MG ZT CDTI 2L - Acceleration

GARYGOR · 6th December 2008, 14:38

Hi all

I have two questions I have read with interest about the EGR valve and it associated problems.

Is it true bypassing this valve cooks the turbo?

I lost power on Thursday and had be brought home by the AA, the diagnostics was that there is a fault on the EGR valve the AA man told me that it would be a built up of crud and oily deposits today preventing the valve seating correctly, I took out the valve and cleaned it up but to no avail, I still have the acceleration problem.

The car ticks over with no problem however the revs will not go above about 1400, does anyone have any ideas, could the EGR valve be still the problem or could the fault be something else.

Regards

Gary

mark_bonsai · 6th December 2008, 14:43

I wouldn't say it's the EGR and bypassing it won't cook the turbo. More likely the fuel pump IMHO. Possibly the MAF, but even witha completely dead one, it should still rev to some degree. However, worth unplugging and trying.

Greeners · 6th December 2008, 14:44

Try the PCV that lives on top of the engine under the cover. It's a service item on the BMW schedule, but not on the MGR one/ YOu can clean them in white spirit, BUT WEAR GLOVES.

Have a search as there's plenty of info on the subject.

Greeners · 6th December 2008, 14:45

As Mark says, try unplugging the MAF and see how it runs. was it raining when you broke down.?

GARYGOR · 6th December 2008, 14:49

Hi Mark

Thanks for the info, I will look at your suggestions, the fault of the EGR unit came up on the AA computer diagnostics.

Regards

Gary

GARYGOR · 6th December 2008, 14:51

Hi Greeners

It was raining very heavy with a lot of motorway water spray, this happened once before I pulled into the service station and after a few minutes the engine was fine again.

Regards

Gary

Greeners · 6th December 2008, 14:54

Almost certainly a wet maf then.......

mark_bonsai · 6th December 2008, 15:10

Yep, I agree with David. However, if it still won't rev with it unplugged, I'd still lean towards the fuel pump. Must admit I hadn't even thought about the PCV, but that's usually the case...

GARYGOR · 6th December 2008, 16:00

Thank you very much to both of you I have stripped the air filter cover off and will disconnect the MAF tomorrow and try it.

Had the car in for a full service last month doesnt look like the air filter was changed and the bottom of the air filiter box has bits of debris in it too much for a one months driving and a gold service at that, wont be going back that dealer.

Regards

Gary

GARYGOR · 7th December 2008, 12:06

David/Mark

Thank you both it is the MAF unit disconnected the full range of revs is available.

What do you recommend for a permanent solution and how can I protect from wet weather in future.

How long can I drive with the MAF disconneted and will it cause any damage.

Regards

Gary

6th December 2008, 14:38	#1
GARYGOR Newbie MG ZT Join Date: Dec 2008 Location: ANDOVER Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	MG ZT CDTI 2L - Acceleration Hi all I have two questions I have read with interest about the EGR valve and it associated problems. Is it true bypassing this valve cooks the turbo? I lost power on Thursday and had be brought home by the AA, the diagnostics was that there is a fault on the EGR valve the AA man told me that it would be a built up of crud and oily deposits today preventing the valve seating correctly, I took out the valve and cleaned it up but to no avail, I still have the acceleration problem. The car ticks over with no problem however the revs will not go above about 1400, does anyone have any ideas, could the EGR valve be still the problem or could the fault be something else. Regards Gary

6th December 2008, 14:43	#2
mark_bonsai I really should get out more....... Rover 75 CDT Saloon Join Date: Sep 2008 Location: Lancaster Posts: 2,219 Thanks: 24 Thanked 39 Times in 39 Posts	I wouldn't say it's the EGR and bypassing it won't cook the turbo. More likely the fuel pump IMHO. Possibly the MAF, but even witha completely dead one, it should still rev to some degree. However, worth unplugging and trying. __________________ Re-mapped. EGR bypass. De-catted. 18" Apex's. ZT190 brakes & suspension. Xenon projectors. Powerfold bullets. Electric rear sun blind. Auto dipping rear view mirror. Wood and leather steering wheel. Wood handbrake handle. Full leather sports seats. Harman Kardon speakers & sub. Navall 2 double din through 500w Kenwood amp. Fully chromed front grill.

6th December 2008, 14:44	#3
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Try the PCV that lives on top of the engine under the cover. It's a service item on the BMW schedule, but not on the MGR one/ YOu can clean them in white spirit, BUT WEAR GLOVES. Have a search as there's plenty of info on the subject. __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

6th December 2008, 14:45	#4
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	As Mark says, try unplugging the MAF and see how it runs. was it raining when you broke down.? __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

6th December 2008, 14:49	#5
GARYGOR Newbie MG ZT Join Date: Dec 2008 Location: ANDOVER Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	EGR unit Hi Mark Thanks for the info, I will look at your suggestions, the fault of the EGR unit came up on the AA computer diagnostics. Regards Gary

6th December 2008, 14:51	#6
GARYGOR Newbie MG ZT Join Date: Dec 2008 Location: ANDOVER Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	Egr Hi Greeners It was raining very heavy with a lot of motorway water spray, this happened once before I pulled into the service station and after a few minutes the engine was fine again. Regards Gary

6th December 2008, 14:54	#7
Greeners Moderator MG-ZTT Join Date: Mar 2007 Location: Ware, Herts Posts: 19,798 Thanks: 161 Thanked 1,249 Times in 1,036 Posts	Almost certainly a wet maf then....... __________________ *David* Impecunity is the mother of ingenuity Useful how to's for common problems Car Of The Month Jan 2014 [SatNav Power Down] [Coolant Level] [SatNav Repair] [Diesel Non Starting] [Paint Codes] [Rear Light Seals] [Reversing Light Switch] [Bleeding Brakes][Sunroof Drain] [Early ZT's][Instrument Pack Diagnostics][ATC Diagnostics]

6th December 2008, 15:10	#8
mark_bonsai I really should get out more....... Rover 75 CDT Saloon Join Date: Sep 2008 Location: Lancaster Posts: 2,219 Thanks: 24 Thanked 39 Times in 39 Posts	Yep, I agree with David. However, if it still won't rev with it unplugged, I'd still lean towards the fuel pump. Must admit I hadn't even thought about the PCV, but that's usually the case... __________________ Re-mapped. EGR bypass. De-catted. 18" Apex's. ZT190 brakes & suspension. Xenon projectors. Powerfold bullets. Electric rear sun blind. Auto dipping rear view mirror. Wood and leather steering wheel. Wood handbrake handle. Full leather sports seats. Harman Kardon speakers & sub. Navall 2 double din through 500w Kenwood amp. Fully chromed front grill.

6th December 2008, 16:00	#9
GARYGOR Newbie MG ZT Join Date: Dec 2008 Location: ANDOVER Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	Egr Thank you very much to both of you I have stripped the air filter cover off and will disconnect the MAF tomorrow and try it. Had the car in for a full service last month doesnt look like the air filter was changed and the bottom of the air filiter box has bits of debris in it too much for a one months driving and a gold service at that, wont be going back that dealer. Regards Gary

7th December 2008, 12:06	#10
GARYGOR Newbie MG ZT Join Date: Dec 2008 Location: ANDOVER Posts: 18 Thanks: 0 Thanked 0 Times in 0 Posts	Maf David/Mark Thank you both it is the MAF unit disconnected the full range of revs is available. What do you recommend for a permanent solution and how can I protect from wet weather in future. How long can I drive with the MAF disconneted and will it cause any damage. Regards Gary