General Croma 2005 Rear Tyre Wear

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General Croma 2005 Rear Tyre Wear

Yes, a 1400Kg job. I fitted a Bosal detachable bar which weighs quite a lot, and the first time I towed the caravan with the Croma it felt awful! The rear suspension is simply not up to the job in terms of damping and I have had to reduce the noseweight on my outfit quite considerably - after doing this the car seems a lot more settled. I will be towing to France in August and intend fitting some Bilsteins before I go, my only debate is whether to go for B4 or B6 shocks - the B6s are stiffer.

I feel that 13000 miles is wholly unacceptable for rear tyre life - my last car was a VW Sharan (most unreliable vehicle I've ever owned) and even with a detachable bar fitted that would still get well over 30000 miles out of the rears. The Epsilon platform is overweight and the standard rear dampers have been known to seize/leak/fail on Vectras and Signums at well below 20000 miles.

It's not to say they're all bad though - there are some owners on the Vectra C forum who say they're getting 40000+ out of their rear tyres. Perhaps it's just a matter of finding what causes it and applying the fix. I'll let you know if the car feels any different with new rear shocks, should be some time later this month.
 
My impatience got the better of me, the car now has some Bilstein B4s fitted. I ordered them from EuroCarParts.com and they arrived next day. The part number is 625880375 and can only be ordered over the phone, which is handy...total was £81.54 delivered but if you have a branch near you you'll save £8.81 on delivery.

Took just under 40 minutes to fit them, you don't even need to take the wheels off. Immediate improvement, it's hard to describe but before I changed the shocks it seemed that bumps were felt more from the back of the car than the front, and a sudden dip in the road was quite uncomfortable. Now the car feels more balanced and planted, with no wandering in crosswinds. I know there will always be a placebo effect but I have tried to be objective.

Interestingly, the shocks are listed as being for Saab 9-3 and Vectra, and there is no listing for the Croma, so if Fiat are after lots of money for parts it might be worth checking out your local Vauxhall or Saab dealer for running gear components.

Finally, as this is a tyre wear thread, I am doing my own experiment - up until the wheel alignment and shock change my car had done nearly 5000 miles on new tyres and they are now down to an average of 6.2mm all round. I'll check again in another 5000 miles and see if there's been any change in the wear rate.

I now feel that I have done as much as I can to make the car right, and it's driving better than it ever has done. Just a shame that Fiat & GM couldn't do better to start with :confused:...
 
Engine Malfunction

Well this post is for amusment at my expense :)

Last weekend I returned from my annual pilgrimage to Italy, Dolomite mountains to be precise, where numpty me broken my Croma.

Whilst pulling off, up hill, into a layby on a hairpin bend I beached then car on a very will disguised and raising slope faced rock the same white colour as the surrounding compacted dolomite compacted stones/chippings/gravel.

What a horrible sound. My heart sank. The annoying thing is that as every year there were pricks on motorbikes acting like lunatics (every year another roadside memorial of flowers and stones appears) and also a gaggle of 6 German Lotus Elise burning up the tarmac. Being beached in the hairpin I was really concerned that my car would be collected by one of these sensless drivers so I took the decision to promptly reverse out.

Well more grating noise followed by "PING", "Engine Malfuction" and the good old Engine light coming on.

A quick inspection revealed that the rock had grated its way along the central tunnel. Fortuneately the sills and bodywork were not involved.

Drove slowy back to the caravan (which we tow to Italy every year with the Croma) and set about sorting out exactly what damage I had done.

Always prepared :)

Fired up my laptop PC, plugging my scantool (Gendan EngineCheckPro) in and revealed "P2085" error code "Exhaust gas temperature sensor intermittand (Bank1 Sensor 2)". BUM!

