Just wanted to post some info and a few pics for anyone that ends up with similar issues.

My car's a 2002 Mini Cooper R50 with 109,000 miles.

The check engine light is on, and the code it is showing is P0303 - Cylinder 3 Misfire detected.

In order to save some money in labor costs, I opted to remove the cylinder head myself. I'm not an experienced mechanic, but I have a few people at my disposal who could coach me through any snags I ran into. I surprised myself and was able to do almost the whole job on my own with the Bentley manual by my side.

The process of removing the head wasn't too bad. I made sure to put everything in labeled ziploc's. I'm sure that will be helpful when I reassemble the engine.

I got the head off today and found a burned exhaust valve in cylinder 3. The rest of the valves and the head itself don't look damaged.

I'll be sending the head out to a machine shop next week for a valve job. I'll try to update this thread with info on whether the valve job cleared up its SES light/misfire issue.

 

Wow.

 

Got the cyl head back from the machine shop. It looks almost like new.

Here's what they did to the head:
-cleaned it
-replaced four exhaust valves
-cleaned all other valves
-replaced all eight exhaust valve guides
-removed & reinstalled camshaft
-16 new valve seals & reassembled the cyl head
-resurfaced the head

The old valve in the pic below is the burned one from cyl 3. There were 3 other valves (the other cyl 3 exhaust and both cyl 4 exhaust valves) that were showing signs of wear, so they got replaced, too.

 

Way to go. Looks great!

Jeremy

 

Great to hear it is working out. Keep us posted on your progress after you get it back on.

 

Here's the status...

I finally got everything put back together yesterday, new oil, topped off the coolant [didn't do a complete flush during disassembly, just emptied out the hose under the radiator]. Front wheels are on and the car is back on the ground after almost a month on jack stands. I've only had time to work on the car a few days a week.

So, I connected the battery and turned the key, and it turns over, but does not start. I think I've seen someone on the forum describe it as going "yun-yun-yun."

The battery I got with the car from the previous owner seemed pretty old/weak so I went to autozone this morning and found out that it is indeed bad. I bought a new battery and installed it... but the car is doing the same thing as before. I'm sure it's a good thing that it has a new battery, so that's fine, but it didn't solve my problem.

I have triple-checked that everything is plugged in and hose connections are made. There seems to be fuel pressure, I stuck some needle-nose pliers in the little valve on the end of the fuel rail and a spray of fuel shot out.

The previous owner has an MSD ignition coil and MSD wires in there. I'm wondering if it has died, or the wires are bad. I'd be slightly surprised if the coil decided to die now... It was working when I parked the car in the garage, even with one badly burned and three slightly burned exhaust valves, the car was running. Would swapping out the coil to an OEM be a good next step?

Any other ideas as to what the starting problem might be?

 

Just swapped out the MSD coil pack for a brand new Duralast. No change in symptoms. Starter cranks but doesn't start. Haven't changed out the spark plug wires or the spark plugs yet. The plugs are just about brand new. I bought and installed them right when I bought the car last month, just before I found out what rough shape the engine was in.

After swapping the coil pack with no luck, I cleared out the codes that have been sitting in the computer from before I started this whole project. I keep forgetting to mention (since it didn't seem as big of an issue and the codes didn't show up until just before I disassembled the car) that the computer threw codes P0201 P0202 P0203 and P0204 - "Injector Circuit/Open - Cylinder 1" (2, 3, 4)

I wouldn't imagine that that would keep the car from starting... anyone have experience with those codes? Originally, I was hoping that once the car ran, I would clear the codes and see if the P020_ codes came back or if they were a fluke. Worth mentioning them now, though, I guess...

 

Set the timing?

 

I think the timing should be right where it was when I took the camshaft sprocket off... I marked it and used a BMW tool to ensure that the chain went back on in the same exact location as it came off.

Someone mentioned to me today that maybe there's something going on with the crankshaft position sensor, and that that could cause the car not to start. Next chance I'll get to work on the car will be Sunday or Monday... Guess I'll take the intake manifold off again and take a peek at that sensor. I think the cable may have taken a bit of a beating when I was sneaking the intake manifold in and out without unplugging the sensor cable. Maybe it's partially disconnected, or maybe it was on its last leg and I killed it for good.

I'm seeing it called the "Crankshaft Pulse Generator" here: https://www.penskeparts.com/Diagrams...4&rnd=03192010

and "Crankshaft Sensor" in the bentley manual... I'm only talking about one part, though, right?

 

I would clear fault codes. Disconnect battery for 10 minutes. Confirm coil pack harness and cam position harness is connected. Then refire. If no fire up then I would check crankshaft position sensor harness/connector. Good luck!

Jeremy

 

I don't see a CPK causing it not to start... I see the potential codes of injector circuit Open.... You verified you have fuel pressure, but are your injectors spraying to make the spark.... ?

Do you have enough gas ? Might as well ask it...

 

A crank sensor will most certainly cause a no-start.. on every car ever made.

And it will also knock out injector and spark operation.

A quick test is verify spark operation.. if you have it, then you know the crank sensor is at least functional (however, timing can be an issue..)

 

To clairify, I was mostly asleep while typing that. I don't see it causing it not to start in this situation. It was working before, hesitantly and after repairs it just stops ? Not the CPK. It has to be something else that was dismantled.

Ignition system has been replaced , so as a basic thought, shouldn't be that.

Again, I would check the injectors. Verify that theyre receiving power and not messed up. If a PO thrashed this car and tried to do maintenance... For whatevwr reason and removed the injectors... Say set them down in a pile of dust rather than treating them right... Issues begin.

Check quantity of gas.

Check to see if your bypass valve isnt stuck shut, and the SC isn't spinning enough on crank to allow oxygen into the motor... Or even your Throttle body isn't messed up ..

Think about things you've touched that could create the same problems, rather than one simple operating switch that doesn't tend to fail as often as it leaks that's causing it to be replaced.

My $.02

 

All good stuff guys, thanks. I'll be looking at the car again on Sunday & will investigate what you've mentioned.

 

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