Engine "pinging"

[edhackett]

Originally Posted By: Mfrank84
"Pinging" most prevalent when rpms drop under load, like climbing a hill. It doesn't "ping" or knock unless it happens as I described above under load at lower rpms. Thanks.


What is the actual RPM range where the pinging occurs?

Ed

 

[drolds]

I am with the others in suspecting a malfunctioning EGR valve. You should try to get it replaced under warranty (the emissions controls warranty) on all new cars sold. I think the engine is too young to have other causes, although the knock sensor is a possibility. The knock sensor should throw a fault code in most cases of it malfunctioning. Higher octane fuel should not be needed on this vehicle with an exception of towing. You did an excellent job of eliminating the maintenance items ( PCV, plugs & wires) which were due in another 20,000 miles or less anyway.

Dr. Olds

 

[artificialist]

In my family there have been 2 cars that made pinging noises, despite proper octane levels and maintenance. 1 1999 Honda CRV and 1 Toyota Solara 2AZ-FE.

The pinging would only happen if you pushed the accelerator hard, and if you went 4000 RPM or higher.

I don't know why this happens.

 

[gathermewool]

Originally Posted By: Mfrank84
Originally Posted By: gathermewool
It's not under warranty?


Jeep had a 36 month or 36K warranty. Is the EGR valve covered for a longer interval, like emissions?


Wouldn't this be covered under the POWERTRAIN warranty?

 

[tswm]

Originally Posted By: tswm
(and check for the color of each as well as for too wide a gap prematurely induced possibly by antifreeze from out of blown head gasket),


To clarify, if it be a scenario where coolant leaks into combustion chamber, in due time that particular spark plug will be discolored according to the dye of antifreeze (on the ceramic housing), and more notably, you may see a rusted spark plug, more or less; I don't know if that's the case with long life platinums and iridiums but a few years ago I saw that a basic, cheaper spark plug exposed to blown head gasket problem had rust on the metal part, and the ceramic part was somewhat stained with green antifreeze color.

And this is stating the obvious, but because I recently saw a new car, less than 15K miles on the odometer, whose coolant reservoir was not emptied but dangerously close to doing so, therefore if you haven't done so, I would urge you to check the level in your coolant reservoir. Car manufacturers in general say an occasional pinging under load like going uphill is normal, but you're saying this is now happening regularly, which is definitely not okay.

And I've read of head gasket problems where combustion gases leak into coolant jacket.

Logically, these new MLS (I think it stands for multiple layer steel) head gaskets are designed to almost make impossible such problems in the latest new cars. It appears back in the days of producing aluminum head and iron cylinder block, many failures, according to my cursory reading that especially spurred the development of sturdier head gaskets. I assume that your motor is all aluminum.

There are different reasons for seriously bad engine pinging, and hopefully it's not any such head gasket issue causing your problem.

 

[Sierra048]

Thanks for the input. Coolant level is fine. I've got everything ready to change the plugs and wires today and I'll give the old plugs a good look. Did a Seafoam treatment last night via brake vacuum line and added 8oz of Seafoam to the gas tank. I was almost completely empty so I added 8 gallons of gas to reach the suggested Seafoam ratio. I'm still going to get some Techron and run some through as was suggested earlier. We shall see. I hope it's not EGR related since it appears removing and replacing the valve is a pain due to the trouble of accessing a certain bolt. I'll still replace the knock sensor first since it's really cheap and easy to replace.

 

[Sierra048]

Well,

Good news I think. I changed the spark plugs and wires this morning. Jeep came with Champion RE14PLPS double Platinums and I replaced them with NGK Double Platinums spec'ed for the Jeep. Changed out the factory 8ohm Wires with some Denso 7ohm wires. Took it for a nice test ride of about 20 miles and it felt peppy and responsive. I didn't hear any noticeable pinging in my usual spots as I had before. Don't want to get my hopes up just yet (placebo effect) but maybe my pinging issues are behind me.

All the spark plugs that came out looked OK for a vehicle with 40K. Nothing out the ordinary on any of them and they all looked pretty much the same. The only difference I found was one of the plugs had a gap of about .040 instead of the recommended .050 that the other five were at, or extremely close to it. I checked and rechecked to make sure that I had gauged them correctly. Could this have been the reason for the pinging, or at least a factor? Could one ohm less resistance in the spark plug wires make a difference. A combination of both? I'm just trying to swag my through this. If the pinging reappears, I'll change the knock sensor next and if that doesn't do it I'll focus on the EGR system.

Many thanks for all the suggestions and input. I'll revisit this subject again if I need additional help.

 

[tswm]

Originally Posted By: Mfrank84
Did a Seafoam treatment last night via brake vacuum line and added 8oz of Seafoam to the gas tank. I was almost completely empty so I added 8 gallons of gas to reach the suggested Seafoam ratio. I'm still going to get some Techron and run some through as was suggested earlier. We shall see. I hope it's not EGR related since it appears removing and replacing the valve is a pain due to the trouble of accessing a certain bolt. I'll still replace the knock sensor first since it's really cheap and easy to replace.


Hopefully it's only a knock sensor issue.

IMO Seafoam in the gas tank only for now. Some time in the future Techron in the gas tank, is better it seems to me.

 

[tswm]

 

[lomez]

My first checks would be:

* search for vacuum leaks (would be lean)
* use name-brand gas of adequate octane rating
* EGR clog (but I suspect this would throw a code...P0401?)

Modern cars should not ping.

 

[Silverado12]

Try 89 octane gas and see what that does.

 

[artificialist]

Originally Posted By: lomez
My first checks would be:

* search for vacuum leaks (would be lean)
* use name-brand gas of adequate octane rating
* EGR clog (but I suspect this would throw a code...P0401?)

Modern cars should not ping.

OBDII cars do monitor the EGR system. However, it isn't perfect. I have certainly dealt with various failed or failing parts that the ECU does not recognize as failing.

 

[Oldmoparguy1]

I just spent a half hour searching the internet for "jeep pinging".

Amazing! It's happening across all engine types, and, it's mostly late model low mileage models. The same engines used in cars and minivans don't ping....

Obviously, It's a combination of timing and mixture.. Both controlled by the engine controller... Looks to me like Chrysler has tuned the jeep right to the edge in an effort to get the best fuel mileage... The fix is to add more fuel, or back off the timing a bit.

In the old daze, we would fiddle the timing, change the carb jets, raise the float level a touch... Can't do that now. With my old turbo 2.2/2.5 mopars, there is at least one source of custom programmed computers. If something like that were done with the problem jeeps, I'm just saying......

If it were my jeep, I would try to rig up some type of water injection, at least to see it it helped.

Wayne