Ping/detonation

[lexxus]

My girlfriend's 94 SC300 pings like hell. I accused her of using regular, and she says she always uses premium. Must be something wrong. Any ideas? I don't mean a loud knock either. It's not a bearing. it's definitely a ping like bad gas, and it's been that way for a while now...

[skipper]

My girlfriend's 94 SC300 pings like hell. I accused her of using regular, and she says she always uses premium. Must be something wrong. Any ideas? I don't mean a loud knock either. It's not a bearing. it's definitely a ping like bad gas, and it's been that way for a while now...

GENERALLY, when an engine "pings" it has a great deal to do with the timing of the spark -detonation process to the position of the pistons. I'm not fasmiliar enough with the model, but sounds to me like the timing is set too fast. !Removed! the timing by turning the distributor back.

I found with a german car I formerly owned someone had the overhead cam belt off- then didn't get everything lined up correctly- talk about a ping- thought the entire valve train was going to expose it's self.

See if the distributor is loose?

[UCF3]

Also try using some Prestone Engine Clean when you add more fuel. When you're changing your oil i'd add some Restore; it may take the pinging out. You could probably get this done now.

[Alex-us]

Clean the air filter and check/clean the MAF sensor. Either of these can cause a lean condition which results in pinging. :)

[bartkat]

Carbon buildup can cause pre-ignition knock.

[anthonyiez]

Carbon buildup can cause pre-ignition knock.

bingo...just what i was going to say on an older car.