Thought it was about time we had a common problems FAQ. Some problems apply to more than one marque so I've tried to cross-reference where possible.


Mk1 Polo

Tinworm - Arches and sills are the worst places, see general for specific places to look.

Engines can suffer from low oil pressure (poor oil pump design - I think it might be mileage related rather than random occurrance) best solution is replacement bottom end from a later car (which has a much better oil pump).

Distributors can be troublesome (they have points and are difficult to set up correctly). A replacement from a Saab can be used that has electronic ignition See my other FAQ Here.

Oil soaked air filter - blocked breather. A good article on that can be found Here.

Poor starting/cutting out/wont idle - perished carb to inlet manifold gasket, disconnected vacuum line, incorrectly set ignition timing, incorrectly set idle mixture and/or speed. Those are the main ones, but similar symptoms can be caused by worn out ignition components (spark plugs, HT leads, dizzy cap, points, rotor arm)

Engine looses power on motorway/generally at high speed (cold weather) - This is usually caused by carb Icing (water in the air condensing and freezing around the carburettor jets). The cure for this most people use is to redirect the hot air flow to the main intake on the airbox, as opposed to the secondary one where its located originally.This thread may explain things better than me, it also has a pic.


Mk2 Polo (Early, German Built, 1981-1985, cars with engines with 8-bolt camshaft covers)

As above plus:

Fan only working on speed 3 - Faulty resistor pack on heater fan housing. New ones are available from GSF (not cheap) some can be repaired by soldering.

Location in relation to battery (Scuttle tray removed)


Remove the white connector...


And that yellow/brown thing with the wires around is the resistor pack.


Mk2 Polo (Late, German Built, 1986ish-1988, Cars with engines with hydraulic tappets and 3-bolt camshaft covers)

As above (Except mk1 dizzy and engine problems) plus:

Car suddenly dies for no apparent reason, but will restart later (then seems fine till it happens again) - dodgy hall sender on the distibutor. Replacement is around £40 from GSF but is not the simplest of jobs to replace.

Poor starting/cutting out/wont idle/poor mpg - Usually the Pierburg carb is blamed for this, more specifically the automatic choke. Ideally the whole lot should be binned in favor of a weber carb (1.3s only, the 1.05 usually already has one) But it may be possible to convert the pierburg to manual choke, although its been a long time since I've seen a manual choke conversion kit of any kind. Alternatively you can convert to injection. See my other FAQ Here for more info on that.


Mk2 Polo (Spanish Built)

As above really. some say they are more prone to rust than their german counterparts.


Mk3 Polo

Same as late mk2s apart from carb autochoke problem plus:

Poor Economy can usually be attributed to some sort of sensor failure; Blue temp sensor on the thermostat housing and the throttle position sensor (GT) are the worst for going wrong. Also the lambda probes can play up. These problems are also assoicated with poor running. The hardest one to diagnose is the lambda probe. Best way of detection for these problems is an air/fuel ratio meter. I have one of these in my GT, made by a company called Duostyling Several people have reported problems with these though. Having said that I've had mine for 12 months and its been fine. Price was reasonable too.


General Info, Applies to all.

Rust - Worst places for it are around the rear arches and sills, particularly where the fuel filler pipe joins the tank: The filler neck traps dirt behind it. This corrosion can spread to the rear axle mounts, at which point it becomes pretty terminal. The fuel tank can also corrode in this area for the same reason (and is usually the first thing to go)

Rust at the back the battery tray, under the rest bracket - Theres a few theories on this one, some say its caused by a leaking battery, others suggest its down to an oversight/design flaw. I've not seen an early mk2 with this problem as yet, so my vote is with the design flaw theory for now. To be fair though I dont think you can rule it out on any polo mk1-mk3. The solution is to cut out the old section and weld a new one in.

Engines - Will go on and on if servicing has been followed. Sometimes valve stem oil seals can start leaking at high miles. leaks from the rocker cover gasket,sump gasket headgasket (above the alternator) and camshaft oil seal are all fairly common (hopefully there arent many engines out there with them all!) The oil leak from the alternator can also cause premature alternator death.

