"OMG" that looks like the worst sickness I have ever seen! How many more out there are like this? As I type I am replacing the heater core in my 96 due to ZERO heat, though I believe my issues is vacuum I still found a bunch of crap during the flush procedure. New engine, new water pump, new thermostat, hoses are mint and a new B Cool radiator. Removing the heater core I also took one of the end tanks off, quite rusty but no where near as bad as this one pictured.Here's a pic of the inside of my son's heater core from his 94 ... and he had a touch of heat.
As touched on throughout the thread, you most likely have a blocked Heater core and should try to Flush it out first. If that does not work, then it may be time to replace it if you just can't get it clean. If it is not leaking and if you have a radiator repair shop local to you, it may be worth the effort to have them clean it as I don't like aftermarket Heater cores.Hoi guys, the heater of my '91 Caprice doesn't get as warm as it used to be. Temperature of the car is normal. So what can be the cause?
Pretty much how I flushed mine except I bumped the pressure to about 20 PSI. I left the hoses connected at the FW and disconnected those hose down the line that provided a place to easily fill and Blow out the HC in both directions and did this a numerous times....I'm probably overdue on doing this again.Lots of ways to flush. Some use a garden hose, but be careful ... water pressure in a house hose can be 40-80 psi ... and that's NOT ok. I've always attached two long lines to the core (while in the car), filled it with water (and the hoses), set my compressor to 10 psi and blasted the water and cleaner (let it soak) through from both ends ... maybe 10 times till the water flows through easily. I hold my finger on the outlet side hose (switching back and forth) till just before I hit the compressor blast. But look back at the picture ... it didn't last long. My son's problem was rust scale inside the engine ... it just wouldn't stop building up.
Here is a trick that works amazingly well. I discovered it by accident, but would not be surprised if other have also discovered this. I've drained coolant out of these engines so many times, I'm a pro ... and can do it on a new carpet and not get it wet (ha, just kidding, but close).
Fill the engine with coolant. Don't bother starting it. Use a coolant pressure tester to pump up the system to 12-13 psi at the reservoir. As you bring up the pressure, use this opportunity to check for leaks, fix them ... beats the heck out of doing it when you run the engine waiting for pressure and leaks and dealing with everything being really, really, hot.
As well, sometime early on after a few pumps (1-2 psi), open the bleeder at the thermostat and let that air out. When fluid comes out, close it. Way more effective than trying to bleed by gravity (no pressure). Take it on up to 12-13 psi slowly (once all leaks are cleared).
Now ... release the pressure quickly at the pressure pump, however that is done on your pump unit, but do it in quick bursts, maybe 4-6 psi at a time. You will hear a very audible gurgling sound ... that is the air being forced through the system to the high point (bleeder and reservoir).
The fluid level in the reservoir will drop. Fill it back up to the fill line. Repeat this process as many times as it takes till you no longer hear the gurgling sound and the reservoir level stabilizes ... and don't forget to let the air out at the bleeder early in each pumping cycle (at low pressure).
When done, do one more cycle all the way to 16 psi (including the bleeder step) and let it sit for a few minutes and check for leaks. Release that and start up the engine. I still check for air a couple of times after running the engine, but only to make sure I didn't miss a gurgle cycle and to fill the reservoir after things settle.
For all you serious techies. This works on the principle of expanding gas. Coolant does not compress at all, but air does, big time. As the air expands when we quickly release the pressure, it moves violently ... thus working it's way up to the bleeder and reservoir. You could probably accomplish the same effect by slamming the engine with a huge sledge hammer, but this is far easier. Just takes a few minutes.
Thank you very much, I appreciate your time. It was in the low to mid 60s here in coastal NC today so I had he car out. Drove to a local show and ended up putting 80 miles on the car. Still no heat, but I believe there is light at the end of the tunnel.This is available from Stant. Screws onto the reservoir and gives you a standard radiator cap for the pressure tester fitting.
This is the pressure tester (pump) I use ... has a standard radiator connector. Atlas model PT-10.
An interesting trick for a tricky cooling system. :smile2:Deputy ... Trust me on this gurgle trick. I have never had air left in my cooling system doing this. Dozens of times. Before ... my fair share. Running up the pressure without heating the engine is a big plus (still have to do that, of course), but finding leaks when cool ... priceless.