Letting the level go too low can cause airlocks which expand when hot and push the coolant out of the cap. One of those "damned if you do, damned if you don't" situations.
There's a very good reason for pulling the fuel pump fuses (#11 & #13) and besides the obvious fire risk from the fuel vapour floating around, the fuel that is injected will cause "fuel wash" in the cylinders. As #4 was probably the last one you got to, not only would it have had the most time to get fuel wash but there was probably a longer time between doing #3 and #4 than any of the others because #4 is awkward to get to. This would just add to the effect.
I'd suggest buying a new compression tester and repeating the compression test. This time pull fuses #11 & #13 to prevent fuel wash. Volvo quote the B200F as being 0.9MPa which is 130psi.
https://www.ebay.co.uk/itm/200779373166
That should do the job and because it holds the pressure reading, much easier to read and to use, once screwed in to each cylinder means you can get in, floor the throttle and then crank. What isn't clear in the photos is there is a pin on the side of the "neck" of the tester that you press to release the pressure after each test, you can just make it out in the photos. That holds the pressure until you release it.
As for the 945 being more sluggish than a 145, the 145 with B20A was only ~82bhp if memory serves and weighed ~1200kg. The 945 with B200F is ~112bhp and weighs 13-1400kg so yes, it's heavier and i suspect has higher gearing. Max torque on the B200F is 158Nm which is ~120lbft@2800rpm, i can't remember the torque figures for the B20A (assuming that's what you had, if you had a 145E with the B20E engine then that had 135bhp and was much livelier!) but either way the 945 with B200F wouldn't be much different to the 145 with the B20A - definitely underpowered in such a heavy body!
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Jun 16th, 2021, 13:43
pressure test
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