Heater Matrix Problem

Afternoon all,

I have been lurking for a few weeks, trying to work out what I needed to look out for when buying a Jimny. 

A few days ago, I took the plunge and splurged on a 58 plate Jimny that appears to be rust-free (or as close to that as they come) and I got it for a steal.

It seems as though there is an issue with the coolant system resulting in the following symptoms:

• The heater will not blow hot
• The engine temp suddenly went into the red as soon as I came off the motorway on the drive home.
• Top pipe was hot and rigid

All of which I would usually put down to a faulty thermostat or a blockage somewhere else. However, I noticed that the cab got more and more damp as I drove home.

Upon inspection this afternoon, I found a random pipe (looks distinctly like a coolant pipe) underneath the passenger seat and the passenger footwell is full of coolant.

Soooooo..... I fear it is the heater matrix. Based on the requirement to remove the entire dash, does anyone know roughly how much it is likely to cost me to have it sorted? ....... just trying to prep my bank account for the pain!

Thanks!

I sell the heater matrix for around £75 delivered (depending on where you are) but have never changed one. I would check around that nothing such as a pipe or actuating lever has been kicked off by the driver or passenger

Martin

Never heard of anyone having heater problems like this. But however there is from time to time overheating problems with the m13 engines, either cracked cylinder head or head gasket.
Worst case it could be that something has cracked open from the overheating causing the coolant to leak.

sorry for the scare, hoping it is just a hose.

It sounds like the matrix itself is leaking. I expect your coolant level is down, which is why the car has over-heated.

The pipe under the passenger seat is a mystry, is it matrix pipe size or bigger?

The heater matrix has two pipes coming off it, both steel, a feed pipe (hot water) and a return pipe which go in to flexible pipe, but as far as I know the flexible pipes are inside the engine bay, not the passenger compartment, unless someone has bodged/modified it.

If the flexible pipe was leaking, it would leak in to the engine bay not the vehicle interior.

I guess as a quick test, you could bypass the heater matrix inside the engine bay to see if the engine still over-heats, that narrows it down to the matrix.

Good luck

Robin

I've recently paid £500 for a local garage to fit a matrix to a gen 3. That was labour only, I provided the matrix. They had to remove the dash. I don't think I was ripped off, I think it just takes a long time to do and beyond my skills. At least I hope I wasn't ripped off.....!!

Is the water in the footwell the same colour as the rad. water or is it clear like rainwater?

Roger

Thanks Chilton!

Roger, it's very much coolant coloured!

Right. It's been into the garage and the good news is that they can stop the overheating; it was just a hole in the radiator pipe.

The bad news is that in their opinion, the heater matrix has been deliberately bypassed because it leaks, and bypassing is a cheap alternative to the dash-out replacement option. It's pretty much what I feared but they then quoted 13hrs to do the job 

Martin, once I've got over the shock and found someone who can do it a little quicker, I'll be in touch to buy the part.

On the SJ (Jimny gen 2) when they get old, the heater matrix often is full of debris, leaves and such. I once just cut a hole in the heater casing to access it for cleaning, and glued a piece of plastic over the hole afterwords. (the lid of an ice cream box)

Maybe such a repair is possible on the jimny gen 3?
Cut it off/open, swap the matrix and glue it back together?

Or find the actual leak, and solder or glue the leak in the matrix in place if possible?

This guy replaced his heater matrix, it took 6 hours, most of that time was removing the dashboard. Scroll down he gives a list of what needs to be undone.

auszookers.com/forum/viewtopic.php?f=5&t=54362

There are other Youtube videos where people say cut the heater matrix pipes and it will come out without removing the dash, but then you have to have flexible pipes to connect the matrix and I wouldn't fancy that.

A garage should be able to get the dash out, heater changed and back in in 6 hours or less, so shop around.