Oh No! Heater matrix leaking?

[lnparry]

Happy New Year everyone.

I think I have found another reason for my heater feeling a little less hot (see recent post on temperature gauge. A slightly damp driver's carpet with a slick feel and sweet taste plus occasional topping up of coolant suggests my heater matrix is leaking.

There are some very useful and detailed guides in FAQ about how to go about replacing the heater core and it looks a horrendous job necessitating removal of half the dash. I'm debating if this is within my ability and paying for it to be done would probably cost more than the car is worth.

Has anyone replaced a heater matrix before as a first timer and is the job as horrendous as it looks or is it just a matter of methodically ploughing on and getting there in the end? Any tips would be appreciated.

Car is a '97, 945 LPT with aircon.

Thanks,
LeeP

[capt jack]

I've done several heater boxes on p1x70 cars and it's a doddle, but I am aware that on the 900-series it's a fairly major undertaking.

I guess it depends on how much time you have, how much you're prepared to invest in the car, and how much your alternatives will cost you.

If you can afford to be without the car for say a week, then to start methodically stripping the dash out on a Saturday morning, taking it step-by-step, and working your way through without any pressure to get it finished by Sunday night, well, that would be a reasonable plan. Assuming of course you've got somewhere suitable to work.

The good thing about older Volvos is that they are well-engineered, and as a rule things do come apart fairly easily, and do go back again afterwards.

If on the other hand the car is in daily use, you don't want to go DIY and you couldn't be without it, then your choice is between paying to get it done, or paying to replace the car.

Either way, would it be an idea simply to bypass the heater for now from within the engine bay? That way the leak won't get any worse, or do any more damage to the interior, and it will give you a bit of thinking time. Time enough to research the repair and get some quotes. Downside is of course the heater won't work!

Oh, one last thing, how do you know that the leak into the footwell tastes sweet......?

Jack

[john.wigley]

Originally Posted by lnparry

Happy New Year everyone.

I think I have found another reason for my heater feeling a little less hot (see recent post on temperature gauge. A slightly damp driver's carpet with a slick feel and sweet taste plus occasional topping up of coolant suggests my heater matrix is leaking.

There are some very useful and detailed guides in FAQ about how to go about replacing the heater core and it looks a horrendous job necessitating removal of half the dash. I'm debating if this is within my ability and paying for it to be done would probably cost more than the car is worth.

Has anyone replaced a heater matrix before as a first timer and is the job as horrendous as it looks or is it just a matter of methodically ploughing on and getting there in the end? Any tips would be appreciated.

Car is a '97, 945 LPT with aircon.

Thanks,
LeeP

Hi, Lee. I had this problem back in 2002 with my 745 and had the same reservations that you are now experiencing. From my records, I see that Volsaa in Derby charged me £115.78 to do the job. They obviously did it well as I had no further problem with the heater for as long as I owned the car - an additional 14 years - so I feel that it was worthwhile.

I don't know what it would cost today, but this might give you some idea if you were able to allow for 18 years inflation?

Regards, John.

[lnparry]

Originally Posted by capt jack

I've done several heater boxes on p1x70 cars and it's a doddle, but I am aware that on the 900-series it's a fairly major undertaking.

I guess it depends on how much time you have, how much you're prepared to invest in the car, and how much your alternatives will cost you.

If you can afford to be without the car for say a week, then to start methodically stripping the dash out on a Saturday morning, taking it step-by-step, and working your way through without any pressure to get it finished by Sunday night, well, that would be a reasonable plan. Assuming of course you've got somewhere suitable to work.

The good thing about older Volvos is that they are well-engineered, and as a rule things do come apart fairly easily, and do go back again afterwards.

If on the other hand the car is in daily use, you don't want to go DIY and you couldn't be without it, then your choice is between paying to get it done, or paying to replace the car.

Either way, would it be an idea simply to bypass the heater for now from within the engine bay? That way the leak won't get any worse, or do any more damage to the interior, and it will give you a bit of thinking time. Time enough to research the repair and get some quotes. Downside is of course the heater won't work!

