Coolant isn't circulating in the engine of a Jeep 2002 Grand Cherokee V8. Radiator was just replaced as well as the water pump and thermostat.

SOURCE: 1996 jeep grand cherokee blower works but no heat

Since your blower is working and it is a heat issue,thats where we'll start,First thing is have you checked the coolant level in the radiator when engine is cold,make sure it is filled to top,next verify you have coolant in reserve ,Start your van and get it up to normal operation temperature,If your heat gauge on the dash works correctly it should be 190 degrees,Now lift the hood and locate the two heater hoses going into the heater assembly at the fire wall,Both hoses should be hot to hold on to,if both are hot and no heat inside your problem will be the blend air door in heater assembly.
if neither hose is that hot you need to replace the thermostat in the engine to get it up to 195 degrees.
if one hose is hot and one is luke warm then the heater core is blocked and to blame. hope this helps you.

Testimonial: "Thanks!!!"

SOURCE: 1993 JEEP GRAND CHEROKEE 4.0

did you check rad 4 leaks and make sure all aluminum mesh is intaced beetween cores i had a jeep do same thing or could possibly have air pocket let run with cap off while circulating through block check fluid level add if nessisary also they sell a very good product called water wetter its a synthetic helps fluid flow freer good luck

SOURCE: Very rough idle on 2002 Jeep Grand Cherokee Limited Edition V8

If you haven't changed the plugs or had the fuel system cleaned, now would be a good time to do it. The number 1 culprit for rough idles is dirty injectors or plugs. You can try an injector cleaner in a can (or bottle) for under $10 and see if it helps, and then work from there. If there isn't any improvement then if you are able to, check the plugs for any gunky buildup and if you find a bad plug, make sure you replace them all (or have them replaced) at the same time.

ZJ Limited

• 17989 Answers
• Posted on Nov 13, 2009

SOURCE: how to replace radiator

WARINING
Do not remove the cylinder block drain plugs or loosen the radiator drain **** with the system hot and under pressure. Serious burns from coolant can occur.

WARNING When removing the radiator or A/C condenser for any reason, note the location of all radiator- to-body and radiator-to-A/C condenser rubber air seals. These are used at the top, bottom and sides of the radiator and A/C condenser. To prevent overheating, these seals must be installed to their original positions.

Removal & Installation:

1. Disconnect battery negative cable.
2. Remove radiator pressure cap.
3. For access to radiator draincock, remove radiator grill mounting screws and remove grill.
4. Attach one end of a 24 inch long x 1 / 4 inch ID hose to the radiator petcock Put the other end into a clean container. Open petcock and drain radiator.
5. Detach power steering fluid reservoir from fan shroud and lay aside.
6. Disconnect electric cooling fan electrical connector, if equipped
7. Disconnect CRS hose from radiator filler neck and remove from shroud retaining loops.
8. Remove the four (4) viscous fan/drive assembly nuts from the water pump pulley and remove fan/drive assy.
9. Remove the four (4) fan shroud to core support mounting screws.
10. Remove the electric fan (if equipped) and shroud assembly from the vehicle
11. Remove radiator upper crossmember.
12. If equipped with air conditioning, separate radiator from condenser by removing condenser-to-radiator mounting brackets.
13. Disconnect upper and lower radiator hoses.
14. If equipped, disconnect and plug automatic transmission fluid cooler lines. Quick Connect Fitting Release Tool 6935 may be needed. If equipped with remote transmission cooler, remove line to cooler from bracket at bottom of radiator
15. Lift radiator straight up and out of engine compartment taking care not to damage fins.
16. If radiator is to be replaced, be sure to remove and transfer any components not included with replacement radiator.

1. The radiator is supplied with two alignment dowels. They are located on the bottom tank and fit into rubber grommets in the radiator lower crossmember.
2. Lower radiator into engine compartment. Position alignment dowels into rubber grommets in radiator lower crossmember.
3. If equipped with air conditioning, attach condenser to radiator with mounting brackets
4. Install radiator upper crossmember and four mounting bolts.
5. Install radiator upper crossmember-to-isolator nuts. Tighten nuts to 86 inch lbs. (10 Nm) torque. If isolator-to-radiator nuts had been removed, tighten them to 47 inch lbs. (5 Nm).
6. Connect radiator upper and lower hoses.
7. If equipped, connect automatic transmission fluid cooler lines. If equipped with remote cooler, attach cooler line to bracket at bottom of radiator.
8. Install electric fan (if equipped) and shroud assembly. Insert alignment tabs at bottom of fan shroud into slots in bracket at bottom of radiator. Tighten mounting bolts to 31 inch lbs. (3 Nm).
9. Connect electric cooling fan electrical connector.
10. Install power steering reservoir to fan shroud.
11. Install grill.
12. Connect battery negative cable.
13. Fill cooling system with correct coolant.
14. Install pressure cap.
15. Check and adjust automatic transmission fluid level (if equipped)
16. Start engine and visually check for leaks.

SOURCE: 2001 jeep grand cherokee. no leaks losing coolant,

Most serious item I see is oil pressure. Put a mechanical gauge on the engine and get an accurate reading. Also make sure that the passage to the sender isn't blocked. If you did the pump yourself, did you find any coolant in the oil? In 99% of all low oil pressure situations, the oil pump has not failed. Rather, either a cam bearing or crank/rod bearing is worn. You do not have to have one spun or completely worn out bearing. Even wear of all bearings that is somewhat excessive can bleed off enough pressure to cause problems (plastigage the engine bearings to determine wear).
As far as coolant loss. A cylinder head gasket can fail between cylinders, into a water passage, into an oil passage or any combination of those and externally as well. The cylinder heads on engines beginning in about '98 are prone to "micro-cracking" which can lead to all kinds of hard to diagnose coolant loss problems. It may help if you have a shop do a dye test and a hydrocarbon test on the cooling system and see what they find.
I have seen several kinds of block sealing systems available. Though I generally do not recommend them, as the longevity of the repair isn't predictable, you could try that as a option of last resort.
There is no quick easy solution to your problem but with a bit of "poking around" you may be able to cure it. Don't bother repairing one problem before finding out what the other one is first though as together, it might be smarter to replace the engine.