Canary94GT

I've had pinging under load in my stock 5 speed 94 GT for a few thousand miles or so. Before that, I didn't notice it. It has 81500 miles on it now.

I've taken it to two different mechanics and neither could help me out. I've had the EGR valve replaced (cracked and pooped out), and the mechanics retarded the timing to 8 degrees (further than the factory 10 degrees...), which theoretically should minimize pinging as much as possible, right? I also changed the fuel filter a couple thousand miles ago.

I've just cleaned the MAF sensor, cleaned the throttle body & air filter, and replaced the dizzy cap and rotor and it still pings, seemingly just as much. The plugs and wires are new from the mechanics, though I haven't pulled the plugs to look at them.

I don't have a check engine light on.

I've tried 87, 89, and 91 octane gas (highest offered near my house), and none seem to make a difference. However, one of the mechanics told me it may be caused by the ethanol they put in gasoline these days, so next fill-up I will try gas from an ethanol-free gas station.

What would cause my pinging? I've heard bad o2 sensors might cause pinging, but that's not something inexpensive enough to just replace as a guess that it might fix it.

What do you think?

Canary94GT

Put about a half a can of seafoam through the brake booster line and let it sit about 35 minutes.

Might have been too long or something because when I drove it afterwards I didn't see any white smoke. It also didn't seem to do anything about the pinging, though that could be due to severe carbon build up if there is.

Might be because the seafoam was a few years old or something. But I have a new can that I will use tomorrow and put half of it in the gas tank.

In the mean time, any more ideas?

4rdnut

If the engine is running too hot it will ping and rattle. check the engine temps with a reliable gauge.

9redfox3

Here's alittle information read? might help......
http://www.stangnet.com/mustang-foru...ally-gone.html

Canary94GT

Replaced the ECT and ACT sensors, did not fix it. The ECT I think was actually faulty as I was getting engine code 116 which means it was not reading correctly.

Running another 1/3 pint of seafoam through it atm.

AdderMk2

seafoam will not fix your problems...

Canary94GT

What will?

Could a weak fuel pump cause my pinging problems? I don't have any engine codes indicating lean conditions or anything, but I have heard weird gurgling sounds from my fuel pump area and when I walk near the back of my car while it's running, I hear a constant whining noise.

Here's a video of the whine from a couple years ago: http://www.youtube.com/watch?v=UFP7acsZ1eI.

It seemed to use to only happen when the tank was empty to 1/4 full, but I just heard it today and it's 1/2 full.

Could this cause the ping?

AdderMk2

check your fuel pressure. If its in spec... then no

Canary94GT

Will do if I can either buy or borrow a fuel pressure gauge

Thanks man.

Canary94GT

Sigh, I was going to try to adjust the timing down to about 6* from its current 8*, but found out the distributor hold down bolt is either torqued down extremely hard or it's seized in there like a SOB. Can't get it loose.

It doesn't help that I have approximately 1/16 to 1/8 of a ratchet turn space to loosen it.

Makes me wonder if the mechanics were giving me a line when they said they adjusted the timing.

Edit: Found out a 90 degree bent wrench might help.