I guess this has been a progressively worsening situation. I've been researching the past couple of days and can't find anything related.
I checked the plugs, wires, coil pack, BPV (DT) and battery. The coil's post had a bit of corrosion but wiped off with a towel, everything else was fine.
Basically when I tried to drive the car this morning the engine revved much higher than it should have.

In 1st gear at 4k RPM I was only going 15 mph! It could barely make it up a small incline.

I recently broke a header after hitting a pothole and I replaced it my R50s old header and gasket for the time being. The header was in OK shape.

Now that was about a month ago. Since that I've noticed much more heat in the engine bay than normal. Not sure if the 2 are related. Right after the install the car threw a CEL for a bad post cat O2 sensor. Just FYI. But I continued to drive the car for almost a month like that.

I'm at a loss here. I've seen other post on sluggish R53 MINI'S, but there weren't really any answers out there.

Only "mods" are Alta CAI, DTBPV, Alta 2% crank pulley.

Thanks in advance!

 

That right there says it's the clutch. If your motor is revving up, but your car's not going anywhere......it's the clutch. I just went through that myself......not a bad job if you do it yourself. Expensive if you have a shop do it.

 

A code saying the rear 02 fault doesn't necessarily mean that the sensor is bad it just means it's reporting an abnormal reading.

With all the symptoms you describe I would say that the catalytic converter is clogged on the header you just installed.

 

Over revving with an 02 fault and excessive heat tells me bad cat. The car will have to rev higher to force the exhaust through the clogging cat.

Or his clucth decided to let go at the same time. That wouldn't surprise me either.

 

If the motor is revved up way more than it should be, and the car is going slower than it should be.....it's the clutch. If he said it was just down on power, that would be one thing.....but he specifically said that the motor revs up to 4,000rpm and the car is only going 15mph........that's the CLUTCH!

Unless he's explaining it wrong.....I don't see how a slipping clutch could not be at least one of the problems.

 

Andrew...if you get on the highway and put the car in 5th or 6th gear.....and then stomp on the gas, does the engine rev up without the car gaining speed like it should? If so....then it's the clutch.

 

I'm able to get the car up to speed. It's slower than a freaking bicycle, but I can eventually get it up to around 60, with all this I don't want to push it. The thing is it shifts fine. I've noticed a bit up grinding when shifting and it has been hard to get into reverse a time or 2.

Never thought the clutch...

Also a clogged cat? Makes since. I guess. When it's cold out and I open the hood I have been able to see a bit of exhaust leak from the header.

Well... Guess it's time to start stripping the front end down and get a new header and clutch kit ordered.

Not good news.

 

Yea... It's been getting progressively worse. The engine revs up and then it takes off. Like all the boost is being dumped at once. Not a good driving experience.

 

Yep.....definitely sounds like the clutch.

 

I trusted your previous comment enough I've already ordered one! Stockwise Auto has the clutch and flywheel kit for around $300!

So along with the other parts my MINI should be good to go for awhile.

• Mods Waiting Installation
• -2% ATI Crank Pulley
• Bilstein Touring Shocks all around
• ALTA 15% Pulley

Also supercharger maintenance will be done.

It might be a while until the MINI is back on the road. God, I hope I can get at least 10k miles without any more hiccups. MINIs are killing my wallet.

 

It sounds like the clutch is toast, you must smell the clutch slipping big time----with that amount of slip the clutch would be literally burning what is left of it.

 

Nope, I really haven't smelt any clutch burning. Only thing that is odd is my power steering pump fan is going bad, I can hear the bearing rattling around. But other than that and the header exhaust leak no other real troubles are visible, heard, or smelt...

Odd?

 

I'm still saying clogged cat.

 

If you have the time, drop the exhaust just after the Header, and take it for a short drive and see if that allows the car to run as expected (it is going to really loud). At least this will rule out the exhaust system.

Motor on!

 

The exhaunt is one solid piece from the motor to behind the cat, it is very unhealthy for the motor to run with nothing at the block. There is no way to seperate the cat from the manifold without cutting the pipe.

 

Veritas, I think he's saying to drop the exhaust just after the header, where the 2 bolt up towards the middle of the cars bottom.

How could an exhaust foul up so bad that it would cause this kind of power loss? When I drive my MINI I drive it! I mean it sees a steady rate of high rpms on the highway, and I don't take off lightly from a stop. I prefer to call it "cleaning the carbon out".

 

I was not suggesting cutting the pipe, just dropping the back half of the exhaust system.

It sounds like you drive your MINI as I drive mine...

The other Power loss issue I know of for the W11 engine is the Timing Chain/Chain Tensioner. Either the chain wears out and or the tensioner and that adds chain lash which messes up the valve timing giving you a power loss.

Motor On!

 

How would dropping the exhaust after the cat rule out the cat as being clogged?

The cat needs to be removed from the system to rule it out.

I was not suggesting or condoning cutting anything. Was just stating that unfortunately for our cars with the stock exhaust there is no way to temporarily remove the cat due to it being solid to the manifold which I feel was a poor design choice on the manufactures part.

 

His symptoms include extra Bay heat, and a code for an abnormal reading from the 02 sensor. Now if his symptoms were just power loss and the code, I'd say the sensor was bad. And maybe the clutch. But the extra heat says to me that the cat is clogging up and retaining heat, which will give a funny o2 reading, as well as make the engine strain harder and cause higher rpm.

I've had these EXACT same symptoms in an Rx7, cat was clogged. As well as many online searches will return a diagnosis of clogged cat for all these symptoms.

 

Agree with both JABOWDERS and Veritas.
Have seen a clogged cat cause an engine to run poorly and basically put out no power. Engine is a big air pump, if the exhaust is severely restricted then this acts counter to the engines power.
To diagnose, because its the easiest way, we did exactly as JABowders suggests, disconnect the exhaust pipe at the header. Night and day result.
Even if this isn't the problem, its pretty painless and free. I would do it b4 I went to the trouble of swapping a clutch. If not the problem then you have lost nothing but time.
Good Luck!

 

Time to bring in the pictures. Look at this stock manifold. It's all one solid piece until after the Cat. There is no way to remove the cat from the system without unbolting the manifold from the block. Which is very inadvisable.

That's all I'm trying to say, it's harder to rule out the cat besides replacing the manifold system with a known good one.

 

What I were to put my broken header back on and then take it for a drive? I know for certain that the cat on it is not fouled. Although it's cracked at the cat near the bottom joint, would this help to rule out fouled exhaust?

 

I'd carry it to a shop and have them weld the crack then throw that one back on permanent!

But yes. I'd still get the welded first. That way if it does fix the problem you won't have to remove it again.

 

I agree 100%. Only 2 bolts to disconnect the exhaust. I'd much rather change a header over a clutch any day.

Also, I forgot to add, when the problem started to bother me and make its big entrance I would reset the ECU through the dash and the car would drive "better" it seemed. It seemed like the power was back and the RPM never got as high, but this slowly diminished.

Maybe it was all in my head and just a placebo effect?

 

Dunno on that one. If read conflicting info on whether or not "resetting" the ecu even does anything. And I see where the other guys are going with dropping the back half of the exhaust but that's all after the Cat, if the cat isclogged that still leaves the "plug" in the exhaust.

Get your old one welded up and throw that one on.

Or drop the exhaust as suggested previously and gut the cat on the car and see what that does for you.