My 94 GT with 81500 original miles has been pinging for a few years now, or about 3000-5000 miles. It's stock minus a JLT cold air intake and a flowmaster cat-back exhaust.
When I first began driving it about 4 years ago, I did not notice it at all, so it appeared to begin happening suddenly.
The pinging occurs at nearly any rpm if the engine is under load. It will happen from 800+ rpm when I get going on flat ground in 1st gear. I don't hear pinging when I'm cruising at a steady speed on flat ground. It will also ping regardless if it's 40 degrees out or 90 degrees out.
I have aggressively searched google and tried several things to fix it, including:
- Running 89 octane currently (running 91 doesn't seem to help any.. also note: contains up to 10% ethanol)
- Had shop replace broken EGR system (so it is supposedly fixed, it was broken)
- Replaced fuel filter <3000 miles ago
- Cleaned MAF sensor with MAF cleaner
- Replaced ACT sensor
- Replaced ECT sensor (was getting CEL code 116)
- Changed platinum autolite 25 plugs to copper autolite 24's (one step colder) and gapped them correctly (were gapped incorrectly at .042 rather than .052)
- Replaced cap and rotor (wires are relatively new)
- Ran a couple rounds of seafoam through a vacuum line (didn't get much smoke)
- Retarded timing from 8* to 6* (didn't seem to do anything really)
- Checked and found balancer is NOT spun
- Checked fuel pressure, is 32 psi w/ vacuum and 40 psi w/o vacuum
Since I started this thread:
- Replaced PCV valve and PCV filter (was really gunked up)
- Reinstalled factory air cleaner to see if the CAI was causing issues. The switch didn't change the pinging.
- Tried 89-octane ethanol-fee gas (assuming the station still sells ethanol-free), and noticed little to no difference
- Changed o2 sensors - might be noticing some improvement. Only took for a short drive and maybe it takes some time for the computer to adjust to them?
The last mechanic that I went to (who replaced the EGR system) said it could not be fixed because of the ethanol that is put in gas these days. However, I will not take "no" as an answer - I believe it can be fixed.
Does anyone have any ideas on what is causing it? If more elaboration is needed on my part, I'd gladly do so.
When I first began driving it about 4 years ago, I did not notice it at all, so it appeared to begin happening suddenly.
The pinging occurs at nearly any rpm if the engine is under load. It will happen from 800+ rpm when I get going on flat ground in 1st gear. I don't hear pinging when I'm cruising at a steady speed on flat ground. It will also ping regardless if it's 40 degrees out or 90 degrees out.
I have aggressively searched google and tried several things to fix it, including:
- Running 89 octane currently (running 91 doesn't seem to help any.. also note: contains up to 10% ethanol)
- Had shop replace broken EGR system (so it is supposedly fixed, it was broken)
- Replaced fuel filter <3000 miles ago
- Cleaned MAF sensor with MAF cleaner
- Replaced ACT sensor
- Replaced ECT sensor (was getting CEL code 116)
- Changed platinum autolite 25 plugs to copper autolite 24's (one step colder) and gapped them correctly (were gapped incorrectly at .042 rather than .052)
- Replaced cap and rotor (wires are relatively new)
- Ran a couple rounds of seafoam through a vacuum line (didn't get much smoke)
- Retarded timing from 8* to 6* (didn't seem to do anything really)
- Checked and found balancer is NOT spun
- Checked fuel pressure, is 32 psi w/ vacuum and 40 psi w/o vacuum
Since I started this thread:
- Replaced PCV valve and PCV filter (was really gunked up)
- Reinstalled factory air cleaner to see if the CAI was causing issues. The switch didn't change the pinging.
- Tried 89-octane ethanol-fee gas (assuming the station still sells ethanol-free), and noticed little to no difference
- Changed o2 sensors - might be noticing some improvement. Only took for a short drive and maybe it takes some time for the computer to adjust to them?
The last mechanic that I went to (who replaced the EGR system) said it could not be fixed because of the ethanol that is put in gas these days. However, I will not take "no" as an answer - I believe it can be fixed.
Does anyone have any ideas on what is causing it? If more elaboration is needed on my part, I'd gladly do so.