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Bad knock retard/ping

Posted: Sat Jun 22, 2013 2:41 pm
by beachking2000
Thought i just had a bad tank of fuel so ive waited but been 4 fillups since and i can get up to 12 st knock retard and 4lt and its not even at wot. After it hits 12 it pings like a bastard... 2010 ram 1500 5.7 no performance mods and running premium on 87 oct tune. Also tried dif gas stations

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 2:41 pm
by beachking2000
Will post logs shortly

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 6:12 pm
by Mike_Levy
Running 93 on the 87 tune? Thats gotta be false knock. Or you have an intake manifold full of oil or some sort of cleaner in the tank. First step would be to check to make sure theres no metal on metal contact anywhere that the sensors can be mistaking for detonation. Then pull the intake and TB and make sure the manifold doesn't have oil in it.

If you have a borescope, it also would hurt to pull a plug or two and check to make sure the pistons aren't chipped or anything. Bits of piston rattling around in the cylinders would definitely drive the sensors crazy.

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 7:03 pm
by beachking2000
Crawled underneath unplugged both sensors no sign of corrosion in connectors, no melted wires but i did notice a difference in catalytic convertor coloration one looks like its running hotter then the other. Heres a pic. Btw i have mds disabled so it shouldnt have anything to do with that. Heres a pic of where the exhaust joins both cats are same color as seen in difference in pic

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 7:21 pm
by beachking2000
Plus im sure it isnt false it sounds like a pulse motor sound in the exh when it retards

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 7:28 pm
by Mike_Levy
That cat looks overheated. Could be clogged.

You wouldn't know if the knock was false by the exhaust sound. The ECU is gonna pull timing either way.

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 7:42 pm
by beachking2000
Whats normal cat inlet and outlet temps warmed up

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 8:21 pm
by beachking2000
Cats themselves

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 9:15 pm
by beachking2000
Will probably replace them with high flows and replace o2s then cut apart and peak inside...then take a wait and see attitude...recommend any highflows? Edit: just read snow against a hot cat causes it to contract being i live in a snowy place it prolly contracted and fractured the cat... Will get both replaced with high flow and will prolly solve my problem

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 10:20 pm
by Mike_Levy
Does Magnaflow make downpipes or cats for the Hemi Ram? If they do and you don't want to get headers, they'd be the way to go.
That passengers side cat looks bad.

Re: Bad knock retard/ping

Posted: Sat Jun 22, 2013 11:08 pm
by beachking2000
Whats a good header for these. Arh?and if i wanted to remove cats is there something i can add in their place to maintain slight back pressure so i dont lose hp....plus i would have to have the rear o2s turned off by a cmr ?

Re: Bad knock retard/ping

Posted: Fri Jul 12, 2013 11:33 pm
by johnny248
I noticed that I was also getting ST and LT retard with any tune I was running. I would even get readings while just cruising on the hwy at like 70. I restored the stock tune and monitored, and same thing. Regardless of octane fuel that is in the tank. I do have a Volant intake on my '11 Hemi, and I've read that intake noise can trigger the knock sensors also since the there aren't any resonators or anything. I haven't monitored with the stock intake on. Don't really care to reinstall it just to test. Therefore, I would say that it isn't tune related?? I've read that people who have Hemi Fever tunes don't have this issues because some of the spark has been removed. They claim there is unneeded advance in the can'd tunes. I don't know if this is true or not. I have not been able to hear any spark knock from the engine, so I think this may be normal, or false readings? I'd like to get more feedback.

Re: Bad knock retard/ping

Posted: Sat Jul 13, 2013 11:24 am
by electricmarquis
Check your knock sensors as well. I think there is a test by checking resistance on the senor through a couple of wires. Ill google it in a sec.