Catalytic converter fault

[Jonny3777]

My catalytic converter is due a change only had the car since Friday, and already I've had to get the wheel alignment done to try correct the car from pulling to the left which hasn't worked..... Then driving along and the engine light comes on, brought it to the mech and he said fault was with the catalytic converter and 5 other faults that wouldn't show a code?? Very confusing, how much are convertors for a 2006 2.0 z4, I've searched for a price but no clear amount??

 

[Smartbear]

Hi, I don’t think you can buy the cat separately as it’s integral with the exhaust manifold. Have you tried running some cataclean through it?
Did you buy it from a dealer? What did the dealer/owner say when you mentioned the car pulling to the left on the test drive? I’d be going back with it if it came from a trader.
Rob

 

[Ewazix]

If you search the forum a lot of 2.0 owners have been told that they needed a new cat' when it was in fact a cracked exhaust manifold and associated O2 sensors that were down. Worth have a search and read

loads of threads on the problem including https://z4-forum.com/forum/viewtopic.php?t=39373

 

[Jonny3777]

Hi, I don’t think you can buy the cat separately as it’s integral with the exhaust manifold. Have you tried running some cataclean through it?
Did you buy it from a dealer? What did the dealer/owner say when you mentioned the car pulling to the left on the test drive? I’d be going back with it if it came from a trader.
Rob

Hi Rob, yes it's from a garage dealer, but sold as seen no warranty on cars 10 years plus that's their policy... The test drive was fine pulled very slightly but as it was in the city there wasn't much chance to go above 50mph, it wasn't until I was bringing home on the motorway that I noticed the intermittent pulling to the left. Now as for the converter I found replacing the whole unit was €450 before labour l I absolutely love the car, I just don't want it to become a money pit, its only got 79k on the clock so it's low mileage and the mech said she runs nice the slightest of a shudder when in idle so may need some fine tuning. Just want to drive it lol not have it serviced every 10 miles, we only own these for the love of them otherwise we wouldn't look twice am I right

 

[Smartbear]

I don’t think a trader can sell cars without a 3 month warranty, find out your statutory rights.
Rob

 

[Silverstar]

I don’t think a trader can sell cars without a 3 month warranty, find out your statutory rights.
Rob

I believe it's 6 months regardless of the age of the car, the dealer can't seller it to a private buyer as sold as seen.

 

[Silverstar]

I just found this online: https://www.theaa.com/car-buying/legal-rights

I would go straight back to the dealer and demand the car is properly repaired or reject it and get your money back. Their sold as seen policy is not valid.

 

[Jonny3777]

I just found this online: https://www.theaa.com/car-buying/legal-rights

I would go straight back to the dealer and demand the car is properly repaired or reject it and get your money back. Their sold as seen policy is not valid.

Thanks sliverstar appreciate the info, I will ring citizens information tomorrow to find out

 

[tug]

Unless you are really unlucky, the cat will be fine. You could find that the "cat cover" is cracked which can be TIG welded for little money.

I own a 2.0i and had all this when i first bought it 5 years ago. The engine light (emissions) is notorious on these N46 engines so don't be fearful that you have bought a bad zed. Just buy a cheap code reader & you can see what the code is for & turn the light out. My zed suffered from this terribly at first and the code is always P040 Catalyst below threshold.

I overcame this problem when i realised that the N46 likes to be driven hard occasionally. I when possible, always take her up to at least 4000 revs through the gear range & very, very rarely see this light come on. Although on a rare occasion when stuck in traffic for a long period it will appear randomly with the same code. I have a couple of friends with the same engine & this is typical with theirs also.

You mention the idle is not perfect, this is also a very common characteristic on the N46 which can be sorted by having the valvetronic adaptations cleared, ISTA software can do this.

As mentioned, i have had mine for over 5 years & love it to bits. Like all older cars they have their foibles but it all adds up to their character, the only thing i don't like on mine is the measly 150bhp but its fast enough for me

Cheers, tug

 

[jock156]

I'm having similar issues on my 2006 2.0L.

I had it code read after the engine light came on and was told it was the "Cat. Con. CONVERSION".

Would this be the same thing tug?

Is it easy enough to spot ie. taking it to my local exhaust place asking them to put it up on a ramp then looking for the crack and simply welding it or am I missing something?

Sorry Jonny for the tread hijack!

TIA

 

[tug]

Hi Jock,"Cat. Con. CONVERSION" is something i aint heard of :idunno: Perhaps somebody else here knows. All i know is that the 2.0i is notorious for the engine light comin on, which is just an 'emissions' thing.

It normally manifests itself as a P040 code which can be turned out with any cheap code reader.

You can get these from Amazon or Fleabay for little money. Do you have any other symptoms, i.e. bad performance or misfire? Listen to the engine. Does it sound odd like a 'put,put,put' sound?

Mine did!, thats when i took mine in and had it checked, it turned out to be a cracked cat cover/container. So, had it TIG welded up. Cost me £140 But since then the light only very occasionally comes on as described above

Hope this helps.

Cheers, tug.

 

[jock156]

thanks!

