Roger Blassberg

Normal right-handed thread/turn clockwise to screw the piston in. Best wishes RB

Thanks Jon vr6. Don't forget that the car in question is, in fact, a Passat B4 (a sneaky interloper in this esteemed company.....) but maybe similarly laid out. The glovebox is occupied by an airbag in this case.

Thanks again . I'll get the code from the report. Any idea where the relay is that engages the resistor - in the ABS ECU perhaps? Best wishes RB

Thanks RW1 for your usual very high standard of response - I almost knew from the outset that it would be you who would reply to this topic. My thinking on this problem is as follows; The fault only seems to occur after a slow tight manoeuvring turn, below the 25mph EDS/EDL/TCS inhibition speed, so maybe it is indeed linked to that function and this is causing the pump to operate in such a way that it flags up a fault. I am confident that the front sensors and cables have been ruled out as the culprits, and the gaps (sensor/slotted hub ring) are within tolerance Does the fact that the fault clears after leaving the ignition switched off (eg overnight ) give you a clue to the underlying cause? I'll clean the contacts to the resistor - do you happen to know the design resistance value? Thanks and best wishes RB

There's a socking great big resistor on the side of the ABS valve body. What is its function please, and what happens if its connections get dirty/corroded or the resistor itself develops a fault? What is the normal resistance? This is actually a question relating to my Passat B4 (LHD) which has a persistent ABS warning light malfunction, but Passat Forum lads have not come up with a solution . Most of the time it works as it should (goes through light on / light off sequence on startup) but occasionally the light comes on after turning the steering hard to full lock one side or the other at slow speed. Light then goes through on/off sequence after restarting but comes on at about 10mph. If left overnight, it sorts itself out. New front sensors, new front cables from sensors to inside, replacement ABS ECU. 1551 shows an intermittent pump malfunction. I have just changed the brake fluid to no effect. Trying to avoid changing the valve block/pump, so doing "cheap" fixes first. Best wishes RB

Thanks Matt, switch received a day after ordering. Fitted and seems to be fine. Best wishes RB

All Hail the omniscient Hayrick !! Different MAF, different behaviour. So far, after a day of running with a different MAF, (found lurking in the back of my garage from a few years ago), the car hasn't stalled once even in circumstances which would have definitely provoked such behaviour before the swap Still very light pinking if floored at 3000rpm. I don't think there were any messages on VAGCOM ( Hasan - didn't it read "No Faults" ?). Much, much improved and generally a smoother-running engine when idling and slow running through traffic. Thanks all RB

Yes, as Hasan says, change the rather odd shaped rubber gasket between the face of the head and the housing, and also the ring on the end of the transfer (so-called "crack") pipe. Whilst you are there, change the O-ring seals for the 2 (or 3 if you have A/C) sensors. Use 3 new bolts - they are typical VAG socket-headed bolts, made of marshmallow and easily rounded out; get the Allen key well and truly into the hexagon before turning it. If you wreck the short, most inaccessible one, you will probably have a dreadful job to get it out. The four bolts holding on the coilpack need to be similarly treated- steel theaded into aluminium always sticks hard. Take the opportunity to have a really good look at the various hoses as you disconnect them. If they are originals, there may well be damage around the clips. Best wishes RB

I take it you mean the VALVE block. Open bonnet, look at the back of the engine compartment, on your right looking from the front, mounted on the bulkhead near to and just below the coolant expansion tank. Lots of brake pipes and a couple of electrical connections leading to it. Best wishes RB

I have now changed the dashpot throttle damper, which makes gearchanges much smoother as the revs drop much more slowly in the "in between" time. Hasan and I checked the throttle potentiometer sender and that looks ok (thanks for your time this morning, Hasan, good to see you again !!). We also checked the ISV, again no problems. So it does look like the dear old MAF. Incidentally, Im getting the faintest hint of pinking on hard acceleration, even on Tesco 99Octane, using standard NGK plugs. So maybe the mixture is a fraction lean- may also point to MAF? Best wishes RB

Thanks Hasan, I'll call you some time today. I have free time over the weekend. I have now found the OBD2 article lurking in the archives. It looks rather daunting......... Best wishes RB

robo22sri, tell me more please. Best wishes RB

I looked for the OBD2 conversion article in the Wiki, but couldn't see it. Are the necessary parts fairly widely available second hand? Hasan, do you have Vagcom or some other means of measuring the throttle plate angle? I'll replace the damper/dashpot, lubricate the ISV (which I hadn't done after cleaning it out), look again at the throttle body including replacing the gaskets, check voltages at the MAF and take it from there. Regards and thanks for all advice. RB

Thanks for all responses. Could someone explain how the ISV works please? What do I need to do to check the MAF, other than the "pull the plug off and see if it idles worse and then dies" (which it does incidentally)? What do I do to convert to OBD2? Best wishes RB

