1990 5.0 LX HOT inside of the car..normal?

Well ... it *IS* still summer...

Are the vents open?

Even if your control knob is in the off position, that doesn't mean your vents are necessarily closed.

Has the sound-deadening/insulation material under the carpet been removed ?

Does the car have catalytic converters? If they're clogged, they can get red hot.

Do you have coolant in the radiator or just straight water?

Well for starters, the control knob shouldnt be off, it should be on as in turn on that damn a/c...hahaha...lol....JK, Anyhoo, I coulldnt resist....please excuse me on that one.....lol. In all seriousness tho, I think your big problem is that someone got in there and pulled all your insulation and sound deadening material out of your car. Your interior definately needs all that stuff in there in order to keep that thing from becoming exactly what it is now, a giant pressure cooker..!!!!

The stuff could have been removed for a number of reasons but more than likely what happened is that the backing was smelling very bad from a mildew problem that happened over an extended peroid of time. These cars have a tendency to leak either from sunroofs or rear quarter windows that dont seal properly to worn out window gaskets and too many trips thru the automated car wash not knowing about any of the above and thats just for starters. I dont want you getting the idea that foxes are as bad as gm products when it comes to leaking so dont get me wrong. These are general maintenance issues that when addressed individually over time can be handled quite easily and relatively inexpensively with the exception of the quarter windows perhaps.

The point here tho is that you need new backing and insulation for your carpet. I dont know where you are financially as well as where you are in your fix up plans but there are a couple of ways you could proceed. One way is to scour the local pic and pull and find yourself a stang like yours that has its carpet/insulation/backing setup intact and snag it. The only catch to that deal is that you have about a 50/50 chance or maybe a bit less of finding your carpet in a car that has had its windows rolled up and to make matters a bit more complicated just for funs sake, finding it in better shape as in it hasnt had the same problem and is loaded down with mildew and funk.

Another way is to go thru a website like Latemodel Restoration Supply and buying a whole new setup including new carpet, padding and insulation. That would be a sweet, sweet deal although more expensive and usually at the tail end of someones fix 'er up list of things to do cuz it will get trashed in the process of doing everything else. Know what I mean?

So there ya go. Just a couple of ideas to ponder. Hope I could help some.....l8r

jcint said:

control knob IS off
sound deadening removed? not sure.
No cats X pipe flowmasters dump.
new radiator with coolant.

Click to expand...

To check for the sound deadening insulation, just remove your door sill and lift the carpet a little. If it's not there, that could definitely be the problem.

And check to see if the heat is coming out of your vents (just a black plastic box with an opening pointing at your feet. Even though the knob says the vents are closed, the door could be stuck.

Also check your firewall in the engine bay....maybe the last guy drilled some extra holes (you never know...)

Remove your upper shifter boot and make sure there's a lower boot on there to keep transmission heat out.

Make sure your transmission fluid is good. Change it if you're not sure.

If none of that helps....maybe try a new thermostat - although I don't think that's the problem, because if it were you should notice higher water temps.

I don't know what else to suggest right now...

Or...if you're a "cup is half full" kind of guy....maybe you just have a REEEEAAAALY good fan that's blowing all that hot air out of your engine bay.