So...I dropped off my 09 R55 (125k) at a mechanic friends place to have the timing chain replaced. While he was at it I decided to have more work done. Including...

- Turbo resonator delete

- Catless downpipe

- 2nd cat and resonator delete

- DV+ diverter upgrade

- larger intercooler

- (already had AEM CAI)

While installing the downpipe, he found out that the wastegate was loose. I decided I might as well upgrade the turbo and get a tune. I ordered a k03/k04 hybrid and stage 3 tune. That's about the time everything went South...

My mechanic took the car for a spin after the work was done and it backfired loudly once and puffed black smoke from the exhaust. It had bent the exhaust valves and popped the rockers off the top of those valve springs...

He sent the head to a machinist and had the valves replaced, reinstalled the head and it bent valves again...

Where do I go from here? My mechanic insists the turbo is too much for the car and that he can get it running with a stock turbo.

My mechanic has rebuilt multiple engines and I trust his work...and at the same time the seller of the turbo and tune has a great reputation. I'm at a loss of what to do now...do I spend the money on forged parts?

None of us are sure why the car has had such issues. Does the car have to many miles (worn parts)? Is the turbo and tune too much for the motor? Did my mechanic miss something?

I'd love to hear input from others with a modded 2nd gen Cooper, where do I go from here?

 

It happened once to me after a rebuilt and 3k miles later...I was selling the car when the guy pushed on it and the rocker arms flew inside the head...the issue was....I did not tighten the crankshaft bolt to spec...

So, ask your mechanic what was the torque and angle and if he had replaced these bolts including the camshaft bolts. and what the torques were for those two>?

 

Going to move you to the Gen2 section, better fit for your questions.

 

Thanks!

 

Crankshaft bolt torque spec has changed from 100 deg to 180 deg. Using the wrong spec can cause bent valves. Also, not setting the valve lash preload correctly can cause the same problem. If your mechanic hasn’t done MCS timing before, that’s another possible cause. Be sure all the TTY bolts are replaced —- stretch bolts are NOT to be re-used.

 

He's done multiple timing jobs on the n14. Anyone can make a mistake though.

 

Any update?

 

Yeah...he got the head back from the machine shop, installed it...and it immediately bent and broke valves. Now he's telling me I need a new motor.

I want to take the car to another shop so badly right now...but I don't want to pay to fix an issue I didn't cause. At this point I just want my car back in good running condition. I can live without the extra hp I guess.

 

Wow that sucks! Unfortunately, I see no happy ending in this scenario and if one of the valves broke the engine probably is trashed. Just building a motor and building a BMW motor are two entirely different things. Different processes and different specifications, with more than few gotchas thrown in for good measure.

 

Sorry to hear it....that $uck$!

 

Send it down/up to me and I'll take care of it

 

Wow I just saw your post! Car is still sitting... and needing a new motor. Where are you located? I'm almost tempted.

 

Im in northeast philly pa.
needing a new engine is a big deal. So if i were to do it, i would test and diagnose the engine anyway and only replace what's damaged.

 

I'm in Indiana. I think I'm going to talk to a lawyer and see what I can do. I don't think I owe him anything more. He needs to own up that he made a mistake and owes me the repairs. I was hoping it wouldn't come to this...

 

As a person that owns a shop I can't fault the mechanic on the initial failure. He didn't do anything with the valvetrain on the stuff you had done they failed after he drove it. And since you installed a bigger turbo with a tune that very well could be the failure. And we can't tell the mechanic oh you drove it hard. As a mechanic I do often push the car a bit as I want it to break while I have it, not after giving it back to a customer.
Now after doing the repair of new valves and such why did they now fail? That is the next question. Is it the boost and tune? Possible. Is it a timing when put back together? or something else. At this point some diagnosis to why it happened again is needed to determine a repair and later who is at fault for the 2nd repair.

 

How would we go about determining what went wrong? He already took the head off the car. It was only one valve that broke this time and it damaged a piston when it snapped. The engine blew up as soon as he turned the key, that doesn't sound like a tune or turbo issue to me. What would cause it to go to bits so fast?

 

Before taking it apart they should have checked timing to see if that is why if did that. Then if it was correct start looking for the reason. If it was off try to figure out why?

 

And I bet since the heads off that its anyones guess as to why now... I'm not sure what to do anymore

 

I know of only three things that can cause valve / piston contact and leave the valve intact, just bent ---
- Timing error
- Valve "preload" not set after new and correct part number valve installed
- Rocker arm not seated on valve correctly,
- OK, loose / broken rod, but highly improbable in this case
Timing is set by the person putting it all back together, while valve train assembly and preload is done by the machine shop doing the head work. As I mentioned earlier, crankshaft center bolt may have been tightened to the wrong spec, if it was ever tightened. There's no need to loosen it for disassembly, so a quick check should let you know whether or not it's loose.

 

The 1st time it bent 3 valves (if i recall correctly), the 2nd time it snapped one valve.

 

When mine let go, it was on the hiway and all 8 ex valves were bent --- intakes were fine. Found a loose crankshaft center bolt --- my bad! I also didn't leave all the parts with the machine shop to do a preload check, after all new valves, one seat, and several guides --- strike two! This's when I learned about "valve preload".

If you're only losing a few valves, consider checking your hydraulic valve lifters --- some may be stuck and not compressing. Also, get part numbers of the replaced valves and ensure they're the right ones. Then, can you get the valve preload spec your machine shop used --- if they even did the preload check?

There's absolutely no way a turbo or tune can cause bent valves without burning them, which almost always breaks off chunks of the valve. And, it's got to be run long enough to get hot enough to burn the valves --- won't burn on a cold engine. If lifters and part numbers are OK, this is definitely a workmanship problem, caused by either the machine shop and / or your mechanic / installer. They should resolve the issue and "make it right" for you.