K Here Goes Gmtech Question.

[2010LTZ4x4]

No heat at idle unless the rpms are up around 1700 than the heat starts coming out and this is after the motor is at operating temp.

 

This is what has been looked at or done by the dealer.

 

1-Complete coolant flush

2-new thermostat and rad cap

3-made sure 100% air pockets or bubbles where removed

4-pressure tested was done and passed

5-crossover tube was inspected for leaks and passed

6-monitored coolant level all summer and it never changed

 

The GM service manager has been very patient through the whole thing but we both are out of ideas.

 

 

Van has 80000miles

Anymore ideas would be helpful.

[00Silverado4x4]

No heat at idle unless the rpms are up around 1700 than the heat starts coming out and this is after the motor is at operating temp.

 

This is what has been looked at or done by the dealer.

 

1-Complete coolant flush

2-new thermostat and rad cap

3-made sure 100% air pockets or bubbles where removed

4-pressure tested was done and passed

5-crossover tube was inspected for leaks and passed

6-monitored coolant level all summer and it never changed

 

The GM service manager has been very patient through the whole thing but we both are out of ideas.

 

 

Van has 80000miles

Anymore ideas would be helpful.

 

 

Apologize ahead of time for not being a GM Tech, also have absolutely no idea what a crossover tube is or what it does, but what about your heater core? I know you said you get heat when at 1700rpm and engine at operating temp just seems to me faster speed, faster flow, pushing the fluid past a possible core blockage? I could be wrong, but I am curious as to what you find out.

[Jsdirt]

Vacuum issue causing blend door issues? Just a guess.

[govtech]

interesting reply but the system was flushed ...but with what and how .,....

 

it makes perfect sense,,

 

plugged htr core

 

and wrong website ...you need in the future www.grocerygettersoccermomposminivan.com..

 

sry i had to do it lol

 

i did make a ton of cash from them at the dealer lol

[ChevyTech77]

If,

 

1. there is for sure no air in the cooling system

2. there is no combustion gases getting into the cooling system

and

3. you have a good thermostat in the vehicle

then

 

TSB # 00-01-38-011C. GM does not want this pump installed on any of the 2000 and newer vans but I can assure you, that if you do, you'll have blasting hot heat at an idle with no issues.