I'm having a bad day. I'm a woman with only limited mechanical knowledge, so my questions that follow might seem pretty basic.

I have an '05 MCS with 22,000 miles on it. Today my SES light and DSC lights came on and stayed on. I call my dealer (1.5 hrs away) and they fit me in at 2pm. While I'm there I ask them to check the slave cylinder on my clutch as there seems to be a slight catch when I press in on the clutch. Initially, I'm not that worried. The SES light is on solid and no EML light so I'm thinking...no misfire. WRONG. Evidently it was a misfire. In fact they do a compression test and the engine has a 60% compression loss in cylinder 1...huge according to them. They indicated that it appears the head may have been torqued incorrectly from the factory and that they may need to send the head out to be machined. Also, as they are still trying to get to the bottom of exactly what caused all this, but they also think it might need a valve job.

Ok. So in case that wasn't enough. The slave cylinder issue. Well not only does it need a new slave cylinder, it has a defective flywheel and needs a whole new clutch. I've driven manual transmissions since I was 15 (I'm 42) and gone over 90,000 miles on a couple vehicles and never needed a new clutch.

And one final thing. The DSC light that is still on...well evidently no fault code is stored in the computer so they aren't exactly sure what is wrong with it. They'll deal with it after they fix all the other stuff and hopefully it will be related to one of the other problems...although they weren't exactly confident that would be the case.

Anyway, the car is now at the dealer ('til at least Tuesday) and all will be covered under warranty. I fully intend to ask my mechanic more about all this on Monday, but quite frankly I'm sure I only took in half of what he was telling me as this was such a surprise.

In the meantime, my questions are mainly about the cylinder head & the machining:

1. Aren't things like cylinder heads built with exact tolerances...if so, how can you simply machine something (thus changing the tolerance) and then have it work properly? Are cylinder heads overbuilt so that they can be machined and still be within the tolerance?

2. If it was torqued incorrectly, are they machining it to fix a warp (so the way I would picture it is they are machining the botttom & top of the head to make it flat again).

3. What about a valve job (they seemed to be pretty sure that is the case)? Do the valves slide down and if they were damaged would they have also caused damage to the head and thus the head would need to be machined in that area. I've heard of machining a port to accomodate a larger valve, but what about machining a port and using the same size valve that was originally in there. Or would they put in a larger valve?

4. And how do valves get damaged? Isn't there some sort of protection in the head for the valves?

At this point I'm so confused any light you could shed on this would be helpful. I've done a bunch of searches, but nothing quite matched this scenario.

Thanks in advance. Kim.

 

i just had my flywheel and throw out bearing replaced and when they were performing that job they found a leak on cylinder headgasket and replaced it. I was in shock and asked them what would be the reason, the first thing they said "misreplacement, or defective part". When everything finished, they took it on a test drive and the car threw DSC and SES and after further inspection they changed the DSC module and cam sensors. Now everything is fine. Flywheel problem is common on early 05 models.

Since everything is covered under warranty, i am a happy camper, which should apply to your situation. I am on the same page with you driving manual for years. Ohh, btw, since you have close to 20K, and sice they are opening the gearbox, pressure them to replace your clutch too.

Mine took 10 days and i was given a Mini loaner.

Good Luck

 

If the head is warped they should replace it. They will let you know on that as soon as they get into it.

good luck Kim, and keep us posted

Berk

 

if the head is warped, you most likely will get a "valve job". I cant see them using the old valves? No?

 

Wow, I have an 05 and hearing all this kind of scares me! I just got a pulley installed yesterday as well! I hope I do not run into problems like this. Best of luck to you and hope you get your mini on the road asap! I know i missed my mini when I had to take it in for paint work. it was out for 3 weeks!

Garrett

 

Don't worry Kim...with a screen name like RenaultF1, you can't loose What ever is wrong, I'm sure they'll fix it under warranty...

 

If possible try to push for a new head. It really depends on what kind of relatioinship you have w/ your dealer and how far they're willing to go for you. If they want they CAN give you a new head. But try to be nice and polite, they'll respond better that way

If the warping isn't bad, machining is enough to straight out and the material lost can be added back by using a thicker head gasket.

A valve job refers to regrinding the valve seat. basically they're grinding the area where the valve rests at on the ports for a tight fit.

It should be fine if it's performed correctly, just see if they'll give you a new head as a precaution and a peace of mind. Hope it works out for you!

I'm rooting for Sauber/BMW myself :p BMW is with sauber this upcoming season right? Or is it starting next season...?

 

I've had any number of rebuilt / machined heads and have always had great performance from them. If my 2005 MCSa needed to have this work done on it I'd have no problem with the head being machined so long as the work was done correctly. And believe me, if the rework isn't done right you'll know very quickly.

