TideLog Posts Tagged “misfire”

I was on the 471 on Saturday on the way to Greg’s from Jenny’s, one of First’s Wright Urban Gemini bodied Volvo B9TL double deckers and as soon as I sat at the back, and the driver set off I knew straight away something was wrong. It juddered badly upon acceleration, and the engine was making a machine gun type noise whilst being sluggish. This told me straight away the engine had a problem, possibly a misfire.

The cylinders in Volvo engines can be shut off electronically by the Engine ECU if there’s a fault, so it could have been a result of this shut off caused by a misfire. The bus wasn’t in limp-home mode, it was still quite responsive. As soon as the driver let off the accelerator the shuddering stopped, so I knew it wasn’t a powertrain problem, so this excluded the gearbox, propshaft and differential.

It also couldn’t have been crankshaft or conrod big end bearing shells either. Anyway, being a respecting mechanic, as I got off I had this conversation with the driver:

Me: “I think you should call Comms and get this bus straight into the garage, your engine sounds like it has a misfire or internal problem.”

Driver: “A misfire, are you sure?”

Me: “Can you not feel how it judders when you accelerate, and stops juddering when you don’t? The engine sounds like a machine gun back there!”

I glanced down at his dashboard infodisplay, and sure enough the CHECK indicator was lit. There was no message displayed as he had it set to INFO rather than MESSAGES.

Me: “Even your CHECK light is lit. I’d call it in to be safe. If it gets any worse the bus computer will put the engine in limp home mode, you’ll notice it go really weak. The STOP exclamation indicator will come on your dash too.”

Driver: “Thanks for letting me know! How do you know all that?”

Me: “I work with buses like this nearly every day, for a friend in the Midlands”.

Driver: “Ah, it’s good to have guys like you to notify us of issues, us drivers can’t always tell there’s a problem when we’re in the cab at the front here. I’ll let someone know!”

Anyhow, I went on the 471 again yesterday to get to Manchester through Bury to get the tram to Manchester to catch a train to go back up to Birmingham, on the SAME BUS, with the SAME problem! It either hadn’t been called in, or it hadn’t been fixed! If that’d been Rikky’s bus, it would have been out of service within ten minutes of the problem being noticed, and wouldn’t be out again until fixed!

Just goes to show First don’t give a shit about a machine in their fleet that costs DOUBLE the cost of your average semi-detached HOUSE!! The single decker Volvo B7RLE’s are £130,000, and the doubles can be up to £200,000! It shows just how disposable they treat their equipment!

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