Spark knock

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Jan 9, 2020 | 06:42 PM

srsbjohnson

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Cross-Country

Joined: Mar 2008

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Spark knock

Hi all, I know this has been discussed but I don't know what else to do. I have a 1996 F150 5.0 automatic 4x4 with 230k miles. In the process of chasing this spark knock issue I have replaced the following items either new or from a working vehicle.
NEW
Spark plugs at both standard gap and 6 Liter gap
MSD cap, rotor and coil
Ford 8.8 wires routed properly
Distributor
ICM (ignition control module)
TAB and TAD
EGR valve
Fuel Pump
Pressure Regulator

SOURCED FROM WORKING VEHICLE
MAF sensor

Im sure i am missing something. Anyway I have adjusted the timing ranging from 14* down to the current 8*. I don't know what else to do other than change the timing chain but if I'm going that far at 230k I might as well rebuild. Help!

Thanks

Jan 9, 2020 | 06:51 PM

Tedster9

Post Fiend

Joined: Apr 2002

Posts: 19,311

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From: Waterloo, Iowa

Worn timing chains will tend to retard valve timing, this will cause sluggish response, though not ping.

Jan 9, 2020 | 09:29 PM

88n94

Cargo Master

Joined: Jan 2004

Posts: 3,118

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From: South Dakota

I would retard the timing another 3 or 4 degrees at a time until the spark knock quits and see how the engine acts.

Jan 11, 2020 | 07:47 AM

Scndsin

FTE Chapter Leader

Joined: May 2006

Posts: 12,341

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From: Central Mississippi

With 230K excellent chance that carbon has built up enough to raise your compression and/or has created a hot spot in the combustion chamber that pre-ignites fuel/air charge.

Jan 11, 2020 | 12:07 PM

DBGrif91

Cargo Master

Joined: Jul 2009

Posts: 2,541

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From: Des Moines

Have you tried checking for trouble codes? Even without a check engine light codes can be stored. Being a 96 it should have the OBD2 connector under the driver side dash - code readers can be found cheap or many parts stores will check them for free.

Jan 11, 2020 | 12:22 PM

srsbjohnson

Thread Starter

Cross-Country

Joined: Mar 2008

Posts: 73

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Ok, I adjusted my timing some more and I am roughly at 5.5* to 6* with no spark knock with normal and aggressive driving. I have not try towing anything yet. Now with the timing set this low it is not peppy at all and shifts at around 4200 rpm with my foot to the floor.

I do know that the engine has alot of miles and carbon could be the issue so what would be the best option to help with this, Seafoam or good ole ATF?

I have checked for trouble codes and there are none whatsoever and this was with the reader they use at AutoZone.

Jan 11, 2020 | 03:31 PM

EllieMae94

Elder User

Joined: Dec 2016

Posts: 854

Likes: 39

From: Mid Missouri

You could try Seafoam, Kreen oil, MMO, or even water if you have carbon build up. I haven’t had much luck with any of these, but others have.

A bore scope is a cheap investment to see how bad build up is on the pistons. If it’s bad, head removal, or better yet, complete tear down may be your best bet.