Author Topic: Mk3 Issues.... A guide to the common faults and fixes  (Read 144850 times)

Offline boneybradley

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I have started this thread and hopefuly this will make things easier when you get the Common "Mk3 running issues!" The list is quite long and every car will behave differently and even 2 cars with similar issues will have 2 different faults! (hence why no "my car is stalling" info)...
So if your car has the common engine running issues...read this thread.

Hopefully this will help people locate and fix thing's when the problem's start but the common fault's seem to be


1 dirty throttle body Lumpy idle/Stalling at idle
Buy some carb cleaner for around a fiver. If it isnt 100% clean this is well worth doing and solves many idle/stalling issues.



2 faulty ecu relay no 30 rough running
Both the 8v and 16v have the same #30 ECU   The #30 relay part # is 165 906 381
Check them by feeling how hot they are after 15 minutes of driving. they should be warm to touch. so cold relays means faulty relays!

3 faulty fuel pump relay no167  rough running
Make sure you get a light grey/brown coloured one with 'made in germany' on it and it comes brand new in a vag box. The originals were made in Tunisia and are a known issue!!

4 hall sender 5000rpm limit
Fixed to the side of the dizzy and also stops the engine reving over 5000rpm. Should show on vag-com as an error but its also worth checking the wires as these get brittle and break with age!

5 Crank angle sensor/engine speed sensor/pulse sensor Cutting out/oil light flashes
The part # for the 'crank angle sensor' is...037 906 433 and is the same for 8 or 16v cars, You can buy non-vag, the brand is called 'FACET' (made in italy) Its the same part with the same # on the box and a bit cheaper too 

Fitting: you need to remove the front engine mount bracket so need at least 2 jacks. one to lift the car and the other to support the engine while the bracket is out. The sensor is behind this bracket and is held in by an allen key which is likely to round.the engine mount bracket has the flippin starter motor attached The bolts go through the starter motor and into the bracket.

6 ecu temp sensor stalling only when hot/cold
When starting from warm the car behaves as it's running with the choke out, the rev's are too high and often don't want to settle below 2500rpm and this controls the fuelling and when faulty it makes the mixture richer (as the engine believes its still cold). this also works the other way..stalling when cold but ok when warm.

7. Oil breathers rough idle/running
split or gunked up breathers can make problems... As the youngest mk3 is now 10 years old these are starting to show there age. You can remove the pipes and check for blockages or even hear a whistle when split.
clean them using petrol etc or get new oil breather pipe (and other vacuum pipes)

8. cam belt and 5000rpm limit and recently had new cambelt
If this is fitted one notch out it stops the car reving above 5000rpm as the engine goes into safe mode..and can also give flat spots and idle issues!
Fixing: The engine timing belt needs to be removed and refitted, It could be wise to get a timing light to check as its not the easyest of jobs!!

9. Coil   Stalling when wet/damp
This will normally show itself when its damp or wet and makes starting hard or the engine cut out!! There is no fix for this, so a new one will be needed. the only way to see if its the coil is look at the coil when dark and you may see it sparking! Or when the car cuts out, miss fires etc spray some wd40 aroung the coil and if it runs better..thats your culprit..

10. Car stalls/wont start but wiggle the key and it's back to life
This means a faulty ignition switch... The part is cheap but it does mean taking the wheel off to replace. On later cars you cant simply replace the whole unit as the key is coded to the ecu. Early cars are much more simple without either airbag or immobiliser

I will update this thread with pictures etc and other info that is relevant....please pm me any pictures,fitting tips or otherwise and the thread will be ammended!
« Last Edit: 27 March 2009, 10:47 by boneybradley »
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Offline boneybradley

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Re: Mk3 running issues.... A guide to the common faults
« Reply #1 on: 27 March 2009, 10:46 »
The purpose of this thread is to give an FAQ section for mechanical items only.  At present it is not planned to cover to "how do I change my seats, how do I put bigger wheels on".  It is designed to help fault diagnose when things aren't running well.

Types of topic to cover are misfires, weird knocking noises, loss of PAS, that kind of thing.  It is intentionally low level, so that novice DIY'ers can grasp it.

The content is from my experience and the experience of others - so is only as good as that experience. 

This will hopefully aid the use of the search functionallity and free it up for abuse banter

Power Steering Belt

Symptom:
Steering suddenly becomes very heavy, particularly in the rain, reverts back to normal (sometimes a little belt noise can be heard)

Poss cause:
Worn/loose power steering belt

To test:
No real test – a belt is about £10+vat, may as well change it.


Gearbox fault

Symptom:
Many - mine were
  • an increasing whine from what sound like the front wheel area
  • jacking the front of the car, turning the pass side wheel caused a clunking kind of noise
Others report not holding reverse gear

Poss cause:
Worn out gearbox

To test:
No real test, you can run the risk and keep going, or get it sorted while mobile.

To fix:
Replacement box I'm afraid.  A salvage (with 1 month warranty) will cost around £100, a recon box around £400, and labour anything from £150-£300.  There is a DIY guide here http://www.golfgtiforum.co.uk/index.php?topic=62370.0 - under "Full tranny change", but beware, you need a SPLINE socket, not a "triple square"  :grin:

Gearbox linkage adjustment

Symptom:
Very difficult to select gear

Poss cause:
Poorly adjusted gear linkage

To test:
No real test, other than to try and adjust the linkage

To fix:
Search for 'gear linkage' in the advance search for MK3's.  There are 2 boxes and 2 types of gear linkage depending on the gearbox you have

Clutch bleeding (02A gear box (so 16v and VR6 only I think?))

