2017 sprinter 2.1 limp mode 165 thousand miles l

[Scoooby1989]

Van is going into limp mode.

Fault codes showing:

• P0263 Cylinder 1 contribution/balance

• P0266 Cylinder 2 contribution/balance

• P0272 Cylinder 4 contribution/balance

Coolant has a glitter/sparkly look in it. I tested with a magnet and it doesn’t stick, so thinking block sealer rad sealer may have been used by a previous owner.

Heaters are blowing out hot air, and the van starts and sounds completely normal with no obvious misfire. Idles smooth.

No injector knock or rough running, which is what’s confusing me given the balance codes.

Before I start throwing parts at it, has anyone seen this exact issue before or got advice on what to check first?

Any help appreciated