75ZT Community

good evaning gents.....Mot day today didnt pass due to tyre, no probs and juddering in the braking system, had a look and the lower suspention arm going into the hub looks twisted on the drivers side, the question is would this be the juddering ???? i have to replace it anyway.......thoughts on this if you would .....and finaly failed on emissions all pass exept lambda air to petrol mix, could this be the aftermarket air filter (k&n type) or possable leak in the exhaust, or maf related .......thoughts on this as well...........thanks all Andrew

I would have thought the juddering under braking would be down to the discs to be honest, how do you "twist" cast alloy

havent long put new top strut bearings on...and think the platform lift (lifts just the front while up in the air on the lift) may have twisted it , but would this cause judder as you say , discs are new well 1 tear old ebc with green stuff pads..could be warped ?

Damage to the lower arm wouldn't likely cuse juddering, as Dave says. More likely pulling to one side or uneven tyre wear.

Even if the discs look good, they could be the problem. My Tourer had a little when I bought it. The rears looked ropey so replaced them, no change. Replaced the fronts as it was getting worse: instant cure. Were they OE discs, or a known brand?

Regarding the emissions.

Could be an intake air leak, worn plugs, faulty lambda probes, injector / fuel pressure problems. But not MAF (Mass Air Flow Sensor) as it has a MAP not a MAF, though this could and has been known to cause problems if contaminated with oil. Unlikely to be an exhaust leak as gas would get out, not air in. Do you know if it was rich or weak? If the system is detecting the problem it would normally adjust to correct. An Italian Tuneup may even help.

Duncan wrote:Damage to the lower arm wouldn't likely cuse juddering, as Dave says. More likely pulling to one side or uneven tyre wear.

Even if the discs look good, they could be the problem. My Tourer had a little when I bought it. The rears looked ropey so replaced them, no change. Replaced the fronts as it was getting worse: instant cure. Were they OE discs, or a known brand?

Regarding the emissions.

Could be an intake air leak, worn plugs, faulty lambda probes, injector / fuel pressure problems. But not MAF as it has a MAP not a MAF, though this could and has been known to cause problems if contaminated with oil. Unlikely to be an exhaust leak as gas would get out, not air in. Do you know if it was rich or weak? If the system is detecting the problem it would normally adjust to correct. An Italian Tuneup may even help.

ebc front brakes with green stuff........aftermarket ...............RICH by 1% over i think car still in garage so dont have mot recomendations to hand ...ps thanks for taking the time mate Andrew.......may waite till wed for new ball joint and will post more if the emmissions have not been rectified

Duncan wrote: Unlikely to be an exhaust leak as gas would get out, not air in.

Air can be drawn in through a leaky exhaust, I have seen it firsthand more than once. I can only explain it by possibly venturi action dragging fresh air in and upsetting the lambda reading at the tail pipe.

Bernard wrote:

Duncan wrote: Unlikely to be an exhaust leak as gas would get out, not air in.

Air can be drawn in through a leaky exhaust, I have seen it firsthand more than once. I can only explain it by possibly venturi action dragging fresh air in and upsetting the lambda reading at the tail pipe.

Oh. I stand (well sit) corrected. Still seems odd, but there's no denying first hand experience. Would have to be venturi effect I guess.



That being said, the OP has now said it's actually rich, so overfuelling. Either overreading on how much air is going in (MAP sensor), not igniting the fuel properly, or misreading the Lambda.

Had a friend who had a golf fail on emissions. Quite new car, too. He brough the car to me so we could read fault codes: nothing. Anyway he took it back and it was well within. Either poor test proicdure, or possibly a decent 60 mile round trip to clear the 'lungs'.

Might be worth getting a dial gauge on the disks to check for run-out. From the description it certainly seems a likely place to start.

Had a friend who had a golf fail on emissions. Quite new car, too. He brough the car to me so we could read fault codes: nothing. Anyway he took it back and it was well within. Either poor test proicdure, or possibly a decent 60 mile round trip to clear the 'lungs'.

Thanksl ,DUNCUN your point above i had mentioned to the mot test guy.....as i have a twin exit tail pipe and possably he didnt push probe up correctly or as you say cleared the lungs first ....i.get what your saying there

Raistlin , have to have a closer look at this but as they are new it would be unuseual but possable

Thank you all,. the guy in the garage is away tues but back wed , he is fitting the new LS ball joint as it needs replaceing and hope it sorts the judder....i hope as for emissions got a few things to test now and to look at ....

Are not the green stuff pads harder than normal. So there could be more heat / better braking but potential disc warping which would give juddering

Paul

Looked at a few of the suggestions above so here is the final post

Passed mot today .....Emmissions was due to the mot guy not putting the probe up the tail pipe correctly apparently its due to me haveing a twin exit tail pipe which is feed as we know by one pipe.....juddering was 98% cured by replaceing the lower susp arm ball joint, and tracked the front (was out by a fair bit due to replaceing top srtut bearing) but they found the drivers side brake disc was slightly warped/runout. bought EBC with green stuff in march 09 ...phoned ebc but out of guarentee and he said they never had any commplaints but also suggested they were not fitted correctly ,,,,,cant realy cock it up really as its only 1 grub screw.....thoughts gents and finaly thanks to all who posted , put a few of them to the mot guy and a few of you were correct in what was said ....many thanks Andrew.....

Good news it's sorted.

A common problem when fitting discs, and I'm not saying this is what happened, is the mating surface of the hub isn't cleaned up. A couple of flakes of rust can cause it to be off slightly, and that can cause uneven wear leading to thick/thin problems.

Other problems can be slightly dragging pads that overheat and warp the disc, or a faulty disc that distorts once it's been hot and cold a few times.

Duncan wrote:Good news it's sorted.

A common problem when fitting discs, and I'm not saying this is what happened, is the mating surface of the hub isn't cleaned up. A couple of flakes of rust can cause it to be off slightly, and that can cause uneven wear leading to thick/thin problems.

Other problems can be slightly dragging pads that overheat and warp the disc, or a faulty disc that distorts once it's been hot and cold a few times.

have to have another look and remove the disc and check again , have noticed a tick tick tick when the wheel was spinning when first fitted, so i removed ,cleaned, reaplyed copper grease, greased sliders etc etc but still there .....like you say slight dragging ......i work in the steel industry and for a disc to warp it has to get very hot much hotter than a standerd road car can achive by simple driving , if i was raceing and breaking like a f1 car yes but on a ztt ....thats not to say the steel is substanderd and was faulty at manufacture , and why didnt it happen to the other one if as you say hot cold a few times ......puzzeling hay...i would just change them but they cost about £300+ thanks for your suggestions mate hope its just a flake of rust ....

Had EBC's on the front of mine with Green Pads fitted by Lates and within 18 months the front side passengers was juddering and the garage said it was warped.
I got a different make fitted now and its starting to judder again on the same side.
No run out when first fitted but definetly judder after about 12 months or so and only on the passengers side.

I was thinking of have the discs skimmed as its a bit excessive changing them every 18 months.
The first set of discs where on from new for around 5 years with no issues other than they had worn out.

MN190 wrote:Had EBC's on the front of mine with Green Pads fitted by Lates and within 18 months the front side passengers was juddering and the garage said it was warped.
I got a different make fitted now and its starting to judder again on the same side.
No run out when first fitted but definetly judder after about 12 months or so and only on the passengers side.

I was thinking of have the discs skimmed as its a bit excessive changing them every 18 months.
The first set of discs where on from new for around 5 years with no issues other than they had worn out.

And they are not cheep to replace eather