[Author Prev][Author Next][Thread Prev][Thread Next][Author Index][Thread Index]

Re: CVH leak?-NO. ...then??

>Probably not. common sign of exhaust leak.  Check for broken studs  or
>missing, loose nuts at ex. manifold, or cracked manifold.

    Definitely an exhaust leak, just didn't have access to my car/engine bay
in order to check out my 'theory' :-) so I thought I'd risk humiliation and
ask the list.
    I have already had my E.M. studs replaced and remember a lister writing
that once an I-5 E.M. is removed and replaced using new studs and gasket, it
should not cause any more problems since it had already fully bent due to
heat expansion and would not pull away from cylinders 1(frnt) and 3(rear),
the cause of the broken studs, again. Is that right? ...I don't remember if
that applied only to E.M.s that were ground down or also to ones that just
recieved a new gasket...?
     Believe/HOPE it's leaking aft of the E.M., but.... I do know that at
least one of my inlet/exhaust manifold link plates is missing a bolt thus
making it useless. I don't know how much weight those links support nor how
much strength they add to the assembly, but would guess that if both links
are not connected then at least some extra stress would be placed on the
E.M.s top row of studs. If one of these link plates is not bolted on
properly, should I be concerned? Could that possibly be an indirect cause of
the ticking noise? If both of those link plates were found to be without
bolts, should I then be 'really' concerned?
     Many weeks ago a lister suggested to me that the leak is possibly coming
from a hole?(usually sealed-by a bolt?) forward of the cat that allows a
probe? or sensor? of some sort to be inserted for gas measurements, but I
never checked it out and have since lost all my data due to a Win95 problem
that forced me to format my hard drive. Does the C-GT exhaust have that hole
that I've seen mentioned here on the list? If so, is that a typical leak
site? Thank you.

>Is the ticking worse when engine is cold? Then disappearing after warm-up?
Cracked >mfld. often seals with expansion(temporarily).

     No, ticking remains throughout extended drives. It is quite noticeable
when idling, loudest under full throttle at low rpms, relatively quiet when
coasting, slightly annoying to me when cruising, but barely noticeable when
the I-5's wonderful turbine-like whine is at full scream! ...just another
excuse for me to rev the sucker!  :-)  Thank you all again.

Allan Jones
'86 Commemorative Design Edition Coupe GT