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Exhaust manifold heatshield 900 1994

I understand cold air intakes help performance. I'm wondering if there's any value to the heatshield on the exhaust manifold used to preheat the air intake. Im in Miami Florida where never gets below 70 while the car is still near pristine but with 145,000 miles unlikely it will be going very far north ever again. The shield comes off for easier access to replace motor mounts I was thinking about not putting any of it back on.








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    Exhaust manifold heatshield 900 1994

    Tear it off and leave it off. It serves no purpose at all. Volvo engineers were stupid enough to put the heated air source on inter cooled 740's. Heat the air and then send it though the intercooler. Dumb. They deleted it on the later cars hoping no one would notice.
    No modern car uses heated air at this point. It isn't done. On carbureted engines it allowed the choke to come off faster, but on fuel injection its a waste of time.
    Lots of folks have reported that the blend valve sticks on the hot air position and wipes out the mass meter. Thats reason enough to pitch the heat shield.
    In the warm states it makes no difference. With a mass meter it probably make no difference in Alaska.








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      Exhaust manifold heatshield 900 1994

      I regularily drive my 240's in-35c weather reliably without the heat shield
      witch I remove whenever I get a car to preserve amm . The remark of it helping ac components is probably valid but would better be served with a shield not attatched to manifold.
      --
      Rene








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      Exhaust manifold heatshield 900 1994

      I have removed this and plugged the opening in all my 240's with no ill affects. If you have an AMM and the air box thermostat fails it sends heated are to the AMM eventually causing it to fail,
      Dan








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    Exhaust manifold heatshield 900 1994

    Dear soundmiami,

    Hope you're well. The purpose of the heatshield is to keep hands away from the exhaust manifold, which gets so hot it can instantly cause burns.

    The corrugated aluminum tube - that connects the heatshield to the airbox - allows warm air to flow into the engine. The faster the engine warms-up, the sooner the engine reaches operating temperature, the more completely fuel is burned, and the less pollutants are produced. Thus, the warm air supply is an anti-pollution feature.

    Because auto-makers seek to save every penny possible, they'd not have installed the heatshield - and the cross-engine bay aluminum tube - without a good reason. If so, then I'd not second-guess the engineers.

    Hope this helps.

    Yours faithfully,

    Spook








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    Exhaust manifold heatshield 900 1994

    The air intake is through the inner fender if a turbo, or out front of the radiator if NA, so the exh mani heat shield would have no effect. Unless you're talking about the hot air tube to the airbox on NA cars, (late turbo's don't have this) in which case you could simply block it in the airbox, permanently shut the 'door' in there.








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      Exhaust manifold heatshield 900 1994

      Yes 94 NA with the tube system across the engine to the air box. The question is does the heat shield do anything other than radiate heat back toward the engine and provide the heat source for the tube. Without the heat shield seems like the engine would run cooler, service access would be easier and the potential source of some noisy harmonics would be gone.








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        Exhaust manifold heatshield 900 1994

        I suspect that the heat shield helps reduce the amount of heat radiated by the manifold onto the nearby A/C components (and possibly ABS pump/brake lines). I noticed diminished A/c performance last summer in my 93 NA 945 when I was running around without the shield for a couple of days.

        john
        --
        1989 245 245K / 1993 945 131K








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        Exhaust manifold heatshield 900 1994

        Out here if you take that off, you fail smog. But, I hear what you're saying, and don't think taking it off would have any ill effect. Maybe someone else has a thought...







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