Heat shield needed??? (Page 1/1)
branger AUG 02, 01:57 AM
Hey gang, in my 1986 2M6 notch back (stock), I have a heat shield attached to the catalytic converter, it rattles and is also just below the oil filter... do I need it? Does it serve a purpose? If I get rid of it to get rid of the rattle, will not having it cause other issues?
Thanks!
Patrick AUG 02, 02:45 AM

The heat shield is there for a reason. Cats get very hot. I'm sure you can figure out a way to re-secure the shield so it doesn't rattle.
fierofool AUG 02, 09:04 AM
My first Fiero had a mesh shield on the bottom side and a solid shield above. There was a space between each shield and the converter body. I'm guessing in part to allow air flow, and maybe to prevent leaves from falling directly onto the converter body which would be hotter than the shield. Both shields eventually broke off and luckily I never had a problem. I later removed the converter completely and replaced it with an off road pipe. The 86 I have still has the converter with a shield, though it is an aftermarket converter. The 87 doesn't have a converter.
branger AUG 02, 09:34 AM
Thanks Fierofool and Patrick, I will see if I can secure it, with better screws and maybe some lock tight or something.
theogre AUG 02, 02:48 PM
Yes Cat gets hot.
Beside Exhaust heating it to start, get hotter still because cat generates heat to do its job.
Worse when engine problem(s) running too rich or lean, burning oil or coolant, etc, causing cat burn w/ case outer surface of it reaching 1500+°F

Many OE cats have Heat shield that rotted away. Replacement cats often don't and many need to make one or more to go on the cat or other places like the starter.
Most cats have insulation between inner and outer case you can't see w/o cutting the case. Even then cats get hot to very hot.

If cat shield is loose... best case is tack weld at the seems if they have big seems. Otherwise very easy to blow holes in the outer case.
drilling for screws is bad in most areas.
If you wire or clamp a shield on any exhaust parts... use SS. Many "hose clamp" types are SS only for the band, maybe the shell for the screw but not the screw itself. That screw quickly rots from water on hot exhaust parts.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

darbysan AUG 03, 11:00 AM
Metal tie wraps might be an option for securing it. They are available at Harbor Freight. You can connect them together to make a longer length if needed. Or you could use the old Bailing Wire technique

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'87 GT , '00 3800 Series II SC, 4t65e, Vue Power Steering. (SOLD)