Weird engine noise afte 5 speed swap

[Serban]

Hello fellow 240 people, I'm hoping you guys can help me figure this out because at this point, I'm stumped!

Last week I did a 5 speed swap in my '92. Aside from the transmission needing to come out again because it has a crunchy second gear, I'm getting a weird noise from the engine, at first I naturally thought it was the transmission since that noise wasn't present before dropping the boat anchor (auto trans).

Everything was done correctly, new pilot bushing, correct flywheel bolts, etc. Noise doesn't change when you press the clutch in, so I doubt its the release bearing. We can rule out stupidity on my part (I hope). :wan:

I'm not able to pin point it, but it sounds like its the very front of the engine. I've removed all belts to make sure its not one of the accessories, or the clutch fan, and the noise is still still there. However, it doesn't change with rpm, but at higher rpms it seems to go away. But at idle, and just free revving, its there. As you drive, under load, its not noticible.

Its difficult to describe the noise, but almost sounds like a tapping noise, nothing like a rod knock though. Nothing was touched on the engine during the swap, aside from having a socket on the crank pulley to hold it while I take off the flexplate, and put on the flywheel.

I'll most likely start pulling this transmission tonight to replace it, I'm hoping the noise was somehow related to it, but I just can't see how it would transfer the sound to the front of the engine?!

Any help would be appreciated.

PS: I apologize if this has been covered before, but every time I try to search on here, it just displays a blank white page.

[di-devol]

Make sure the flywheel is torqued correctly. You did use the manual transmission flywheel bolts? THe auto bolts are shorter.

[Serban]

Yup. Correct bolts torqued properly.

[zerodameaon]

If its from the front you might be the unlucky recipient of the extremely common timing chain rattle. It can appear overnight with nothing being done to the engine, so the fact that it appeared after the swap is just be a coincidence. Look up on youtube what timing chain rattle sounds like.

[Serban]

Both upper and side chain guides were removed a few months ago. Thanks for the suggestion though.

[zerodameaon]

Both upper and side chain guides were removed a few months ago. Thanks for the suggestion though.

Doesn't matter your tensioner can be stuck if its still the OEM or just old.

[Serban]

http://www.youtube.com/watch?v=wVYBKr5PFHY

Here's a video of the noise if it helps anyone identify it.

[zerodameaon]

Ok yeah that does not sound like timing chain rattle. Videos always distort sound so to me that sounds like an exhaust leak with how fast it is but that would not go away with more RPM.

[Serban]

Doesn't matter your tensioner can be stuck if its still the OEM or just old.

I've already taken the valve cover off to look for anything that may have broken in there, chain was still tight, tensioner still had tension.

[Serban]

In the video, it does kinda sound like an exhaust leak, not the same in person. And its closer to the front of the engine, which made me think it was one of the accessories.

[zerodameaon]

In the video, it does kinda sound like an exhaust leak, not the same in person. And its closer to the front of the engine, which made me think it was one of the accessories.

Grab a long extension/screw driver and put it up to each one then listen to the end of it that might help to narrow it down. Just don't get caught in any moving parts, that makes a much worse noise ;).

Edit: Maybe one of them is loose on the brackets.

[CantSTOP]

Wow, it does sound like an exhaust leak. When I installed an aftermarket header it made that noise cause my egr hole on the header was open.

[Serban]

Grab a long extension/screw driver and put it up to each one then listen to the end of it that might help to narrow it down. Just don't get caught in any moving parts, that makes a much worse noise ;).

Edit: Maybe one of them is loose on the brackets.

I pulled all the belts off and started the car, noise was still there, with none of the accessories spinning.

Wow, it does sound like an exhaust leak. When I installed an aftermarket header it made that noise cause my egr hole on the header was open.

I've checked for exhaust leaks, didn't find any. I'll check again before I pull that transmission out again.

[CantSTOP]

Dang this sucks, but like zerodameaon said if its an exhaust leak the noise would not go away.

Maybe something is loose, wish I could help :\

[Serban]

I'm really hoping its some weird noise some how caused by that transmission. I just don't see how it would do it if its not even in gear. Maybe I'll try to start it without the transmission to see if the noise is still there.

I hate noise gremlins.

[zerodameaon]

I'm really hoping its some weird noise some how caused by that transmission. I just don't see how it would do it if its not even in gear. Maybe I'll try to start it without the transmission to see if the noise is still there.

I hate noise gremlins.

Just what I was going to suggest.

[Serban]

Took the trans off and started the car. Still makes the noise. Guess I'll drain the oil next to see what story it tells. :-/

[zerodameaon]

Oilpump maybe?

[godsmack]

How is the crank pully? Did you happen to accidentally loosen the bolt? I know it's not likely but you never know.

[Serban]

I was thinking oil pump as well but never heard a bad one to compare the noise. I've got a friend coming by tomorrow to help diagnose it. I guess 2 heads are better than one when hunting strange noises.

[zerodameaon]

dw7zkriDSBM

Could always try that, might not answer your question but an entertaining video as its hard to find one with specifically saying its a bad oil pump noise.

[Serban]

Looks like when I put the pilot bushing in, I didn't tap it far enough and the input shaft made it mushroom out. Could that have caused some issues with the crank on the front of the engine?

[Serban]

Still haven't figured it out yet. Tried to see if the crank has any play, maybe when I forced the input shaft into the pilot bushing it caused something weird to happen, but no play. Took the valve cover off and started turning the flyhweel by hand, at some point I would hear a noise, but it was just when the chain would get a bit of slack at the top between the cam gears, once you turn it, it tightens up.

Just cranking the engine with the valve cover off revealed no noise. The noise is only there when the car is running. I still don't know if its the oil pump, but I'll put an oil pressure gauge to see where the oil pressure is. The dummy light turns off as soon as the car fires though.

I am beyond stumped right now. I'll be picking up another transmission tomorrow and I'm just going to put it on and drive. Either the noise goes away, or I'll just get another engine when this one pops!

[Serban]

Got a new transmission, this one works better now. No more grinding gears. The engine noise is still there, I'm no closer to figuring it out.

Haven't gotten around to the oil psi gauge, maybe later today.

Here's another video:

http://www.youtube.com/watch?v=R7KEbzqn51U

[Serban]

Oil pressure on cold start was between 55-60psi, once engine was warmed up, it dropped to 20psi, never went below that. Looks like the oil pump is still in good shape. Might just have to start pulling the front of the engine apart to see if I overlooked the chain tensioners.

[zerodameaon]

Maybe check the little timing dowel and see if its hitting the crank pulley.

[Serban]

Ok I may have figured it out. Driver side timing chain guide broke and flipped over. So chain is not riding on it smoothly. Already started pulling the front end apart. I've got to get the front cover off to change it, and the oil pan to find all the broken pieces. I'm sure it'll be a fun few days.

[Serban]

Update (if anyone cares):

It was the timing chain guide (the long straight one). All the broken pieces were in the oil pan just hanging out with the sludge. The chain was basically riding on the lower bolt, and part of the chain guide that was left on the upper bolt.

I've been driving the car this last week, and all is well again.