Clicking/tapping engine noise: Flywheel?

[Brian]

Originally Posted by svx_commuter

Get DOWN on the ground behind the front wheel and listen. If the tap tap tap is LOUDER then it is the flexplate.

It is louder from underneath than from above, but once underneath, it's not necessarily any louder from behind the wheel as opposed to the front. It does decrease with increasing RPMs.

Here's my next question: I'm waiting for the trans. shop to have an opening for me to take it in, but I did talk with the mechanic there today. He said that if the dowel pins aren't correctly aligned, the problem would have been there from the onset, rather than appearing 2 months later. *Is that correct?!?*

And he said that wouldn't explain the "original" flexpalte's failure. That seems plausible. Afterall, it had been many times longer since it was touched, back when I had my short block replaced in 2004. He said he's never seen a Subaru flexplate crack like that, and suggested that maybe there's some play in the engine's position that could cause it.

[SVXRide]

Originally Posted by Brian

It is louder from underneath than from above, but once underneath, it's not necessarily any louder from behind the wheel as opposed to the front. It does decrease with increasing RPMs.

Here's my next question: I'm waiting for the trans. shop to have an opening for me to take it in, but I did talk with the mechanic there today. He said that if the dowel pins aren't correctly aligned, the problem would have been there from the onset, rather than appearing 2 months later. *Is that correct?!?*

And he said that wouldn't explain the "original" flexpalte's failure. That seems plausible. Afterall, it had been many times longer since it was touched, back when I had my short block replaced in 2004. He said he's never seen a Subaru flexplate crack like that, and suggested that maybe there's some play in the engine's position that could cause it.

Brian,
play in the engine's position is only going to translate into a flexplate issue if the trans and engine aren't lined up correctly - it's the offset that loads the flexplate against the end of the crank and results in the circular crack almost exactly the size of the mating surface on the crank. If you actually have both dowell pins installed - and they are the correct size - and the holes in the trans case aren't out of round - then the flexplate shouldn't crack unless there is excessive crankshaft "walk" that is resulting in a uniform longitudinal loading (think of a potato masher pushing against an inflated balloon).
Maybe this is what your mechanic meant by "play in the engine's position"?
-Bill

[SVX-FF]

Originally Posted by SVXRide

Steve,
You know, opening a bag of charcoal (the kind without the lighter fluid in it) does wonders to absorb paint fumes

Doesn't sound like you've got a flexplate problem. The typical flexplate "hammering" actually goes away with higher rpms (i.e., it's worse at idle). The fact that the noise is louder when the engine is warmed up points toward something expanding due to the heat...can you provide any more details?
-Bill

Thanks for the charcoal idea Bill, I will try that the next time we paint.

As for the car it is hard to always hear the noise. If I am driving at freeway speeds and the RPM's go over 3k and I am next to a concrete wall with the windows down I can hear it a little. When I accelerate and break 3k I can hear it loud but when I back off the gas at over 3k the noise goes away quick. I sounds very much like a valve tap from loose rocker arms.

I need to replace the valve cover gasket on the driver side so I will look at things a little closer then. I am just lucky my NEW job is only 10 minutes away. I never see a main road.

Steve

[Brian]

Originally Posted by SVXRide

play in the engine's position is only going to translate into a flexplate issue if the trans and engine aren't lined up correctly - it's the offset that loads the flexplate against the end of the crank and results in the circular crack almost exactly the size of the mating surface on the crank. If you actually have both dowell pins installed - and they are the correct size - and the holes in the trans case aren't out of round - then the flexplate shouldn't crack unless there is excessive crankshaft "walk" that is resulting in a uniform longitudinal loading (think of a potato masher pushing against an inflated balloon).
Maybe this is what your mechanic meant by "play in the engine's position"?

Thanks, Bill. "play in the engine's position" is actually my paraphrasing of what he said (in an attempt to explain it more accurately). He probably said something like the "engine shifting" or "moving". Although your description is helpful, my big question is this:

If the dowel pins are the cause of the problem, would the problem have been there since the flywheel was first installed? Or is it possible that it could have taken 2 months for the problem to develop?

I'm still waiting for the transmision shop to have an opening so they can take a look.

[SVXRide]

Originally Posted by Brian

Thanks, Bill. "play in the engine's position" is actually my paraphrasing of what he said (in an attempt to explain it more accurately). He probably said something like the "engine shifting" or "moving". Although your description is helpful, my big question is this:

If the dowel pins are the cause of the problem, would the problem have been there since the flywheel was first installed? Or is it possible that it could have taken 2 months for the problem to develop?

