How JustAnswer Works:
  • Ask an Expert
    Experts are full of valuable knowledge and are ready to help with any question. Credentials confirmed by a Fortune 500 verification firm.
  • Get a Professional Answer
    Via email, text message, or notification as you wait on our site. Ask follow up questions if you need to.
  • 100% Satisfaction Guarantee
    Rate the answer you receive.
Ask sprinkles08 Your Own Question
sprinkles08, ASE Certified Technician
Category: Car
Satisfied Customers: 22986
Experience:  ASE Master and Advanced level certified. Factory trained with 15 years dealership experience
Type Your Car Question Here...
sprinkles08 is online now
A new question is answered every 9 seconds

Hi I have a 2007 grand jeep cherokee laredo 3.7L v-6 I replaced

This answer was rated:

Hi I have a 2007 grand jeep cherokee laredo 3.7L v-6 I replaced water pump and thermostat due to the water pump went the pulley was flopping like crazy but anyway after i replaced them it blows cold air out the heater no hot air and it will overheat took it apart 3 times did a flush and everything looks good but didnt fix problem check fluid no oil in coolant fluid checked oil no coolant on oil dipstick was is wrong just cold air and keeps overheating
Hello and welcome to JustAnswer!

Can you explain how you are filling and bleeding the cooling system?

Customer: replied 4 years ago.

filled with 50/50 coolant try to bleed by cap what for coolant to get low during idle after it bubbles air out then topped off then put cap back on did this step 4 times no more bubbles then couldnt understand why no heat i also thought it might be air so loosed water pump bolts to see and coolant come out fast so put back together and bleed again still nothing

If you weren't having any problems before replacing the water pump then your lack of heat and overheating are due to air in the system. It has become trapped because the system wasn't properly bled when filled.

Follow the top radiator hose to the timing cover and you will find a 5/16" allen pipe plug. This is the bleed plug and it must removed when filling the cooling system.

With the engine cool now remove the radiator cap and remove the bleeder plug. Add coolant until a solid stream of coolant comes from the plug with no air. Once there is solid coolant and no air then you can reinstall the plug.

With the coolant level near full, leave the radiator cap off and start the engine. Let the engine run until it's at full operating temperature and bubbles are no longer seen coming up, which will be at least 10-15 minutes, longer if it's cold outside.

Since there is air trapped in the heater core you may also need to raise the engine RPM's while the cap is off to help force coolant back into the heater core.

Once you have heat, it's at full operating temperature and no more bubbles are coming up then you can then install the radiator cap and go drive it, you should find all your problems are gone.

Customer: replied 4 years ago.

ok thanks for the help

You're welcome!

Please rate my performance only when you are satisfied with my help. If for any reason you feel you cannot rate my help with at least "Ok Service" or better please click the Reply to Expert link and let me know any further questions you have.

Good luck with your Jeep!
sprinkles08 and 4 other Car Specialists are ready to help you