Thermostat

Thanks, I'll keep that in mind Joe Carroll

There are some simple truths...And the dogs know what they are." Joseph Duemer

Heh heh heh, amen.

Not in 2000, mine uses the old fashioned green stuff

Well, then that narrows the date of the antifreeze change to 2001 or 2002. My 2002 requires the new G-05

I just checked the service manual (on CD) for 1999 Grand Cherokee model WJ. Perhaps they introduced the new antifreeze sooner in this model. Mopar's G-05 antifreeze is orange

An excerpt of the specifications page (section 2 page 2) is below: "SPECIFICATIONS

FLUID CAPACITIES

FUEL TANK

All . . . . . . . . . . . . . . . . . . . . . . . . . . 78 L (20.5 gal.)

ENGINE OIL W/FILTER CHANGE

4.7L . . . . . . . . . . . . . . . . . . . . . . . . . 5.7 L (6.0 qts.)

COOLING SYSTEM

CAUTION: Vehicle may be equipped with long life

coolant. Extended life coolant is identified by an

orange color. Normal coolant is identified by a

greenish color. It is recommended that the two

types of coolant not be mixed.

4.7L . . . . . . . . . . . . . . . . . . . . . . 12.3 L (13.0 qts.)*

The 2002 manual is the first one that specifically mentions HOAT vs. OAT and warns that mixing other types may lead to engine damage and voiding of your warranty. (Section 0 page 3)

" CAUTION: MoparT Antifreeze/Coolant, 5

Year/100,000 Mile Formula (MS-9769) may not be

mixed with any other type of antifreeze. Mixing of

coolants other than specified (non-HOAT or other

HOAT), may result in engine damage that may not

be covered under the new vehicle warranty, and

decreased corrosion protection."

And later on that page and continuing to the next page:

" COOLANT SELECTION AND ADDITIVES

The use of aluminum cylinder blocks, cylinder

heads and water pumps requires special corrosion

protection. Only Mopart Antifreeze/Coolant, 5

Year/100,000 Mile Formula (glycol base coolant with

corrosion inhibitors called HOAT, for Hybrid Organic

Additive Technology) is recommended. This coolant

offers the best engine cooling without corrosion when

mixed with 50% distilled water to obtain to obtain a

freeze point of -37°C (-35°F). If it loses color or

becomes contaminated, drain, flush, and replace with

fresh properly mixed coolant solution.

CAUTION: Do not use coolant additives that are

claimed to improve engine cooling."

Ok, picked up a new thermostat from local dealer, parts guy recommended against going with the new anti-freeze if I had the old stuff already. Said it wouldn't be good for seals and such. Put the new one in in about 1/2 hour. Used a little permatex to put everything back after cleaning all the surfaces. Could't tell if it was still necessary but old habits die hard. Thanks for all the help/suggestions... Joe Carroll

There are some simple truths...And the dogs know what they are." Joseph Duemer