Oh, one last thing, how do you know that the leak into the footwell tastes sweet......?

Jack

Hi Jack and thanks for the reply,

Your thoughts mirror my own and as I can manage without the car for a while, I may have a crack at it especially as it still looks so good and has just passed a (no advisories) MoT. At the moment the leak is manageable but I may try the heater bypass until the weather warms up as I will have to work on the drive.

Regarding sweetness, I just squidged my finger in the dampest part of the carpet and tasted with the tip of my tongue - antifreeze tastes sweet, rain water doesn't (don't try this at home kids).

Cheers,
LeeP

[Laird Scooby]

Originally Posted by lnparry

Happy New Year everyone.

I think I have found another reason for my heater feeling a little less hot (see recent post on temperature gauge. A slightly damp driver's carpet with a slick feel and sweet taste plus occasional topping up of coolant suggests my heater matrix is leaking.

There are some very useful and detailed guides in FAQ about how to go about replacing the heater core and it looks a horrendous job necessitating removal of half the dash. I'm debating if this is within my ability and paying for it to be done would probably cost more than the car is worth.

Has anyone replaced a heater matrix before as a first timer and is the job as horrendous as it looks or is it just a matter of methodically ploughing on and getting there in the end? Any tips would be appreciated.

Car is a '97, 945 LPT with aircon.

Thanks,
LeeP

It might be an idea to try some Radweld Lee.

[aardvarkash10]

bypass it. Do it when the weather is better. Use a blanket and hot water bottle in the meantime!

Its the final big job on my list too - but getting the sunroof sealed comes ahead of it. It is not a technically difficult job - as you say its just a case of methodically ploughing through it. Take lots of photos as you do it - if you have a sport camera that does one-photo-every-two-seconds set that up and just record the whole process so you can review in sequence if needed.

[lnparry]

Originally Posted by Laird Scooby

It might be an idea to try some Radweld Lee.

Hi Dave,

I wondered about radweld or whatever the modern equivalent is but isn't there a risk it will clog up all the narrow waterways elsewhere in the engine and cooling system?

Cheers,
LeeP

[Laird Scooby]

Originally Posted by lnparry

Hi Dave,

I wondered about radweld or whatever the modern equivalent is but isn't there a risk it will clog up all the narrow waterways elsewhere in the engine and cooling system?

Cheers,
LeeP

You should be ok on the 940 Lee, Radweld is still a current product and to be honest, i've not had a problem with it.
However it used to carry a warning "Not fur use in Rover 827/Honda Legend 2.7 Models" because it would clog the very small waterways around the cold start valve and i've never used it in any of my Rovers for that reason.

However i have a slight weep from my cooling radiator so will be using it on my 760 soon, fairly confident the 940 doesn't have any smaller coolant channels than that does.

[loki_the_glt]

There's a very good thread on the forum (https://www.volvoforums.org.uk/showthread.php?t=43621) that detailsthe procedure. It deals with the A/C-equipped models but the basic principals apply to non-A/C ones.

The first, and most important, thing to do is identify which heater matrix is fitted to your car as there are a couple of similar but subtly different units. It's also worthwhile replacing the hoses - you may have to do this as the old hoses might refuse to part company with the heater pipes - at the same time.

Space as well as time comes into the equation as the job is more easily done with both front doors open for (relative) ease of access.

[Paul240480]

I had a faulty blower motor on my old 240. Virtually the same amount of work as getting to the matrix.
I tried to get a matrix as belts and braces , but struggled to find one at that time. I spoke to the now retired Tony aka ‘ The old Volvo man’ at Braydons Volvo in London. He advised that the matrix’s themselves rarely fail and to just flush it and stick it back in unless it had actually failed of course. I did just that and added a new heater motor.
That was in around 2012/13. The car is still going with it’s new owner and all is still fine.
So I’d just see if you can remove some trim and get a lamp in there first see if you can identify the leak source. You may be pleasantly surprised.....