Breezy_Pete

Sounds almost like immobiliser but can't imagine why that would only affect warm start. I think with low cranking speed it wouldn't start at all. Not sure on that though.

Yep, red light is oil pressure.

For oil pressure warning, disconnect the the single wire plug from the pressure switch and see if it has oil inside it. If it does that's a solid indicator of failed pressure switch.

Low cranking speed can cause failure to start warm in these I think. Try charging the battery and see if that helps. Does the battery light correctly illuminate when you turn on ignition?

Fuse 9 or 11 on battery fuseholder, depending on exact build date. The 5 Amp blade fuse with a thin red/violet wire coming off it. Try removing that the next time you see unexpected fan running.

In that case it has a fan control module hanging off the nearside chassis leg, close to where the bottom hose attaches to the radiator. Your symptoms suggest that a relay within this is sometimes sticking on instead of clicking on and off according to radiator thermoswitch control input. You could prove that this is what's happening by disconnecting the smaller of the two plugs going to it while the fan is running. If fan keeps running, module is faulty. Access isn't super easy though, much better from below with undertray removed. There's a fuse you could remove to demonstrate the same thing, one of the blade fuses in the battery fuseholder. I'll try to find which one. Those blade fuses hide under a plastic cover, to the right of the strip fuses as you look from in front of car. One of the 5 amp ones, from memory.

Does this car have air conditioning?

Apparently this car has a wiper module, rather than a wiper motor. So only three wires, permanent 12V (which ought to be full battery voltage), earth and a LIN data connection to the BCM/onboard supply control unit.

Hi Myles, I have just sent you a message relating to this.

I think the inlet manifold is your vacuum source. Only diesels have tandem pumps as far as I know. I think since the only gas flow here is from servo towards engine, the oil must be brake fluid. Source of that must be master cylinder I reckon.

Rear shocks for this VIN are showing as 5Q0 513 029 KF, which was dropped Sept 1st 2023 and replaced with 5Q0 513 029 RR. RRP is £119.50 + VAT each, from Skoda in UK currently.

Might it be brake fluid rather than engine oil?

That part number ending 011 isn't the shock part number, I suspect. It'll be a sub-part number or some such. I'll message you to request VIN, so I csn look up correct number for you.

Yep, very welcome contributions, just what I was hoping for. There's a cbza on ebay with only 43k miles on it that's tempting (123k less than current cbzb). If I can create enough space in my garage to store it for a while I may grab it.

Fuse 36, 5 amp. Also supplies the number plate lights, so check if they are working or not.

Definitely myself. But not definitely doing it yet. The current engine may be worth doing some work on, even though it has high mileage; it sounds healthy. It just has hesitation from low revs, so my partner who is the main driver complains it is difficult to pull out from junctions with confidence. The fuel economy is also worse than I expect. I know the turbo actuator has play where it attaches, and I know the chain timing is being reported by VCDS as a problem. More info here https://www.briskoda.net/forums/topic/531352-petes-rescue-roomster/

Thanks Jack. I've made a screenshot in case those get removed by an over-keen mod.

Thanks Jack, that's very helpful. Much appreciated.

Looking at acquiring a spare engine for our CBZB-equipped Roomster, and some of the better value looking ones are CBZAs rather than CBZBs. Wondering if anyone has knowledge of what hardware differences there are, if any, between these engine codes? Candidate items that might differ strike me as being things like injectors, turbo, throttle body?? Probably something I can painstakingly look up part by part, but being lazy and hoping someone can tell me. 😁 Thanks for any info.

The window motors wouldn't need coding if you bought matching part numbers but I have a feeling that broken wires in bellows at either or both A-pillars will be found and mending those will solve the problems.

There isn't a negative for the washer pump, the polarity of the supply to that motor is dependent on whether front or rear screen washing is requested. By forcing it to earth, you risk blowing fuse 15, if the function is selected which now shorts that to earth. X-relief relay sounds like a good candidate for some of the malfunctions, but I haven't the time or energy to look up which just now, or tomorrow daytime.

Sorry, never had any dealings with Mk1 Octy stuff.

Passenger side can work from its own switch for 10 minutes after first powered up (refitting its fuse, or reconnecting car battery) but after that if it doesn't get any communication from driver's side motor module, it goes to sleep. I will message you @OG-Skoda since you don't have enough posts yet to send a message.

The key to effective bleeding of the rear wheel cylinders, I think, is to do so with the rear beam at its normal working angle. If you look at images of people doing stuff to rear drums with the beam hanging down in the position it falls into when jacking just on the bodywork, the wheel cylinder tilts at same angle as arms of the beam. That results in the cylinder being at an angle to the horizontal. The bleed nipple is central in its length, so an air bubble can sit above and beyond the entry point of the bleed nipple, like a bubble in a tilted spirit level.

You have a very "can do" attitude. 👍 I wouldn't have looked at that and thought "yeah that may be repairable". 🙂 I replaced one on a Vauxhall something-or-other for one of my neighbours, and it was only about a dozen quid for aftermarket. Looked similar inside after post mortem dissection.