Michael,

 

The bolt should be torqued to a value specified for the bolt size.  Thus, the preload will be correct for the specified bolt.  While your mechanic may be right about the blanket compressing, there are other considerations.  Heated Fiber glass and carbon fiber can flow a bit over time - this can cause some loosening and these bolts should be checked at each annual condition inspection.  Another problem could be if more three threads show outside the nut - it is possible to torque the nut onto the bolt shoulder at the end of the threads so that it cannot tighten the parts it is fastening any more.

 

Scott Krueger

 

The engine mount bolts on my IV-P (through the firewall) spin fairly freely when I turn them with a socket and my fingers. 

Does anyone have the proper torque values for these bolts?

 

Any ideas why they might have loosened up? I have a mechanic saying that the fireproof blanket compresses over time and that this is why they loosen.

 

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Michael Newman	Dragonnorth Group
401 Sandy Valley Road Westwood, MA 02090	Cell: 617 821-4608 Home: 617 566-7975 Fax: 617 566-7975
www.dragonnorth.com	mnewman@dragonnorth.com