Misfire in 4 Cylinders + possible faulty Starter Motor

[caleballen]

Hello all.

I am after some help troubleshooting 2 problems.

First is starter motor.
Second is rough running - 3 or 4 cylinders are misfiring.

Vehicle is a 2004 L322 with the BMW 4.4L M62TU V8 engine.

I have recently replaced the timing chains, guides, vanos seals, PCV, cooling hoses, ahd the fuel injectors refurbished. When I put everything back together is was running like a dog, and also super super rich. Fuel basically coming straight out the exhaust. (Yes, I know that is basically how these engines use fuel when running perfectly.)
Turns out I had the timing wrong, so I rectified the timing. The exhaust camshaft on bank 2 (cylinders 5-8) was 180 degrees out. So I sorted that, but it is still running very rough and rich. Did I damage something here?
White smoke billowing out the exhaust, smells strongly of fuel and burning something. I didn't replace the throttle body gasket when I did the PCV, so I replaced that, and it made it slightly better, but still very rough and rich.
Scanned for codes with the IID tool, nothing. Plugged in a generic bluetooth OBD2 scanner, and got codes:
P1300
P0304 (cylinder 4 misfire detected)
P0308 (cylinder 8 misfire detected)
P0306 (cylinder 6 misfire detected)
P0307 (cylinder 7 misfire detected)
P0155 (O2 Sensor Heater Circuit)

Also the orange engine light is flashing on the dash.

Installed new spark plugs (the old ones were only about 1,000kms old).
I cleared the codes, and started it up, not much change. The P0155 code has disappeared.
When I rev it up to around 3k rpm, it smooths out a bit.
I moved the coil packs around, to see if the misfire followed the coil packs. No dice.
With the coil packs moved, new spark plugs, I now have codes:
P1300
P0304
P0308
P0306
Cylinder 7 seems to be firing correctly, or just not throwing a code yet.

I have checked best as I can for Vacuum leaks, I pulled the front of the intake manifold off to check the pipe that goes from the rear to the front, and that was seated correctly.

I did not replace the valve cover gaskets - they need doing, and I thought I purchased replacements - however I clearly did not. The plug wells seem to be mostly dry and free from oil.

Any ideas for the running problem??


And for the starter motor:

To complicate the troubleshooting - I think my starter motor may be dying / dead.
When I turn the key to start, there is a single tick, and then nothing. Sometimes there is a loud horrible noise that is incredibly unnerving, it sounds like I left a bucket of bolts in one of the cylinders. But when / if it starts, the noise goes away. Then I tried starting it again today, and there was some whirring, like maybe the starter wasn't retracting properly.
Is there any further starter motor troubleshooting I can perform before replacing the thing? It's not a particularly cheap part - $1500 on Ebay in Australia, about $300 - $400 from overseas. Has anyone had any luck refurbishing the starter motor with a new solenoid maybe?
Or have I maybe damaged the ring gear / flywheel when I was mucking about with the TDC locking pin?
Battery is fully charged, I have had it on a charger. Testing shows it is putting out about 800CCA.

I am really keen to get it back on the road - it's been almost 2 months now sitting there. To make my life slightly more interesting, my backup vehicle has decided to randomly stall whenever it feels like it at the lights. I like to think of it as a stop/start fuel saving feature.

[67hardtop]

First thing I would do is give it a compression test.

[FisherX]

Yep I agree. You are going to need a compression check. White smoke is unburnt fuel probably due to low compression. With the exhaust cam 180 out I'm sorry to say I think you may have bent some valves.

I wouldn't run the engine again until the compression check is done cause the last thing you want is a broken valve banging around in a cylinder. That might junk the engine.

Also don't forget to remove the relay for the fuel pump and squirt a bit of oil down each cylinder before checking the compression. I've heard these engines can over fuel on start and wash out the cylinder and give you a low compression reading.

After the compression check and if you find them low, you could also do a cylinder leak down test to confirm bent valve before you pull the heads off.

[caleballen]

Excellent, don’t I feel like a muppet if I’ve bent a valve.

For a compression test I’ll need a working starter motor right? (I guess I will need one long term too.)

[FisherX]

Was your starter working before? The rattling when the starter was engaged could have been the pistons hitting the valves maybe.

To do the compression check you could run a wire from the solenoid on the starter to battery positive to engage it to crank the engine over without using the ignition.

[FisherX]

Excellent, don’t I feel like a muppet if I’ve bent a valve.

For a compression test I’ll need a working starter motor right? (I guess I will need one long term too.)


Hey Caleb any updates?

[irubix]

Hey Caleb any updates?

Busy working 8 jobs to pay for his interference engine rebuild :D

[caleballen]

Well, I replaced the starter motor and performed a compression test.

7 cylinders are showing around 130psi give or take, one cylinder has 0 psi.
The 0 psi cylinder is #8 I believe (passenger side, closest to firewall).

Looks like head/s off, valve replacement.

Question/s:
1. Should I remove the head with the (presumed) bent valve, and just replace the valve/s and head gasket.
2. Remove both heads, get them skimmed, replace valve stem seals etc etc.
3. Set the vehicle on fire and claim insurance.
4. See if I can find a complete second hand head from another L322 / X5

I'm leaning towards option 2, aka financial ruin and divorce.

The (not) funny part of this whole saga is that originally I replaced the timing chain guides to avoid having to replace a bent valve.

The long version of the starter motor is as follows:
I ordered one from America, via Amazon. Brand new, generic no name, about $150 AUD. Second hand one from Land Rover wrecker in Adelaide was $500.
The day it arrived at the post office, I went to pick it up in my other car (obviously, because the L322 is off the road). I collected it from the post office, and stopped in at Repco for some unrelated parts. After I came out of Repco, I went to start my car, and no lie - the starter motor in my other car crapped itself! What are the odds of a) owning two vehicles with simultaneous failed starter motors, and b) having a brand new starter motor (for a different vehicle) in the boot. So that chewed up some time that I could have spent on the Range Rover.
When I removed the L322 starter motor, I discovered two things.
One was a previous owner had installed a starter motor from presumably a BMW X5.
Second was the X5 starter motor had a cracked housing, as shown in the image below.
This cracked housing is what was making the horrible noise when operating the starter motor. The piece that had cracked off was rattling round, so I had to fish that out.

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