Found a place to park the car over an incline and large drain to crawl underneath to find:

Ripped the aluminium heat shield towards the rear, ripped out the rear fixing stud from the floor pan and bending another. Exhaust temperature sensor 2 cable was sliced in half and the DFP filter was slightly dented. Also scraped and dented the central hollow tunnel box section where the heatshield mounts.

Had to reroute the sensor wire to gain some end overlap. Removed sensor, striped back insulation and applied two (crappy but very useful) Scotchlock connectors to rejoin the wires. Wrapped in tape, wrapped in aluminium foil (this was the hard part as the campsite owner's English was not very good and my Italian is worse) and then wrapped it another layer of tape. The reason for the aluminium foil is that the DPF filter gets to over 600deg.C during a cleaning recycle and the plastic tape and Scotchlocks would be the first to melt.

Reset the fault code. Yipeee we were back on the road.

Called dealer in UK, (parts manager John Banks at SGM in Southampton who I have known for many years as we have both moved around the dealerships and have a great mutual working relationship) and asked him to order the sensor, heatshield, diffuser vane and fixings for me ready for my return to the UK.

I actually had the Workshop Manual and Parts CD with me in Italy which made life a little easier. At first I thought I had dented the CAT and was concerned that I could have damaged the honeycomb and would possibly get an MOT emissions failure in the future. When I found it was the DPF filter costing £1000 my heart really sank. Further technical reading on the CD/DVD helped me come to the conclusion that a slightly dented DP filter would possibly affect the pressure differential across the filter box and at worst stop the recylce (very very highly unlikely) or possible cause the recyle to occur more frequently which at worst would affect fuel consumption and oil service interval.

Well 1500 miles later everything was still working fine. My Croma is perched on ramps on my drive, exhaust lowered and old heatshield removed. I've antirust primed the scratches through the PVC undershield coating and waiting to this to dry. Tomorrow the new shield, sensor and diffuser go in and I'll be just over £100 lighter in my wallet.

So. If nothing else you have learnt

1) Taking tools, schotchlocks, fuses, wire, hoses, nuts, bolts, hose clips etc. on holiday takes room in the car, puzzles the other half but saves your bacon and stops your holiday being ruined. (I now have some cooking foil in my tool box (y) )

2) Cheap Scantools do have a use, even if it is only to reset the engine management light

3) The Croma is lower than you think! (n)

This last point is worth noting. The Croma does have a long wheel base and is quite low. Couple this with road surface cambers, small steps in tarmac level and entry on/off the road whilst on hard steering lock can damage your Croma's health.

Enjoy

Nick /////
 
Engine Malfunction

Well this post is for amusment at my expense :)

Last weekend I returned from my annual pilgrimage to Italy, Dolomite mountains to be precise, where numpty me broken my Croma.

Whilst pulling off, up hill, into a layby on a hairpin bend I beached then car on a very will disguised and raising slope faced rock the same white colour as the surrounding compacted dolomite compacted stones/chippings/gravel.

What a horrible sound. My heart sank. The annoying thing is that as every year there were pricks on motorbikes acting like lunatics (every year another roadside memorial of flowers and stones appears) and also a gaggle of 6 German Lotus Elise burning up the tarmac. Being beached in the hairpin I was really concerned that my car would be collected by one of these sensless drivers so I took the decision to promptly reverse out.

Well more grating noise followed by "PING", "Engine Malfuction" and the good old Engine light coming on.

A quick inspection revealed that the rock had grated its way along the central tunnel. Fortuneately the sills and bodywork were not involved.

Drove slowy back to the caravan (which we tow to Italy every year with the Croma) and set about sorting out exactly what damage I had done.

Always prepared :)

Fired up my laptop PC, plugging my scantool (Gendan EngineCheckPro) in and revealed "P2085" error code "Exhaust gas temperature sensor intermittand (Bank1 Sensor 2)". BUM!

