Birty Dastards Jeep Club

Tech Forum => Workshop => Topic started by: Brynjaminjones on December 19, 2014, 03:45:05 PM

Title: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 19, 2014, 03:45:05 PM
Not a happy bunny - just on my way back from uni when I noticed that there was a small amount of steam coming from the vents (with the heater set to 0). I turned the heater on and the windscreen momentarily steamed up. No smell initially, but as I drove it started getting more and more steamy with a definite coolant smell. The coolant level looked okay, but I've just got safely back to the parents' and the coolant is at the minimum.  :banghead:

I'm guessing that this is the heater core, but is there anything else it could be or that I should check first?

Any advice/pointers etc. will be much appreciated.



Title: Re: Sodding heater core (I'm guessing)
Post by: Dutch on December 19, 2014, 03:59:38 PM
Had the same with the V8 WJ. Very interesting driving in winter with all windows open  :icon_rolleyes:

Run the whole show as hot as you can - but still able to get rad cap off.

Rad weld in there - Heater on 11 (full chat) and run engine at higher revs to circulate the juice properly.

If the crack/hole is still small enough you might nip it in the bud.



Title: Re: Sodding heater core (I'm guessing)
Post by: XJ Fan on December 19, 2014, 04:33:05 PM
 :iagree:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brachunky on December 19, 2014, 04:44:35 PM
Its always worth a go before having to get that bastid core out :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 19, 2014, 05:19:36 PM
No disrespect meant to anyone, but while I'm sure Radweld etc. would work, I really don't feel happy putting that kind of thing in the XJ. I've heard how these kind of products can clog up more than they're supposed to, and as I'm planning on keeping the XJ for as long as I possibly can, I'd like to fix it properly (or at least without risking affecting other parts of the cooling system).

In the mean time, is there any way that I can easily bypass the heater core? I can (relatively) happily survive without the heater, so could this be an option until I get the time to sort it?

Cheers guys!
Title: Re: Sodding heater core (I'm guessing)
Post by: Brachunky on December 19, 2014, 05:48:01 PM
Its a simple joining of the two heater pipes running alongside the valve cover. A pair of 19mm plastic elbows will do the trick.
Title: Re: Sodding heater core (I'm guessing)
Post by: wildwood on December 19, 2014, 05:53:36 PM
 :iagree: best way and no worries about stuff in your coolant. It all depends on how long you can live without a heater....... :icon_twisted:

But by the time spring arrives you'll be well 'ard and won't be missing the heat......
Title: Re: Sodding heater core (I'm guessing)
Post by: thorna on December 19, 2014, 05:58:39 PM
Bypassed my TJs back in October; easy enough to do. TJs hoses were different sizes so I brought a hose tail to tail adaptor off ebay for a couple of quid to make the join easier. 20-30 mins to do it.
Try to blow out all the water in the matrix to start letting your cab dry off.
It's no fun driving without heat though.
Title: Re: Sodding heater core (I'm guessing)
Post by: Dutch on December 19, 2014, 06:35:58 PM
Abe,  I have been told that it only solidifies (welds) when it comes into contact with open air i.e your small hole.

You can always chuck some in - weld the hole - then flush the crap out with a cooling system flush.

Winter hasn't even started in anger yet and no heater gets a bit of a nuisance after a bit.

Your girlfriend (or boyfriend) will not appreciate/share your romantic views  :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brachunky on December 19, 2014, 06:44:40 PM
She's 'ard too :hysterical:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 19, 2014, 08:51:59 PM
Thanks for the advice guys - I really appreciate it. I think for now I'm going to look into bypassing the core. Thorna, might you be able to point me in the direction of the adapter you used - XJs have different sized pipes too, and I think they're probably the same as a TJ. Dutch, there's no-one else to worry about "keeping warm" at the moment, thank you very much!  :003:

If I don't bypass the heater, I think mum has found that she can put me on the TJs insurance for a while for a decent price now that I'm 21, so if that happens I think I'll tear the XJ apart.

