My '09 pings, no matter what fuel I use...

[KMeloney]

Hey folks,

I've tried different grades of gas, and from different gas stations, and octane boosters as well; but no matter what, my truck pings under load. I initially thought there was something loose under the truck, but I'm afraid it's detonation I'm hearing.

I know that "bad gas" is the typical culprit for detonation. Assuming that I've already had "good gas" in the truck with no improvement in pinging, is there a MECHANICAL issue to check into that could be causing the detonation?

Thanks, folks.

 

[Lancaster]

How many miles are on you plugs, filter and wires? Have you done the Throttle body and MAF recently? This is a popular topic this time of year as things are warming up.

 

[KMeloney]

Yeah, it's very warm here in the NE… When I was getting a slight shudder at idle a couple years ago, I cleaned the MAF and TB. It didn't do anything for the shudder, and I don't recall that it did anything for pinging, either. But maybe it's time to look into plug and wires… Almost 60K on the OD. Not a lot -- and it's been doing this for quite a while now.

Thanks for your reply.

 

[08grey]

Try Marvel mystery oil mixed in the gas 93.

 

[Lancaster]

Yeah, it's very warm here in the NE… When I was getting a slight shudder at idle a couple years ago, I cleaned the MAF and TB. It didn't do anything for the shudder, and I don't recall that it did anything for pinging, either. But maybe it's time to look into plug and wires… Almost 60K on the OD. Not a lot -- and it's been doing this for quite a while now.

Thanks for your reply.

My plugs were well past due when I did them at 100k. Wires were brittle too. Maybe more due to years than miles? Either way MAF, TB, plugs and wires would be where I would start after the gas. Maybe fuel filter?

 

[ccapehartusarmyINF.(ret)]

pull out one of your spark plugs take pic and post it
if you think its detonation your hearing the conditions of the spark plugs will confirm it
hers an example i found

 

[YukonXLPerk]

nock sensors?

somebody check my spelling....

 

[Lancaster]

pull out one of your spark plugs take pic and post it
if you think its detonation your hearing the conditions of the spark plugs will confirm it
hers an example i found

Good point - this is going back to to some early 2000's gm v8s. I remember the knock sensors were under the intake. It was common for those who washed their engines to get water under the intake, water would get trapped in the wells the knock sensors would sit in. The sensors should pick up knock, message the PCM/ECM, retard spark, and decrease detonation. The old manuals said that a little ping was "normal" under load due to the time it took for this process to take place. The PCM should "learn" and adjust automatically for conditions. Honestly, I have not read my current manual regarding this- just assumed it was taken care of over the years.

Does any one know where the current knock sensors are located?

OP - have you recently washed your engine?

I think this is exciting as these cars are now aging a bit we may be learning something new.

 

[KMeloney]

I have never directly washed my engine. Any wetness under the hood would be from water getting in during an exterior wash, or from rain. Neither seems that likely to get much water in the engine compartment, I'm guessing.

Thanks for any and all info. Keep it coming!

 

[ccapehartusarmyINF.(ret)]

i washed my engine yesterday i just sprayed everything down with simple green let is set and sprayed the whole thing down there was so much caked on grimey dirt
if your worried about doing damage dont because i hosed down everything and it started up immediatly

 

[ezdaar]

After washing your engine, allow it to fully warm up and dry completely.

 

[ccapehartusarmyINF.(ret)]

well in arizona this time of year you dont really need to start it
when its 110 outside everything will be dry before you can hop in and start it up
also keeping your engine clean helps cooling

 

[mattluttrell]

It helps with keeping grease off hoses which makes them last longer.

The torque app will tell you about your timing advance as you drive. You can see it bounce around at different throttles and RPM's. Although I bet yours is fine, I'd be curious for you to watch your engine with the app. I wonder if it is adjusting correctly or it is has bad mixture or timing.