hi everyone
please could someone tell me how easy it is to change O-rings on heater matrix and what do you have to remove to get too it. also I think one of my blender motors has gone I think.
cheers Steve.

Despite everyone saying it's an awful job, I've now done three lots and the last time it took me under half an hour. You need to remove the centre console side panel (one self tapper at the bottom then slide it down and out) and the panel below the steering column (4 screws). I find that putting the suspension on high and then kneeling on the floor next to the car gives the best view of them. No need to drain the cooling system as all you are going to lose is the contents of the heater matrix so a Tupperware sandwich box stolen from the kitchen when he missus isn't looking is ample to drain it into when you undo the clamp screw.

You'll need a long, and I mean LONG, 12" or longer, number 2 Pozidrive screwdriver to slacken off the clamp screw. If the screw doesn't want to slacken off, try tightening a fraction first and then undo it. Don't take it all the way out, leave a couple of turns on the end (it's a very long screw) so the pipes can be separated but don't flop around everywhere. Take the old O rings out (which will probably come out in pieces), make sure both sides are clean, dunk te new ones in anti-freeze, slip then on and push the two parts back together. If you give the pipes a bit of a wiggle as you do the screw back up, it'll make sure they are seated correctly.

If you've got aircon you'll need to follow the "quick" guide and drill two holes to get the duct to the rear seats out. You don't need to cut it like some sites say, you just need to bend it (and the side of the centre console) out of the way with a block of wood.

Getting the short elbow pipe from the driver's side blower to the airbox off will help you see the actual fittings.

My god, there are some supermen on here! Took me about 4 hours to do mine.
Second time round I could be quicker.

Took me about 2 to do the first but that was on my ex-police P38 that doesn't have the ducts to the rear footwells. As Gordon says though, even if you've the ducts they can be bent out of the way so you can thread the screwdriver in.

Took me quite a few hours. The hardest bit for me was tightening the clamp back together whilst holding the pipes with one hand and screwing with the other as my pipes kept moving and then getting the air duct behind the dash back in place.

too start with gilbertd made it sound easy, but anyway I have ordered a 16" pz2 so will give it a go at the same time (sorry same weekend) as I try to do my obd connection (thanks for info Martyuk ). she has got air con so I suppose ill just have play nicely.
thanks to every one for your help
cheers Steve

If you are in there, then it is also worth checking the fascia loom around where the heater core is... there just so happens to be a splice under the heater core area in the loom for all the diagnostic wires - where they split off from the diagnostic socket. Both the Pink/Red and Light Green/Red wires have a splice in the loom somewhere just under where the heater core drips coolant... Have found a couple of P38's now where the splice has corroded and stopped diagnostic communication...

Maybe one of those 'Whilst you're in there' chances to take a look at it and maybe fix both the problems in one go!

Marty

thanks for that Marty, I will definitely be having a good look at the soggy wires.
cheers Steve

And consider swapping the pipe fixing screw for a a stainless allen one.

Easier to keep the driver in place when tightening and won't rust.

I fitted a stainless allen screw in mine as well.

I fitted an Audi heater core, so I never have to worry about O-rings again...

I've also just been working on putting together some kits with everything needed to so the Audi swaps... have found that the matrix units I've sources have close on 18-19mm hose couplings aswell, so all the reducers and 16mm hose I bought (as the original Audi core I put in mine had 16mm hose connections, as writeups on Rangerovers.net all mention...) are now redundant...

But it's good in a way... it means that you don't have the reducer fittings, 4 less hose clamps, and to me the less number of joins the better. I just need to find a reliable way of clipping the P38 heater temp sensor to the hose as it's a bit thicker than the metal pipes...

Marty,

Is there a special closure needed to seal the hot air at the end of the Audi core, or does the existing one do?

The Audi heater cores fit pretty well, but the end cap that the P38 core has doesn't fit to hold them in/seal them up.
However, every heater core I've sourced so far comes with some sticky-backed foam in it, and when this is used at the open end, it seals up pretty well. I then just drill a couple of holes through the flange (before installing the core permanently so as not to damage it) where the RR cap clips in, to then be able to wrap a couple of cable ties through, which just stops it from sliding back out again - not that it can move very far in the first place....

That's a picture of the one I installed in Snog - I took the heater box out to give it all a clean up whilst I had the chance!

One thing to note with the Audi swap, is that because of the sealed end (LHS) of the heater box, the actual metal part of the core doesn't fully cover the LH side of the chamber. One of the new ones I bought for testing has a slightly smaller end tank on it, and fits a bit better, but still doesn't quite fully cover it. I only mention it for the 'purists' out there, but regarding heat output, you can't tell the difference. It's passenger side of mine, and the missus gets cold pretty easily - but she's never complained that it doesn't get hot enough for her, so I don't think it's much of a big deal.

I was going to look into cutting the other end of the heater box off, to be able to centralise the core more (because I want it to be 'perfect') but you then introduce other problems - like then having to seal the other end back up again once the core is in, which to me sounds like making a mountain out of a mole hill!

hi everyone, just to say I eventually got home from working away and seals replaced, I could not get passed air con duct so cut it out then replaced. while I was in there I looked at wiring and just as Marty said the pink and red wire connection was all corroded, so cut back and soldered in a new piece of wire and hey presto my nanocom now connects.
thanks very much for all the info.
cheers steve

Glad it's all done and working! - both O-rings and diagnostics :)