2012 Mini Cooper S
Borla S Type Catback Exhaust
WMW Catless DP
WMW Resonator Delete Pipe
WMW Silencer Delete
JB+ Tuning Chip
K&N Typhoon CAI
Forge IC
WMW Exhaust Manifold

I just got done replacing the head gasket on my mini. It only has 67000 miles, but I've been running it pretty hot. Anyways, everything was put back together, new thermostat, head bolts, serpentine belt, timing chain replacement, valve cover replacement, new battery. We took a couple of test drives and it seemed to run fine. We get to my friends house, and after a little bit of revving, we get to leaving. I'm backing out and all of a sudden my brakes go stiff, and my turbo seems to be making less boost. Both going at the same time leaves me to believe it's a vacuum issue. The turbo still spools as I drive, it just barely makes boost. Noticeable less power and throttle response. I checked the vacuum lines to the turbo, the pump, and the vacuum box, and all seemed to be connected in the right spots. What I'm curious about is if it could be a leak from the lines itself? Or maybe the vacuum pump went. The only thing is if the vacuum pump locked up, it would be catastrophic engine damage. And mine still runs so I'm scratching my head. I also saw something about air leaking from the valve cover, could that be the case? A local shop told me it's most likely a vacuum pump, but I want to be sure before purchasing a new one since they are upwards of $400. Any help would be greatly appreciated. Thanks!

 

@netj0x

First, take the vacuum pump off from the head and to visually inspect the tines of of the pump. Second, rotate the tines to see if its locked or there’s some resistance. If there is no resistance of the pump, your pump maybe headed out to lunch. Also use your handheld vacuum pump to see if holds vacuum. If it doesn’t', then you’ll know you have a leak somewhere on the line.

 

^ I just bent 16 valves because of a failed vacuum pump. Same kind of diagnosis with the hard brakes.

 

Did you experience the same loss of vacuum before it locked up on the cam? Ive been driving mine for a week and it hasnt locked up so im worried it might just lock up one day. But I'm going to check the tines like you said as soon as the weather clears up. I'm hoping it's not the pump since they are so expensive. I don't think it is since I spun it when I put it back on after replacing the headgasket and it had resistance. The lines might be more of a pain in the *** to replace but far less expensive.

 

We had the same loss of pressure before it locked up. It started to make timing chain noises so we replaced the timing chain, the on the test run when we put it in sport mode and got the advanced timing to kick it, it seized up. All the cam rockers were off the valve and the timing chain sprocket on the crank hub got welded into one. It was just a ticking time bomb for us

 

I figured if it was going to lock up it would've happened by now. I've put at least 500 miles on it since the engine has been running at half power. I don't really have any other mode of transportation. If you're saying you've lost vacuum a while before it locked up i should really stop driving it. A vacuum pump is no cheap fix but repairing all the rods and an entire cam shaft doesn't sound too cheap either haha. I'm definitely gonna look at it asap. Do you know of anyone ever losing vacuum because of the valve cover not being sealed?

 

Not that I know of. I know we had to replace the valve cover because of a PCV failure which could have been caused by the vacuum pump

 

My car recently threw the code for PCV failure so it might be worth the while to replace the valve cover while I'm at it. Snapped a couple of bolts when torquing it down too

 

Rough, I've snapped about 3 during my whole rebuilt process

 

How did you get them out? I ended up drilling into them which is pretty sketchy, can you just punch them out

 

I got super lucky and was able to use a flat head to spin them out. Drilling is pretty sketchy, I know welding a nut on the sheered bolt usually works but you need a welder

 

That seems a lot safer, i probably hit the thread a little bit when i drilled it. I'll try the flat head since I don't have a welder and hope for the best

 

How does one snap bolts when they're only supposed to be tightened down to 10 Nm (~7.4 ft-lb)?

 

I didn't use a torque wrench haha i impacted them