I had an issue yesterday. The car is a 03Z with a stock motor and a A&A it on it. The SC kit has been on for about 1000 miles. Yesterday I was out and driving. I got on it in second gear and spun the tires hit the rev limiter, let out and got back in it straighten out and shifted no problems till I looked down and I had a check gauges error. I look over and had no oil pressure and then it came right back to 40 psi. The car had been making some noise inside the car, what I would consider an exhaust leak. I figured the primaries to midpipe conection was leaking as I can see black suit that has formed on at the connection. Well after the incident the sound was louder. The sound the car is making you can't hear from outside when it's idling. You can hear it in the car though. It really sounds like an exhaust leak or some kind of weird knock. But nothing like I have ever heard before. I was only a mile from home when this happened. So I took the car home and put in the garage. This morning their was Antifreeze on the ground under the car. The antifreeze looks like its coming from the back of the engine and not the front. When I pulled the car into the garage the temp was 192. So the car never got hot.

I fully expect the something broke in the engine it's just really weird and the knock sound is weird. I could hear the noise in the car from a 1000 rpm to about 1400 and then it would clear up.

Any help would be much appreciated. I also put a new clutch in the car about 1400 miles ago.

UPDATE****
#5 piston broke a ring land. Which in turn cracked the sleeve and block on the LS6.

I sourced a LS2 block which is at the machine shop getting worked. Will be stroked and bored for a 402 stroker.



KT

 

My 2 guesses are cracked head due to too much boost or blown head gasket due to the same reason. Time to bare minimum take off the intake and investigate or do a compression check of the cylinders.

 

The check gauge may pop up after bouncing the revs... however, the noise on the inside could be a number of things. 1. press the clutch in to see if the noise goes away. 2. does the noise sound like sewing machine, or like a rod knock? the rev limiter may have knocked the valve train loose and increased knocking through the exhaust leak.

 

Well definitely something happen. I wouldn't drive it till some investigation going on. Take off valve covers and inspect drive train to start with. But i'm pretty sure you hurt something.

 

The noise remains with clutch in.

 

it’s a weekend car so I won’t be driving at all. Another guy said it could be a bent pushrods.

 

Went out and did a quick cold start video of the engine running before I left for Christmas vacation but can’t load the video because it’s to big.

 

Sorry but that makes no sense...

Pull the dipstick and check for the presence of water in the oil. Any milky color would not be a good sign. Cross your fingers for a blown head gasket.

Also keep in mind if a cylinder should fill with water, you could get a hydraulic lock and do some serious damage starting the engine... proceed with caution.

Good luck... GUSTO

 

I pulled the valve cover and checked the pushrods and rockers. Everything checked out good. Looks like the problem is lower in the motor. I have not found the antifreeze leak. I will try and go rent a pressure tester this weekend to try and find the leak.

KT

 

I started the engine again after putting the the pushrods and rockers back on to see about the antifreeze leak. The weird thing is that the motor didn't knock. I took RPM up to 2k and expected the double knock noise on the idle down and nothing. I have no clue what is going on now.

I still have the antifreeze leak that I can't find on the back side of the motor.

Any help would be greatly appreciated.

KT

 

I'd guess head gasket or a water cross over (I'm not familiar w/your engine for coolant crossovers)

 

I was able to get a coolant pressure tester on the car tonight. I have a nice slow steady drip on the drivers side dripping from the batwing. I can't find the leak to save my life. I thought it was the back steam block or head gasket. I of course couldn't see anything behind the engine so I pulled the intake off to find the leak. Of course I still didn't find the leak.

Anyone have any ideal on what to do next?

KT

 

Cracked block, cracked head or blown head gasket. My guess would be number 3. How many miles overall on the engine????

 

It has 36k on it.

 

There are steam lines under the intake! There are small oval like seals beneath the hook up maybe you need to tighten or replace those. There’s also a coolant engine plug! On the passenger side of the head I had totally forgot to remove my old one out of the 853 and transfer to my 243! This could be on either side depending how the head were place maybe ! Head gaskets once those come off you should always replace that and the head bolts. Crack in the tank lines ? My plastic connection lines at the bottom of the tank were disintegrated given these are a pressurized tank maybe coolant is spraying out? Old hoses? My guess is if everything above checks out to be good then you cracked the head or your block or maybe both! Next go around if your up **** creek already use something other then factory springs / lifter and pushrods. A ounce of prevention will save ya a pound of headache in most cases!

 

I pulled the intake and the steamlines are not leaking. I can't find anything leaking on the back of the heads.

 

Pulled all the plugs and did a compression test.
Number 5 plug looked wet.
Number 1 and 3 185psi
Number 5 and 7 75psi.

Guess I found my head gasket leak. Started tearing motor down.

 

Like I was trying to tell you ! no biggie it should clean up fine and dandy! Good luck

 

I would suggest you install a 4 corner steam line kit while you have it apart and put in a remote oil pressure sensor line. Just did that on my Z.

 

Well found the problem.