Hi all - the heater core is clogged on my 2009 LR3 resulting in no heat on the driver side. I tried back flushing it, as well as flipping the inflow and outflow hoses. The latter improved the heat maybe 15%, the former did nothing (which my indy already said it wouldn't). I tried flushing anyway and a small amount of debris came but no clogs or anything. It flows fine. (Side note: in hindsight I think a good preventative measure would be flipping the intake and outtake every year or so.)

So...it looks like I need to dig in to replace this. The issue is there is crap information on this. For something I thought was fairly common I cant find any step by step guides. I see some people say its a nightmare, others say its not that hard at all. Ive seen a few posts on a shortcut method but its just snippets.

Can anyone point me in the right direction?

Appreciate it!

 

Im not sure if they are attached. lets try.

 

It worked. Open the heater core one first, it directs back to the instrument panel

 

Oh sweet! Thank you!!! Pulling up now.

Have you done the job? Any tips? Very little info on the Internet about this...

 

Have not done it yet. Should be straightforward after you get access to the core.

 

You might try to flush it with something a little stronger before you tear it out. My mechanic flushed mine with sulfuric acid and it cleaned it out. Now, the downside of that is that sulfuric acid reacts with aluminum and can actually melt it. But, if your dilution is OK and you get it in and out pretty quick, it might work. Hey if your heater core is toast anyway, it might be worth a shot. I was getting ready to do the "dig in" deal myself.

 

Diluting acid increases aluminum etching if the acid is reactive, simple physics. You must do it right and use the CORRECT acid. Nitric acid is wonderful with aluminum as it oxides the aluminum itself to which protects it while dissolving the things you don't want in the core.

As for replacement, look up on Google about the procedure. I think there is a method which involves cutting the input/output tubes and putting a few cuts in the area round the core. Then it slides out. With the new core, cut the tubes again then connect using heater core hose. Saves a ton of time and labor.

 

I cut the tubes on my '08 to replace the heater core. I would have preferred not to, but my original pipes did not have the intermediate disconnects as shown in Abran's PDF. Still it was a pretty fiddly job for a couple of reasons: (1) getting the new o-rings compressed enough to start the u-clamps is not easy (2) there's limited space to work, so cutting the pipes, de-burring, and getting the hoses seated adequately is tricky. Initially I also had a tough time keeping the hose clamps tight, even with new high quality worm drive clamps. They would get loose over time and start weeping coolant. Keep in mind the cut pipes don't have the sealing ridges that a proper part would have. I eventually solved this by putting safety wire through the screw driver slot of the clamp and around the clamp body (search google for examples of this technique).

I've gotten to where I trust this setup now, but I wouldn't do it this way again. I'd bite the bullet and pull the dash.

I'd also note that replacing the core did not improve the driver's side heat. I also replaced a stepper motor with no improvement. I can get heat on the driver's side by cranking up the temperature, but can't get a steady but slightly warm output. I can achieve a warm output at a more moderate temp at startup, then it levels off and feels cold. I've also tried the "re-initialize" routine at the control panel with no change. I'm beginning to think this is just the design of the automatic climate control, or a bug in the firmware. Seems like a lot of folks see this behavior but there's no conclusive fix.

 

@Husker thanks! Are you planning to do yours soon?

@DakotaTravler is there any that you would recommend? My indy told me he used a pump to flush it with a descaling solution for a couple days and it didnt have any impact. He was very negative towards trying to flush it.

@jagman thanks for this! I have lots of questions for you! There is such little good info online about this. I have a 997 and am use to having tons of good DIY guides from the forums. I will certainly make one on this if I make it through alive

1. Do you just need to remove the center console side panel and glove box?

2. Ive seen a post for the Range Rover Sport that said you need to cut the metal dashboard frame to slide the core out, then try to bolt it back together somehow. Is this correct? Is the only way around this taking the entire dashboard off?

3. Can you explain more about how you cut the pipes and what model core you used. My indy told me if you buy the LR core for ~$500 you can disconnect the pipes and dont need to cut anything. But if you get the OEMs for ~$150 you need to cut the pipes.

Did you take any pics while you were in there. Im still trying to get a lay of the land to build my confidence before I dig into the project. This is the only project on the LR that seems daunting. Rebuilding the air compressor was a pain in the ***, but at least there were a ton of posts on it.

 

Actually this stuff works really well and its very safe. Just don't overdo it. As for not flushing? Makes no sense, that is what you HAVE to do, flush it out.

And where the above product comes into use:
https://www.bobistheoilguy.com/forum...tric_Acid_Flus

Mercedes even sells an actual flush product.
https://www.fcpeuro.com/products/mer...s-000989102511