Larry29135
Member
Truck seems to spark knock when shifting into lower gear
Spark knock
- Thread starter Larry29135
- Start date
Larry29135
Member
3.5
Larry29135
Member
Rock62
Well-Known Member
Assuming your diagnosis is correct......suggest you take it to the dealer. Describe the symptoms and conditions when the symptoms manifest.
Let the mechanics do their work to isolate the problem.
Engine control systems are not a good place for the Backyard DIYer to be playing in. Good way to push the truck into FUBAR land.
FWIW, spark does not knock. Pre-detonation of the fuel is the source of knock. If you are correct, then something is not quite right. Knock typically only manifests when the engine is under load, while downshifting the engine is not loaded.
Let the mechanics do their work to isolate the problem.
Engine control systems are not a good place for the Backyard DIYer to be playing in. Good way to push the truck into FUBAR land.
FWIW, spark does not knock. Pre-detonation of the fuel is the source of knock. If you are correct, then something is not quite right. Knock typically only manifests when the engine is under load, while downshifting the engine is not loaded.
24-7
Well-Known Member
What year 3.5?
How many miles? Maybe stale gas? or is it there all the time on other fuel stops. I can tell you I don't get any spark knock out of my 3.5 running a top tier 87 e10 grade fuel.