Also, thinking along Dutch's lines of radweld then flush, is it at all possible to run the radweld stuff only through the heater core? As in disconnect pipes, and flush hot water through somehow?
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 19, 2014, 09:51:07 PM
if your not going to chuck in a small bottle of rad weld, only solidifies in contact with air, the use and egg white.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 19, 2014, 10:08:55 PM
It's either you lot or the beer, but something is causing me to be more and more tempted by that stuff...
Title: Re: Sodding heater core (I'm guessing)
Post by: Dutch on December 19, 2014, 10:24:42 PM
Its your money pal ...... which you aint got  :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: YT on December 19, 2014, 10:31:05 PM
Plus, it's not so much you gettin cold, it's more not bein able to keep the screen clear in winter. :)
Title: Re: Sodding heater core (I'm guessing)
Post by: Denis O on December 20, 2014, 04:44:18 AM
Could try a pot of Kalimex.

I used it in the past on a couple of Range Rovers with suspected matrix "O" ring leakage. Both of them went on for another 30k each, prior to being sold, with no more leakage and no problems with blocking cores or overheating.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brachunky on December 20, 2014, 11:35:18 AM
I tried that Kalimex on my zj's heater core & did nowt :icon_sad: Sadly, its a case of bypassing until getting around to whipping the dash out :icon_sad:
Title: Re: Sodding heater core (I'm guessing)
Post by: georgen on December 20, 2014, 04:01:22 PM
I too don't like rad weld but have used it when stuck on a Sunday afternoon out green laning so can confirm it works, but rad weld seams to lump up so you do get large solid bits into the system, Kweld in my opinion is a much better product and better at its job, just make sure you shake whatever product you use up well before use. bypass as said is easy but I could not go the winter without heaters so you must be Arder than me LOL.
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 20, 2014, 05:31:32 PM
keeping the ice off the inside of the windows is not easy on a cherokee
Title: Re: Sodding heater core (I'm guessing)
Post by: Dutch on December 20, 2014, 06:32:25 PM
keeping the ice off the inside of the windows is not easy on a cherokee

When you're 'ot 'n ard its a doddle  :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 20, 2014, 10:28:12 PM
Okay, I've spoken to my mechanic, who usually helps me make my final decision, and he also thinks that I should just bypass it for now, and he's also hopefully managed to get me a connector to do so this afternoon.
He then said that he'd put me in his workshop for a weekend when we've both got free time to fix it properly.


I know it's going to be cold, but the temperature hasn't dropped too much yet, and I have many coats, a scarf and gloves! If it gets to the point that I can't de-ice the windscreen, Mum has found that she can put me on the TJ's insurance for not much more money  8-)
Title: Re: Sodding heater core (I'm guessing)
Post by: YT on December 20, 2014, 10:41:13 PM
Inverter & hairdryer for the windscreen. Seen one of those nutters on ice road truckers do that couple of days ago.  :lol_hitting:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 20, 2014, 10:53:10 PM
Now that's a good idea! :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 21, 2014, 11:07:50 AM
and you complaining,

try a cj, at least my heater is on or on
Title: Re: Sodding heater core (I'm guessing)
Post by: Bandit on December 21, 2014, 02:51:42 PM
If you need a heater matrix I got 2 spare ones here, one for mine for when it goes and another one for when the spare one goes  :003: but im happy to let one go if your stuck fella  :icon_biggrin:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 21, 2014, 02:53:15 PM
That would be incredibly helpful! Do pre-facelift XJs use the same matrix as mine (1998)?

How much would you want for one?
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 21, 2014, 02:55:28 PM
Damn, I've just looked and it would appear that they're different (assuming RHD is the same as LHD) :icon_sad:
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 21, 2014, 03:32:46 PM
you'll be lucky if that was the case
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 21, 2014, 03:54:14 PM
It looks like RHD probably is the same as LHD, as the pipes enter the bulkhead in the same location, and the core is (I believe) centrally mounted. Either way, it looks like I'll be going for an eBay one for £100, or would Lighthouse have them for less?
Title: Re: Sodding heater core (I'm guessing)
Post by: Jonny Jeep on December 21, 2014, 06:10:59 PM
The parts list shows the heater hoses entering on different sides on RHD/LHD models. I expect like the TJ that the heater box and matrix are mirror images of the LHD parts.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 21, 2014, 10:48:52 PM
Ah that's interesting. I'll have to have a good look tomorrow, as I've not touched the Jeep since I dumped it at home in a bad mood!
Title: Re: Sodding heater core (I'm guessing)
Post by: gazjeep on December 21, 2014, 11:54:02 PM
£26 - £39 on rockauto but guessing thats for LHD only

Try USA automotive too
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 22, 2014, 12:02:40 AM
Cheers Gaz. How had I never come across USA Automotive before!? Is all of their stuff in the UK? I ask as I have very limited time to do install the new matrix, so need to order it soon.

