# 2001 Mercury grand marquis glowing red and sparking underneath vehicle

**URL:** <https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329>\
**Category:** Maintenance/Repairs\
**Tags:** mercury, grandmarquis\
**Created:** [September 5, 2016, 4:58am UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329 "2016-09-05T04:58:54Z")\
**Posts on this page:** 7\
**Page:** 1

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**Author:** ![trbrown716](https://avatars.discourse-cdn.com/v4/letter/t/b2d939/32.png) [@trbrown716](https://community.cartalk.com/u/trbrown716)\
**Post date:** [September 5, 2016, 4:58am UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/1 "2016-09-05T04:58:55Z")

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Changed intake manifold on it, because it had cracked and warped. After changing, now the exhaust line that leads under the car is glowing red and sparks were seen coming from under the car too. Cannot figure out why. It was suggested that something may have fallen in when we changed the intake manifold but I don’t remember seeing anything falling in. Any other suggestions or should I just take it to a shop

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**Author:** ![Mustangman](https://sea1.discourse-cdn.com/cartalk/user_avatar/community.cartalk.com/mustangman/32/44130_2.png) [@Mustangman](https://community.cartalk.com/u/Mustangman)\
**Post date:** [September 5, 2016, 4:06pm UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/2 "2016-09-05T16:06:32Z")

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Car and fire is BAD, Have it TOWED to shop.

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**Author:** ![trbrown716](https://avatars.discourse-cdn.com/v4/letter/t/b2d939/32.png) [@trbrown716](https://community.cartalk.com/u/trbrown716)\
**Post date:** [September 6, 2016, 8:37pm UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/3 "2016-09-06T20:37:03Z")

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Not really fire it does glow red hot underneath the chasis

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**Author:** ![kurtwm1](https://avatars.discourse-cdn.com/v4/letter/k/13edae/32.png) [@kurtwm1](https://community.cartalk.com/u/kurtwm1)\
**Post date:** [September 6, 2016, 8:58pm UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/4 "2016-09-06T20:58:45Z")

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what’s glowing, the catalytic converter, exhaust pipes? I second the suggestion to have it towed to a shop, unless there is one within less than 5 miles. In that case I would take the chance and drive it (with a fire extinguisher at the ready).

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**Author:** ![trbrown716](https://avatars.discourse-cdn.com/v4/letter/t/b2d939/32.png) [@trbrown716](https://community.cartalk.com/u/trbrown716)\
**Post date:** [September 6, 2016, 10:43pm UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/5 "2016-09-06T22:43:19Z")

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Yeah there’s a shop less than 30 seconds from my house. And it’s the catalytic converter that’s glowing

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**Author:** ![kurtwm1](https://avatars.discourse-cdn.com/v4/letter/k/13edae/32.png) [@kurtwm1](https://community.cartalk.com/u/kurtwm1)\
**Post date:** [September 6, 2016, 11:48pm UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/6 "2016-09-06T23:48:25Z")

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sounds like the manifold gasket may have been incorrectly installed.

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**Author:** ![the\_same\_mountainbike](https://avatars.discourse-cdn.com/v4/letter/t/c89c15/32.png) [@the\_same\_mountainbike](https://community.cartalk.com/u/the_same_mountainbike)\
**Post date:** [September 7, 2016, 1:15am UTC](https://community.cartalk.com/t/2001-mercury-grand-marquis-glowing-red-and-sparking-underneath-vehicle/95329/7 "2016-09-07T01:15:54Z")

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A glowing cat converter is usually because it’s plugged internally.

Or because way too many unburned hydrocarbons are getting to the converter and undergoing the “secondary burn”, where unburned hydrocarbons have the opportunity to split apart and bond with the newly freed (by the catalyst) oxygen atoms. That process is the very definition of combustion. In short, you may have too much unburned gasoline getting into the exhaust stream and burning in the converter.

Have it towed to your trusted shop. It’s extremely dangerous the way it is. It needs a complete checkup.
