GM service this month talks about a loose ground bolt on diesels. Has any one seen the bulliten or the number. It talks about it causing it might cause injector clatter, knocking, etc.http://www.dieselplace.com/forum/smileys/Wacko.gif

seen it, tried it as a repair on mulitple trucks...didnt fix any of them...

There's another useful bulletin. http://www.dieselplace.com/forum/smileys/Ermm.gif

Rvfool,

Thanks for the heads up! I checked the the August GM Tech Link (http://service.gm.com/gmtechlink/images/issues/aug04/TLaug04e.html) and there is an article on the loose ground bolt as follows: Ground Bolt on Diesel Engine (http://service.gm.com/gmtechlink/images/issues/aug04/TLaug04e.html#story16)
"Some Chevrolet and GMC vehicles with 6.6L (LB7 LLY) diesel engine may exhibit rough idle, clatter noise, stall and/or DTC P1223 through P1244. The fuel injector balance rates fluctuate during the rough idle. TheIGN 1 voltage may read 12.9 volts all the time, regardless of rough running condition.

After completing the published diagnostics, and the concern describedabove remains, check for a loose ground bolt at the lower right side of the engine block (G102 and/or G106) to correct this concern. Refer to SI for the location of ground bolt."

There are also articles on the Allison and LLY Injector Seals.

http://www.dieselplace.com/forum/smileys/Geek.gif Edited by: jbplock