 

[Jonny3777]

Unless you are really unlucky, the cat will be fine. You could find that the "cat cover" is cracked which can be TIG welded for little money.

I own a 2.0i and had all this when i first bought it 5 years ago. The engine light (emissions) is notorious on these N46 engines so don't be fearful that you have bought a bad zed. Just buy a cheap code reader & you can see what the code is for & turn the light out. My zed suffered from this terribly at first and the code is always P040 Catalyst below threshold.

I overcame this problem when i realised that the N46 likes to be driven hard occasionally. I when possible, always take her up to at least 4000 revs through the gear range & very, very rarely see this light come on. Although on a rare occasion when stuck in traffic for a long period it will appear randomly with the same code. I have a couple of friends with the same engine & this is typical with theirs also.

You mention the idle is not perfect, this is also a very common characteristic on the N46 which can be sorted by having the valvetronic adaptations cleared, ISTA software can do this.

As mentioned, i have had mine for over 5 years & love it to bits. Like all older cars they have their foibles but it all adds up to their character, the only thing i don't like on mine is the measly 150bhp but its fast enough for me

Cheers, tug

Thanks tug, that's put my mind at ease, especially when you said you experienced the light come on sitting in traffic for long periods, that's when it's been happening with me to, I've started using redex in every tank to keep her clean maybe it'll help? I did notice another odd thing only happened twice the display on my dash and radio dim to almost invisible in low gear, only twice but noticed it was in 3rd or 4th gear the dimming started, any thoughts?

 

[Smartbear]

Unless you are really unlucky, the cat will be fine. You could find that the "cat cover" is cracked which can be TIG welded for little money.

I own a 2.0i and had all this when i first bought it 5 years ago. The engine light (emissions) is notorious on these N46 engines so don't be fearful that you have bought a bad zed. Just buy a cheap code reader & you can see what the code is for & turn the light out. My zed suffered from this terribly at first and the code is always P040 Catalyst below threshold.

I overcame this problem when i realised that the N46 likes to be driven hard occasionally. I when possible, always take her up to at least 4000 revs through the gear range & very, very rarely see this light come on. Although on a rare occasion when stuck in traffic for a long period it will appear randomly with the same code. I have a couple of friends with the same engine & this is typical with theirs also.

You mention the idle is not perfect, this is also a very common characteristic on the N46 which can be sorted by having the valvetronic adaptations cleared, ISTA software can do this.

As mentioned, i have had mine for over 5 years & love it to bits. Like all older cars they have their foibles but it all adds up to their character, the only thing i don't like on mine is the measly 150bhp but its fast enough for me

Cheers, tug

Thanks tug, that's put my mind at ease, especially when you said you experienced the light come on sitting in traffic for long periods, that's when it's been happening with me to, I've started using redex in every tank to keep her clean maybe it'll help? I did notice another odd thing only happened twice the display on my dash and radio dim to almost invisible in low gear, only twice but noticed it was in 3rd or 4th gear the dimming started, any thoughts?

The light sensor’s by the light switch, if it’s shaded by your arm it will dim the instrument lights
Rob

 

[jock156]

It turns out my light was to do with calibration. After I had the valve stem oil seals replaced along with other stuff the engine needed recalibrating etc. So sorted now!

 

[tug]

Glad you got it sorted jock, can i ask how much to have the valve stem seals replaced cos i think mine are not 100%

If i leave mine idling for a long while, say 20 mins and pull off, i get some blue smoke which clears almost immediately and then goes back to normal. Have been told not to worry about it by my local indie its relatively normal for age and mileage of the zed. But i would like to have it sorted if i can afford it.

Also, recalibrated? what did they do mate? just interested in what that does to the overall running and performance.

Cheers, tug

 

[jock156]

I don't know what they done but will ask when I collect it.

Please se the following for your BMW Z4 Valve Stem Seal replacement.

Labour - £750
- Removal of Rocker & Timing Chain / Cams & Rockers - Installation of Valve stem seals x16, install new timing chain & tensioner recommenced inc new rocker gasket, clean Vanos units and test.

Parts
- Timing Chain Kit FULL £255
- Elring Rocker Cover Gasket £50
- Valve steam seal x16 £45

TOTAL: £1100

Recommend Oil & Filter Change
Motul Oil & Mahle Filter
£165 extra

 

[Tanel]

I have a 3.0si and there is a rattling noise coming from the exhaust. When under the car you can hear it around headers, where the cats are. Is it possible that one of the cats has come loose? :headbang:

 

[tug]

WOW! thats some work done there mate! Think i will just "not worry" bout mine its a lot cheaper that way. :?

I have a 3.0si and there is a rattling noise coming from the exhaust. When under the car you can hear it around headers, where the cats are. Is it possible that one of the cats has come loose? :headbang:

I would first off get the zed up on the ramp & have a good look at the cat "containers" to see if any cracks have appeared. There was a rattle on mine also. But after the TIG weld all was well again. Hope its as simple as that for you mate.

Cheers, tug

 

[ph001]

I think it’s virtually unheard of for the 6 pots to suffer cracked manifolds, more likely one of the exhaust bracket suspension rubbers is split / missing. You will need to get under the car or get it up on ramps to check.