I have just done Basic Settings after a battery disconnect, cleaned out the ISV, checked the MAF and also for vacuum leaks. All seem ok, and yet the car (VR6) regularly stalls, particularly if there is a high alternator demand and almost always when I dip the clutch after a period of closed throttle running such as going slowly downhill in traffic. The throttle damper seems to be in the right place, but investigation reveals that it is not actually doing any damping - there is no noticeable resistance to the piston being pushed in. Is this a common problem, indeed is it a likely case of the engine stalling in the circumstances described? Best wishes RB

To change the front wheel bearings you'll need access to a press - the bearings are pressed into the carrier and the hub into the bearing. Lower ball joints are fairly cheap and easy to fit. The rear bushes on the front wishbones may well need changing - a bit of a hard job to get the new ones in without a proper tool. The best solution may be to get new wishbones with bush and balljoint as a unit. Top mounts may need changing too. Get genuine VW parts if you can afford them. Have the geometry checked after the work is completed. Best wishes RB

Yes, sorry for leading you up the garden path with VR6-related stuff. I'll make it another New Year Resolution to read ALL the information provided before jumping in with both feet............. Anyway, it looks as though you have found a very likely cause for your woes, which is good news. best wishes RB

Have you disconnected the battery or replaced the throttle position sensor recently, and then not carried out the Basic Settings routine? If so, there will be a lack of coordination between the throttle and various fuelling and ignition timing settings. Look at the Basic Settings routine in the Knowledge Base for the procedure. Are you getting high fuel consumption? Maybe a lambda sensor/wiring fault. Is your MAF (Mass Air Flow) meter known to be good? Disconnect it at idle; that should cause the engine to splutter and stall if it is working well. Take it off, clean the connector block with contact cleaner and spray the fine platinum wire inside the body with contact cleaner too. Otherwise, check for air leaks in the induction system. Are there any loose clips, are there any perished hoses, is the small diaphragm valve on the intake trunking/cylinder head junction split? Best wishes RB

Make sure that the HT leads are for a coilpack setup. The ones for the distributor engine are longer and flop about all over the place with a coilpack. Best wishes RB

I have been having all sorts of strange goings on with the ABS on my '94 Passat. All sensors seem ok and the slotted rings on the hubs are new and clean. I decided to disconnect and clean the loom connector to the ABS ECU. That seems to have done the trick - these things operate at low voltages and any increased resistance, eg a dirty or corroded connection, can upset the ECU. It's worth a try in your case. Best wishes RB

What plugs are you using? I had a set of Bosch something-or-others, straight out of the box they were truly dreadful and misfired exactly as you describe, despite being the ones recommended by Bosch. I replaced them with the standard NGK items BKR5EKU from Sparkplugs.co.uk and the difference was like night and day. As has been said many times, even though your chains are apparently quiet, after 160 000 miles the top tensioner will be worn and it's quite likely that at least one of the chain guides will be damaged too. Best wishes RB

Hasan, the bolts go in from the top, through the elbow and screw into the captive nuts which are set, I assume, into the underside of the flange on the radiator (otherwise they would pull out when doing up the bolts). So the question is, if I cut off the bolt heads, will the remaining threaded stud and the captive nut move downwards and away to enable me to refix a new nut from the underside? What next with this car?? Roger

The top hose plastic elbow/radiator joint is weeping. The elbow itself seems to be ok, I replaced it fairly recently, so I suspect the O-ring seal. I tried to undo the bolts (one short, one long) , but the captive nuts in the radiator flange are turning and the flange itself has cracked across the outside of the long bolt hole. I propose to cut the heads off the bolts to remove the elbow, repair the cracked flange with Araldite or similar and then use longer bolts and nuts that bear onto the top and under side of the flanged connection. The big question is this; if I cut the existing bolt heads off, can I then push the remains of the bolts and the captive nuts down through the bottom of the radiator flange, or are the captive nuts moulded into the flange to prevent then coming out. As said, they turn, but I'm not sure that they can be pushed out. I would obviously prefer to avoid having to buy and fit a new radiator; the leak is very minor and I can live with it for the time being, but I want to sort this out eventually. Best wishes RB

When I start the engine (VR6, 209,000 miles) there is a knocking noise from the engine, directly related to engine speed. It disappears above 2000 rpm when the oil is cold, and completely at any engine speed once the oil is warmer than 60 degs. If it were a bottom end bearing I would expect the knock to be more pronounced at higher engine speeds and at higher oil temperatures when the oil is thinner. It is totally absent once the engine is warm. The engine goes very well, burns very little oil and the plugs are all clean. I use 10/40 Chevron oil and change it every 4-5000 miles. The head, chains, tensioners and guides are all recently renewed - it's not a tappet or timing chain rattle. 2 alternatives come to mind piston slap or a noisy oil pump. Any comments would be gratefully received. Best wishes RB

Perhaps he means "Camber". Very slight camber change when swapping bottom balljoint, most adjustment is available on the hub carrier/strut bolted connection. Best wishes RB