 

Oh yeah no doubt if it's machined properly it'll be no problem. I just wonder what other dmg the head might've suffered during 20k miles she drove with improperly torqued head bolts. My thinking is 20k, that's practically a brand new car and I'd want the materials to be like new also, and a rebuilt head doesn't sound too appetizing for me. lol

But like you said, a properly rebuilt head or whatever will be fine, just personal preference/opinion

 

This is the first time I’ve heard of a MINI service department having a head machined and a valve job performed. Usually the head is replaced out right. Depending on the amount of material removed when the head is trued determines whether it can be used in conjunction with the stock pistons. More than likely it will only take a small amount to make it flat and they do have a slightly thicker head gasket available to keep compression and valve clearance safe if it is necessary. I would guess any amount over 0.3 mm would probably render it out of spec. At this point there isn’t enough information to comment on the valve work but, yes, the valve seat and stock valve can be re-worked and be just fine if not better for flow gains. Once again I would be very surprised to hear that they would go through the expense of valve-seat work rather than replace the head. If they are going to go through with this it would be advantageous to invest in a little port clean up at the same time.

 

k-huevo you make a good point. Most companies just replace the part outright if it fails. But this might be similiar to the infamous rod-bearing recall on the E46 m3's. BMW will determine whether replacing the part or rebuilding the part is cheaper(including labor) and go the cheaper route. It's a BIT more complicated but that's the gist. I suppose MINIUSA found machining the head to be cheaper than replacing it.

 

My car and yours might be a few that went out the factory with a bad head. My car is currently @ the dealer having the cylinder head replaced. They say the head isn't flat and isn't making a proper seal to the block.

 

Hi guys...thank you so much for responding. I feel better about all this after reading your posts and now I have more to go on when I talk with the dealership on Monday. It will definitely be warranty work so I'm not worried about that. My concern was more about how the car would be after such a major repair. To that extent, you've definitely relieved my worries. Thanks!

I'm going to ask and see if they can't replace the head as some have suggested. It definitely sounds like that would be the better way to go. I have a great relationship with my dealer and they've gone the extra mile for me in the past. When I left there yesterday, they said I would be getting a whole new clutch (not just the flywheel) so I think I'm all set there. Although I'll double check that.

Oh and FWIW, mdsbrain, ours aren't the only 2 with the head problem...my dealer has seen a few of them.

I'll post back here as I know more. Thanks again guys!

p.s. Hey Barnabas...BMW purchased Sauber at the end of last season, so they're running as BMW/Sauber now.

 

Hope you get a new head and get your MINI performing well again Yeah I saw the qualifying this morning...Schuey seems to be on track to sweep the season...ugh

 

Ok...here's the update. I got my car back yesterday morning (I would have wrote this sooner, but I misplaced the work order with all the info). Not bad...in at Friday 2pm and done by Tuesday 9am and all covered under warranty (they had the head back from the machine shop by 10am Monday). Oh and the dealership called me today to make sure everything was ok and the car was running well...great people!

Regarding the cylinder head, the work order reads:
"Fault code stored: P0301, misfire in cyl1. Performed compression tests on all cylinders. cyl1-90, cyl2-100, cyl3-140, cyl4-140. Performed misfire testplan using gt1 and found misfire in cyl1. Performed cylinder leakage test using both shop air and smoke machine. Found cyl1 to be leaking 60% thru exhaust valve. Determined problem to be cause by a faulty cylinder head. Sent head to machine shop. Replaced cylinder head with remanned head from machine shop. Replaced head gasket, exhaust mainfold gasket, both intake mainifold gaskets, valve cover gasket, spark plug tube gaskets, 12 cyl head bolts. Torqued head bolts to proper spec plus 90 degree yield. Reassembled vehicle. Reset adaptation values and fault codes."

I had called the shop on Monday and asked about the cylinder head and whether they could simply replace the whole thing. They said they would love to but that MINI/BMW does not send out complete heads - they are empty of the valve train, and when they receive a new head it needs to be sent out for machining. Also they indicated that the only time they are able to get a complete head is if the car overheated and it can be determined that the head was warped. So I'm sure the reason must be as Barnabas guessed. It would be cheaper to have a head machined and do a valve job (especially as each type of repair has a set #of hours that MINI/BMW will pay for...go over and it is on the dealership.).

Regarding the clutch...they replaced the clutch and flywheel assembly. In the end they determined that the slave cylinder was fine, but that there were faulty pressure plate fingers. They indicated that now whenever anyone has any clutch issues, they automatically replace the flywheel as there is a better part than what comes from the factory.

Now that the car is back, I can easily say that the clutch was never right from the day I picked the car up. Also, the power seems way smoother on the car...definitely has more pickup, especially at the low end.

Thanks everyone who chimed in on this...you calmed me down and I learned a lot! Kim