Engine knock

When I started my truck the Engine made a knocking sound. The knocking only lasted for a few seconds. This has happened a few other times. Any help diagnosing this problem would be appreciated.

 

Oil level low? Does it do it when the engine is cold at first start up?

 

Just had the oil changed two weeks ago. Yes, the knocking has only occurred on a cold start.

 

Reason I ask is cause oil thins out when it get warms, resulting in the noise going away. I would check the level. To me it sounds like a lower rod/bearing knock which is not good. If that’s the case a little trick of the trade is to use diesel oil. Usually 15w40, thicker oil eliminates the noise

 

Record it and share here if you can.

VVTI gears can rattle on cold start.

 

Oil level is good. I was also told to Marvel mystery oil. I’m guessing that would be the same as add Diesel oil

 

Never tried it. Good luck tho!

 

Piston slap is very apparent on the 1grfe engine during cold starts. This is totally normal operation. Knock will usually get louder with RPMs.

 

People assume its piston slap. Its never been proven. The bottom ends on these truck have a hollow knock sound sometimes. most people report they can hear it right near the cat.

 

year / model

how many total miles

when was last service

has the engine been run low on oil

 

I would be watching the red oil pressure indicator closely on all starts and see if it's staying on when you have the knocking sound. It should shut off almost instantly when you start it and stay off.