[SOLVED] Cylinder 1 Misfire - P0301 / P0300 Mystery

[Toothbrush]

Originally Posted by ard

Agree.

Or a valve retainer clip slipped off or wasn't properly seated....

Something in the back of my mind is telling me I read something like this before...here or BF...

Well, you appear to be on to something. Pulled the valve cover off again and took a better look and seems the keepers aren't seated correctly for one of the exhaust valves.

A little bit of relief at the moment, hoping this is indeed the whole issue. Just need to figure out the most expedient DIY to fix it. I guess I'm a sucker for learning the hard way. The up side is this problem has increased the number of tools in my garage, experience, and intimacy with what's under the hood of this X5.

Does anybody know of a way to compress the spring without removing the cam or using the AGA tools? Some variation of a universal spring compressor? I have an OTC 4573 Universal Overhead Valve Spring Compressor, but it's too bulky to work.

Assuming this is the actual problem, once I get this rectified and (hopefully) no longer have a misfire I'll update the thread title/first post for others.

[pshovest]

Well that sure looks like the cause of the compression problem. Valve stem in right photo doesn't even stick thru the retainer. Where did the keepers go? I wonder what prevents valve from dropping into cylinder......friction w/ valve stem seal perhaps, hopefully it isn't bent.

[Toothbrush]

It's hard to tell from the picture, but the top of the valve stem is actually where it's supposed to be.

I think one (maybe both) keepers is still gripping the stem, but somehow under the retaining plate. I took a pick and made sure the keeper is still there. Sadly, the other keeper must be on the 'bottom' side hidden by the rocker so I can't tell if it's where it should be, if that makes sense.

[ard]

Hope that is it, and no damage is found....

[Toothbrush]

Have AGA tools on the way, supposed to arrive tomorrow at some point, so might be fixed before the weekend assuming there's nothing else undiscovered to tackle and I don't have to replace the spring plate or something - can't seem to find those for sale anywhere (discontinued/unavailable). Thankfully, I still have extra unused keepers I bought laying around somewhere.

I broke the back tab of the eccentric sensor, so will be removing it and inspecting to make sure it's still structurally sound. It popped off quite easily when I disconnected it, so may have been snapped but dangling this whole time. Had a bit of a scare as while searching for that small bit of plastic, I found it laying just inside one of the rear oil drain ports. Carefully extracting it was not fun, to say the least.


Also, I lost a valve cover grommet somewhere in the removal process, which means tonight is going to be full on search party. It must have been pulled off as I maneuvered the cover out. I imagine lots of time under the engine tonight.

I really, really, really hope I can just remove it all and re-install and be good to go.

[AlphaBetaX5]

Originally Posted by Toothbrush

Have AGA tools on the way, supposed to arrive tomorrow at some point, so might be fixed before the weekend assuming there's nothing else undiscovered to tackle and I don't have to replace the spring plate or something - can't seem to find those for sale anywhere (discontinued/unavailable). Thankfully, I still have extra unused keepers I bought laying around somewhere.

I broke the back tab of the eccentric sensor, so will be removing it and inspecting to make sure it's still structurally sound. It popped off quite easily when I disconnected it, so may have been snapped but dangling this whole time. Had a bit of a scare as while searching for that small bit of plastic, I found it laying just inside one of the rear oil drain ports. Carefully extracting it was not fun, to say the least.


Also, I lost a valve cover grommet somewhere in the removal process, which means tonight is going to be full on search party. It must have been pulled off as I maneuvered the cover out. I imagine lots of time under the engine tonight.

I really, really, really hope I can just remove it all and re-install and be good to go.

If you have ISTA, you can test the sensor using one of the service functions to verify whether it works properly.
So you don’t have to remove it.

Keep posting.

DME relies on the ES sensor to command the VVT motor to change the eccentric shaft angle in different RPM ranges, which subsequently changes the valves’ lifts.

If that sensor is faulty, the VVT will be blindly turning the eccentric shaft gear. Which in turn results in rough running.



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[Toothbrush]

I recently re-installed ISTA but get an error every time it loads. I've been trying to fix that off and on, but haven't yet. It's on the to-do list.

UPDATE - Problem SOLVED!

It was the keepers on the first exhaust valve for cylinder 1 sitting incorrectly. Somehow I missed it the when I did the original work, even though I quadruple checked everything and thought I was being meticulous about it. Also missed it the first time I removed the valve cover after the misfire appeared.

Either way, I was concerned, to say the least, about getting the spring plate off without damaging anything as I couldn't compress it directly. So... ended up carefully getting the AGA short foot between the spring and spring plate to release the tension on the plate. That took about 1.5 hours to work out ... After that, it was a matter of gently rocking the plate until one of the keepers came lose. I had a bit of a scare though, as the second one fell into a little oil and hid from me for a while. Thought maybe it was AWOL and all those thoughts of potential damage... Very glad I have a number of magnets I can poke around with (found it that way)

Valve stem seemed straight and held near 100% with the leak down after I put it all back together with new keepers. Put it all back together and no rough idle, no misfire, no odd sounds and no codes!

