Heat malfunctioning...

Im having some problems with my heat and air vent. Is tehre anything i can do to increase the air flow coming from the lower vents? It liek barely trickles out and doesnt even reach the rear vents. i need some seriouse air flow. any help?

Have you looked to see if all the vacuum operated doors in the heater box are moving through their full range of travel?

You've checked the fan? Are you getting air to the other vents?

AZ Jeff said:

Have you looked to see if all the vacuum operated doors in the heater box are moving through their full range of travel?

Click to expand...

what in tarnation? lol you can take that as a no.....how would i do this and where are the vacuum opperated doors?

There are a number of flapper type doors inside the heater box on any given automobile (and truck). These are usually moved by vacuum motors that are controlled by the heater/vent selector control.

So.....let's start with some basics:
1. does the fan work in all four positions?
2. if it does, what heater/vent selector positions does it blow out of with the most force?
3. are there any positions where it does not blow out at all?

Answer those, and maybe we can help diagnose better.......

would a problem with the vaccum system in my car cause this? because i have known that i have a vacuum leak somewhere for a while ive just never ben able to find it. It blows the most out of the top near the windshield. I need the heat down by my feet and if possible back through the console to the back. thanks guys and keep the ideas coming...

Your symptoms sound like a vacuum leak in the engine compartment. On the early XJ's the common failure point is a hard plastic line that runs under the battery.

When the vacuum system has a major leak, the vacuum operated motors in the heater system I spoke of cannot actuate. When that happens, the default setting for the heater doors is the "defrost" position, and you will only get air out of the defrost vents.

It sounds like you need to chase down a vacuum leak. Do a search on this forum, as lots of guys have this problem.