No heating

[RichC4]

Driving in the cold recently I noticed the cabin heater had stopped working. It eventually started working again after a while, though the output is not great. Engine temps seem normal on the gauge, coolant level is as expected.

I had a poke around with a warm engine last weekend. The feed coolant hose is hot, both sides of the valve. Warm on the return. Valve control seems fine as I could see it move and the temperature was the same both sides.

I'm thinking this probably means blocked matrix? I had a look in my Hayne manual and it suggests I'll need to get the A/C degassed and remove the evaporator to change the matrix. Anyone done his and know what the score is?

 

[Shayne]

If you have drained coolant , or have a leak , leave it ticking over with the heating on full and see if you can top up the rad some more .

Heater pipes are higher than the radiator so the system can seem full until you use the heater .

 

[RichC4]

I need to change the radiator anyway, so I'll drain it down and see what I can see then I think.

 

[Tractionman]

Raise the front end while doing as Shayne says, you could also try 'burping' the hoses as your doing it to help expel air.

 

[AndycruiserguyLomas]

Before I started taking anything to bits I'd check the flow through the heater and heater valve with a hose pipe. If the rear heater is connected up you could always bring that into play to warm the cabin.
Taking a heater matrix out is an involved job although I've not done one on a Collie I did one on my 80, this is the degree to which you have to strip it down.

 

[SteveJB]

Andy that picture looks like the aftermath of a very bad car crash

 

[AndycruiserguyLomas]

Yep Steve it was a bit of a job, good thing I had a perfect matrix out of a scrapper they were very expensive new. Took me five nights to reassemble as you have to take the whole interior out to the back seats. Very satisfying though, having a heater which doesn't leak.

 

[SteveJB]

Well if mine starts leaking it's either a dog turd leak stop or if that don't work heated motor bike gear and a Russian rabbit hat

 

[RichC4]

I tried the rear heater but I didn't get any warmth out of that either. Maybe that's also blocked or just not hooked up. New matrix is about £160 on roughtrax, so not terribly expensive.

Definitely going to try the hosepipe trick - that looks like a non trivial job there!

 

[Grimbo]

Fixed a customers Prado recently with exactly the same issue..... thermostat was stuck open....new genuine one from Roughtrax and job sorted .

 

[BobMurphy]

I had the matrix out of a RAV4 - twice, not a fun job .

Bob.

 

[Shayne]

 

[RichC4]

Fixed a customers Prado recently with exactly the same issue..... thermostat was stuck open....new genuine one from Roughtrax and job sorted .

The radiator thermostat? I can have a look at that while I have the radiator off, it heats up quickly though which I wouldn't expect if that were an issue.

 

[Grimbo]

No, the engine thermostat in the side of the block .

 

[AdventureWagon]

The wife would still be like "how long are you going to be??" or "is it going to be finished soon" despite the dash looking like that and a sea of parts in the driveway.

 

[RichC4]

Started on this today. Radiator hoses have a coating of fine copper particles, I think this is normal but just to double check?

 

[MODVRS]

I'd say more iron oxide than copper, but it looks normal to me.

 

[RichC4]

Oh yes, that would make more sense since it's an iron block.

In other news, the thermostat is fine so it's not that causing issues.

 

[Tractionman]

Some of those pour in head fix solutions can be like that. Blocked instead ?

 

[RichC4]

I haven't had a proper poke at the heater matrix yet as it got dark, that's for tomorrow.