Harsh Engine Vibration

[jackson.sho]

My engine developed a terrible sounding vibration a few days ago. I took off the accessory belt and ran the engine (thinking it was power steering) and the vibration is definetly coming from the engine. However the vibration cuts out, just quits, after about 1800 rpm. At idle it makes me think it is a connecting rod, or bearing, but the fact that it quits above 1800 or so rpm makes me think it could be something else. Does anybody know what it could be and how to fix it? Is my engine on it's way out?
Please help,

Jackson
1993

 

[luigisho]

Is it vibration or is the engine surging? Does the tach follow the vibration? A little more description would help. The good news is there are some good SHO mechanics within driving distance.

<small>[ July 22, 2002, 09:19 PM: Message edited by: luigisho ]</small>

 

[pete c]

possibly a loose exhaust system. The fact that it goes away at higher RPMs would lead me in that dirrection. Well, it's a lot cheaper than a new motor too.

 

[jackson.sho]

It is definetly a vibration, not a surgeing. If you put your hand on the intake you can feel the whole engine vibrating. The vibration does follow rpms, until it smooths out above 1800. What are some good mechanics close to Austin, luigisho?

 

[luigisho]

Well, close to Austin isn't exactly what my geographically challenged comment was suggesting. Within driving distance unfortunately requires a bit of driving. That being said, Sergio Perfetti at Jerry's Automotive in Houston (281-999-1461) is a well known and respected SHO mechanic in that region. Also our own Scott Patterson (sdpatt on this board and you can reach him here) is in Richardson and is highly skilled, meticulous, and really sharp. Ask anyone here. His is among the most respected of opinions when you need help here. So, if you really want a SHO community certified person to work on your car that's all I got.

 

[jackson.sho]

It sounds like a rod or main bearing is going out, to me at least. I have heard some talk about premature rod journal bearing wear in SHO's. If it is a rod knock, the journal bearings could be the culprit. I think I am going to get a second opinion, and then do the journal bearing replacement. Any more ideas on what it could be anyone?

Thanks,
Jackson

 

[ACOK]

You mentioned P/S, disapperance after 1800RPM, and you are not sure if it is something else you mention.

I had my drive-belt tesioner pulley and timing belt idle pulley problem starting the noise before 2000RPM and totally disappear after 2000RPM, and I doubted it as fuel system, intake, my just-finished valve adjustment, and ...