Seems like there are a few coolant posts going around recently! Unlike JR posted below, I do not have oil in my coolant - but quite a few black cinder-like specks which seem to be increasing in number and weren't there a week ago when I last inspected stuff.

I've never seen this before - could it be hose or seal detetioration somewhere in the system? Anyone else had something similar to this? Coolant is about a year and a half old - maybe it's just time for a flush and refill.

-b

Sounds like electrochemical deterioration of your hoses: some cheap EPDM hoses are not too resistant to this and will crack or delaminate from the interior. Dayco has an article on the problem at their website. For best results, use ONLY Volvo OEM hoses.

Dear benfingland,

May this find you well. Further to Tom F.'s post, if the hoses/radiator are the originals, change them over this coming weekend, presuming you can get replacement parts. A 12-year-old radiator does not owe you even a penny. The same applies to radiator and/or heater hoses. These items' working life is no more than 10 years.

If the number of "specks" is growing rapidly, something unpleasant is about to happen.

Radiator hoses are cheap. OEM [Volvo] heater hoses are US$30/each. While this isn't "cheap", these hoses are not easy to access, so a case can be made, for spending more, to get a longer change interval.

If you would not otherwise do so, drain the system using the drain port on the passenger side of the engine (US/Canada models) towards the rear. I believe it can be open/closed with a 12mm open-end or box (ring) wrench (spanner).

Post again, please, with your findings.

Yours faithfully,

spook

I would lean toward a hose breaking down. It could be plastic from the radiator too. Swab some specks up with a paper towel to make sure it’s not oil.

1993? – when was the radiator and the hoses replaced?
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Tom F. Couple of Volvos Mods, RainX & cup holders.

All hoses + reservoir replaced 3 years ago along with radiator, then the radiator was replaced again (due to dreaded green pressure cap problem!) last year, along with heater valve. This couldn't be the headgasket, could it? No trace of coolant loss or water in the oil.

I not sure but I’m still leaning toward a hose issue. ScanTech hoses? Did you replace the heater hoses? The connection at the block is a hot spot. Was the heater core forced flushed? The particles could be leftovers from the old system and just taking it’s time to show up in the reservoir. I’d drain the coolant and try to catch some in cheese cloth. If you’re sure it isn’t oil do a through power hose flush, block, heater core and radiator, then use the new Prestone universal coolant. You will need a new T-stat gasket. Inspect the inside of the hose that connects to the thermostat cover.
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Tom F. Couple of Volvos Mods, RainX & cup holders.

Thanks guys for all the advice,

I think I might just replace all the hoses again, anyway. I know that the reservoir hose is OEM, but the others could be suspect - when I replaced them it was on a semi-emergency basis and I didn't have the option at the time of waiting for the highest quality materials. It seems like a generally sound insurance policy! And I'm not so happy with the second radiator I put in, either - I believe it's a CSX or something like that, and it definitely doesn't fit as well as the Nissens which I put in before. But I had limited options at the time - stranded in a parking lot, I could either pay $200 to have it towed to someone who knew what they were doing, and then pay tons more for parts and labor, or jump in a friend's car to the nearest radiator shop, drop $200 for the part, and do a self-install in the parking lot.

If the specks are still there after I replace and flush, I'll post back for more opinions. Maybe the radiator is as rough on the inside as it is on the outside.

-b