fordguy17

my car is pinging pretty bad, almost knocking under the right conditions. i have checked the timing and it is set at 10*. i am running 87 octane, and i would like it to stay that way, considering today's gas prices.

what else should i check? spark plug gap? i already cleaned all the carbon off the dizzy cap and rotor.

can this problem be caused by too low of a fuel pressure? right now its set at 37 w/o the vacuum line at idle.

i have also heard that an exhaust leak can cause this. how do i check for an exhaust leak?

thanks in advance.

vfast

or a wore out timing chain

fordguy17

is there anything else i could check first before i tear into that? how do i check for exhaust leaks?

thelast50ho

is your car an auto cause a cracked flex plate can sometimes sound like pinging or knocking

Aliate X

Use those ears, lol. Just listen for ticking, you will hear it if its there.

fordguy17

so i listen for ticking at all those hose clamps on the exhaust?

how do i check for a cracked flexplate? can i see it if i crawl under the car?

Aliate X

Listen mainly at the headers, just listen where the header bolts up, might be a lose bolt, blow header gasket, etc. Even the bolt being 1/8th turn lose will cause an exhaust leak. Theres a lot of pressure in there.

fordguy17

ok, thanks. i'll check that.

i think i'll throw some 93 octane in there one time and see if it goes away. that would eliminate the possibilty of it being an igntion problem.

any other suggestions?

Quik

well if your pining it will sound like a spray can. [spray paint] it will have a rattling effect. that is detonating. i wouldnt run 87 in my stang if you paid me. chances are you may have a worn out timing chain or you are timing yoru car at the wrong mark

Pure5.0

Do what you said...try 93 octane first. If there is a difference then try one grader lower until you hear it. If you get ping with 93 then you really have a bad ping problem.

Timing has the biggest effect on ping. Check that first.