Hi Guys,

we have a 2009 Chevy express 3500 6.0l and when engine warms up there is a knocking noise coming from the engine. Changed the oil. The pressure is 38/40 on highway and 21/22 on hot idle. I tried on hot idle to rev up and when letting the gas off it quit downs and then a few seconds later starts knocking. We opened the oil pan and it looks clean the screen is clean too. Will change the oil ring too today but it’s frustrating.

has anyone experienced this issue before. The van has 125k on it.

Tim

 

An engine that knocks has to be torn apart or replaced to fix.
Just baby it and use it as long as it lasts.

 

We changed the oil ring on the pickup tube in the oil pan. Now the pressure is 32idle 41-42 driving. There is a bit of knock but definitely smaller. Will try to baby it and save money for a new engine.

 

You skipped over a few things here. For one, you mentioned that the knock is after the engine warms up. Is that the only time? At specific or all rpm’s?

Engine tolerances change as parts heat up or cool down. It could be as simple as a lifter collapsing. Changing out lifters is certainly cheaper than a new engine. Bad lifters left in an engine will slap the cam lobe and flatten it out so even if you do replace the lifter later, the damage is done.

How old is your oil? What weight are you running?

Go see a local mechanic and try to isolate the location of the knock.

 

Thanks a lot for your reply, it’s after the engine is warm up for like 5-10 min. The oil is the 5w30 fully synthetic. I changed the oil. The van was previously owned and we did change the oil and same noise. I got a mechanics stethoscope can I use it to narrow the noise?

should I try with conventional oil?