Performance comparison needed

Alun · 18th May 2008, 11:08

Hello to all!

I have just purchased a 52 plate ZT-T CDTi with 60K on the clock. I had it for its first decent motorway jaunt last week where it returned on average 42 MPG over 720 miles.

I have a question for you though,

The wife has a 2.0 TDI 140 bhp jetta which absolutley flies in comparison to the MG. I realise we are talking about a smaller car here, but the supposed difference in power is pretty much negligible. I was wondering if anyone has driven both vehicles and found similar?

I have checked under the bonnet and there is a PB MAF with one of Ron.s boxes, and I have a receipt for £700's worth of new injectors fitted last year. I'm wondering if the previous owner was having performance issues...

I have tried different settings on the MAFAM, and disconected the MAF, all which make no apparent difference to performance.

I gave it a bit of stick on the way into work last night and had a ticking noise (audible witht the window down) from the engine bay at 3500RPM+

To me there doesnt seem to be any definate 'boost zone' if that makes sense, and on a flat out test on my private airstrip it seemed very reluctant over 100, really struggling to pull through 110.

Any Ideas

TIA

Cheers,

Alun

P.S. sorry for the long rambling post

GreyGhost · 18th May 2008, 11:39

Welcome to the club and the forum.
Not too familiar with diesels but I would say that if the performance was the same with the MAF disconnected then I would suspect it has failed.
Some Diesel heads will be along to confirm or deny my supposition. Have you checked Rons site for further details?
http://tuning-diesels.com/ with one of his boxes and good maf you should be getting around 150BHP with tons of low down torque.

MGOracle · 18th May 2008, 12:46

Hi

With the MAF disconnected, the car will behave totally different to one with the MAF connected (either dead or fine). With the MAF disconnected the car will rev far more freely. With a good (or dead) MAF connected, the revving is far more lazy.

Its possible that your seals to the intercooler are shot causing boost leak.

Also, dont presume that because you have a CDTi you have the 129bhp engine. You could have a 116bhp engine as standard. Do a search for checking your VIN against power output, also check for a sticker on the passenger B pillar.

Other factors could be a dead turbo (unlikely) or a blocked EGR valve and/or blocked PCV valve.

By comparison, although my CDTi is slightly more fettled, I and my passengers physically find it hard to pull your head of the headrests when accelerating in 2nd, 3rd or 4th from around 1800rpm. That should give you an indication to the power you should be getting.

Alun · 18th May 2008, 15:17

Quote:

Originally Posted by MGOracle

Hi

edit...

Its possible that your seals to the intercooler are shot causing boost leak.

...edit

Other factors could be a dead turbo (unlikely) or a blocked EGR valve and/or blocked PCV valve.

By comparison, although my CDTi is slightly more fettled, I and my passengers physically find it hard to pull your head of the headrests when accelerating in 2nd, 3rd or 4th from around 1800rpm. That should give you an indication to the power you should be getting.

Intercooler seals are shot.....

Whilst de-crudding the egr (which was manky) I checked the pipes down to the intercooler. Found 1 ring popped out and the other snapped in two, but still in.

Currently in the process of front bumper removal.

Can someone point me in the right direction for replacement seals?

Cheers,

Alun

MGOracle · 18th May 2008, 15:34

This will definately be causing problems for the turbo loosing boost like this.

Speak to Pondweed, he had some seals on order from Vikon IIRC.

Alternatively, the seals are available from Rimmer Bros around £2 or £3 I think.

tigerchubs · 19th May 2008, 09:23

I have driven both the cars stated, and numerous other TDis of varying BHP, and to be fair the power delivery of the MG Rovers is far less aggressive than the vast majority of cars out there.

(Puts on tin hat)

Kev

MGOracle · 19th May 2008, 10:33

This is a fair point.

The 75 does obviously weigh more, but by how much, I'm not sure.

Assuming even 25kg, thats a large dog, more than enough to shave some poke out of the car.

pondweed · 19th May 2008, 11:33

no, thats an urban myth. I looked in the brochures. like-for-like MGs weigh more than Rovers, someone saying because they have more metal in the suspension.

Remarkable, heh?

Rover lightweights.

Roverron · 19th May 2008, 15:22

Quote:

Originally Posted by pondweed

no, thats an urban myth. I looked in the brochures. like-for-like MGs weigh more than Rovers, someone saying because they have more metal in the suspension.

Remarkable, heh?

Rover lightweights.

Ah but the Rovers carry a lot of additional extras - pipes, slippers, incontinence bags, walking sticks, zimmer frames, tweed jackets...

(name and address withheld)

Alun · 19th May 2008, 17:26

Cheers for the info chaps. have sourced some viton (sp) seals from a local bearing company, cost me the grand sum of £0.00 as the bloke didnt have any change!

Anyway, seals in, car back together and ther is definately an improvement of sorts.

