E51 The E51 Catalytic Converter Problem

[Rayc]

Collected an x5 from the dealers for a customer (couple of years back). The guy had ran out of funds at £8000 & car was still a non runner...

: Didn't realise there was a recall for Elgrand cat issues!!!

 

[Mark76e]

Just the same as any other car.
They can all go wrong at some point.
If you worried all the time about what could go wrong then you would never buy a car.
This was the first problem I had in nearly 4 years.
I had a Range Rover that cost me 6k to repair in 2 years.
2k to get through it's test one year (dpf valves and the engine had to come out.)
And lost 10k when I sold it.

We had a perfect 1.9 205gti, pre-cat and tweaked and maintained by LAD Motorsport. I spent a fortune on it. Days after fitting a competition clutch it decided to throw a planet wheel in half, took out the diff (naturally), the gear box was a write off, and a lot of the bottom of the engine.
This was weeks before our wedding so the thousands it cost really hurt .

So yeah, anything can happen.

 

[Lpgc]

You're far too nice

On balance he wrote a post which comes across as hard hitting to us but he's only repeating what mechanics generally expect, on most vehicles if a cat fails it doesn't cause major engine problems, just replace the cat and away you go. Even in the UK AA and RAC men don't believe the cat problem will damage an Elgrand engine.

It's not bad to have members who are prepared to stick their neck out and say things contrary to accepted beliefs.

 

[Steve Thompson]

On balance he wrote a post which comes across as hard hitting to us but he's only repeating what mechanics generally expect, on most vehicles if a cat fails it doesn't cause major engine problems, just replace the cat and away you go. Even in the UK AA and RAC men don't believe the cat problem will damage an Elgrand engine.

It's not bad to have members who are prepared to stick their neck out and say things contrary to accepted beliefs.

Good point.
Well made.

 

[Mark76e]

On balance he wrote a post which comes across as hard hitting to us but he's only repeating what mechanics generally expect, on most vehicles if a cat fails it doesn't cause major engine problems, just replace the cat and away you go. Even in the UK AA and RAC men don't believe the cat problem will damage an Elgrand engine.

It's not bad to have members who are prepared to stick their neck out and say things contrary to accepted beliefs.

Yes it is



(Sarcasm)

 

[P4ddy]

Guess Nissan don't know what their talking about then.

http://www.Nissan.co.jp/RECALL/DATA/report3225.html

So is 2007-10 a better bet

 

[Highway Dave]

On balance he wrote a post which comes across as hard hitting to us but he's only repeating what mechanics generally expect, on most vehicles if a cat fails it doesn't cause major engine problems, just replace the cat and away you go. Even in the UK AA and RAC men don't believe the cat problem will damage an Elgrand engine.

It's not bad to have members who are prepared to stick their neck out and say things contrary to accepted beliefs.

On balance could be right, but this section of his post got to me a little, not good from a newbie

You guys talk about mechanics not understanding what you're talking about when you go to them with your personal diagnostic, then blame the professional mechanic for not being knowledgeable.. no.. they just cant fathom why your vehicles would act entirely different than every other vehicle ever.

 

[JohnK]

I think this was a wind up and whoever is behind the iNSANE post has certainly achieved their intended goal.
Whoever it was registered and posted within 15 minutes or so and hasn't been seen since. I suspect they are still laughing at us.
Might be worth admin checking them out - are they genuine?
We all know the post was a load of bo77ox. I won't be losing any sleep over it.

 

[Lpgc]

The best proof of the cat problem damaging engines is on this forum.

Nissan whitewash over the issue, they only say a blocked cat may rattle and cause the engine to stall which is much the same as what @THISiSiNSANE says a blocked cat will do. But really Nissan must be aware that blocked cats on Elgrands can lead to engine failures - they very much play the problem down.

Nissan's explanation of the fuelling recall is also dubious, they explain that it corrects a problem of not enough air reaching the engine during over-run conditions when really the recall doesn't effect how much air the engine gets during over-run, what the recall really does is turn off all fuelling during over-run (when the recall isn't done the engine gets 0.7ms injection pulses during over-run.. which is too lean to burn in the engine cylinders so the explanation of 'not enough air' is incorrect) but this won't protect against the cat problem.

