Some wierd problem I have been experincing for two weeks now.
Only when I turn on the A/C I get this knocking and pinging sound from the engine compartment. Once I turn on the A/C it will do it. The A/C doesn't have to be on. Just turned on once during a drive. Up hill, down hill flat ground it just does it.
I can drive it no problem if I don't turn on the A/C. Once I turn it on, it knocks and pings. I stop on the side of the road, shut off the engine and startup with out the A/C, back to normal. Turn on the A/C, problem starts again. Pull on the side, shut down, startup again, no problem.
Has anyone heard of this problem? Is there a knock sensor on this model? It has a 2.6 inline 6.
Timing is still at factory specs, I have retarded the timing only to have very poor performance and still the same problem. I have since changed it back. I have also tried using different gas hoping I got bad gas. I have also tried octane booster by Synergyn. No luck so far.
Any ideas would be greatly appreciated.
Thank you in advance.
1987 260E Charcoal Grey 157,000 Miles
1987 260E Forest Green 120,000 Miles