Adding bleeder valve to cooling system.

ryanmcgrim · Post by **ryanmcgrim** » 03 Feb 2019, 08:07

So I've been chasing down a no / poor heat problem on a 96 850 na with 250k. The cars heater core (a sweedish car parts eBay replacement) gurgles and bubbles like mad when pressing the gas. Sounds like a ton of air is in the heater core.

I took the heater core out again and verified it's not leaking. Deleted the firewall heater pipe coupling unit and replaced with hr heater hose since the unit was cracked. Took out the thermostat and verified the bleeder hole was placed pointing forward. Fixed the blend door problem / recirculation blend motor. Added larger foam to the heater core perimeter to prevent air bypassing the find. Ran it like crazy with the coolant reservoir cap off. And i am still getting a ton of air trapped in the heater core.

The car is very slow to heat up the cabin. Blows at 70-80 degrees unless you floor it in which case it will hit 110 but only while engine is at 4000rpm. As soon as you cruise it goes back to 70. I'm told that this is classic air in the heater core issue. I know these systems should be self bleeding but it's just not happening. This is making me think there is a head gasket issue and it's just adding more and more air into the heater core faster than can be naturally bled out.

This car just needs to get through this winter with heat. Is there anyway to add a bleeder valve / self bleeding piece between the engine and the heater core inlet to get the air out before it hits the heater core? I'm desparate here. She is freezing. How would I need to set this up with a pressurised system. Could I just connect a hose to the coolant reservoir from the bleeder valve or would I need a secondary coolant reservoir to accomplish this? Any ideas?

Post by **jimmy57** » 03 Feb 2019, 08:21

You may get relief by adding a T in the heater hose and then Ting that into the small hose to coolant tank. Not a big hose, just 1/4 or 5/16. I also wonder if it isn't a blockage. Has stop leak been put in the cooling system? Revving up the engine would push more coolant through a restricted heater core. The noise may not be gas but just turbulent coolant flow.

ryanmcgrim · Post by **ryanmcgrim** » 03 Feb 2019, 08:37

That's interesting. I assumed I would need some sort of valve to ensure only air was getting out, but a t seems like an easy solution. I don't think the heater core is blocked because when I took it out I ran water through it and there was no resistance. I did notice that the inlet hole of the heater core was about the size of my pinky, but the outlet hole was closed by plastic leaving only a 2mm hole drilled. I assumed this was on purpose to force coolant to fill up the heater core. Can anyone verify that this is correct?

Post by **erikv11** » 03 Feb 2019, 08:42

ryanmcgrim wrote: ↑03 Feb 2019, 08:37 ... I did notice that the inlet hole of the heater core was about the size of my pinky, but the outlet hole was closed by plastic leaving only a 2mm hole drilled. I assumed this was on purpose to force coolant to fill up the heater core. Can anyone verify that this is correct?

Bingo. Not normal at all, both holes should be completely open.

Post by **precopster** » 03 Feb 2019, 14:26

+1 to above. The orifice size there should be much larger. Both orifices should be penetrable with a finger.

ryanmcgrim · Post by **ryanmcgrim** » 03 Feb 2019, 14:37

That's crazy, it's definitely manufactured this way. It's smooth with a cleanly drilled hole. Is this just a pilot hole and they never came back over it? Man I've been screwing with the heating system for 3 years and it's all because of this. Not happy with sweedish car parts. I guess I figured out why the new and improved heater core isn't so improved. Did I get a bunk one or are they producing all of them like this? Surprised I'm not having over heating issues.

Post by **ZionXIX** » 03 Feb 2019, 14:54

Ignore the copper washers but as you can see both ports should be equal diameter.

Post by **precopster** » 03 Feb 2019, 15:46

My Swedish Car Parts heater core cracked on the bottom seam after only about 70,000kms.
I'm another victim, however rare.

Post by **Chuck W** » 03 Feb 2019, 17:07

I just got a heater core from SCP a couple days ago. Both ports are the same size.

Sounds like you got a defective one. Get in touch with them and get a replacement.

Post by **ZionXIX** » 03 Feb 2019, 17:08

Should be an easy fix. Drill out the port, flush out the plastic debris and enjoy the heat.