Possible Cracked Flex Plate on '97

My 1997 Cirrus just rolled 130k miles. I've never had to have any other repairs done, other than installing a new timing belt for prevention reasons.

For the past two months it has been making a very loud knocking noise, but it is intermittent and most obvious while idling. I am not sure if it makes the noise while I am driving, because basic road noise may be blocking it out.

Mechanic Number 1 (who I really don't know or trust, but is close to my work) said, "It's the lifter, take it to the dealer. Good luck."

Mechanic Number 2 (who I've been working with for 3 years and has always been good to us) at first said he simply couldn't diagnosis it, but did assure me it was not a lifter and my oil pressure is A-OK. The noise stopped for him while he had it in the shop, she he only got a small taste. He said it sounded like it was coming from inside the engine, but it could be one of a hundred tiny little parts knocking together.

I brought the car back to him this week for an unrelated problem (Oil Pressure light flashing and oil pressure was still A-OK) and he thinks he was able to better diagnosis it. He said that they could hear it best by the oil pan and that it may be a cracked flex plate. He is conscious of my strained budget though and explained that it would cost me about $150 just for them to be 100% sure that this is the problem and that it would then been quite costly to repair.

I trust him (and his upfrontness about the costs), but 1) Is there an easier way to figure out if it is the flex plate (other than taking mounts off) and 2) What kind of damage could this do? He said that I could probably delay for a bit, but that if the noise changed at all to bring it in ASAP. And I guess, 3) How much is a LOT?

Had cracked flex plate on 96. At first I thought it was internal engine problem because it could be heard near the oil pan. A shadetree mechanic friend diagnosed it as the flex plate when I told him the noise stopped when I put the tx in reverse. The mechanic can unbolt the tx and see the plate to look for cracks. Cost me about $1000 in labor/part for the repair. If the flex plate comes apart, ie, the outside separates from the center where it is bolted, you will have major damage and be stranded. Tough call on an expensive repair because it is very hard to lower that tx.

Thanks! A cousin of mine has a nephew-in-law that is in high school and heavily involved in auto-mechanics. You've given me more motivation to get my car in to his school and be fixed for the price of parts.

I'm thinking it is the flex plate, although I haven't tried putting it in reverse to see for sure yet. My mechanic was also puzzled at first because the noise was so close to the oil pan.