New Jeep Cherokee Owner, Advice Please.

Fuse.

Oil pressure sender failing or the wire running to it is loose. On the 4.0 it's right by the oil filter. There is only one wire that runs to it. piccy.

Your talking about the fan on the engine? If so, that's normal because it has a clutch. At high RPMs the clutch is designed to relax. Usually the jeep is at speed and there is enough air just from forward motion.

Thanks for the speedy answer Doug. I was talking about the heater/blower fan. It slows down as the engine revs but in every other car I have had it has always stayed the same or increased in speed slightly. I am bewildered as to why it would slow down as the engine is producing more electric.

Ah, then I dunno. :/ Voltage is reguated quite a bit better in newer vehicles so there isn't the old swing up to +18V anymore. Could also be the battery is tired or low on water. Check your local auto parts stores, the ones over on this side of the pond will check batteries for free.

Thanks - you have answered my question - the battery is indeed not in great condition!

Any help on my original Q about what basic checks / precautions I could take on an 118,000 miles engine with no service history? I read that there is no cam belt on these 2.5 petrols - is this true?

If the mesh wire ground from the engine to the firewall goes ratty, you can have the body mounted systems lose power when the engine needs more.

Mike

True. All the Jeep engines used chains that are good for way over 200,000 miles.

Long list of things.

Start with a trip to a dealer and have them check your vin for any recalls and get a printout of the build-sheet.

The basics so you know when they were done. Oil and filter Air filter Fuel filter Spark plugs, wires, rotor, cap. Drivebelt/unibelt if it's looking shabby. Clean the throttle body.

Check the all the lube points. Steering links drive shaft

Pull the wheels off and check the brakes for wear.

It's also not a bad idea to slowly go over all the hoses and connectors under the hood. Remove the connectors, clean them with some spray cleaner that's safe for plastic (wear eye protection and use a towel to keep splashes off the paint) then put some dielectric grease (sparkplug grease) in the connector and put it back on.

Check for swollen spots or soft spots on the radiator and heater hoses.

There are other things you could do, but that all depends on how much work you want to do. One is to empty/refill the power steering fluid. (or just siphon out the existing fluid and add new) (make sure you use the correct fluid)

The other is to have the brake fluid drained/flushed/refilled, but that is not something usual. Normal you only do this if there is some other reason, like swollen brake lines or such.

That's not all you can check but it's enough to keep one busy for a few weekends. :)

You could look at some mods to improve power. The easiest one is putting in a 4.0 throttle body in place of your 2.5. It gives a bit more power but takes some work to install.

Ignore the spacers/air swirrly things. They are junk.

Thanks Doug.

Will check back with progress :-)

I would add that synthetic fluids, while not required, will give better performance and longer life. The extra cost is worth it.. to me.

If you are unaware of the age of the hoses I would recommend that you change them all at the same time that you flush and refill the radiator coolant.

Be sure you get the proper coolant. You can use the new spec G-05 coolant that is only available in the states in Valvoline's Zerex brand or the old spec "American Green' coolant. Problem is....... very few companies in the states still make it. Valvoline still makes their Zerex 'Original Green version.

Be sure to pick up a repair manual for your Jeep. The factory manuals are far and away the best.

Is the speed actually changing or perhaps are the HVAC doors moving and the distribution (and sound) changing.

I could be a vacuum leak.