Massive loss of power 2000 rpm max

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   I think this lives under general technical, although it occured on my 523i, it can occur on any car with a cat.
If you have experienced a sudden loss of power and car refusing to rev over 2000 this might be for you.
Check of fault codes reveals no codes
No warning light
Check your catalytic convertor. Knock it gently if it rattles it might be the fault, it might be the fault anyway even if it doesn't rattle.
How it happened:
Last Thursday Jan 24th the M6 got jamed up south of Manchester because some lorry had shed a load of acetylene cylinders and they were worried they might go bang! The queue as I came out of work was massive. Not to worry I know all the back roads. Took one, and within seconds hit another queue... apparently I wasn't the only one who new these back roads! I grabbed for my map and luckily there was a tiny lane that took me more or less past the traffic. I shot down this road gleefully and within seconds had hit a huge pothole / puddle. I didn't notice much change, but the next day the car was "growling" more. That evening as I gunned it home the growl got worse and I noticed a drop in power. Following morning I was taxi for my kids and the power got worse and worse. By Sunday I could hardly get up hills!
I got the laptop out and plugged in to diagnostics, no fault codes nothing! I was begining to suspect the exhaust but the first quote of �600 was a bit too much on a hunch! So I hopped on to this forum looking for similar issues, nothing that quite matched. There was a long thread in the US which sort of matched, but no one could quite find the issue, under the loop was Vanos, so I was getting very worried (����������)!
Checked vacuum leaks, checked injectors, changed fuel filter, checked fuel pump nothing worked! 
Went to BMW for them to run diagnositics, no codes nothing but they agreed it could be the cat. It would be over �1000 for BMW to supply the new complete system.... 
I called a firm "Harveys" and they could do me the whole system at under �500... by this time it was an easy choice!!! After a very embarissing drive of 22 miles at 10-15 mph  I eventually arrived to find the new system tail pipe didn't fit! Panic I asked if they could just cut and only fit the cat using a sleeve which they accepted to do... it worked and only cost a little under �300 
Talking to "Phil" of Harvies apparently Catalytic convertors are really prone to damage from sudden large splashes of water, it quite simply cracks the element in the convertor, and more to the point once this happens the exhaust becomes blocked a little causing the oxygen sensors to react and alter the mixture. Total loss of power and horrible noise when you rev the engine. Many thanks to this garage, they saved my day (and a lot of cash)!
I have heard it is possible to have a cat just "cut" in to your exhaust for about �100 to �150. They cut out the old one and weld in a new one, apparently they have a web site...I haven't foud it yet!

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Jerry 523i Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced Newbie Joined: 21-January-2007 Location: Cheshire Status: Offline Points: 23	Post Options Post Reply Quote Jerry 523i Report Post Thanks(0) Quote Reply Topic: Massive loss of power 2000 rpm max Posted: 30-January-2008 at 23:31
	I think this lives under general technical, although it occured on my 523i, it can occur on any car with a cat. If you have experienced a sudden loss of power and car refusing to rev over 2000 this might be for you. Check of fault codes reveals no codes No warning light Check your catalytic convertor. Knock it gently if it rattles it might be the fault, it might be the fault anyway even if it doesn't rattle. How it happened: Last Thursday Jan 24th the M6 got jamed up south of Manchester because some lorry had shed a load of acetylene cylinders and they were worried they might go bang! The queue as I came out of work was massive. Not to worry I know all the back roads. Took one, and within seconds hit another queue... apparently I wasn't the only one who new these back roads! I grabbed for my map and luckily there was a tiny lane that took me more or less past the traffic. I shot down this road gleefully and within seconds had hit a huge pothole / puddle. I didn't notice much change, but the next day the car was "growling" more. That evening as I gunned it home the growl got worse and I noticed a drop in power. Following morning I was taxi for my kids and the power got worse and worse. By Sunday I could hardly get up hills! I got the laptop out and plugged in to diagnostics, no fault codes nothing! I was begining to suspect the exhaust but the first quote of �600 was a bit too much on a hunch! So I hopped on to this forum looking for similar issues, nothing that quite matched. There was a long thread in the US which sort of matched, but no one could quite find the issue, under the loop was Vanos, so I was getting very worried (��)! Checked vacuum leaks, checked injectors, changed fuel filter, checked fuel pump nothing worked! Went to BMW for them to run diagnositics, no codes nothing but they agreed it could be the cat. It would be over �1000 for BMW to supply the new complete system.... I called a firm "Harveys" and they could do me the whole system at under �500... by this time it was an easy choice!!! After a very embarissing drive of 22 miles at 10-15 mph I eventually arrived to find the new system tail pipe didn't fit! Panic I asked if they could just cut and only fit the cat using a sleeve which they accepted to do... it worked and only cost a little under �300 Talking to "Phil" of Harvies apparently Catalytic convertors are really prone to damage from sudden large splashes of water, it quite simply cracks the element in the convertor, and more to the point once this happens the exhaust becomes blocked a little causing the oxygen sensors to react and alter the mixture. Total loss of power and horrible noise when you rev the engine. Many thanks to this garage, they saved my day (and a lot of cash)! I have heard it is possible to have a cat just "cut" in to your exhaust for about �100 to �150. They cut out the old one and weld in a new one, apparently they have a web site...I haven't foud it yet!
	1998 523i SE Touring 75k

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kbannon Members Profile Send Private Message Find Members Posts Visit Members Homepage Add to Buddy List Admin Group E39 525i Sport Individual Joined: 09-October-2002 Location: 64 Zoo Lane Status: Offline Points: 15508	Post Options Post Reply Quote kbannon Report Post Thanks(0) Quote Reply Posted: 30-January-2008 at 23:41
	I had it go on mine a few years ago. Heartbreaking to see the car struggle. Even worse to see the bill to fix it!
	Current: 2009 E60 520d "Sport" tractor Previous: 1989 E30 320i SE 1997 E39 523i 2003 E39 525i Sport Individual

Jerry 523i Members Profile Send Private Message Find Members Posts Add to Buddy List Advanced Newbie Joined: 21-January-2007 Location: Cheshire Status: Offline Points: 23	Post Options Post Reply Quote Jerry 523i Report Post Thanks(0) Quote Reply Posted: 22-February-2008 at 14:03
	There is extra good news with replacing the Cat... the car is now doing average 27.5 MPG, 3 MPG better than before, torque is up feels like about 20 - 30 hp more! At this rate I have paid for the Cat in around 12 months on fuel saving!!!
	1998 523i SE Touring 75k