Can oil vapors cause engine knock?

[JTK]

I drove my 2019 Ram 1500 5.7L from ~7K miles until ~60K. Luckily I never noticed any knocking or pinging. It was smooth, very pleasant drivetrain for me.

I did a few times experience a lifter tick, but only after a very specific set of circumstances, which was starting the engine just long enough to move the truck a few feet and shutting it back down. On the next restart, I may or may not be greeted with 3-4sec worth of lifter tick. This happened to me maybe 3x in the time I owned the truck.

FWIW, I ran nothing but synthetic 5w30 in it. I did do additives for some time as well. Either Lubeguard biotech or a bottle of MoS2 with each 5000mi OCI.

 

[Nick814]

Are you getting audible knock, or are you just monitoring the knock sensors and noticing a lot of knock readings?

On modern engines, knock shouldn't ever really be audible since the sensors should pick it up and immediately retard ignition timing. I'd try a tank of 93 octane. If the sound doesn't go away, then it's probably a mechanical issue, not spark knock.

Its audible. 2nd or 3rd gear. Load on engine (1/2-3/4 throttle) from about 3-4k rpm. 93 does clear it up. And. I also feed it the onions and make sure it cleared out. Will see what happens at next oil change. Gunna scope the cylinders too

 

[OVERKILL]

Its audible. 2nd or 3rd gear. Load on engine (1/2-3/4 throttle) from about 3-4k rpm. 93 does clear it up. And. I also feed it the onions and make sure it cleared out. Will see what happens at next oil change. Gunna scope the cylinders too

Sounds like you need to replace the knock sensor.

 

[SubieRubyRoo]

Sounds like you need to replace the knock sensor.

Like post 2…

 

[Nick814]

Worth a shot, but from what i understand, that would throw some codes, and it would be down on power and mpg. Dont know about mpg right now as it is winter in Wisconsin.

 

[OVERKILL]

Worth a shot, but from what i understand, that would throw some codes, and it would be down on power and mpg. Dont know about mpg right now as it is winter in Wisconsin.

Not if it's just starting to fail.

 

[Vitamin Yoda]

Other than all kinds of advice, seems like the most sensible thing to do would be read any codes that might be set in the ECU. You don't even need security gateway or security bypass to do that. It would set something along the lines of P0325 or P0332.

 

[Furious]

Worth a shot, but from what i understand, that would throw some codes, and it would be down on power and mpg. Dont know about mpg right now as it is winter in Wisconsin.

Sensors can fail "within" spec so it won't throw a code. Never rely on codes to diagnose a vehicle.

 

[Nick814]

Other than all kinds of advice, seems like the most sensible thing to do would be read any codes that might be set in the ECU. You don't even need security gateway or security bypass to do that. It would set something along the lines of P0325 or P0332.

Just did full scan with Topdon. No codes

 

[Vitamin Yoda]

Just did full scan with Topdon. No codes

It's pretty reasonably priced. I would replace them on both banks. Torque them down to about 15 lb-ft.

You gonna have to get under the truck on each side under the driver's door and the passenger side door to get to them:

 

[Nick814]

It's pretty reasonably priced. I would replace them on both banks. Torque them down to about 15 lb-ft.

View attachment 200192


You gonna have to get under the truck on each side under the driver's door and the passenger side door to get to them:

View attachment 200193

Thank you

 

[Armkb]

Is a common phenomenon with Toyota 1GR V6 engines after an oil change. Have experienced it myself