Strange compression

[szewczyd]

I recently took my car to AMS to get it fully tuned. While they had it on the dyno he said he couldn't get rid of the knock, even at 14 psi he would pick up to much knock. So the car would not make any power. He thought maybe I had a bad knock sensor, so the next day they pulled it off the dyno and tested the knock sensor. Tested out just fine. They then tested my compression and it showed no/zero compression in cyclinder number 3. They then removed the valve cover and inspected the valve train and it look fine. Put it back together and redid the test and now the compression is good all the way across now. They were stumped but really demanded that I needed a new short block and they could hook me up for one for 3k plus whatever the labor is to put it in!!! They said that there was a vibration in my bottom and I needed a new one. I guess I am a little lost and not sure what to do. Car runs and drives great other than it has a slight studder or hestition when driving. Almost feels like it is misfiring and then catches and then misfires. Please help!

P.S The studder seems to happen pretty much all the time, whether crusing or accelerating.

 

[EclipseTrbo420A]

All I know is, you can do your own "shortblockin" for much less. Thats is also very weird, Do the compression test on more time yourself. As for vibration....Thats vauge. MY motor vibrates liken o other...B-shafts gone and poly-motor mounts. See if your harmonic dampener is on its last leg. causing the bad vibration, mine did them came apart at 70 mph. Maybe your ECU is getting toasted. I would look in to the problems first.

Did you change out plugs and wires? Test other ignition components?

To add Im sure AMS know what their talking about...was that 3K for a built everything?

EDIT comming back again..... I see fully built race motors head/block and stuff going for less than they want for just the block. I dont know its your call. Goodlcuk though. Heres a 2.3 for just 600 more http://www.dsmtuners.com/classifieds/showproduct.php?product=50412&cat=7

6 bolt again....$550 http://www.dsmtuners.com/classifieds/showproduct.php?product=49523&cat=7&page=3

 

[szewczyd]

I just don't see how a perfectly running motor could be junk? I burn maybe 1/2 quart between oil changes and it doesn't smoke or anything? I will be doing a compression test this week myself and checking my dampner, and my base timing.

 

[EclipseTrbo420A]

I just don't see how a perfectly running motor could be junk? I burn maybe 1/2 quart between oil changes and it doesn't smoke or anything? I will be doing a compression test this week myself and checking my dampner, and my base timing.

Smart, I didnt know if you were one of those people who would jump if a vendor saif you need a this or a that. I just wanted you to see you could save some money.

I would 1.) do my own compression test, then 2.) diagnose my missfire problem. Goodluck.

 

[szewczyd]

I am going to work on it this week, I hate to say it but I think they were possibly trying to feed me a line? Wouldn't you think to check the timing, and dampner before saying yep you need a new motor?

 

[EclipseTrbo420A]

I am going to work on it this week, I hate to say it but I think they were possibly trying to feed me a line? Wouldn't you think to check the timing, and dampner before saying yep you need a new motor?

I was thinking the same thing myself, but I wasnt there and have no personal experience with them, so I cant say a word. i was just pointing out 3K is ALOT. Do you have a friend you could swap parts with?

 

[szewczyd]

I have a few buddies with dsm's but not sure what we can all swap. I have new wires that I am going to put in. I am going to check the timing. That is all I can think of as far as the studdering goes. compression is a different story.

P.S Not bashing vendors or doing vendor reviews but I have not had good experience with them as of yet!

 

[EclipseTrbo420A]

I have a few buddies with dsm's but not sure what we can all swap. I have new wires that I am going to put in. I am going to check the timing. That is all I can think of as far as the studdering goes. compression is a different story.

P.S Not bashing vendors or doing vendor reviews but I have not had good experience with them as of yet!

Just checked out your mod list. I think you know what your doing. Im saying goodluck and start where you stated. Hope you get it figured out.

 

[Blocking_Da_Sun]

The studder could be bottom engine light knock or ping! Just to be safe man drain some oil from your oil pan. Inspect the oil to see if its dark or have any tiny bits of metal shavings. If you do take the downpipe off and then the oil pan. Check for play in the rod caps/bearing there might be very little or none. Your rod bearing could be going out. Replace them before they do furture damage to the crankshaft. If that is the case you need a better cooling system or thicker oil.
But who knows it could be a misfire. BUT CHECK to make sure I could save your crankshaft.