Lingerin' question

[DETSHO]

I just acquired a 93 SHO from a private dealer who did care for the car pretty well. Although he did take alot of road trips (150K on the dash). My problem is when i am sitting inside the car with the radio all the down every so often maybe in 5 to 7 min intervals I can hear a small knock in the rear of the car. Like someone is taking a small hammer and hitting the gas tank or somewhere around there. Is this very bad. I heard about the crankcase Cancer thing from SHOTIMES, it runs good and I just had a 60K service done. THEY did not touch my valve shims or cams though.

 

[sdpatt]

Something loose in the trunk? It could be a suspension component such as the upper strut mount, sway bar link or a worn strut. An inspection would be needed to determine for sure.

 

[DETSHO]

Okay I don't have anything loose in the trunk and I wouldn't think that would be a factor in the sound. I am talking about when i am sitting in the car in park or at a complete stop at a stop light.

DETSHO:
I just acquired a 93 SHO from a private dealer who did care for the car pretty well. Although he did take alot of road trips (150K on the dash). My problem is when i am sitting inside the car with the radio all the down every so often maybe in 5 to 7 min intervals I can hear a small knock in the rear of the car. Like someone is taking a small hammer and hitting the gas tank or somewhere around there. Is this very bad. I heard about the crankcase Cancer thing from SHOTIMES, it runs good and I just had a 60K service done. THEY did not touch my valve shims or cams though.

 

[jthomas68]

http://www.shoforum.com/cgi-bin/ultimatebb.cgi?ubb=get_topic;f=18;t=001016#000000

 

[Mike Kopstain]

Be nice JT. Look at his post count.

Anything is a posibility, but it is most likely a suspension component. When I used to stop at a stop light I could hear my old struts clunking and slowly rebounding (150K miles ) Now I gots some madz Tokicos. Another thing to look at is the rear sway bar endlinks and mounts. That could definetly be smacking up against some things.

 

[Detenator]

This may sound out of the blue but...
this one time i was driving the SHO and i heard something simmilar to what you heard. Ever hit a rock that flies up and hits the floor of your car? Ever leave your oil fill cap sitting on top the engine and then go flying onto the ground when you go around a curve? it hits the ground, bounces then hits the floor with a nice clunk! well anyway, so im driving the car and clunk! clunk! *CLUNK*! this same sound occures a few times. Problem is that the engine sputters with each clunk. I concluded that its the engine backfiring. The tailpipes and the mufflers (which are in the back of the car) carried the sound all the way back there, making it sound like a susspension problem. I don't know if i am correct or not, but it is a thing to concider while diagnosing the problem.

 

[remy_zero]

I had the same problem in my 89. It was the upper rear strut mount. I replaced the two rear struts and the mounts and installed the heavy duty police car style mounts. My old rubber mount was in fact cracked.
If you replace the mount, you might as well replace the struts and the sway bar end links as well. It's a tough job, but you can do it yourself if you have any mechanical inclinations.
Good luck.
Rem