Well almost.

Went for a drive in a friends IROC this evening. Drove the car for more than 20 miles before it would push any heat into the car. The fan is working, the car warmed up properly and when it did push heart it was not very warm.

Any ideas where we should start looking?

 

Hmm.. off the top of my head the first thing that comes to mind would be a clogged heater core.

Hopefully it's something a little more simple though.

I guess first check for:

Coolant level: make sure the car is full on coolant and there are no air bubbles in the system.

Coolant leaks: make sure there are none, especially between the heater hoses

Heater diverter valve operation: If the car has one (you'll know its a big ugly valve probably sitting somewhere on the passenger side with three coolant hoses going to it near the passenger side valve cover.) Make sure it has a vacuum hose connection going to it. However, I believe these CLOSE coolant going to the heater core if they get vacuum, so if it doesn't have vacuum, it may let coolant flow freely to the heater core. ANYWAYS, make sure it isn't stuck closed, you may have to undo the hoses going to it and see if you can see valve operation with vacuum applied. I don't think this would be your issues though, I hear these fail more commonly by leaking, and not getting clogged.

After checking for these, I would next check:

Blend door operation: This is a little more of a pain to check, it is the door that opens or closes based on the heat selection on the climate control settings. The cold/warm selection on the climate control panel has a cable attached to it. This cable is connected to the blend door which is in front of the heater core. If you take off the lower dash panel on the passenger side (I believe it is only held in by three or four 7mm bolts), you should be able to see the cable connection underneath the heater core housing. Move the setting back and forth from cold to warm and see if the cable is moving anything. You might be able to hear the door move back and forth if it is moving at all. You should probably be able to feel resistance in the selection too if it's moving the door.

If that seems to be operating correctly, then I think the heater core would be clogged, which seems somewhat probable due to the age of the vehicle.

Changing the heater core can be done with the bottom panel removed. You should be able to take out the heater core housing from underneath with a bit of dexterity which will save a lot of hassle. There are a few bolts on the housing you can't see, but you can reach with a 1/4in socket set and extensions and 7mm (or maybe 10mm) long socket and short sockets.





Anyways, this is the info I can think of, hopefully you find out or someone else may have some other ideas what may be causing it!!!
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Edit: And what I mean by clogged is it's almost clogged fully so barely any coolant is flowing through the core. If that's the case, it will let some heat in, but not a lot due to the small amount of coolant flowing through it.

IF you determine it is probably clogged, and you look under the dash on the passenger side and it doesn't appear to be leaking, you can try using a coolant flush kit and see if you can unclog the core. You may get lucky this way, but be prepared to have to replace it eventually. Things like the heater core and radiator wouldn't clog for no reason. Usually they will clog, then start to leak due to corrosion or something. Make sure to only use distilled water and antifreeze! NEVER USE TAP WATER/WELL WATER or fishtank water you get the idea! All those have stuff in them that will react with the metals in the system and corrode it over time.

 

Good stuff Bubbajones_ya!
might also ask your friend if he has recently changed/REMOVED the thermostat. If he hasnt removed it, I would go ahead and replace it. and do this FIRST. Its easy and its cheap and is the culprit alot of times. Sounds like the thermostat is either stuck open, or missing altogether(removed). Stuck open or removed will cause the car to take forever to heat up, and when it finally does, it wont be hot heat...