolant and mechanic said if it happens again will need a new head gasket...like 850$ US. .. What ****es me off is that they used a non hoat I believe light green type of coolant when I checked. I will call the manager tomorrow. Manual says to use hoat. Why the hell would these clowns use prestone non hoat???

Gunk in coolant does not equal a new head gasket. I'd like to hear that explanation. As I said before stay away from this garage. I could go a good flush and get some gunk from my engine because coolant and other components break down over time.this means very little. Stuff will come out. If the wrong coolant is used like DEX COOL (OAT) or worse yet OAT mixed with existing HOAT you could expect gunk.


They likely didn't flush the system like the video... They likely drained and filled. Did you watch them do the flush? If it is a full flush and fill with distilled and flushed and filled with IAT you may be ok. I still use HOAT.


Where are you located? What you need to do is find a good shop that works on 4x4 or jeeps. Or a local jeep club. They are up selling you.. It's a tactic of a dishonest group.
 
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I don't trust garages at all. Parts changers, well, that part didn't work lets try this other part. Mean while dollars are flying out of your pocket.
 

There are more then this one but you could get an idea on costs. I just looked up an engine flush. Parts $16-$25 labor $64-$82.. Part of the thermo replacement is a flush and fill. Parts $35-56. Labor $64-$82.


Do it yourself.. $35-56 and piece of mine it's clean and the correct fluid is used.


http://www.napaautocare.com/estimator.aspx#
 
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