Demodding nightmare...

alright, so need some help on this one.

I have a guy interested in buying my SE, but i decided to take the top end off so i can eventually top swap my GT. kept all the original heads and everything from when i did the top swap on my SE, so a buddy and i did the work.

Just finished the car yesterday, and it ran great. Drove it home, took it out to dinner last night and got home around 11pm. Went out this morning, started it...and the damn thing sounds like a diesel. It sounds like a horrible knock. I checked the oil, and its full and clean, no coolant in the oil (thats the first thing i checked)

now the funny thing is...once the car gets to operating temp, it goes away...absolutely no knock.

The knock sounds like its coming from the rear, so I'm hoping its just an exhaust leak. Maybe when the exhaust heats up, it makes the flange expand :screwy: i did take the exhaust off to take the ZZP downpipe off. I wont be able to check for a few days since i dont have access to a shop right now. Hopefully its not the heads. they have been sitting around for a while, and i was going to send them to the machine shop to get cleaned and pressure checked...but decided not to since i was crunching for time. All gaskets are new.

i took a video with my cell to show you guys, but for some reason when i transfer it to my computer it doesnt have any sound. i will try and figure it out though.

i appreciate some thoughts. thanks again

Could it be from the lifters?

is the coolant level full?

coolant is full. Im hoping its not a stuck lifter. I may be pulling the heads off again :runaround:

What did you torque the rocker arms too?

And does the car missfire at all? Or just make the sound?

What did you torque the rocker arms too?

And does the car missfire at all? Or just make the sound?

the rocker arms were torqued to spec (11 ft ibs plus 90 degrees)

the car does not misfire at all. it feels like it has full power, and runs like a dream otherwise.

funny thing is...it didnt do it this morning when i left for work. i am at work right now and get out in 5 mins. as soon as i get home i will let you know if it did it again (fingers crossed)


Edit: it did it again. This time it only did it for maybe 45 seconds, and went away. So it didnt do it at all this morning. Went to lunch at 1:00 and didnt do it at all then either, then after work it did it for a very short time. This is driving me insane. Seems like maybe one of the valves is starving for oil. this sucks.......

yesterday i put a bottle of seafoam in the gas tank, and thought that had helped. I think this weekend I'm going to put some in the oil, then do another oil change and see if it helps at all.

I cant get the video from my cell phone to play with sound either. I will try and get a video with my camera in the next few days.

Did you use new bolts? TTY bolts sometimes fail when reusing them

It sounds like the oil filter anti-drainback valve is not working properly. What brand oil filter are you using?

Try the Seafoam in the crankcase and then do an oil and filter change. With the Seafoam just run the engine for a few minutes.

It sounds like the oil filter anti-drainback valve is not working properly. What brand oil filter are you using?

Try the Seafoam in the crankcase and then do an oil and filter change. With the Seafoam just run the engine for a few minutes.

The oil filter is a Car Quest oil filter. I'm gonna do the seafoam tomorrow and see what i get.

The oil filter is a Car Quest oil filter.

Do you know if the original box the filter came in said WIX normally found on the bottom? Carquest filters are made by WIX and have the silicone anti-drainback valve versus nitrile but it doesn't mean it didn't go bad.

Well...did a seafoam on Friday morning. Put a bit into the crankcase and ran the car for 5 mins or so and did another oil and filter change.

brought the car on about a 120 mile round trip to my GF's parents. Car ran awesome, got about 34 MPG. No knock on startup, even on Saturday morning when it was about -15* overnight.

however when leaving from work today, the car did it for literally 10-20 seconds, then went away. This knock sounds pretty damn horrible too. :banghead:

I'm just about to say pi$$ on it and tell the guy $500 and its yours.

This car ran awesome up until i took the top end off. I just dont understand what could be causing this? Before i did the top swap, the car ran like a dream too.

I wish you could get us a video of what it is doing.

I wish you could get us a video of what it is doing.

the video from my cell is mp5 format...could this be the issue? The video plays fine, it just doesnt have any sound.

Is this more like a rod knock or lifter knock/chatter/rattle? Go back and check the rocker arm bolts and torque values. How did you adjust for the extra angle called for? 15 lb-ft plus 90 degrees. Technically you should use a torque angle meter/gauge.

Is this more like a rod knock or lifter knock/chatter/rattle? Go back and check the rocker arm bolts and torque values. How did you adjust for the extra angle called for? 15 lb-ft plus 90 degrees. Technically you should use a torque angle meter/gauge.

i did use a torque meter, however i torqued to 11 Ib-ft plus 90 degrees. You suggest 15 Ib-ft??

it is much worse than a little lifter knock. i would describe it as a rod knock for sure. It is completely intermittent now...and has not done it since i posted. I'm at a complete loss for idea :screwy:

Wait, you top swapped back to the stock heads and intakes? How about the harmonic balancer? Did you also take the L67 one off and put the L36 one on? If so, the rubber on the harmonic balancer could be deteriorated and making a knocking sound much like a rod knock. When you turn your car off, do you hear a few slight clunk clunk clunks as the motor winds down?

Inspect the balancer for cracks or breaks in the rubber, and maybe take the belt off and see if it still knocks.

good thought Tim, but the Harmonic balancer was not changed when i did the top swap originally. Its been the same one the whole time.

finally got the video to play with some sound. here ya go

http://s14.photobucket.com/albums/a302/racingprix97/?action=view&current=Video0008.flv

good thought Tim, but the Harmonic balancer was not changed when i did the top swap originally. Its been the same one the whole time.

Hmmmm, How did you rout a L36 serpentine belt to the supercharger pulley? Just wondering.

finally got the video to play with some sound. here ya go

http://s14.photobucket.com/albums/a302/racingprix97/?action=view&current=Video0008.flv

Yikes.

Sounds deeper than a lifter, but not as deep as a rod knock.

If it were my car, I'd remove them valve covers, start it, and touch each one of the rocker arms with it running. You should be able to pinpoint if it is in the valvetrain for sure.

yeah...it doesnt sound good. Just doesnt make sense to me

I don't know, I'm almost thinking collapsed lifter. Yank that back valve cover off and do like I said above, you should be able to pinpoint it.

Pushrods all went back in the same spots (for wear purposes)?

They aren't aftermarket pushrods are they?

I was not aware you could run the motor with the valve covers off lol.

as a side note...I've been driving the car very regularly now to see if it acts up again. I've been keeping a real close eye on the temp gauge, and it seems to fluctuate a little more than I'd like to see. Even while running at a steady 70MPH on the freeway sometimes the temp gauge will climb up to just under 210, then go back down to around 180.

I'm hoping its not the LIM. I'm not tearing this motor apart again :headshake

coolant reservoir is still full...so i dont believe i am loosing any coolant

you are fine running it for a short time with the valve covers off. I have done it quite often on numerous motors to find ticking/knocking sounds. Just don't want to do it long enough to heat the exhaust manifolds up hot enough to start a fire with the oil that drips onto them.

well...coolant light went on tonight while going down the freeway on my way home from work. Hope this coolant isn't leaking into the cylinders. Didn't see any leaks on the ground. looked around the Fuel injectors and i dont see any coolant. Definitely had to add about a gallon of coolant. If this motor is junk...idk what I'm going to do with this car :banghead: Oil still doesn't have any coolant in it, I'm puzzled

what about the upper intake manifold? Did you check for warps before you put it back on?

what about the upper intake manifold? Did you check for warps before you put it back on?

that is what i am suspecting. Probably an internal leak. exhaust doesnt seem white though, and the car does not miss.