SwaintaN

have a 2007 ls stock engine.

was getting onto Highway, cars behind us and semi wouldnt get over.. so either get ran over or go faster.. car red lined for about 4 secs. now there is this loud knocking noise coming from front passenger side. doesnt matter if in gear or not in gear.

got home, lifted hood. had her put it in gear and n and p and u could hear it in all of them, if you rev the gas, knock gets louder and faster. all from front passenger side.

what should i start checking?

knock sensor has threw code long time ago and never replaced it. thats just fyi.

firemangeorge

Timing chain tensioner came apart maybe?

A loud knocking sounds like major trouble no matter what. A little hard to diagnois over the internet though.
Maybe use a mechanics stethoscope and pinpoint exactly where the noise is coming from.

Snoopy

Other than little easy things like a serpentine belt that has "knobs or tears", I think, as mentioned above, you have major problems. If that is the issue, then you'll need a qualified professional for assistance.

Oh, and I would NOT drive it.

Curious though on how and under what circumstances it stayed at red line for about 4 seconds?

SwaintaN

we only drove it home, it got louder of the drive 22 miles. but i checked the oil, no leaking oil, oil still at level. i know i needed to change the oil 25 miles ago. figured that isnt it either. i have a mechanic friend coming over in am to see... i was just trying to get a heads up on everything.

it didnt drive weird at all when driving it, but it did shut off the engine at stop sign, i had to restart it it.

Lucky

Removing the valve cover you can see most of timing chain and guides for a visual inspection.

SwaintaN

merging onto highway so on ramp, semi didnt get over, cars behind us, only option was to floor it, i didnt hear/see it red line for 4 secs, wife is the one who said it red lined... i told her it was probably high line cause of the passing gear from stomping the gas.

SwaintaN

ok quick update... took out flash light.. im not losing oil, only lost a lil while driving it.

no oil on ground, no puddles, no major oil loss. HOWEVER there is oil on passenger side of suspension components, bottom of motor and near what looks like the pulley for the a/c clutch.

843de

It doesn't sound good at all, knocking sounds combined with oil being puked out usually indicate a terminal or near terminal condition.

It could a failed timing chain tensoiner allowing the chain to slap the inside of the timing chain cover.

Your chain guides may have disintegrated, or it could be a rod knock where either the bearing on the wrist pin or big end have failed allowing the rod to start "hammering".

Keep us updated, but I have a sinking feeling that your friend the mechanic is going to ruin your day.

But used engines are available starting in the $600-$750 range and on up, if your engine is terminal, that's one option to pursue.

SwaintaN

im hoping its just the timing chain system busted out.. i can get a new timing chain with all components for 175.00 the plus the labor... waiting to hear from him... how do u tell the difference from timing chain and rod? i thought when u blew a rod it went threw the engine

firemangeorge

Only if the rod breaks. You can have a failed rod bearing or wrist pin that could knock but still be attatched. If it's still connected with a bad bearing it will sometimes beat through the bearing and then start beating against the crank. It won't last long before it "hand gernades" the rod. Usually out the block.