I'm still waiting for the transmision shop to have an opening so they can take a look.

Brian,
It could easily take 2 months for the problem to develop. How many miles did you actually put on the car in the 2 months? It took me ~1,000 miles to crack my second flexplate (lacking both pins when reinstalled....)
-Bill (still kicking himself for not listening to Tom K when he said "I can run back to the shop and get two pins....)

[Brian]

Originally Posted by SVXRide

Brian,
How many miles did you actually put on the car in the 2 months?

About 2,300 miles.

[Brian]

The transmission shop finally started the work yesterday! The mechanic said that the flywheel was definitely cracked. (He must have been pretty sure if it before, since he'd ordered the new one & had it delivered before I even brought the car back to him.) But it turns out that it is no longer a simple matter of replacing the flywheel, because it already "tore up" the rebuilt transmission. One of the parts he said that got ruined was the pump. There were others too, but that's the one that stuck in my mind. (I think another was the solinoid, if I remember correctly.) So, it's the weekend now, and then it will take a "few days" until they finish.

When I asked if the dowels were O.K., he said they were. He said he's never seen a flywheel go like this before. He got the new one from the same parts yard he got the last one, and the guy there had never heard of a repeat flywheel problem. In fact, he's only ever sold 1 SVX flywheel before this. (I saw the new one, and it looks to be in very good shape.) The mechanic asked if there was a shim that is supposed to go between the flywheel and the engine (that may have been left out when previous work was done). I didn't know if there was. Again, the only other explanation he could offer was if the engine was moving.

[Brian]

O.K. First of all, the transmission shop said that these repairs are covered under the warranty: I won't have to pay!

They finally got it up on the rack. Unfortunately, it looks like there really is an internal engine problem causing the failures, so the new flywheel and re-rebuilt transmission will just get ruined again.

I misunderstood the mechanic's explanation before. He wasn't saying that right-left lateral shifting of the entire engine was causing the problem, but that a front-back motion of the flywheel is what's causing it to crack and the transmission to become damaged. He said that's what happened last time (before he rebult it) and this time. He showed me the marks where the flexplate was biting into the engine block. It's not bad, just 2 partial arcs of shallow scratching, but it does support his claim of the forward stroke of the back-and-forth motion.

It will still be "a few days" until he has time to work on rebuilding it again. He said that the next time, it won't be covered by the warranty. He guessed that maybe bad bearings or a bad crank shaft could be causing this motion. He suggested I could have it taken somewhere to have engine work done while he rebuilds the tranmission. I'd be better off looking for a whole replacement SVX rather than sinking anything even approaching $1,000 into it, considering that mine also needs to be repainted and minor bodywork.

[Brian]

At the end of last week, 7 weeks after I took the car in to the transmission shop, they finally finished! The mechanic kept at his tired claim that it was caused by play in the crankshaft. Today I took it to a shop called Harry's Automotive in Butler, PA, which was recommended by another member, and had the play measured. It's well within spec. To be precise, it's 0.020", and according to the mechanic, spec is between 0.014" to 0.045".

[SVXRide]

Originally Posted by Brian

O.K. First of all, the transmission shop said that these repairs are covered under the warranty: I won't have to pay!

They finally got it up on the rack. Unfortunately, it looks like there really is an internal engine problem causing the failures, so the new flywheel and re-rebuilt transmission will just get ruined again.

I misunderstood the mechanic's explanation before. He wasn't saying that right-left lateral shifting of the entire engine was causing the problem, but that a front-back motion of the flywheel is what's causing it to crack and the transmission to become damaged. He said that's what happened last time (before he rebult it) and this time. He showed me the marks where the flexplate was biting into the engine block. It's not bad, just 2 partial arcs of shallow scratching, but it does support his claim of the forward stroke of the back-and-forth motion.

It will still be "a few days" until he has time to work on rebuilding it again. He said that the next time, it won't be covered by the warranty. He guessed that maybe bad bearings or a bad crank shaft could be causing this motion. He suggested I could have it taken somewhere to have engine work done while he rebuilds the tranmission. I'd be better off looking for a whole replacement SVX rather than sinking anything even approaching $1,000 into it, considering that mine also needs to be repainted and minor bodywork.

FYI -- once the flexplate cracks you WILL get the scratch/gouges on the back of the engine block from the flexplate hitting it.

Hope the rebuild works for you!
-Bill