Found a place to park the car over an incline and large drain to crawl underneath to find:

Ripped the aluminium heat shield towards the rear, ripped out the rear fixing stud from the floor pan and bending another. Exhaust temperature sensor 2 cable was sliced in half and the DFP filter was slightly dented. Also scraped and dented the central hollow tunnel box section where the heatshield mounts.

Had to reroute the sensor wire to gain some end overlap. Removed sensor, striped back insulation and applied two (crappy but very useful) Scotchlock connectors to rejoin the wires. Wrapped in tape, wrapped in aluminium foil (this was the hard part as the campsite owner's English was not very good and my Italian is worse) and then wrapped it another layer of tape. The reason for the aluminium foil is that the DPF filter gets to over 600deg.C during a cleaning recycle and the plastic tape and Scotchlocks would be the first to melt.

Reset the fault code. Yipeee we were back on the road.

Called dealer in UK, (parts manager John Banks at SGM in Southampton who I have known for many years as we have both moved around the dealerships and have a great mutual working relationship) and asked him to order the sensor, heatshield, diffuser vane and fixings for me ready for my return to the UK.

I actually had the Workshop Manual and Parts CD with me in Italy which made life a little easier. At first I thought I had dented the CAT and was concerned that I could have damaged the honeycomb and would possibly get an MOT emissions failure in the future. When I found it was the DPF filter costing £1000 my heart really sank. Further technical reading on the CD/DVD helped me come to the conclusion that a slightly dented DP filter would possibly affect the pressure differential across the filter box and at worst stop the recylce (very very highly unlikely) or possible cause the recyle to occur more frequently which at worst would affect fuel consumption and oil service interval.

Well 1500 miles later everything was still working fine. My Croma is perched on ramps on my drive, exhaust lowered and old heatshield removed. I've antirust primed the scratches through the PVC undershield coating and waiting to this to dry. Tomorrow the new shield, sensor and diffuser go in and I'll be just over £100 lighter in my wallet.

So. If nothing else you have learnt

1) Taking tools, schotchlocks, fuses, wire, hoses, nuts, bolts, hose clips etc. on holiday takes room in the car, puzzles the other half but saves your bacon and stops your holiday being ruined. (I now have some cooking foil in my tool box (y) )

2) Cheap Scantools do have a use, even if it is only to reset the engine management light

3) The Croma is lower than you think! (n)

This last point is worth noting. The Croma does have a long wheel base and is quite low. Couple this with road surface cambers, small steps in tarmac level and entry on/off the road whilst on hard steering lock can damage your Croma's health.

Enjoy

Nick /////
 
Well if nothing else it's nice to know I haven't bought an off-roader. Out of interest, do you know of any aftermarket devices which will get rid of the 'oil change' warning? Also, there was a breaker selling a 2.4 DPF in their shop a little while back for £100, it may come up again at some point I suppose.
 
Well here is some data for you all to mull over.
This data is for the 1.9 JTD 16V, 150 Eleganze model, manual.
Data is for rear wheel allignment ONLY and comes from three sources as indicated.

Standard 0 = vehicle unladed & 8 litres of fuel
Standard A = vehicle unladed & full tank of fuel

1) Fiat Croma Workshop Manual - Jan 2006 - P/N:60448552

Standard 0: Rear Toe-In: +0.0mm to +2.4mm
Standard A: Rear Toe-In: +0.3mm to +2.7mm

Standard 0: Rear Camber: -1.3 deg. +/- 0.5 deg
Standard A: Rear Camber: -1.5 deg. +/- 0.5 deg

2) Fiat Service News 44.10.06 - Inlcuded with Product Update 5138

Standard 0: Rear Toe-In: +0.3mm +/- 1.2mm
Standard A: Rear Toe-In: +1.1mm +/- 1.2mm

Standard 0: Rear Camber: -1.4 deg. +/- 0.3 deg
Standard A: Rear Camber: -1.6 deg. +/- 0.3 deg

3) Protyre 4 Wheel Laser Alignment System

Rear Toe-In: +0.1 deg. +/- 0.05 deg. (+1.66mm +/- 0.75mm)**
Rear Camber: -1.5 deg. +/- 0.50 deg.

