Thread: Remove pipes from heater matrix D4

Originally Posted by veebs

I'm also getting close to doing this - passenger side is generally pretty cold now.

I'm tempted by Banana's approach, though wonder, are the pipes sold with the Nissens part the same size as the stock ones?

Could I use a screwdriver to pry open the crimps in the car, swap the core out for a Nissens model, then use the screw fittings it comes with to clamp everything back together?

Has anyone tried the Nissens?

Haven’t done it yet but seems to me the joint and o ring is identical with different methods to secure the joint. The Nissens with removable pipes is the one to use.

The replacement looks very simple but the how to access the matrix is what I’m unsure of which way to go - cut or full disassembly so a detailed guide would be good. I’m surprised LR Time have not tackled this yet as surely Vera would have no heat in the D3 in a LHD.

I’d also remove the two hoses in the engine bay near airbox and blow or suck the coolant out of the matrix first so there’s minimal spillage inside the car.

You can also prime the system this way with water first and check for leaks after changing the matrix. Rigging a little pump and bucket is very easy. Finally fill with matrix with coolant and reconnect hoses.

During recent radiator change I spent an hour trying to unblock my matrix using the pump method above in both directions using a radiator flush product. Straight CLR would be next step. I also used air gun to shoot water backwards through the matrix. Could see crud coming out and not sure yet if a performance improvement was achieved to the passenger heating. Worth a try though.

I also noticed that the fuel cooler circuit at bottom of the radiator (EU4) was similarly a crud storage area. Blew out nicely.

Thinking much the same PD, water flush, then air blow to reduce spillage inside the car, and hopefully, make any spillage water rather than coolant.

I pulled a bit of trim away in seconds to be able to see, but that wouldn't be enough to replace. I'm hoping the removable pipes means a combination of bending and pushing aside plastic plus liberal doses of swearing from me of course makes the job possible.

I figure the flush method will always yield half-results - most of the flush will go through the holes that are still open, some might clean out the partially-blocked, but very little will actually get the blocked section unblocked. Same principle as blowing your nose - best results by blocking the 'open' nostril.

If I can get the engine side hoses connected together (ie, bypass the matrix completely) I will feel a lot more confident persisting with this. That way, it won't have heat, but it will still at least be drivable if I make a meal of it... The seat heaters make cold days quite bearable anyway.

Yesterday was a cold day and my copilot thought the heating was satisfactory. Maybe I had a win. I’d go hard as you dare on the caustic cleaner and also plenty of air blasts.

Originally Posted by veebs

I'm also getting close to doing this - passenger side is generally pretty cold now.

I'm tempted by Banana's approach, though wonder, are the pipes sold with the Nissens part the same size as the stock ones?

Could I use a screwdriver to pry open the crimps in the car, swap the core out for a Nissens model, then use the screw fittings it comes with to clamp everything back together?

Has anyone tried the Nissens?

I finally replaced mine last week after having a new one sitting in a box for 2 years. I did exactly what you mention, the only problem with leaving the hoses in place is you have to pull/slightly bend them aside to get the old exchanger out.

I ended up removing the dash to the point of the lower console was removed, I then drilled out the small amount of plastic that was still in the way (and not visible once back together). It's much easier if you pull that passenger seat out too, 5 minute job.

Given how easy it is to remove everything I did, I recommend giving it a go and not taking the shortcut method others do with a big cut in the lower console piece. You won't need to remove the steering wheel, instrument cluster or complete dash this way.

These two videos will help:
https://www.youtube.com/watch?v=Y4WuZTJPEM8
https://www.youtube.com/watch?v=gZHlqi0F8Pk
https://www.youtube.com/watch?v=EibeWoCdS7s

*Only thing i noticed too late is in one video they don't remove the gear shifter(if you have one), which is a mistake. Remove it before pulling up on the lower center console, it's 4 bolts and you just need to pull it up out of the plastic slots it's sitting it. Then the surround goes back in before ther shifter.

Easy weekend job, start early on a saturday though, you don't want to be rushing putting plastic back together.

Originally Posted by Russrobe

I finally replaced mine last week after having a new one sitting in a box for 2 years. I did exactly what you mention, the only problem with leaving the hoses in place is you have to pull/slightly bend them aside to get the old exchanger out.

I ended up removing the dash to the point of the lower console was removed, I then drilled out the small amount of plastic that was still in the way (and not visible once back together). It's much easier if you pull that passenger seat out too, 5 minute job.

Given how easy it is to remove everything I did, I recommend giving it a go and not taking the shortcut method others do with a big cut in the lower console piece. You won't need to remove the steering wheel, instrument cluster or complete dash this way.

These two videos will help:
https://www.youtube.com/watch?v=Y4WuZTJPEM8
https://www.youtube.com/watch?v=gZHlqi0F8Pk
https://www.youtube.com/watch?v=EibeWoCdS7s

*Only thing i noticed too late is in one video they don't remove the gear shifter(if you have one), which is a mistake. Remove it before pulling up on the lower center console, it's 4 bolts and you just need to pull it up out of the plastic slots it's sitting it. Then the surround goes back in before ther shifter.

Easy weekend job, start early on a saturday though, you don't want to be rushing putting plastic back together.

Great info. And what did you do for the pipe joints?

Do you mean remove drivers seat since pipes are on drivers side?

Originally Posted by PerthDisco

Yesterday was a cold day and my copilot thought the heating was satisfactory. Maybe I had a win. I’d go hard as you dare on the caustic cleaner and also plenty of air blasts.

I had a great win cleaning the core. Use lots of air to clear the core of fluid, then release a slug of water into the line and back it up with loads of air. This pushes the water and increases its momentum.

My theory is when it enters the core it's going so fast it can't turn and head up the drivers side so it continues to the passenger side where it his the end of the core and has nowhere to go but to push on the crud in the tubes. I spent several hours pushing water back and forward through the core until nothing else came out and this rectified the cold wife syndrome.

3 years on I still have a replacement core in my lrdirect shopping basket, but I haven't needed it yet.

Like most of my repairs your advice was critical. There’s actually a water blast air tool for the matrix job.

The coolant flow to the matrix (which you want to reverse) is in via the lower pipe and out via the top pipe.

Looking at the firewall in is the passenger side connection and out the drivers side.

Originally Posted by PerthDisco

There’s actually a water blast air tool for the matrix job.

There is. I looked at a few and they all universally oscillated between water and air fairly quickly. Great for a radiator at the inlet. The issue in this application is with that much water in the pipe there's a whole load of air pockets to absorb the shock. Might work well if you shove it into the matrix directly, but down the pipes it's going to reduce the effectiveness of the "shock" value as by the time it hits the matrix it'll just be water with lots of bubbles to absorb the pressure variations.

That's why I blow the whole thing clear, then use one slug of water backed up by 110PSI of air. It then travels as a slug and belts into the back of the matrix. At that point there's nowhere else for it to go but up the tubes.