Another thing the recall does is lean high load fuelling a little (I don't think this is mentioned in Nissan's explanation of the recall), this may help protect against the cat problem a bit (and may reduce peak engine power by a few bhp) but it's still only a minor step in protecting against the cat issue, we know that cats fail and engines are damaged even after the recall.

If I've converted an Elgrand to LPG the fuelling recall won't affect anything when running on LPG anyway... I set the LPG system up to disregard fuel injection pulses shorter than 0.7ms (thus turning off all fuelling during over-run anyway) and calibrate the LPG system to be at the correct mixture for full load (which is just a bit rich on LPG, not as rich as running on petrol even if the recall has been done) regardless of whether the fuelling recall has been done or not.

 

[Mark76e]

In simpleton terms - what's engine over-run?
Thanks!

 

[Lpgc]

In simpleton terms - what's engine over-run?
Thanks!

If you're driving along at say 60mph and you lift off the throttle the wheels turn the engine rather than the engine turning the wheels. Under these conditions you get some engine braking effect.

You could say that whenever this happens (engine braking) the engine is in over-run mode but usually the term 'over-run' refers to the condition in which the fuel injection system stops trying to supply the engine with the correct amount of fuel to mix with the amount of air that it is consuming.

I.e. in some conditions if you are only just touching the throttle during engine braking the engine might still get a bit of fuel which might be less fuel than the engine would need even to idle (to idle if the wheels were not helping the engine to keep turning), in this condition the wheels help the engine to turn and the bit of fuel it gets also helps the engine to turn... But full over-run condition is when the fuelling is totally shut off and only the wheels turning keep the engine turning. Except on early E51's without the fuelling recall done even during full over-run condition the engine would still get a very small amount of fuel, after the fuelling recall the same E51's do turn off all the fuel during full over-run.

Over-run condition is only ever active above a certain rpm (say 1500rpm) and occurs a lot more often on vehicles with manual gearbox than with automatic gearboxes because with an auto the rpms are more likely to fall below the 1500rpm threshold when you lift off the throttle.

Over-run fuel shut-off can also has an effect on sporty driving... Normally for sporty driving you might be in a lower gear than in cruising type driving, over-run fuel shut-off can be a bit of a pain for that... because at (say) 3000rpm if you switch between not touching the accelerator pedal at all and only very slightly touching the accelerator pedal, instead of a nice smooth transition (expecting a tiny bit more power when you touch the pedal just a bit) it can cause a sudden switch between no fuel (foot off the throttle so fuel shut-off is active) and the correct amount of fuel for the given air intake (quite a lot of fuel if the engine is doing say 3000rpm) so you get a sudden change in engine power (you move immediately from quite a bit of engine braking, negative power, to quite a bit of engine positive power)... It can give the accelerator pedal more the feel of an engine on/off switch when you're only slightly feathering the throttle, especially in an automatic.

 

[Mark76e]

If you're driving along at say 60mph and you lift off the throttle the wheels turn the engine rather than the engine turning the wheels. Under these conditions you get some engine braking effect.

You could say that whenever this happens (engine braking) the engine is in over-run mode but usually the term 'over-run' refers to the condition in which the fuel injection system stops trying to supply the engine with the correct amount of fuel to mix with the amount of air that it is consuming.

I.e. in some conditions if you are only just touching the throttle during engine braking the engine might still get a bit of fuel which might be less fuel than the engine would need even to idle (to idle if the wheels were not helping the engine to keep turning), in this condition the wheels help the engine to turn and the bit of fuel it gets also helps the engine to turn... But full over-run condition is when the fuelling is totally shut off and only the wheels turning keep the engine turning. Except on early E51's without the fuelling recall done even during full over-run condition the engine would still get a very small amount of fuel, after the fuelling recall the same E51's do turn off all the fuel during full over-run.

Over-run condition is only ever active above a certain rpm (say 1500rpm) and occurs a lot more often on vehicles with manual gearbox than with automatic gearboxes because with an auto the rpms are more likely to fall below the 1500rpm threshold when you lift off the throttle.