** coverted from deg. to mm for 17 inch rims - suggest you verify the maths (y)

Now these are the measurements for my Croma on Protyre kit

Rear Left Toe-In: +0.45 deg. (+3.39mm)
Rear Left Camber: -2.4 deg.
Rear Right Toe-In: +0.05 deg. (+0.38mm)
Rear Right Camber: -2.6 deg.

Nick /////
Hi Nick
As a recent elderly Croma owner, ( I needed an auto) I am pleased to see some real information.
It seems that adding something like 100 lbs near the rear can alter the rear toe in by .8mm, whatever happens when you go over a few bumps?
When I picked up my car I stopped after some 40 miles and felt the tyre temperature by hand. The fronts were fairly warm, and the rears less, but hotter than I expected. This may not be scientific enough for you, but as an indication of what is going on, I find it quite useful. As I had a GT jtdm before, I could gauge how the alignment was. I have checked the pressures with an unknown gauge, and will try to get an accurate measure soon.
Used to run the Themas with 3mm toe in rear, but thats not relevant here.-
Thanks for the info,
Keith
 
Great news for the 1.9 ,can we have for the 2.4 with the 18" rims. thank you
 
These figures came from Nick, I suppose you would take about 6% off for 18's plus an allowance for extra weight? When you look at the latitude and consider that toe in is normally measured between the rims and the mean value for the 1.9 is about .7mm then I would doubt if anyone could set it that accurately. The front is about 100kg heavier though.
 
so in plain english what I should been checking has I still got the issue on my croma 2.4
what are the right toe in etc..
 
Whilst real excessive geometry misalignment problems may/will lead to discernable tyre temperatures (as measured by human hand) in reality I think that tyre temperature differentionals between the inside and outside edges of a type are not going to be of much indication. On a Croma the rear exhaust box will heat the rear N/S inner tyre edge thus producing a temperature diffenrential on that wheel. Move to the fornt of the car and I would expect the O/S inside tyre edge to be at a slightly higher temperature.

There are tree basics measurements one can/should be able to rely on:

1) Accurate mileage based depth measurments. Minimum of 5 measurements across the tread, per wheel

2) Decent wheel alignment measurements. Compare to mfg. figures. NOTE! as we have found with the Croma and the Stilo original mfg figures can be wrong!

3) "Side Slip" guage. This is a device you drive a wheel over and it detects directional thrust across the tyre. A cautionary note here is that toe-in or toe-out helps the steering dynamics of a car in terms of straight line stability, understeer and oversteer. (won't go into bump steer etc.) This means that sacrafices can be made in tyre wear to optimise handling. Perfect even tyre wear could produce worse handling. Manufacturers try to strike a compromise and thus allow uneven tyre wear.

Nick /////
 
Nick

I have been intensely reading your threads, but at a loss concerning the rear tyre issue. I am on my second set of rear tyres. I have had the rear toe in recall as well. What I find odd is that the 1st set of tyres lasted 53,000 miles and where Goodyear NCT's. The Second set that I have on are Barum Bravius 2's which have done 11,000 miles to date and have a lot of tread across the width of tyre left.

I agree with CROMAN, as the brake compemsator works first on the rears, then on the fronts. I am on my 3rd set of Front Tyres, that were changed 2 months ago, the fronts lasting about 20k.

When I stand above the rear wheel arch on either side, you notice the toe in and the that the wheels sits slightly inward, I take it that looks right?? or not??
 
If you got 53K miles out of a set of rear tyres then you have no issues at all. And lucky for you if the Fiat technicians applied the Fiat Service Bulletin to its word then they will not and should not have adjusted your rear wheel geometry.

What many of us have seen is our rear tyres wearing out, evenly across the tread, at 12K miles or less. Basic cause being excessive toe-in and negative camber.

