NZE90

The other option is putting some product like carb cleaner or upper i take cleaner on top of the pistons and let it soak over night and hopefully break down the carbon. You would have to put some oil down the bores after doing this as the solvent will obviously was the oil off the bores which won't help with compression. I have taken a few N47 engines apart and there was always a lot of carbon around the ring lands. This isn't my pic, but it is an N47 piston with about the same amount of carbon around the ring lands. Thanks EGR!

I assume the bores looked good when you had the head off otherwise you wouldn't have bothered with the other work? It sounds very close to starting, and i think if you CAN get it started and take it for a decent run it maybe ok. The rings could be stuck after sitting around. If it were me i would try putting 2 sets of jumper leads on it in the hope of increasing the cranking speed. One set to the battery terminals under the bonnet (like you already have) and another set with the + directly on the starter, and the earth directly on the block.

Is it possible there might be some carbon stuck under the valves and preventing them from sealing properly?

Try putting a bit of engine oil into each cylinder, then crank the engine over without the injectors to get rid of the excess oil, then recheck the compression. This method is called a "wet compression test" Also how are you cranking the engine over on the stand?

Thanks John, I'm in contact with him.

Reluctantly selling this as we are moving overseas. 2006 323i with 195000km. Has been upgraded from 177hp to 217hp 325i spec with 3 stage manifold. Good fuel economy (6.9l/100km on a recent trip to Hanmer Springs) Factory options include memory/heated front seats, rear window blind, xenon lights etc. Tinted windows. Body is very good for it's age. Gets polished and waxed every 6 months. Always garaged. During my ownership i have done a lot of maintenance and retrofits to the car. Would like to sell it to someone on here rather than deal with Trademe idiots. Maintenance items by previous owner; OEM Water pump and thermostat Genuine eccentric shaft sensor and rocker cover gasket done at BMW in Wellington. New starter motor Maintenance items by me. Sump gasket New radiator and genuine BMW coolant Thrust arm bushes, top shock mounts Trans service with genuine ZF fluid, mechatronics sleeve and trans pan (with filter) New OEM front pads and BREMBO rotors. New genuine shock bump stops all round. Religiously serviced every 8000km and VANOS filters checked/cleaned. OEM oil filter always used. Rebuilt DISAs for intake manifold New OEM serpentine belt, tensioner and idler. New PCV valve and hoses Retrofits by me: All parts were genuine used. Factory bluetooth with USB. Rear PDC. Cruise control with braking function. Sports steering wheel with paddle shift 90ah AGM battery LCI boot lid and tail lights K&N filter inside stock air box. Silicone intake hose. LCI radio fitted to get rid of dead display pixels Upgraded the FRM (footwell module) to FRM2 Instrument cluster with oil temp and cruise control indicator (original cluster comes with car) Not sure how to price it really as prices seem all over the place. $5000 ono? Located in Rangiora, South Island. 0220650835

What are you doing on here then? Sell your piece of junk and move on with your life.

Yep, the N46 has to be BMWs worst engine. The only decent engines they made were the 6 cylinder ones.

Is the bluetooth aerial a genuine BMW one? Any fault codes present?

Can you put up some actual pictures of the car?

Did you ever get this problem sorted out Cam?

The plastic valve covers are known for warping and cracking.

https://www.trademe.co.nz/a/motors/car-parts-accessories/bmw/exterior/listing/3073041811 Have you tried this wrecker? It's very rarely the antenna diversity though, so I'd be looking very closely at that wiring. Or maybe take it to the dealer or a good Indy who knows BMWs. The proper way to diagnose this fault is with an oscilloscope, and you have to know which wires to check with the oscilloscope. Most garages or Auto Sparkies won't have any knowledge of this.

They are only single turbo. Twinpower turbo refers to the twin scroll turbo that they use i think. The engines themselves aren't too bad. They can be a bit noisy and have the usual BMW oil leaks and coolant leaks. They're not the same engine as the normally aspirated ones

Are you talking about petrol or diesel engine?