I have the same issue, I put the scope down the vent and the door moves. Not sure it move far enough, but it moves. Seems a new heater core is in my future.

Jeff

 

You can try a citrus acid flush with the core.

 

I agree and will try that after it is removed.

I have been delaying a water pump replacement (slight noise while idling that is at a different RPM than the engine or belts) So while I have the coolant removed, seems like a good time to pull/flush/replace the heater core as well.

Besides:
The truck is 5 years old, had 140,000 tough miles and well, some times you just have to replace parts.

 

Well if you are removing it you may as well swap, its not an easy project unless you cut the pipes and put rubber coolant hose to couple them in. You can do a citric acid flush with it installed, you can access the lines at the firewall. Or you can just flush the entire system.

The water pump is easy. I am in the same boat at you, waiting for coolant crossover pipe/t-stat housing to arrive. Then I will citric acid flush the entire system, purge it and then replace the pump and crossover. I really SHOULD do all the cooling hoses too, but I will probably get to those late summer, including the nasty ones for the rear heating.

 

I tend to warehouse parts. I buy them when really good sales present themselves and then sit on them waiting to be needed. I have a full set of genuine LR control arms (and all of the bolts and washers) just sitting around and with two of the three trucks approaching 140,000 one on them may need a suspension refresh this year. I have had the water pump for some time just waiting on the time when it will be needed. Same thing with the heater core. If I can clean it out, I will. I can reuse it and avoid buying a new one for the the other LR3 or the LR4 that I maintain (mine plus one each for my son and daughter).

I could try to flush it first, but crawling up on the engine to get to the hoses at the firewall seems almost as difficult as removing the center part of the dash (which I can do sitting down).

Thanks for the ideas, I will consider it as I move forward with the repairs in the next few weeks.

Jeff

 

It is out and sitting on my work bench.
I got the floor console moved a little, the center frame (the one the radio is secured to) and the passenger side dash out. I do not recommend this for the faint in heart. nothing overly difficult, just a lot of things to remove and a lot of things to forget where they went.

I was fortune enough to have the pipes that come apart, so good thing I bought an extra set of o-rings.

I put the scope down the tube and found this:


I see gunk spewing out of the side parts, so I am sure it is clogged.

another view of the clump of "stuff"

So out with the old in with the new. I will be installing this Saturday and then the blend motor on Sunday. I will let you know how it goes.

 

Wow, that almost looks like crap thats formed when two coolants should not be mixed are mixed. Awesome pics though!

 

The only difference is the drivers side heat vents in the front and back didn't have any heat output not too long after the heater core, climate control panel and heater control valve were replaced... so I'm at a loss. Since almost all the suggestions to the problem is linked to those parts that are brand new.. I even had the heater core flushed just incase there was a clog. Even though it was brand new.. :-/

 

After removing the whole dash (and center console), the heater core was easy to get to and replace. I used a coolant pressure tester before reassembly of the dash and let it set with 121 lb of pressure over night, so that gave a good feeling about not dumping coolant into the floorboard when I start the engine. The temp motor seemed like an easy fix, just remove and replace.

Everything went back together and was tested. I was able to confirm no coolant leak while getting the engine up to temp. I filled the system by pumping coolant into the small hose by the throttle body, so I was pretty sure the burping process would be easier and it was.
I thought it was finished.

But it did not happen that way. The left side absolutely gets hot now, in fact it only gets hot. I can see the blend door motor move but it acts funny.

The iidTool shows a number from 0 to 288 on the dial status just like the right side so I am reasonably sure the control head is working properly. The problem is when I set the dial to max cool, the iidTool still shows intermediate on the temp control position while the right side shows max cool. As I move the left dial toward the heat position, the motor actually moves more toward the cool position rather toward the max heat position. I do not know how the logic drives the motor, but I know it is not right.

I plan to remove the center console and left side of the dash, plug the HVAC controls and radio back in as well as reinstalling the steering wheel. Then I can reinstall the motor again and watch it as I work the dial. I may be forced to tear into the heater box itself (I hope not) but either way I may be able to see what I did wrong the first time.

I have been delayed tearing back into the Rover as I have a "MINI" trip with the MINI Cooper group into the hill country of Texas next weekend and my wife does not want to make the trip if the passenger window will not go up or down. I had been putting off replacing the right side window motor and regulator (common problem the the 1st generation MINI's), until I got the rover sorted out, but looks like my plans have changed.

I will update on the motor control when I learn more.

Jeff