Knock Sensor Problems - Need Ideas!
Thread Starter
|
Tuned
Joined: Sep 2001
Posts: 279
Likes: 0
From: Western PA
Knock Sensor Problems - Need Ideas!
My 1996 SC 4WD has a 302 engine with a tick/knock. My old mechanic told me about it years ago when I mentioned it was louder on startup when cold.
I have been dumping some LUCAS in at every oil change. I have run it this way for years, however now the truck is shuddering and hard to start and poor gas mileage. New machanic says the motor internals are worst now and the knock sensor is picking up the ticking and retarding the timing since it thinks I am using cheap gas. Can I install another knock sensor on the inner fender and switch the harness so it doesnt detect the vibration? Or am I just dreaming i can gets some more miles outta truck? He says $1,500 to pull motor and check if a bearing is "spun"????
I have been dumping some LUCAS in at every oil change. I have run it this way for years, however now the truck is shuddering and hard to start and poor gas mileage. New machanic says the motor internals are worst now and the knock sensor is picking up the ticking and retarding the timing since it thinks I am using cheap gas. Can I install another knock sensor on the inner fender and switch the harness so it doesnt detect the vibration? Or am I just dreaming i can gets some more miles outta truck? He says $1,500 to pull motor and check if a bearing is "spun"????
Fleet Owner
Joined: Oct 2005
Posts: 20,780
Likes: 1,746
From: Kentucky
It's as simple as unplugging the knock sensor. But in the long run, you are on borrowed time if the knocking is a bad/spun bearing.
I suggest you check for codes before getting too bent out of shape.
I suggest you check for codes before getting too bent out of shape.
Thread Starter
|
Tuned
Joined: Sep 2001
Posts: 279
Likes: 0
From: Western PA
well took it to another mechanic and he says there is no knock sensor after he removed inner fender and poked around so now dont know what to think. alot of other stuff has broken since first post and while still driving i think its time for a newer truck, cant afford new!!!
FTE Legend
Joined: Jun 2006
Posts: 31,930
Likes: 1,499
From: Ottawa, Ontario
No part of the engine is under the inner fender.. what in blazes was this guy looking for?
The knock sensor can be seen on the top of the rear skirt of the block in the pic below, you could disconnect it but I doubt it'll make any difference to your problem.
The knock sensor can be seen on the top of the rear skirt of the block in the pic below, you could disconnect it but I doubt it'll make any difference to your problem.
Tuned
Joined: Sep 2010
Posts: 473
Likes: 0
From: Farmington, MO
Screw knock sensors. I always hook up a cheap alternative to bypass the issue. A knock sensor is a waste. You should be able to tell if your motor is knocking or not.
Trending Topics
Lead Driver
Joined: Aug 2006
Posts: 5,670
Likes: 12
From: Sand Lake, MI
Knock sensor is a good idea, timing advance is 100% computer controlled. Uses EGR gases to cool combustion allows computer add yet more spark advance at speed.
Computer goes to far sensor gives it feedback, can back it down little bit to compensate.
Without sensor has no baseline, know how much is too much.
Should all of em have it. taking a tad bit of timing out is better than the alternative, letting it knock.
Computer goes to far sensor gives it feedback, can back it down little bit to compensate.
Without sensor has no baseline, know how much is too much.
Should all of em have it. taking a tad bit of timing out is better than the alternative, letting it knock.
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
2026 Shelby F-150 Off-Road: Better Than a Raptor R?
Brett Foote
2027 Super Duty Carhartt Package First Look: 12 Things You NEED to Know!
Michael S. Palmer
10 Most Surprising 2026 Ford Truck Features!
Joe Kucinski
Top 10 Ford Trucks Coming to Mecum Indy 2026
Brett Foote
5 Best / 5 Worst Ford Truck Wheels of All Time
Joe Kucinski
Ford Super Duty: 5 Things Owners LOVE, 5 Things They LOATHE!
Joe Kucinski
Every 2026 Ford Truck Engine RANKED from WORST to FIRST!