Symptom:
Very difficult to select gear - clutch pedal is on the floor

Poss cause:
Air in the clutch fluid

To test:
No real test, other than to try and bleed the clutch

To fix:
Buy/borrow a PRESSURE bleeding system - a regular bleeding kit will not work.  You also need a decent amount of brake/clutch fluid, and poss a clean baster/syringe for taking out excess fluid.  A pressure bleeding kit will cost about £16, full instructions are supplied.

CV Joints (Constant Velocity Joints)

Symptom:
Grease/muck on your alloys (more than normal) a grindy/clunky noise from your drivetrain

Poss cause:
Split rubber gaiter/worn CV joint

To test:
Jack the car up, take off a front wheel.  There are 2 rubber gaiters on each driveshaft (one driveshaft for each wheel), one in the hub, one next to the gearbox.  Check for visible signs to see if the rubber gaiter has split.  A split rubber will mean grease gets out.  If it's been leaking for some time, the joint can make a noise.

To fix:
The driveshaft has to come out.  Loosen the big hub nut (30mm or 32mm I think), then undo the gearbox end (6x8mm spline bolts on the 02A box, also a rubber washer), take the hub nut right off and give the driveshaft a good bang to release it, then remove the ball joint on the hub end (this gives play on the hub assembly to get the driveshaft in/out).  You want to loosen the driveshaft in the hub before taking the balljoint out, but you will need to take the balljoint out of the hub to get the driveshaft out.  You really want to loosen/remove the gearbox end first so you can get someone to stand on the brakes to stop the driveshaft turning..

To replace the CV joints/gaiters themselves, have a little search, this thread: http://www.golfgtiforum.co.uk/index.php?topic=66980.0
and this link are good starters.
http://volksweb.relitech.com/cvjoints.htm
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Offline James9674

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #2 on: 31 July 2009, 10:48 »
I'd just like to say a massive thank you to every body that has posted on various threads on rough running Mk3's, reading all of them has saved me hundreds of £££'s at a garage in labour costs.

Just got a Mk3 GL but beleve it is the same problem as some rough running GTI's

I'm a very novice DIY mechanic and only solved this problem through GolfGTI.co.uk so anyone else can do it too.

Got my golf and it was running pretty rough so the first thing that went on was a new cambelt (a mate did this for me) I now knew the engine was at Top Dead Centre TDC.  The car was really lumpy when accelerating but once you got up to the chosen speed it would cruise without a problem.

Straight away the two new relays went in #30 and #167.  Went for a road test and the ECU had clicked into safe mode 5000rpm then cut out.  Checked the timing.  Draper timing light only £20 from Amazon, Euro car farts wanted £45! Also you can't check it though the pull out cap just unscrew the whole plastic cap, loads easier.  I had to rotate the dizzy about 10mm to get the timing in the right place.

Road test again, running very lumpy again BUT this time it would fly up through the rev range, still a little lumpy but alot better.  When you tried to cruise it just wouldn't have it.  Really lumpy ( the only novice way I can describe it is like your struggling for petrol).

The next thing I read somewhere and can't remember where.  Was to unplug sensors and go for a road test.  When I unplugged the Mass Air Flow sensor located just behind the air filter housing the thing went like a rocket.

Just coughed up about £110 (you also have to exchange your old unit) at my local VW dealership praying this was the answer.

She now runs pucker!!!!

Not in the same league as my old Mk1 1800 Gti I had five years ago, but still a sound old vw.  Drove company civics for 5 years and nice to be back in a dub.

If this helps just one person I'll be happy.

When checking the timing as well it doesn't seem to be an exact science.  My timing mark would not hit the indicator but I got it as close as I could and as consistant as I could.  Just done the timing on my mates mk3 8v GTI track car with piper cams.  His was exactly the same.  Just got the line as close as we could to the indicator and with the most consistancy.  My machanic mate reckons with an older car it will rarely be cock on.

I also bought Vag.com off ebay for £13.  After a bit of messing around I finally got it set up.  When I scanned for faults it came back with nothing!  Any feedback on this would be greatly appreciated.

Cheers,

James 




Offline omex_uk

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #3 on: 28 August 2009, 13:38 »
air mass sensor:

¬ if your car is lumpy idling
¬ loss of power in the higher rev range (esp in 2nd at 3000rpm)
¬ low of throttle response

how to check if this is the culprate is to unplug it the sensor (see picture above) and go for a drive. you should feel an immediate difference.

hope that helps

Offline boneybradley

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #4 on: 26 March 2010, 22:01 »
here's a handy site from a member with loads of running issue info http://javalins.wordpress.com/vw-golf-mk3/troubleshooting-common-fixes/
cheers javalin
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Offline Amberjo

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #5 on: 21 May 2011, 23:34 »
Just wanted to say a massive Thank you for all the helpful advice, unplugged the MAF Sensor/meter and my Car dove like a GTI for the 1st time in months!! I had tried all the obvious Dizzy cap etc.... Took the Meter out and cleaned it up with Switch cleaner that cost all of a Fiver, plugged it back in and job done! Drives like a dream...
Thank you again, you have made this lady very happy  :grin:

Offline jamiethomas

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #6 on: 25 August 2011, 17:16 »
This was awesome, cheers!

Offline allenthehat

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #7 on: 26 August 2011, 21:35 »
Had the stalling issue like many others.  Cleaned my throttle body today as suggested, and not only has it stopped it (so it seems at the moment) my GTI also seems to run a lttle more responsive.
Mk3 Golf GTi 8v.....thats how I roll

Offline DUBboi12

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #8 on: 08 March 2012, 20:52 »
This thread is really useful, cheers dude :smiley:

Offline DanChave

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Re: Mk3 Issues.... A guide to the common faults and fixes
« Reply #9 on: 14 March 2012, 13:59 »
VERY useful thread! Hopefully I'll have my starting problem sorted soon :)