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Discussion Starter · #1 · (Edited)
This is a weird one. The cold and AC work great for summer and the dual climate zones in the front and the auxiliary zone blows super cold too. Now that it’s getting cold out the heat works for the passenger zone only and everything else works fine except absolutely zero heat on the Drivers side. Any thoughts ? For some reason this car had all kinds of fuses removed. It had been sitting in a shop for years and had a few electrical issues that some just came back online after about a week and some took some switch and resistor or fuse replacement. Is there a separate switch/fuse or motor to allow heat on either side in the front area ?
 

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99% it's the heater core clogged up. It seems the heaer core uses the bottom half for the driver side, so when it plugs up you're screwed.

Options:

1) New heater core-$$$$ due to labour to replace
2) Flush heater core

I did #2. There is a chance you will bow it up, but what do you have to loose. There are many threads on how to do this, but what I did was disconnect the heater core hoses, blow out the core with compressed air.

Boiled water and mix 50/50 with CLR. Fill core and let sit for 10 minutes. Blow out with compressed air. THIS IS A DANGEROUS AND MESSY PROCESS, AS THE HOT LIQUID WILL BLOW EVERYWHERE UNLESS CONTROLLED!!!

But it worked for me.

Hope that helps,

Chay
 

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Discussion Starter · #3 ·
99% it's the heater core clogged up. It seems the heaer core uses the bottom half for the driver side, so when it plugs up you're screwed.

Options:

1) New heater core-$$$$ due to labour to replace
2) Flush heater core

I did #2. There is a chance you will bow it up, but what do you have to loose. There are many threads on how to do this, but what I did was disconnect the heater core hoses, blow out the core with compressed air.

Boiled water and mix 50/50 with CLR. Fill core and let sit for 10 minutes. Blow out with compressed air. THIS IS A DANGEROUS AND MESSY PROCESS, AS THE HOT LIQUID WILL BLOW EVERYWHERE UNLESS CONTROLLED!!!

But it worked for me.

Hope that helps,

Chay
Thanks so much bud. I wish I could send you a Canadian tip haha. When you mean CLR (Calcium Lime Rust) the stuff in the silver bottle that they show cleaning the coffee pot and the shower head from calcified water. Which would make sense since this car came from an area that has really crappy water. I’ll get our local heater core guru Jackie Sing giver a go. He’s a legend he’s like 90’ years old and still walks to his shop daily to work on radiators. Cool old dude
 

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Discussion Starter · #4 ·
Thanks so much bud. I wish I could send you a Canadian tip haha. When you mean CLR (Calcium Lime Rust) the stuff in the silver bottle that they show cleaning the coffee pot and the shower head from calcified water. Which would make sense since this car came from an area that has really crappy water. I’ll get our local heater core guru Jackie Sing giver a go. He’s a legend he’s like 90’ years old and still walks to his shop daily to work on radiators. Cool old dude
They’re only like $55-$75 cad. I guess you’re talking about the re and re for the $$$ ??
 

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Part is cheap, labour is supposed to be a killer.

Yeah calcium line rust, silver bottle. It DOES eat aluminum, but I didn't leave it in that long and tripple flushed it. There is also a commercial rad flush preparation that I didn't have access to.

My rad was gunked up too. GM puts a 'pill'in the coolant-it's supposed to seal a head gasket leak until the warranty expires ;)

Seems they sometimes add more than one, they decompose and end up in the rad and the heater core. Thank you GM.

I didn't do it, but hear you have to take half the dash apart to change the core.

Perhaps others could confirm.

Chay
 

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Discussion Starter · #6 ·
Part is cheap, labour is supposed to be a killer.

Yeah calcium line rust, silver bottle. It DOES eat aluminum, but I didn't leave it in that long and tripple flushed it. There is also a commercial rad flush preparation that I didn't have access to.

My rad was gunked up too. GM puts a 'pill'in the coolant-it's supposed to seal a head gasket leak until the warranty expires ;)

Seems they sometimes add more than one, they decompose and end up in the rad and the heater core. Thank you GM.

I didn't do it, but hear you have to take half the dash apart to change the core.

Perhaps others could confirm.

Chay
Thanks a lot Chay. Yeah 100% bout the labour. Somehow I had a Ford bronco 2
That the heater core ninja got in a changed for $120 the heater core was $105 my mum keeps good records since that was 98’ lol. I don’t think that SRX dash will come apart for $120 lol. Gonna have to ask. How long did you leave the CLR inside of the system for if you had to estimate? Like 30 or like 10 minutes?

Thanks
 

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Another possibility is the heating system blend door not working correctly. Either way it is a bit of work. I am not sure, but think you may be able to obtain codes with the right equipment. They are likely body B or U codes for the system.
 

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Sorry for taking so long to reply.

I first blew out the heater core with compressed air, gently with reduced air pressure.

Then I put in boiling water and clr 50-50 for 10 minutes. Blew out with compressed air (DANGEROUS-Still HOT!)

CAUTION it WILL come out like crazy! Air pressure behind water like that-it almost explodes out.

Then repeated two more times, then blew and filled with clean water a bunch or times.

Messy, and not a lot of fun but it worked. It could also blow up your exchanger so it's a hit and miss kind of thing.

Chay
 

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Hi gang, I have been on Forums since 2005 mostly gathering information about my troubles with a 1994 Concours, then a 2003 DTS, now a 2008 SRX. I am having the same problem with my A/C (hot air passenger side and frigid air on driver side). Was hoping for an easy fix but sounds like the fix is way above my ability though since I have old-age problems. Have to let my mechanic have it for a while I guess. Oh well.
 
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