Does anyone have any tips for the job itself? Are there any other parts required?
I'm going to put the Jeep in the middle of the garage so that I have a clean floor, lots of room and the rain won't matter. Mum's even told me that she'll help by doing things labeling up parts! I think she can tell that I'm a bit daunted by this.
Title: Re: Sodding heater core (I'm guessing)
Post by: jay140285 on December 22, 2014, 09:23:15 AM
Just be methodical in your methods and ask for help where needed.

I was daunted when the V8 dropped its valve, but I got there just took my time and lots of research and Donk gave it one final check over before we started it.
Title: Re: Sodding heater core (I'm guessing)
Post by: The Smiths on December 22, 2014, 12:20:38 PM
and if in doubt where things may go back - take a photo
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on December 22, 2014, 01:02:00 PM
and if in doubt where things may go back - take a photo


Excellent advice...it works for me!
Title: Re: Sodding heater core (I'm guessing)
Post by: gazjeep on December 22, 2014, 01:12:19 PM
Cheers Gaz. How had I never come across USA Automotive before!? Is all of their stuff in the UK? I ask as I have very limited time to do install the new matrix, so need to order it soon.

I have ordered front hubs, calipers & Heavy Duty UJ's off them. Although not on their website, if you ring them, they got me HD greasable UJ's from the US, had them in a week.

Best thing is to give them a call young jedi, Lighty's seem dear these days but if they have it in stock it might be worth paying the premium to get it on time
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 22, 2014, 02:13:20 PM
next day delivery from lighty's is standard
Title: Re: Sodding heater core (I'm guessing)
Post by: Bandit on December 23, 2014, 12:04:39 AM
I dont know if the matrix is handed or not, either way there isnt a huge queue waiting for one, dont be phased by the dash out, its not that difficult, if its a mkII then apparently but dont quote me the dash only needs to be moved enough to gain access, unlike a mkI where it needs to be completely pulled out.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 23, 2014, 12:49:10 AM
Thanks for the help guys. I had a proper look today and you're right, the RHD ones are different.

For now I've managed to get the bypass sorted, which I'm happy with. It does drip slowly with the engine running though - what's the best thing to stop that?



Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on December 23, 2014, 06:40:59 AM
Teflon thread tape on every join should stop that.
Title: Re: Sodding heater core (I'm guessing)
Post by: JamesH on December 23, 2014, 07:45:14 AM
Yep, PTFE tape
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 23, 2014, 09:08:15 AM
I've come across that stuff before - do you wrap it around the thread then screw together with it still on there?
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on December 23, 2014, 09:24:45 AM
Yep...cover the whole thread with three or four layers, nice and tight, then screw it back together as normal.
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on December 23, 2014, 03:03:11 PM
couldn't you find anything smaller?
Title: Re: Sodding heater core (I'm guessing)
Post by: eastryjeep on December 23, 2014, 03:12:36 PM
Really tempted to say 'RadWeld' here, but suspect you'd put a hit on me!

When you wind your PTFE tape on make sure you start at the end of the union and wind the tape in the same direction as the thread so it doesn't try to unwind as you tighten the joint.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 23, 2014, 06:32:29 PM

couldn't you find anything smaller?
Believe me, it took an entire afternoon of Mum driving me around St. Austell just to get the pieces I've used!

