Light Pinging Niose when Accelerating

[vaclasypt]

First off thanks for this forum. I have seen many useful discussions and am a true PT Cruiser lover. I have a 2002 Limited Edition with 110,000 miles on it. I am experiencing a light pinging niose when I accelerate or going up a hill. I initially switched gas from regular to unleaded to no avail. This problem is intermittent and I considered repacing the knock sensor as part of my attempt to resolve the problem. Anyone out ther have any advice or suggestions? Appreciate your help and look forward to corresponding.

[CREWZIN]

Welcome to the forum.

Lets start with a basic questions. At 110K miles, you should have had your timing belt replaced along with a few extras like water pump, belt tensioner, serpentine and alternator belt. Back to the timing belt; the reason for changing it is that it can stretch and break leaving you stranded out on the road, but before it breaks it can stretch and cause the timing to go off and one symptom of the stretching would be pinging.

The other thing, you said you switched from "regular to unleaded"? You should have ALWAYS been using unleaded, in fact the gas pumps for "leaded" gas (if there's any left) in the U.S. are made bigger so they won't fit into cars that use "unleaded" fuel. So, did you mean you switched from regular to mid-grade octane? If that's right and the pinging did go away, you'd just be masking the underlying problem of why you had the pinging in the first place.

[vaclasypt]

Thanks for the response.

I have had the timing belt, water pump, tensioner, and serpentine belt replaced. Also, I misspoke about the gas. I was using regular unleaded and switched to mid-grade in hopes that would make a difference but the light pinging didn’t stop. I spoke with my brother who is a half-way decent shade tree mechanic and through our discussion we began to consider the knock sensor. Could be a tune up though as it is due for another one. Any suggestions? Hope that clarifies my situation better.

On a side note, you have some nice pics of your cruiser on the site…looks like a show car.

[GALVANIZEDYANKEE]

Increasing the fuel octane and still getting ping leads me to think (as CREWZIN) that the timing belt has stretched. You go on to say you had the timing belt replaced. If that is when the pinging started I would suspect that the timing belt was installed one tooth off the proper mark.

[alvin201]

I have a 2007 NA with 11,000 mi , and am noticing lately a slight pinging during local driving. At 20-30 mph, if I was coasting with foot off accelerator, when I reapply the gas I hear very light pinging only for about one second or less, then there is none. This happens on level streets with no load. I do not hear it when the engine is working hard or hill-climbing.

Since it's only occassional, and goes away quickly I haven't been too concerned. Should I be?

[quicksilverdon]

Peculiar that you get no pinging when engine is working hard - as in uphill.
When you coast and get ping when you re-apply gas - does transmission downshift? The computer prevents "lugging" by downshifting thetransmission, but it takes a second or two.

[Dino]

Originally Posted by vaclasypt

First off thanks for this forum. I have seen many useful discussions and am a true PT Cruiser lover. I have a 2002 Limited Edition with 110,000 miles on it. I am experiencing a light pinging niose when I accelerate or going up a hill. I initially switched gas from regular to unleaded to no avail. This problem is intermittent and I considered repacing the knock sensor as part of my attempt to resolve the problem. Anyone out ther have any advice or suggestions? Appreciate your help and look forward to corresponding.

Have you tried a different gas station? Maybe the quality of the gas isn't great at the one your using or they are getting too much ethanol in their fuel.

The cheapest and easiest attempt at a fix would be a new set of quality wires and plugs and a visual inspection of the coil.

[mdfrodolives]

After swithching gas stations, did you try the key-trick to see to see if any codes show up? I got my 2003 smogged a while back and the smog guy told me that I had a code show up. When I asked him what the code meant, he said that my engine was running too lean, but that the puter was compensating for it.

So try checking for a code that might direct you to the demon.

Tim

[alvin201]

Have not noted any obvious down or up shifting, but it seems a little like the engine/trans are momentarily trying to get in synch (if that makes any sense).

Next tank, I'll try another gas station and also run the codes. Someone earlier replied that it may be hot weather related, and the last few weeks it has been very hot in NYC.

Thanks all