Ordered a synergy off ron aswell.

will report back when its done, possibly with some pics i took of the job along the way

Cheers

Alun

18th May 2008, 11:08	#1
Alun Regular poster Banana Shaped MG ZT-T CDTi Join Date: May 2008 Location: Northumberland Posts: 35 Thanks: 0 Thanked 0 Times in 0 Posts	Performance comparison needed Hello to all! I have just purchased a 52 plate ZT-T CDTi with 60K on the clock. I had it for its first decent motorway jaunt last week where it returned on average 42 MPG over 720 miles. I have a question for you though, The wife has a 2.0 TDI 140 bhp jetta which absolutley flies in comparison to the MG. I realise we are talking about a smaller car here, but the supposed difference in power is pretty much negligible. I was wondering if anyone has driven both vehicles and found similar? I have checked under the bonnet and there is a PB MAF with one of Ron.s boxes, and I have a receipt for £700's worth of new injectors fitted last year. I'm wondering if the previous owner was having performance issues... I have tried different settings on the MAFAM, and disconected the MAF, all which make no apparent difference to performance. I gave it a bit of stick on the way into work last night and had a ticking noise (audible witht the window down) from the engine bay at 3500RPM+ To me there doesnt seem to be any definate 'boost zone' if that makes sense, and on a flat out test on my private airstrip it seemed very reluctant over 100, really struggling to pull through 110. Any Ideas TIA Cheers, Alun P.S. sorry for the long rambling post

19th May 2008, 09:23	#6
tigerchubs Gets stuck in Rover 75 CDT+ in Yorkshire Gold Join Date: Dec 2006 Location: Sheffield Posts: 975 Thanks: 0 Thanked 0 Times in 0 Posts	I have driven both the cars stated, and numerous other TDis of varying BHP, and to be fair the power delivery of the MG Rovers is far less aggressive than the vast majority of cars out there. (Puts on tin hat) Kev __________________ [SIGPIC][/SIGPIC]

18th May 2008, 11:39	#2
GreyGhost Banned 180+ Sport Auto Join Date: Oct 2006 Location: Bedford Middle Level Posts: 17,787 Thanks: 0 Thanked 18 Times in 5 Posts	Welcome to the club and the forum. Not too familiar with diesels but I would say that if the performance was the same with the MAF disconnected then I would suspect it has failed. Some Diesel heads will be along to confirm or deny my supposition. Have you checked Rons site for further details? http://tuning-diesels.com/ with one of his boxes and good maf you should be getting around 150BHP with tons of low down torque.

18th May 2008, 12:46	#3
MGOracle Banned MG ZT CDTi 135+ Join Date: Mar 2007 Location: Cardiff Posts: 1 Thanks: 0 Thanked 5 Times in 2 Posts	Hi With the MAF disconnected, the car will behave totally different to one with the MAF connected (either dead or fine). With the MAF disconnected the car will rev far more freely. With a good (or dead) MAF connected, the revving is far more lazy. Its possible that your seals to the intercooler are shot causing boost leak. Also, dont presume that because you have a CDTi you have the 129bhp engine. You could have a 116bhp engine as standard. Do a search for checking your VIN against power output, also check for a sticker on the passenger B pillar. Other factors could be a dead turbo (unlikely) or a blocked EGR valve and/or blocked PCV valve. By comparison, although my CDTi is slightly more fettled, I and my passengers physically find it hard to pull your head of the headrests when accelerating in 2nd, 3rd or 4th from around 1800rpm. That should give you an indication to the power you should be getting.

18th May 2008, 15:34	#5
MGOracle Banned MG ZT CDTi 135+ Join Date: Mar 2007 Location: Cardiff Posts: 1 Thanks: 0 Thanked 5 Times in 2 Posts	This will definately be causing problems for the turbo loosing boost like this. Speak to Pondweed, he had some seals on order from Vikon IIRC. Alternatively, the seals are available from Rimmer Bros around £2 or £3 I think.

19th May 2008, 10:33	#7
MGOracle Banned MG ZT CDTi 135+ Join Date: Mar 2007 Location: Cardiff Posts: 1 Thanks: 0 Thanked 5 Times in 2 Posts	This is a fair point. The 75 does obviously weigh more, but by how much, I'm not sure. Assuming even 25kg, thats a large dog, more than enough to shave some poke out of the car.

19th May 2008, 11:33	#8
pondweed This is my second home Waiter, Waiter! I seem to have a Roomster in my drive... Join Date: Nov 2006 Location: Sussex Posts: 3,268 Thanks: 0 Thanked 1 Time in 1 Post	no, thats an urban myth. I looked in the brochures. like-for-like MGs weigh more than Rovers, someone saying because they have more metal in the suspension. Remarkable, heh? Rover lightweights.

19th May 2008, 17:26	#10
Alun Regular poster Banana Shaped MG ZT-T CDTi Join Date: May 2008 Location: Northumberland Posts: 35 Thanks: 0 Thanked 0 Times in 0 Posts	Cheers for the info chaps. have sourced some viton (sp) seals from a local bearing company, cost me the grand sum of £0.00 as the bloke didnt have any change! Anyway, seals in, car back together and ther is definately an improvement of sorts. Ordered a synergy off ron aswell. will report back when its done, possibly with some pics i took of the job along the way Cheers Alun