Cheers for the advice on using the tape. I'll have a look for some tomorrow.
In the meantime, I've driven the Jeep about 100 miles today and it's used no coolant  8-)
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on December 23, 2014, 07:59:12 PM
Go back and nip up all the joints and you may not even need the tape.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 23, 2014, 09:53:34 PM
They were as tight as I could get them using a vice and a big adjustable! I suppose it could be worth trying now it's been through a few warm-up cycles though. The apparent lack of coolant loss however is making me wonder if it's not leaking once up to temperature?
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on December 24, 2014, 06:44:58 AM
Anything is possible...just keep a close eye on the coolant level while you wait to get a new matrix.
Title: Re: Sodding heater core (I'm guessing)
Post by: daggie on December 24, 2014, 07:08:30 AM
errrm why did you just take one of the hoses of and loop it back  :017:
much easier than all that bollocks  :003:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on December 24, 2014, 08:17:51 AM
I did think about that, but I was worried they might kink so I just did the same as people in the States had done. Once I had them disconnected I did quickly try, and they didn't seem to like bending that much.
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on January 18, 2015, 10:30:41 AM
I've finally got a new heater core, as my passengers aren't as fine with the cold as I am.
I now need to start getting things ready to replace it - are there any special tools that I need, or places that I might get stuck?


I know that I have to disconnect the AC lines, so do I need anything special for that? I've also heard mention of having to replace the foam around the heater box...
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on January 18, 2015, 05:31:40 PM

try and leave the ac connected as its a different matrix to the heater core.

expect some scratched knuckles, but only move what you need to do the job
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on January 18, 2015, 05:59:41 PM
 :iagree:....put up with the scatched knuckles and save the cost of the aircon re-gas!
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on January 18, 2015, 11:56:03 PM
Haha, the idea of working air con amuses me! I don't think it's blown cold in the last ten years...
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on January 19, 2015, 05:39:40 PM
there will be gas still inside, all that has happened is that gas has escaped to the point where there isn't enough to create a cold condition when evaporating
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on February 12, 2015, 02:09:39 PM
Sorry to keep asking the same stupid questions about this, but I'm looking to get this done this weekend, so I need some definitive advice!

Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on February 12, 2015, 08:17:11 PM
there should be a block connector for the air con pipes that goes through the bulkhead, which creates a sandwich style joint. so break it there. looking at the manual it appears that the retaining nut is on the blower side of the block.

8mm multispline ring spanner might be the size but it will be tight on space. The splitter tools will not be of use since these joints are in the engine bay only.
Title: Re: Sodding heater core (I'm guessing)
Post by: JamesH on February 12, 2015, 08:19:17 PM
I haven't done it but have stripped most of the dash out before and would definitely allow loads of time and lots of pots and bags for all the screws and fixings, probably take pics too.

Expanding foam might be ok, I'm ready to be corrected on that though. I'd try and do it without disconnecting a/c because the lime green dye and slime goes everywhere and it is just more stuff to put back together, recharge etc.

Have you got the full workshop manual for the correct year? They usually have stages you can miss and still get the job done (like the a/c) and also list special tools that you don't always need. They are handy to have as a reference though.
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on February 12, 2015, 09:24:16 PM


94yr manual implies it's a cartridge heater matrix. looks like you have a harder job now with the face lift cherry
Title: Re: Sodding heater core (I'm guessing)
Post by: Jonny Jeep on February 12, 2015, 11:14:40 PM
If it's like the TJ the whole dash is basically a mirror image of the LHD one. Saving the pics from a LHD write up and flipping them left-right might help as they'd look more like what you'd be looking at.
Title: Re: Sodding heater core (I'm guessing)
Post by: Dave69 on February 14, 2015, 12:46:43 PM
if you need the tools to separate the lines i have a set but i doubt you will need them. but shout if you do.

if your braking the air con system do it from the engine bay in top gear style to save the lube going in the car.

But there again you shouldn't release the refrigerant into the air as it contributes to damaging the environment
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on February 15, 2015, 07:32:01 PM
Cool, thanks Dave. :001:


Is there likely to be any refrigerant in there? The AC hasn't blown cold in about 8 years...
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on February 15, 2015, 07:36:11 PM
It will be lurking...waiting for a chance to make a mess. :icon_winkle:
Title: Re: Sodding heater core (I'm guessing)
Post by: Brynjaminjones on February 15, 2015, 07:45:11 PM
That sounds about right!


As expected, didn't have a chance to get this sorted this weekend. Have done a couple of hundred miles though and the XJ is behaving perfectly (touch wood)  :icon_super:
Title: Re: Sodding heater core (I'm guessing)
Post by: bgbazz on February 15, 2015, 07:51:23 PM
 :icon_winkle:....Good....keep a firm grip on that piece of wood!