: Heater Core Leak ???

11-19-06, 08:24 PM
I am having problem pin pointing were I am loosing coolant from ( on 98 Catera ). After pressurizing system to around 14-15 psi there was a thin BUT steady stream of coolant coming beneath car on drivers side. After looking underneath car it looks like it is leaking and running down the exhaust heat shield at steeing column. After a closer look it appears as if it is coming from some type drain hose that happens to be kind of stashed/positioned at the heatshield near the steering column. I am thinking this is the drain for the A/C ?? or atleast some type of drain, which leads me to believe heater core is leaking. I have looked under hood and can't find a leak any where near that area on drivers side.....as well as nothing on the passenger side. The only signs of coolant appear to be coming from that hose/drain.

Has anyone had a leak in this area ? Also, does anyone know what is involved in changing out Heater Core, or maybe a link to info to do this job.


11-20-06, 04:05 PM
it maybe the heater control valve

11-20-06, 09:22 PM
Hey Clunker, I'd bet almost anything that it's your heater control valve. I just replaced mine 10 days ago. Read the sticky at the top of the home page. This is a VERY COMMON problem with Cateras. I'm surprised that no one else responded. My '98 was doing the exact same thing before I replaced the HCV. Good luck and post a reply if you need any further help.

11-20-06, 09:58 PM
i had my HCV replaced on my '98 a couple weeks ago. seems like the same problem

11-21-06, 06:41 AM
I actually replaced my HCV a few month's back. It doesn't appear to be leaking this time and coolant is actually coming from a drain hose in the area of the heat shield exhaust/steering shaft. What is weird is it isn't so bad at times, but when I pressurized the system around ....14-15psi, it comes out the hose in a small but steady stream. The car doesn't seem to leak terribly bad until engine gets up to operating range ( slightly below halfway mark ). I am thinking at this range and cool weather , outside temp (40F-65F ), the pressure runs around 10-11 psi "correct me if I am wrong" , but pressurizing system to 14-15 psi is enough to increase the leak.

I have a friend coming by today to help try and pin point the leak. He is a Cadillac mechanic .....although he tells me the dealership he works for don't work on alot of the Catera's, but he has worked on them several times and told me he has yet to replace heater core in one, but thinks by the sound of things it is the heater core ( beings the coolant is coming from what appears to be heater box drain and not down firewall or engine ). The only signs of coolant is that drain hose. We printed off R/R on this procedure yesterday and as figured everything has to come out to get to it.

Can anyone speculate on this hose ?

Thanks Again