Over-run fuel shut-off can also has an effect on sporty driving... Normally for sporty driving you might be in a lower gear than in cruising type driving, over-run fuel shut-off can be a bit of a pain for that... because at (say) 3000rpm if you switch between not touching the accelerator pedal at all and only very slightly touching the accelerator pedal, instead of a nice smooth transition (expecting a tiny bit more power when you touch the pedal just a bit) it can cause a sudden switch between no fuel (foot off the throttle so fuel shut-off is active) and the correct amount of fuel for the given air intake (quite a lot of fuel if the engine is doing say 3000rpm) so you get a sudden change in engine power (you move immediately from quite a bit of engine braking, negative power, to quite a bit of engine positive power)... It can give the accelerator pedal more the feel of an engine on/off switch when you're only slightly feathering the throttle, especially in an automatic.

Thanks! Great explanation

 

[ptays1]

To be fair, I have heard this exact same speech from 2 mechanics in my local area. Both pretty much telling me not to be daft and That Elgrands are no different to any other vehicle etc etc.

After doing my my research and purchasing my e51, top of my to-do-list was to do the de cat thing... However, I'm still here 5 months later and it hasn't happened yet.

The First guy from a local stainless exhaust fabricator fobbed me off with this opinion and told me not to waste my money! Second local exhaust place can't get me in until March/April and gave me the impression that they didn't want to do it anyway. Finally I tried Titan in Taunton (who many members have recommended.) And are not exactly local either. To be fair the chap Was fine on the phone but told me to book online and ask for a quote. I don't really know what to ask for other than describe the problem. He's obviously done plenty of elgrands anywhoo he's Never got back to me despite at least 5 messages so given up now. Someone please take my $$$!!!

 

[Elgrandonaut]

Get some secondary decat pipes from @Elementian perhaps? Or offer a swap with someone who has done fronts and wants to replace decored secondaries with intact ones? Or Adrian @Winchester may still be doing secondary decat while you wait?

 

[P4ddy]

Why can I not see the listed members? It keeps saying I must log in or register to see both links? I'm registered and logged in???

 

[dognero]

Try logging out and back in

 

[P4ddy]

Nope, didn't work

Tried on my phone and laptop and and when I try to log in whilst already logged in it says error and cookies must be enabled

Do I require premium membership to view the two links?

I used the search bar for the thread & found it. However links in the thread give the same log in message which doesn't make sense.

 

[SB88]

Hi all, new joiner. In the final stages of buying my first Elgrand it is a 2009 E51 Fresh import. Stumbled across this forum last night and found out shockingly about the CAT issue and emailed the dealer last night.

They’ve said the car has all 4 CATs as this issue only affected the earlier models with a factory recall to update the ECU, they’ve offered to remove the rear CATS for £150 extra but don’t think it is necessary as none of their previous customers have had a problem. They’ve also mentioned the extended warranty doesn’t cover exhausts which I assume would also include this.

would appreciate if anyone would be kind enough to offer any advice?
Many thanks

Simon

 

[Steve Thompson]

H

Hi all, new joiner. In the final stages of buying my first Elgrand it is a 2009 E51 Fresh import. Stumbled across this forum last night and found out shockingly about the CAT issue and emailed the dealer last night.

They’ve said the car has all 4 CATs as this issue only affected the earlier models with a factory recall to update the ECU, they’ve offered to remove the rear CATS for £150 extra but don’t think it is necessary as none of their previous customers have had a problem. They’ve also mentioned the extended warranty doesn’t cover exhausts which I assume would also include this.

would appreciate if anyone would be kind enough to offer any advice?
Many thanks

Simon

Hi Simon,
Don't let it put you off.
It's a well know and understood problem with a proven long term fix.
If you point the dealer to this forum and the wealth of experienced information here I'm sure you can both come to a mutual agreement.
Then with a bit of luck the dealer will pre-empt the issue for his next customer.
It's all a learning curve.
Hope you enjoy the ride.

 

[SB88]

H

Hi Simon,
Don't let it put you off.
It's a well know and understood problem with a proven long term fix.
If you point the dealer to this forum and the wealth of experienced information here I'm sure you can both come to a mutual agreement.
Then with a bit of luck the dealer will pre-empt the issue for his next customer.
It's all a learning curve.
Hope you enjoy the ride.

Thank you very much for the advice Steve, greatly appreciated.

So based on that as well as what I’ve seen on the forum I should really take him up on the offer to remove the two rear CATS for £150.

many thanks
Simon