Hey guys - this is my buddy's bone stock w/SLP lid LS1 '98 Z and here is his description of how it happened...

Cruising at 80 on the way home. Turning off of interstate at stop sign, fast idle, oil pressure fell, almost died. Made the turn. LOUD knocking. Slowed down. Knock went away. 1/4mi down the road, turn again. Accelerate, WORST knock. Pull over. Turn car off. Start car. SOFTER knock. Limp 1mi home. Check oil. EMPTY! Add the only 2q, recheck, now full. Also, just changed oil couple thousand mi. ago. Knocking continues as heard in video...

http://www.youtube.com/watch?v=dlhf7xdf1s8

Any thoughts??

Pulling the valve cover to check push rods and rocker arms now (12:15am EST).

Thanks in advance.

 

Any luck?

 

nothing on the driver side. The noise sounds deep, increases with rpm of course. He changes his own oil and always uses the best of what he can find so i know he didnt short it. He doesnt race this car, just a daily driver and he wasnt wot when he accelerated when this noise occured.

Guess we can pull the pass side cover but like I said, it sounds deeper and more in the middle of the block.

 

no one here can help?

 

Back up for you.

 

Sounds like a rod bearing to me...

 

My thoughts as well...

 

yep, its a rod Stroker time

 

Not everyone is hardcore. This is his daily driver that he was suppose to trade in on Tuesday for a Envoy to tow his boat.

Today I pulled the pass side valve cover and inspected the pushrods and rockers. I did find that the 3rd rocker back seemed dry and the pushrod was very very shiney. It was getting some oil but the others were very wet. At this point I assume the rod bearing is the culprit so i had him crank it to get the oil pumping and the 3rd rocker/pushrod yielded the least amount of oil by far. And the sound seems to be coming from below that assemby's area.

I'm not going to go as far as pulling the head as I dont have the time/tools to get that far and even if I did, I wouldnt have the time/tolls to fix it for him.

Any input on the dry pushrod?

 

I was afraid that it would be something like this. Sucks he was trying to get rid of it when this happened.

 

Its just a guess theres a whole lot of stuff it could be but it sounds like my engine when it spun a bearing. Hows the oil pressure?

 

Shes gone. If he can get a little time on the trade just pick up a 4.8 or 5.3 and throw in it then trade it in. No one will know except for a lack or power. Or he'll take a screwin on a trade with a dead motor.

 

Oil pressure seems normal, idle is normal etc.

I dont understand the single dry rocker and extremely shiney pushrod.

I think hes going to just take a hit and take it to the dealer for the trade in. Its a friend of the family that was going to trade straight up for his 98 Vert Z and an old 94 Sunbird GT that hes had for probably 10 years for the Envoy.

I dont see how his automatic, completely stock LS1 would spin a bearing on the interstate with the cruise control set at 80. Doesnt make sense.. but it happened...

 

Oil pump failure??? If the oil level was very low and the car was stopped quick or turned quick it could have uncovered the pick up too.

 

Just to update those that have replied.

We pulled the pass side pushrods and of course found nothing. So we pulled the pan and found plenty of little chunks of gold'ish metal as well as some metal shavings on the drain plug. It was late so I didnt get a chance to look up into the engine but i am 100% its a rod bearing after seeing the results.

Also, some of the oil seemed to be near the consistancy of grease. Very, very thick and gray in color.

 

Trade it in you will be gon e before they start the car and I am sure they already gave you a price for the car right they usualy just wholesale thecars so they don't care either

Just park where the salesmen can't hear it when you pull up

 

U must not read. lol The car isnt mine. And the dealership he is trading to is a family friend and is doing him a favor and trading the camaro and a beater of his for a nice envoy.

He may just trade it in and take a $2000 hit and apply the balance to the envoy. Esp, if we cant get this bastard fixed.

 

Almost sounds like mine. My oil pressure was good though. Ended up being a broken piston skirt.

http://media.putfile.com/LS1-knocking

 

Really strange that the oil was changed a few thousand ago and it was empty. It definitely looks like bearings and hopefully lesson learned - watch the OP gauge, and check your oil regularly.

 

Not my car. Oh well, he drives it... thats it. Oh and oil pressure still seemed normal and the only time he said it appeared to drop was when it was beginning the knock. Luckly the car only ran for maybe 1 mile after the knock began.

*UPDATE*

pulled the pan and the #3 rod bearing was the culprit... so pulled the rod cap off, pulled the bearing out, will be polishing the light scarring on the crank and throwing in a 5-10 thousandths over stock bearing after we see what the clearance ends up being. Put it back together and off to its destination at the dealership for his trade in.

The damage wasnt bad. It was caught before anything catastrophic occured. Just needs a flush to get whatever copper the filter didnt catch and it'll be ready to go.

If it were my car... I'd obviously tear it down and even take advantage of the situation. But, hes trading it in and they are taking it to auction.