Check your expansion tank !

[griston64]

Decided to to a coolant change and flush today as my last one with Comma G48 was in 2019. I actually did a coolant flush and change when I got the car in 2018 as it had been dry stored for 7 years.

One thing that was slightly worrying was the state of the expansion tank outlet pipe. It comes with metal sleeve fitted to stop it crushing and that had pretty much disintegrated along with a lot of the plastic. I had fitted this secondhand in 2019 and it looked in pretty good nick



Luckily I had ordered a new one from FRF at a very reasonable price with VOC discount



Did a reverse flush and fitted new expansion along with a new gen Volvo hose and clips



Refilled with Comma Super Coldmaster Little drive up to temp and checked for leaks. All good



One thing I did notice was the Comma G48 that came out was very clean and still a nice colour.

Also fitted new horns today as one had packed up

I'm going to relocate them soon but didn't have time today

[BogfordGarage]

Nice work there. Looks smart now. I'm sure it's probably been discussed before but is Comma's G48 good enough for a mixed metal engine, as in is it close to the Volvo Blue green spec. I only mention it as I use Preston's in all of our cars and I've never really thought about using anything else. I wonder if the corroded tank insert was incorrect coolant from a previous owner?

[360beast]

Originally Posted by BogfordGarage

Nice work there. Looks smart now. I'm sure it's probably been discussed before but is Comma's G48 good enough for a mixed metal engine, as in is it close to the Volvo Blue green spec. I only mention it as I use Preston's in all of our cars and I've never really thought about using anything else. I wonder if the corroded tank insert was incorrect coolant from a previous owner?

As long as it is ethylene glycol with or without Silicates it is fine.

[J liddy]

Hi I have always used volvo blue.green genuine in my D24 900 are there any known issues or just keep with it after 23 years on it

[Laird Scooby]

Originally Posted by BogfordGarage

Nice work there. Looks smart now. I'm sure it's probably been discussed before but is Comma's G48 good enough for a mixed metal engine, as in is it close to the Volvo Blue green spec. I only mention it as I use Preston's in all of our cars and I've never really thought about using anything else. I wonder if the corroded tank insert was incorrect coolant from a previous owner?

The Volvo ones last better than Rover 800 ones but in both cases, the metal inserts are still mild steel. There's probably a similar level of corrosion inside the engine but with the insert in the expansion tank, 0.5mm of loss will leave it with near nothing but inside the engine, 0.5mm is next to nothing.

In fairness, any mild steel exposed to moisture for 20+ years is going to corrode though.

[Rversteeg]

If you replace the expansion tank, get one with a level switch.

[griston64]

Originally Posted by Rversteeg

If you replace the expansion tank, get one with a level switch.

Interstingly the one I got from dealer has a float in it. I have a sensor from an 850 tank which looks similar. Wonder if that would work ?

[Laird Scooby]

Originally Posted by griston64

Interstingly the one I got from dealer has a float in it. I have a sensor from an 850 tank which looks similar. Wonder if that would work ?

If memory serves Mark, the same sensor was used on the 9xx, 850 and S/V/C cars from 1998-02 so should fit. Have a look in the Pocket Data Book that Bob12 sent you, should give a part number for the low coolant sensor for the 9xx and 850 models.

It was about 10-12 years ago i researched the low coolant sensors for the Volvo so i night not have remembered correctly.

[baggy798]

Yeah I changed it last year as a slight leak from that connection, plus the old tank was letting the bay down! There was a ring of plastic chunks still stuck in the hose, which I managed to fish out and then ran some water down it with the lower hose off.

[bob12]

Originally Posted by griston64

Decided to to a coolant change and flush today as my last one with Comma G48 was in 2019. I actually did a coolant flush and change when I got the car in 2018 as it had been dry stored for 7 years.
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Also fitted new horns today as one had packed up

I'm going to relocate them soon but didn't have time today

This is where I put my new horns on the 745 (before I made up an extension loom).

Bob.