If the battery was flat, unlocking the door with the key has set the alarm. The alarm system will detect if one door is opened while the car battery is disconnected or flat, and will trigger the siren. For how long was the car parked ? If you happen to park it for longer periods (2-3 weeks or more),...

The one in the trunk its protected from corrosion and also sits vertically so flakes from under the cooling plate wont fall over the control board. But as above, any used one that looks very clean will work, cheap to test. If you have a junkyard close, the second gen S40 V50 has it under the rear se...

Also the MAF sensors get covered with small dust particles. This reduces their performance. However, just cleaning with the MAF spray doesn't really change much. I managed to clean mine with a small brush and there was a good difference on how the engine felt - mine is the non turbo MAF so much easi...

I don't think that will give you a 50/50 mix. Rather mix the gallon of concentrate with a gallon of distilled water, and refill with this in the last step. I have to say, the manual talks about 7.5 liters, however you may find you can only refill with something like 5 liters. Assume 1L is stuck insi...

Not directly relating the pump, linked because it seems a common fault occurring relatively early, worth checking while there

Don't think a belt would 'stretch' at least not an eye-measurable amount. If only the exhaust cam is misaligned, I would guess the person who replaced the belt had the ex cam move off mark. Also careful with the mark on the crank pulley and block - crank has two teeth marked, block has a hard to see...

What kind of key do you have ? If it's the model with flip blade, the transponder is glued inside one of the plastic sections. In theory it's unlikely to break if the key is dropped - unless it's like thrown into a brick wall. However the way your key broke apart makes me think it's not an original ...

For the tb tensioner, the INA ones actually have the manufacturing date stamped behind the small temperature needle. Of course, the tensioner needs to be removed from the car to see the date, but this is not that hard - if you can find a bud to keep the tension on the belt near the tensioner while y...

I have the same on mine. It's a damaged catalytic converter. Basically, the efficiency of the converter is right at the limit of the downstream O2 sensor, so it triggers the light depending on the driving conditions. Mine started to turn on especially in hot days, but got more steady as the miles ke...

I have a few of these, they look nice, no rust, and are very easy to torque correctly
https://www.fcpeuro.com/products/volvo- ... t-febi-kit
A close up pic https://www.fcpeuro.com/products/volvo- ... i-31423735