Michael S. Palmer
The Best F-150 Deal of Every Trim Level (XL through Raptor)
Joe Kucinski
Logistics Pro
Joined: Jul 2009
Posts: 3,635
Likes: 3
From: Lansdale, PA
Too bad you weren't in eastern pa, I'd check it out for you.
Take a video if it some morning and post it for us.
If it's a spun bearing or rod knock then it's toast. Swap in a 351 maybe. Or if you find super cheap 302 then do that.
Tough to diagnose a sound via typing, and we like videos.
Take a video if it some morning and post it for us.
If it's a spun bearing or rod knock then it's toast. Swap in a 351 maybe. Or if you find super cheap 302 then do that.
Tough to diagnose a sound via typing, and we like videos.
Laughing Gas
Joined: Dec 2007
Posts: 959
Likes: 8
From: Imperial, MO
This:
Would be the opposite of what you'd want to do to cure this:
LOS is mostly a 60 grade base stock lubricant with little to no additives. It does nothing more than thicken the oil you are mixing it with, while also diluting the add pack. Nothing about that is helpful in reducing startup knock.
Would be the opposite of what you'd want to do to cure this:
LOS is mostly a 60 grade base stock lubricant with little to no additives. It does nothing more than thicken the oil you are mixing it with, while also diluting the add pack. Nothing about that is helpful in reducing startup knock.
Tuned
Joined: Sep 2010
Posts: 473
Likes: 0
From: Farmington, MO
Lucas does more than thicken. Every time I do another oil change after adding lucas, the oil does not come out as filthy nor do I lose any. True it does thicken it however. But I adjust my thickness of oil as per the season by changing the weights.
Tuned
Joined: Sep 2010
Posts: 473
Likes: 0
From: Farmington, MO
I will not argue over the subject. I know both professional drivers and mechanics that Lucas helps. As well as my own experience with using Lucas as an additive. It's personal opinion on the use of it and it's handiness.
Laughing Gas
Joined: Dec 2007
Posts: 959
Likes: 8
From: Imperial, MO
I didn't see this as an argument. 
What is the LOS helping the professional drivers and mechanics with exactly? Any tangible proof to refute those claims? You're absolutely right that it comes down to personal opinion/choice, but keep in mind that it's human nature to believe that a product is producing a beneficial response simply because one has spent funds on the product (a placebo effect). That's exactly what keeps "snake oils" on the shelves.
Just to add to this, what is so wrong with your oil that it needs "stabilizing", or anything else added to it for that matter? Why would you want to reduce the percentage of the add pack in the total lubricant volume by replacing one quart of normal oil with LOS?
If you're running a quality oil, there is no reason to add anything to it.
What is the LOS helping the professional drivers and mechanics with exactly? Any tangible proof to refute those claims? You're absolutely right that it comes down to personal opinion/choice, but keep in mind that it's human nature to believe that a product is producing a beneficial response simply because one has spent funds on the product (a placebo effect). That's exactly what keeps "snake oils" on the shelves.
Just to add to this, what is so wrong with your oil that it needs "stabilizing", or anything else added to it for that matter? Why would you want to reduce the percentage of the add pack in the total lubricant volume by replacing one quart of normal oil with LOS?
If you're running a quality oil, there is no reason to add anything to it.
FTE Legend
Joined: May 2008
Posts: 56,542
Likes: 0
From: In my own world
I am adding STP oil treatment to my one 5.0. I need it to last two more weekends, then I'll pull it and replace it.
It is like the original poster's engine, Knocking from a rod, a main bearing, and has so much base pressure it leaks everywhere. Smoke actually puffs when you idle with the oil fill cap off.
I, like the original poster just need to squeeze it a tiny bit more.
I don't think the knock sensor is an issue, I think his motor, like mine is just plain old tired
It is like the original poster's engine, Knocking from a rod, a main bearing, and has so much base pressure it leaks everywhere. Smoke actually puffs when you idle with the oil fill cap off.
I, like the original poster just need to squeeze it a tiny bit more.
I don't think the knock sensor is an issue, I think his motor, like mine is just plain old tired