20K miles for front tyres sounds about right. I've just gone over 20K miles and have a little life left yet. I also tow a caravan some 3500 to 4500 miles per year.

Looking at a wheel in relationship to body lines can be very misleading. Camber is more easily judge by visual inspection. Toe-in is far more difficult to judge. In the end only definitive mechanical/optical/laser measurement can be relied upon. Even then these methods have their problems/issues.

Fortunately most methods for most cars, even with large degrees of tolerance and/or innacurracies result in both acceptable tyre wear and handling performance.

When problems occur then 4 wheels accurate laser alignment kit is required to measure and factor all wheel geometry into the equation. From there, rather like an architects building plan you can see how all the measurments go together to make up the building as a whole.

With this data AND the problems being experienced then calculated decisions can be made with regards to possible causes etc. etc.

Give a person a spanner and say "turn nut five times" then "plus 90 degrees" is all well and good. This is the specification and applying the specification is all they can do. When there are issues with the specification, and/or build up of tolerances, and/or additional product changes (eg change from Goodyear to Dunlop tyres) then we have to revert back to basics, fundamental mechanical reasoning etc. etc.

That is what we try to do here.

I'm no more right than other other people/views here. How many scientists agree?

At least we can post views, share data and experiences and hopefully find trends and FACTS that are relevant to out questions/issues/problems.

What we really need is a Manufacturer Technical Support person here reading, learning and repsonding to all the problems, issues and questions we raise.

Now that would be real Brand & Customer Support!

Bring It On FIAT!

Nick /////
 
Finally, as this is a tyre wear thread, I am doing my own experiment - up until the wheel alignment and shock change my car had done nearly 5000 miles on new tyres and they are now down to an average of 6.2mm all round. I'll check again in another 5000 miles and see if there's been any change in the wear rate.

I now feel that I have done as much as I can to make the car right, and it's driving better than it ever has done. Just a shame that Fiat & GM couldn't do better to start with :confused:...

The car has now done a further 9000 miles since I last measured the tyres, as of last night the tread depths are:-

Front - 4mm
Rear - 5.2mm

so I think it's fair to say that the problem is solved on my car (at the moment). Those 9000 miles include 800 miles of caravan towing and 200 miles of towing a big trailer. I know I've fitted aftermarket shocks but I believe the issue has been addressed mainly by the wheel alignment and Goodyear NCT5 tyres.

Hope this helps.
 
I can assure you that the rear tyre wear was caused by the early build cars having the wrong rear wheel alignment. This is official from my contact in Fiat Turin.
 
Since having a full 4 wheel track and new rear tyres in Dec 2007 at 11,438 miles a tread check at 23,123 miles today, 29 Dec 08, shows I still have about 8mm depth left. (Kumho Ecsta Sport KU31 - 215/50ZR17 95W XL tyres).

Looks like the tracking setup I have, as previously posted, has done the trick regarding the original excessive tyre wear.

Just wish I had claim compensation from Fiat.

Nick /////
 
why are you not doing so??

If the recall for rear wheels was done, then you have a case.

Problem is that according to the Fiat Bulletin my car was withing spec, i.e. even tread wear. I chose to go independent and got a full 4 wheel laser computerisd track done, something the dealer could not do. At that time there was no proof that a retrack would solve the problem. That is why I chose cheaper Kumho tyres at £86 each instead of £145 for Bridgestones.

Now 12 months on I have my evidence so migh try and see what the dealer says. Got my 2 year 24K service next week and want that little worry sorted out first.

Nick /////
 
I have a new Croma 1.9 JTD 150 hp from 2005.

The rear tyre wear is also known to me, mine were gone after 20000 kms, I think that they did that that recall after the second set (40k kms).

After the second set, the people from the tyre replacement center put on another make of tyre and now it lasts longer (more normal). I have the optional 18" tyres.
 
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