ping that will not go away

[matrass]

guys looking for some advice on my 96 Jimmy 4.3l. been having problems with pinging and a slightly rough idle.
Here is what has been changed in the last 6 months. plugs, plug wires, cap rotor, O2 sensor, coolant temp sensor,
egr valve, tps. figured the egr and tps were the issue. the egr when checked was sticking and the tps was broke
inside when I removed it to check it. they were original on the truck and had 90,000 on them.the rest of my changes
were done as regular maintenance. I run fp every tank 1oz / 5 gallons of gas. tried adding BG44k to the tank before
my oil change. the idle has improved a little but it is still not where it used to be. at first figured the pinging was due to gas quality being poor. have moved up to 89, little change and even 93 does not cure it completely. any ideas what
may be causing the problem ? maybe MAS sensor ? the idle is not terrible but the pinging is horrible to listen to. thanks for any ideas you may have.

 

[Dagwood]

In the old days, I would just change the timing by rotating the distributer. I don't know how you change the timing on these newer vehicles, but that could be the issue. It might also be a fuel injector acting up? I feel your pain.

 

[Drew99GT]

My Dad has a 1998 4300 Blazer and it seems to have always pinged like a mother. And as you say matrass, even premium fuel won't cure it totally. Auto-RX really helped it out tremendously and others have noted that as well, likely from the ring packs and sides of the pistons getting cleaned of carbon.

Recently my Dad went on a complete fuel system cleaning binge and added about 5 or 6 bottles of various product in about a months time frame and that also really slowed the pinging, although not totally.

I really think it's carbon in the combustion chambers. I doubt it's the MAF sensor.

My Dad's truck has 190 something thousand miles and still runs fine so unless it's just pinging with the lightest throttle and barely a load, then I think it won't hurt longevity too much.

You may want to try a full Seafoam or Mopar combustion chamber cleaning, that really helped the ping in my Toyota and it visibly removed a lot of crud on the piston tops.

 

[matrass]

Thanks for the replies. have tried ti ARX and id did make the engine run a little wmoother with more power.did pour some seafoam down the TB and put some in the tank. did not ping for a tank or so after that, then it came back. guess if the pinging is not hurting anything I can try to ignore it. as far as the idle goes, not sure what could be causing that. use to idle perfect but now there is a little bobble in it. maybe the improved FP will help with the ping a little and keep the engine a little cleaner ?

 

[cousincletus]

Try cold spark plugs. Mix your antifreeze 70:30 (70% antifreeze). This helps cool hot spots in the heads. Although water dissipates heat better, antifreeze is less likely to boil on contact with a hot spot. Try a new higher pressure radiator cap. Double check to make sure your EGR system is working properly.

 

[cousincletus]

BTW I fixed my pinging problem (2001 Dodge Ram 1500, 3.9V-6 with 5 speed manual trans) with this method. I can now run 87 octane w/o any pinging at all.

 

[Dark Jedi]

did this pinging start after changing the spark plugs? if so they might have given you the wrong heat range. I would check the part number and see. but if it is stock heat range. then go one step colder.

are you running a superchip programer? I know in my 03 dakota 4.7L. every time I ran the preformance setting. it would ping liek a MoFo. while changing out the plugs from autolites to NGK V-Power. noticed 3 og my spark plugs was loose. now I dont knwo if it was the plugs causing the pinging or if it was from being loose. but after installing the NGK. the pinging stopped and my truck runs a lot smoother.

so I would try a differnt brand plug and see. NGK makes my truck idle the best and I have tried champion and autolites.


also where do you buy your gas? could be bad gas also.

 

[matrass]

The plugs I put in were acdelco. were the same that was in the truck. truck has always pinged a little but has gotten a lot worse. seemed that the idle getting rougher and the ping getting worse went together. was hoping that our gas crunch lead to worse fuel quality and it would get better. was running 92 or 93 to try and help, it did but not much. at $3+ a gallon the pocket was feeling it. tried a few gas stations to see if there was a change and did not make it better. what gets me is that I have been running FP and even went with 1oz at 3 gallons of gas to look for improvement. hoping that I can find the reason for the poor idle and that will get me back to where I was. I used to be able to run 87 with a little ping, right now it pings very loud with 87 in it.really thought putting a new EGR would resolve it. replaced some vacum lines as well. will see if the plugs are tight and make sure the spark plug wires are connected ok. any other things I can check ? . right now running 89 from Sunoco

 

[Brett Miller]

Much of the noice from the 96 and up 4.3 engines is from the balancer shaft bearings. Mine did it for 60,000 miles.

 

[mjpolge]

Matrass,
You have done everything that I would about the pinging. However, for the idle roughness, you might want to clean the MAF sensor with QD electronics cleaner. You clean the small thin film wires. Spray them with the QD and then very gently take a Q tip and rub to get them clean. If you break the wires, you are screwed. However, you may be suprised at how much better the idle is after doing this. This is especially important if you use a high performance air filter like a K&N that use oiled cotton. By the way, if you use a K&N filter, you may be leaning out the mixture enough to make a cylinder or two go lean and ping. Just my two cents worth! Good luck.

 

[JustinH]

clean the maf sensor, and you might want to try a set of one heat range cooler plugs in that thing.

 

[bruce381]

maf clean it
bruce

 

[punisher]

I'll jump on the MAF bandwagon. If by chance you can find someone with a real scantool, get the fuel trim data. Rich trim at idle with a lean trim under load= telltale indicator of a bad MAF.

 

[mossad]

Try Amoco Ultimate.

 

[[RT] ProjUltraZ]

i would clean the MAF wires very gently, then do the water inj spray bottle trick in the intake. cook off that carbon

 

[Oil stain]

It is possible that your fuel injectors are running lean due clogging or your o2 sensors are lazy and slow which is causing a lean condition.

 

[Jim Spahr]

Replace the PCV valve with an AC Delco valve. Be sure to check the hoses and grommets for cracks and that they are not plugged. RE: idle. Is the idle cycling up and down? if so, clean the IAC (Idle Air Control) device. Long shot- replace the Fuel filter. With all the injector cleaner you have used, it may be that the fuel filter is clogged and therefore not allowing enough fuel through which is causing a lean condition which may cause pinging.

 

[Drew99GT]

The rough idle coupled with ping eludes to a vacuum leak/lean condition under load.

 

[oldmaninsc]

I would have to agree that any of the above are possible problems. On my Ford with the exact same problems - slightly rough idle and excessive amount of pinging the problem was the MAF. It had a big black coating on the wires inside of it. Cleaned it off, and had an immediate improvement and solution to the problems. Now I clean it yearly just to be safe.

 

[matrass]

Thanks for the ideas guys.ran seafoam in it yesterday, before changing the oil. it did smoke a little.... ok a lot lol! the ping was reduced some and the idle a bit better. have been cleaning the MAF once a year and will try that. ! seems to run stronger and more responsive this morning. idle still has some cycling, not much but it goes from near perfect to some roughness. will check the vacum lines as well. saw a post about the IAC, is that located right beside the TPS ? is that cleaned with contact cleaner ?