Cold Ping

[dodge dude94]

We've had a cold snap, low temps have been down in the 30's and highs in the 50s. While driving up a hill, speed 45 mph, 2200 rpm, I noticed I had some pinging going on. Any ideas as to what would cause this? It's done it before, and it doesn't take a massive swing in temperatures to set it off, just cold.


Any ideas would be appreciated.

 

[Merc225hp]

Well as you know the pcm controls the timing in these trucks, a cold morning ping is a sign of too much timing. I would look hard at the temp sensor for the pcm, (you might just have the one for both the gauge and the pcm). Use a DVM to check the readings when cold and when the motor is warmed up. Possible tps as well, and then of course there is the good old plenum gasket that might just be showing it ugly head in the cold, it will have a bigger space when cold as to a smaller one when its warmed up. You could also check the IAT as well see if its in spec range.

 

[dodge dude94]

Well as you know the pcm controls the timing in these trucks, a cold morning ping is a sign of too much timing. I would look hard at the temp sensor for the pcm, (you might just have the one for both the gauge and the pcm). Use a DVM to check the readings when cold and when the motor is warmed up. Possible tps as well, and then of course there is the good old plenum gasket that might just be showing it ugly head in the cold, it will have a bigger space when cold as to a smaller one when its warmed up. You could also check the IAT as well see if its in spec range.

It's pinging when the outside air is cold.

I'm thinking about getting a can of Seafoam and tossing it in the gas and seeing what happens. Might I also be about to reset the PCM and see what happens? It's not serious, but irritating since my plenum is fixed. lol

 

[Merc225hp]

Seafoam the end all fix all in a can lol. If you want to get the carbon out of your motor go take it on the hwy and pin it for a mile or two see what comes out the exhaust pipe.

IAT reads manifold air temp if it's cooler out it will see that and put timing and fuel to where it should be for that temp.

 

[dodge dude94]

So by resetting the battery that won't change anything? What about making it completely reset the values for the MAP sensor?

 

[WhiteExpress]

Are you running stock copper core plugs?
What is this 'ebay plenum' you mention in your signature?
What grade of fuel are you running?

 

[dodge dude94]

Champion RC12LC4 gapped at .040
Aluminum 7075 aluminum plate and bolts from ebay seller 1999blkdakrt.
87 oc winter blend.

 

[GotExhaust.com]

Try running a tank of 93 through it. If the problem goes away it's likely the colder air intake temps are leaning out your A/F ratio which can cause engine knocking.

This could just be from the "winter blend" gas and the old girl is begging you for some high test.... Or maybe your O2 sensors aren't playing nice?

 

[dodge dude94]

Try running a tank of 93 through it. If the problem goes away it's likely the colder air intake temps are leaning out your A/F ratio which can cause engine knocking.

This could just be from the "winter blend" gas and the old girl is begging you for some high test.... Or maybe your O2 sensors aren't playing nice?

Front O2 was replaced this spring along with my cat, so that is fine. I think when I fill up next I'll run 93 in it and see what happens, maybe add some Seafoam.

 

[WhiteExpress]

1/3 bottle of seafoam + premium will very likely cure your ping.

 

[dodge dude94]

You talking Seafoam in the tank or the engine?
I did the engine not too long ago...

 

[dodge dude94]

Yep, July 9th, 160177.
This is why I put the champions back in, to get rid of the carbon build up from in town driving. lol

 

[GotExhaust.com]

1/3 bottle of seafoam + premium will very likely cure your ping.

LOL, I love it. Seafoam truly does solve all problems, ever! That and a sawzall!