Pulled the heads off my 97 F150 5.4L to replace the head gaskets and fix some broken exhaust studs and noticed the upper to lower intake shield has almost completely disintegrated. It's a dealer only item and was wondering if anyone else has just put the manifolds back together without this heat shield. Since mine was basically missing, just wondering how important it really is?

Thanks,
Ron

 

You are talking about the heat shield underneath the intake?





I just removed it completely as it would disintegrate as soon as I touched it. It's been 4 years and I've had no problems or ill effects.

 

The insulating shield keeps the intake manifold cooler for a bit more power, other wise not large drivability issue.
Warmer air before cylinder intake, expands (less density) and does not fil the cylinder with as much oxygen.
Power drops a bit from that effect.
Ox Sensors detect this and reduce fuel injection accordingly to keep the A/F ratio.
Bottom line is less air, less fuel and down on power a bit.
This is an old hot rod trick along with intake tract tuning to boost power from a small displacement engine in a truck application.
Good luck.

 

Great information from both who responded and now I can make an informed decision. The dealership parts department told me they never get requests for that part but had no real explanation as to what it does.

Thanks for the help.
Ron

 

I've taken 5 intakes off with 5 different trucks. ALL 5 were completely wasted. On 2 of those trucks I bought brand new and could never tell any difference. I run without them and love the way my trucks run. FWIW

 

mine never had one

 

That was one of the first things to come off of mine.