Heating oddity

[kurtiswilk]

Hey guys and gals.

I've developed an odd heating issue. When at idle the van will not put hot air into the cabin. The engine is nice and warmed up. If I Rev the van up to about 2000 rpm, I get nice toasty air. There is a small coolant Drip but I keep the level topped up until I can deal with it.

Any thoughts?

[Mr. Flibble]

Water pump failing possible that the idler is dying, Only pumps at high rpm.

Probably want to get that looked at ASAP.

Other possibilities:

Head gasket leak - bad, get you system checked if you see a fluid leak.

Heater core blocked - while engine is hot, feel the hoses going to the heater core, if one is hot, the other cold, your core is blocked.

Air in the system blocking the flow - you mentioned you had a leak, that would add air.

[kurtiswilk]

I'm willing to rule out a head gasket leak,
I don't have any signs, the ones I know to look for anyways, those being :
-No milky oil or increase in oil level.
-Coolant level is not going down any more then it has since I got my out of province inspection done, planning to fix the offending hoses and have the system flushed here soon. It's the tranny cooler lines at the very bottom drivers side
- no white smoke others then on cold mornings
- haven't done a real pressure test, but after sitting for 12 hours, the system still had pressure when undoing the cap to top up.

I'll try bleeding air out of the system, the process I've used is to :
Remove the air bleed screw above the battery,
Warm the engine to operating temperature,
Turn on both front and rear are heaters.
Burnaby throttle until small burp of coolant comes out.

I'm wondering if I didn't get all the air our when I did the block heater. Should the system be burped until fluid is always just visible?

Will also look into the water pump.

Not sure if it matters. Both front and rear are cols at idle and then warm when rev'd


Thanks
For the help