Will keep an eye on it and periodically check for oil leaks, but seems it's resolved now.

Final thing was to put on the V8 cover I bought a while back, but has been siting so lonely and sad on a shelf in the garage.

A BIG thank you to everybody that has posted!

[Entropy]

Been following this thread for a while. Glad you got it solved. Congrats! You got lucky the valve didn’t drop and bend (or a lot worse). This is a good reminder for those of us who are plannng to DIY valve stem seals to be extra uber careful and tedious.

[AlphaBetaX5]

Originally Posted by Toothbrush

I recently re-installed ISTA but get an error every time it loads. I've been trying to fix that off and on, but haven't yet. It's on the to-do list.

UPDATE - Problem SOLVED!

It was the keepers on the first exhaust valve for cylinder 1 sitting incorrectly. Somehow I missed it the when I did the original work, even though I quadruple checked everything and thought I was being meticulous about it. Also missed it the first time I removed the valve cover after the misfire appeared.

Either way, I was concerned, to say the least, about getting the spring plate off without damaging anything as I couldn't compress it directly. So... ended up carefully getting the AGA short foot between the spring and spring plate to release the tension on the plate. That took about 1.5 hours to work out ... After that, it was a matter of gently rocking the plate until one of the keepers came lose. I had a bit of a scare though, as the second one fell into a little oil and hid from me for a while. Thought maybe it was AWOL and all those thoughts of potential damage... Very glad I have a number of magnets I can poke around with (found it that way)

Valve stem seemed straight and held near 100% with the leak down after I put it all back together with new keepers. Put it all back together and no rough idle, no misfire, no odd sounds and no codes!

Will keep an eye on it and periodically check for oil leaks, but seems it's resolved now.

Final thing was to put on the V8 cover I bought a while back, but has been siting so lonely and sad on a shelf in the garage.

A BIG thank you to everybody that has posted!

Congrats!

It sounds very complicated to work on the V8s!
Glad it is fixed now!
Did you tally up the costs? Mostly new tools to the garage I guess!







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[Toothbrush]

Originally Posted by Entropy

Been following this thread for a while. Glad you got it solved. Congrats! You got lucky the valve didn’t drop and bend (or a lot worse). This is a good reminder for those of us who are plannng to DIY valve stem seals to be extra uber careful and tedious.

Thanks! I hope this thread can help prevent the oversight I made, at least once.

I'm really glad that didn't happen. Also glad there was not some other issue (worn piston rings, etc).

Originally Posted by AlphaBetaX5

Congrats!

It sounds very complicated to work on the V8s!
Glad it is fixed now!
Did you tally up the costs? Mostly new tools to the garage I guess!

Are you insane?! Just kidding, I really don't want to total it all up, but I do have all the numbers. You're right, there's a number of new tools I bought using this situation as an excus, erm, reason to get.

Like most things, this wasn't that complicated after getting into it, just a significant amount of learning for a garage 'mechanic'. This forum was a great source of help.

As far as costs in general, I bought this X5 well under it's value, but probably am just about even now. That includes lots more than the valve stem job though. Other than engine parts, everything I've bought will be used on other current and future vehicles, so no loss there.

The original work I did cost: $883.39 USD.

This included:

Torx sockets/drivers
Hex Sockets
Couple new magnet sticks
Valve Cover Gaskets
Upper Timing Gaskets
Vanos O-rings x8
Eccentric Shaft Sensor Gasket x2
Vacuum Pump O-ring x2
Valve Stem Seals x32
Leak down tester
New Spark plugs
Two Radiator hoses (upper and y hose that connects to it)
Spark Plug tubes
Few extra plastic rivets
New set of keepers (still have four new ones left)
New Front rotors/brakes/sensor

On top of that, I had to pay an additional $280 for an eccentric sensor that broke on bank 2. Free labor help isn't always free. Friend that was helping was a little upset at his wife, and well, I shouldn't have let him near anything for a while. Hindsight is 20/20.

Plus, other miscellaneous items/seals (e.g. shop towels, cleaner, etc)

I shopped around quite a bit to find things on sale to keep costs down.

I know I've spent almost as much or maybe more on restoring cosmetic/aesthetics than that though.

I replaced the gear shift cover, bought new floor mats (BMW floor mats are $$$), roundels, fixed most of the interior trim, purchased high quality leather refinishing products (cleaner, conditioner, stain - they look nearly brand new), vent tabs, refinished the melted parts of the grab handles, replaced the cargo hold trunk handle, purchased new covers (e.g. V8 engine cover), and new splash guard.

I still have a laundry list of things to do, but it's all been worth it and all been fun, except leaning over the hood and dropping things under the engine into what we loving call the "BMW abyss". That's probably where I've spent too much time! Having towels stuffed everywhere to prevent those accidents works great, but when it doesn't...

Plus, I got my kids involved, which was great.

About a month ago, I replaced the timing belt in a Camry and that was boring, tedious, 'easy', and not nearly as rewarding.