Loud Engine Noise... Maybe Serious Issue?

[BG1988]

well I don't know, if your sure that it is the engine and it's loosing power and making a slapping noise, but yet no CEL, then I would do a compression test and maybe pickup one of those cheapy inspection camera's at harbor freight and start digging deeper, any metal fragments in the oil? can you take a video of the sound from the engine compartment and post it up? some engine noise is normal and some is not, my 03 Silverado has a tick that comes and goes it may start up and idle just fine for a few minutes and then begin to tick tick tick, rev it and it goes away till it idles down and it comes back, it has done it for years, lately it has stopped doing it the last 2-3 oil changes, it's just a noisy lifter and it's fairly common the engine runs fine and it's not worth tearing it down to eliminate.

ticking noises from the fuel injectors
yeah they are very noisy..

now if your gasolina engine sounds like a diesel

then you have a problem a lifer problem..

 

[Kraig]

Well—were you busy this weekend?

 

[SnowDrifter]

****** up lifters wouldn't cause piston to kiss valve. And as is you'd see some very clear witness marks on the cylinder if that were the case. But a delayed or partial valve press would cause backfires or a false knock. Consider what would happen if your exhaust valve doesn't stay open long enough to clear the cylinder. You can push those hit gasses into the intake when that opens, ignite the fuel there, and get a backfire through the intake. Or you push all that fuel and air through the intake, ******* up the stoichiometry for everything else around it.

 

[superstarsteveo]

I had the lifter issue with my 6.2 liter.... heres the fix...

Run a can of SeaFoam in the oil, seriously. Drive it for 300-400 miles and change the oil to like 20w50 conventional and add another can of seafoam, this time drive 1000 miles, and repeat for a 3rd time except run 10w30...ALWAYS conventional oil... Lifter tick will be gone. Mine took about 10 times to clear but the Seafoam in the engine works and cleans out sludge and all kinds of nasty shiitake.

At a different point I had a constant misfire in #4 cylinder bc one of the rings had carbon on it, it kept oil fouling plugs. Pulled the plug and filled the cylinder with seafoam and left if for 2 days. blew the seafoam out, insert new plug the was 2 steps hotter than stock, repeated the process about 4-5 times...problem solved.