I've just joined the (operational) 940 owners club!

[Moomoo]

Originally Posted by Laird Scooby

I doubt it will Andrew and the video is too short to hear if there's a misfire or any other associated problems that would point to HGF but a pressure test of the cooling system should help identify any leaks and where they are. Probably best done before K-Seal goes anywhere near it though!

Aye, you’re right!🤔

[Badger vs Bodgers]

There's a bit of a misfire going on now on accel, and a fair bit of liquid coming out of the exhaust.

A slightly longer but awkward video as I had to film, press the accelerator and not fall over.

I barely manage the latter on level floors at the best of times!

https://youtu.be/bSUEwfMbOiM

[Laird Scooby]

Originally Posted by Badger vs Bodgers

There's a bit of a misfire going on now on accel, and a fair bit of liquid coming out of the exhaust.

A slightly longer but awkward video as I had to film, press the accelerator and not fall over.

I barely manage the latter on level floors at the best of times!

https://youtu.be/bSUEwfMbOiM

Get yourself a compression tester that screws into the plug holes and holds the pressure until reset then get the engine hot. Pull fuses #11 & #13 to disable the fuel pumps then whip all 4 plugs out. Wedge the loud pedal on the carpet with a brick or similar, fit the compression tester in #1 plug hole and crank the engine for a few seconds. Note the reading and reset the tester, move it to the next hole and crank again for a similar time. Note and reset the tester, repeat for remaining cylinders.

General figure should be 120-160psi depending on your compression ratio but the important thing is consistency, shouldn't be more than ~10% variation between them.

Once complete, refit the plugs, HT leads, fuses etc and check it fires up as it should.
Then consider doing a cooling system pressure test too.

[Badger vs Bodgers]

Well, I compression test (twice per cylinder to check):

4: 155 / 160

3: 150 / 150

2: 125 / 120

1: 150 / 150

Rechecked cylinder 2 at 120.

Sparkplug on cylinder 4 looked a little white but otherwise OK. All the others were fine.



I pressurised the coolant and after finding and curing a couple of drips it lost about 2psi over 20 minutes. Then I saw a bit of water under the car and went investigating - I found it hard to get a picture of it, but it was coming out of the exhaust side of the head gasket, flowing down the side of the block.



Put everything back together and tried running it; lumpy AF with a nasty knocking noise and won't idle. Greeaaaat. Double checked the spark plug leads all went back OK, and that's alright.

Reckon the HG definitely needs replacing at this point.

I've had the spare head skimmed at a local machine shop (Jamieson's in Bedminster for reference; can highly recommend them for machining work). I'm planning on rebuilding it off the car, then swap it in one go. But it's undrivable for now - luckily I've been able to borrow a car for the next couple of weeks.