Hi All!
I have a 1999 XJ Limited with 150K miles and maintained well.
About 2yrs ago, I had a radiator crack, so replaced myself ( I'm an engineer, with many auto rebuilds under my wing, so no worry there)
I also replaced the Tstat (195 deg), and the Water Pump at the same time---Hey want a complete solution, no?
Sooo, now comes last week...all of the sudden I am overheating, and just as I limp into the driveway, a strange "clatter" from under the hood...maybe oil is so hot that tappets are noisy, or whatever... On inspection, very little water in the system.
1) So I figure the TStat at least, and get a new one in that day. Old TStat WAS defective-"frozen" closed. Reassemble, test, STILL instant overheat.
2) So IT MUST BE the Water Pump (Autozone Best--HAH!)--I disassemble and take the pump off, and what falls out LOOSE---THE IMPELLER DISK!!!!!
WHAT A PIECE OF JUNK!!! DO NOT BUY AUTOZONE PARTS IF YOU CAN HELP IT!!!
3) Replace WP with brand name, reassemble, and test--NO OVERHEAT--BUT NOW ENGINE IDLES ROUGH! (No coolant loss, no white exhaust smoke, engine runs fine at speed)
4) Engine now starts fine COLD or HOT, but idles rough intermittently--if I drive for 2-10 minutes on an arterial (0-30mph with stoplights) the engine MIGHT smooth out at idle, might not..it's unpredictable.
5) Yesterday, at rough idle and hot, got a P0303 just as I put it back in gear (automatic), from a stop.
PLEASE give me an idea of where to start on this guy??????
Thanks, Thierry