Air Con: 70: Heating poor after replacing leaking core matrix

[Arnold Layne]

I bought a heater core matrix off eBay last year and undertook the challenging task of replacing it myself, after watching it done on YouTube (a few times). Anyway I thought it was a success, the old one was leaking under the passenger footwell carpet, and now that’s stopped. Unfortunately the heater never really gets hot enough to warm the driver now. The A/C works well, I had it overhauled a couple of years ago, I just really need the heater to work properly now.

It might be related, I noticed that the car’s engine hardly gets up to normal temperature, even after a long drive. By this I mean that the temperature gauge needle doesn’t easily get to horizontal, in the middle of the gauge. It’s an old car, so could it be that the thermostat is faulty? If so, might this be the reason the car’s heating struggles to get warm?

I really need a reliable experienced 850/V70 mechanic near Stockport, any recommendations are very welcome. I’ve been badly let down by Hallmark, don’t bother recommending them.

[Bob Meadows]

I had a similar problem on my '97 V70 regarding engine temperature:~

The thermostat is changed - also opted for the engine sensor as well, problem solved. Careful with the two stat bolts as they can be awkward- once removed copper grease the threads.
This is a straight forward job with inexpensive parts.

(Quality after market parts used and fine to date)
Good Luck.
Bob.

[capt jack]

Definitely worth fitting a new thermostat, but be very careful when undoing the two retaining bolts - don't be tempted to use any force at all. The lower half of the stat housing is made from a brittle alloy, and it will shatter if hit hard.

As for the matrix, my understanding is that some after-market ones don't have the same internal pipework, and aren't as good at radiating heat as the better/more expensive OEM quality ones.

Jack

[hal9000f]

Originally Posted by capt jack

As for the matrix, my understanding is that some after-market ones don't have the same internal pipework, and aren't as good at radiating heat as the better/more expensive OEM quality ones. Jack

Unfortunately, that's correct.

I replaced mine (10 yrs ago) with Nissens and it's about 25% less efficient

At least, it was a fair price...

[Clan]

Originally Posted by Arnold Layne

I bought a heater core matrix off eBay last year and undertook the challenging task of replacing it myself, after watching it done on YouTube (a few times). Anyway I thought it was a success, the old one was leaking under the passenger footwell carpet, and now that’s stopped. Unfortunately the heater never really gets hot enough to warm the driver now. The A/C works well, I had it overhauled a couple of years ago, I just really need the heater to work properly now.

It might be related, I noticed that the car’s engine hardly gets up to normal temperature, even after a long drive. By this I mean that the temperature gauge needle doesn’t easily get to horizontal, in the middle of the gauge. It’s an old car, so could it be that the thermostat is faulty? If so, might this be the reason the car’s heating struggles to get warm?

I really need a reliable experienced 850/V70 mechanic near Stockport, any recommendations are very welcome. I’ve been badly let down by Hallmark, don’t bother recommending them.

I doubt your non volvo heater radiator will be very efficient, you get what you pay for.... Get a 92 degree volvo thermostat too that makes a lot of difference to the heat output.

[Luxobarge]

Agree with all of the above - sounds like you need a new thermostat (get genuine Volvo and make sure it's fitted the right way round) which will at least get the engine up to temperature - and will probably pay for itself before long in improved MPG.

Also as above, the cheaper heater matrices have fewer cores and fins, and are far less efficient - you get what you pay for. As with most Swedish cars, the original heater matrix in these is super efficient, and will quickly heat the car up toasty warm even in serious minus temperatures.

[Arnold Layne]

😩 ugh. I watched and re-watched Robert DIY’s great video on how to do this job, and thanks to all of your helpful comments here, I thought I was up for this job.

Unfortunately one of the screws was going nowhere. It even broke my new T40 wrench, bought specifically for the job 🤦🏻*♂️. Further attempts only achieved me stripping the screw, so I tried to drill it out, and also tried using those drill bits for removing broken screws. No luck.

I’m thinking I might try cut the screw top into a “bolt” shape with my Dremel, so I can try a wrench, but I’m not feeling confident now, particularly because of the very confined space.

Probably end up taking it off to Hallmark next week.

[SteveSarre]

Hi all,

If a bolt snaps when removing the upper part of the thermostat housing (as has happened to Arnold), is it possible, easy or advisable to unbolt the lower part of the thermostat housing from the engine block (with the upper part still attached)?

https://www.skandix.de/en/search/?q=thermostat&k=740

(Set up may vary according to model and year etc)

Steve

[staffy460]

can highly recommend bryn motors in wigan , ask for alex . tel 01942 711112 , they have done work for me and im fussy they are honest and very know their stuff on volvos

[Arnold Layne]

Originally Posted by Arnold Layne

😩 ugh. I watched and re-watched Robert DIY’s great video on how to do this job, and thanks to all of your helpful comments here, I thought I was up for this job.

Unfortunately one of the screws was going nowhere. It even broke my new T40 wrench, bought specifically for the job 🤦🏻*♂️. Further attempts only achieved me stripping the screw, so I tried to drill it out, and also tried using those drill bits for removing broken screws. No luck.

I’m thinking I might try cut the screw top into a “bolt” shape with my Dremel, so I can try a wrench, but I’m not feeling confident now, particularly because of the very confined space.

Probably end up taking it off to Hallmark next week.

I successfully shaped the T40 Torx screw top into a size 13 bolt with my Dremel but that bolt is still not going anywhere

I’ve only further stripped the outside of my newly shaped bolt by trying. I called a local garage and they will charge me £75 per hour labour to do it, which burns my arse!