Cambelt should be changed at 60000 miles and I would recommend the water pump be replaced at the same time. (the originals have fins that can corrode over time and disintegrate)

Headgaskets can last anywhere from 50K to 150K when they do go its around £50-£75 to replace if you do it yourself or around £300 to get it done at a garage. its worth considering getting the head rebuilt if the engine has done a significant mileage. (relap valves, new oil seals, etc)

Other engine related - radiator fan not working - usually faulty switch on the radiator. (about £5 from GSF for a new one)

Gearboxes - not seen as much as a problem on mk1-mk3s but they do suffer from the same problems as later ones, mainly diff bearings wearing out, but also the synchros can wear, particularly 2nd gear (true for most cars id imagine)

Suspension/Steering - Wheel bearings last around 100K. Front ones are difficult to replace, (requres special tools) rears are easy. (and dont).
Rear springs can snap at the top on the last coil. Not as bad as it sounds but it made the tail of my current GT "interesting" in the wet.

Vague steering is ususlly caused by worn tie rod bushes. Also the bolt that supports the steering column can come loose (another mileage issue I think).

Replacing suspension - Some front replacement shock absorber inserts rattle about inside the hub housing. I think the best solution is to put a big washer at the bottom of each housing to take up any free play that the screwcaps cant quite manage.
The rear shock absorber to axle bolts can sieze up. Most people just grind the head off the bolt and saw though the bolt itself on the other side (the nut is very difficult to grind off as its inside the rear axle)

Replacing Brakes

Discs/Pads - front disc to hub screws can sieze up and round off very easily. These bolts arent critical however so its not a serious problem if they do round off, just drill the bolt out.(unless you have special knackered bolt removal tools.
Siezed bleed valves, and unions are common. Make sure you use a proper brakeline spanner and you should be ok (11mm and 14mm. Also 7mm for the rear bleed valves) Brakeline spanners are 5-sided so grip much better than C spanners

G40 Specific

Charger history is very important. A standard one should be serviced about every 50K. Fuel pump and injectior health are vital for keeping the engine from giving your wallet anorexia. G40 chassis's can suffer from greater stress and quite alot of owners have found cracks when restoring thier G's So all important things to look out for. Pitstop is the place to go for G40 specific chat.

Dont hesitiate to add anything I've forgotten. Thats all I can think of for now.

carb to inlet manifold gasket, are these things still available?

Oh and check on these bits as well

leaks from the rocker cover gasket,sump gasket headgasket (above the alternator) and camshaft oil seal are all fairly common

yes all those parts are still available from VW and GSF

how do you solder the resistor on the heater then? My Mk2 golf just started doing this too!

An excellent FAQ post Gaz, well written and informative.
Nice one.
Richard.

I dont know how to answer this question without sounding patronising...but dare I suggest with a soldering iron?

what i ment was - which section do i solder to where? i found mine in 2 piece near the wiper motor! Wasnt even in there any more and the wires are shot! maybe time for a new heater unit!

Youre best off getting a replacement anyway as they get pretty hot so any solder probably wont last terribly long.

I have found wiper relays to be a common fault!

A very good post but may I suggest putting the problem in bold or adding a bullet so it makes browsing through them all easier. It is pretty wordy afterall!

whats the alt code for a bullet point?

[list]

{list} {/list} does that ^^

no

I mean Holding down alt and typing a 3-digit number can produce special characters, eg Alt + 248 = °

ALT-0149

Thanks!

The procedure for sorting the fans out is the same on a Mk3 yes?

Indeed.

Weekend task for me there then.

Anyone know where I can get a replacement Throttle position Sensor/potentiometer? for my Polo GT. I've been studying ebay for a couple of weeks now, but nothings turned up, and I've put in a request for one on www.1stchoice.co.uk, but only had one reply and they wanted £90 which i though was a bit steep. Also, I had a good search through google but no-one seems to do them. I haven't phoned VW yet, but that may well have to be the answer, I’d hate to think what they want when a scrappy wants £90.
Any suggestions?

Last time I checked it was £45 + vat from VW for a new one. www.vagparts.com may well be able to source you one for cheaper.



Do you expect it to go drastically wrong?

No mention of the external fuel resevoir problem?? On the old Pierbergs?? Just in case anyone needs the info - if you have problems with 'warm' starts or cutting out when warm, problem can be external fuel resevior on carb (retro-fitted as internal resevoir got too hot and fuel evaporated). If you get this, it's a simple job to bypass the resevoir. Won't help the hot restarts, but will cure the cutting out..............

Got any more info on why this happens?

From what I remember, the external resevoir got fitted to alleviate the problems of the internal resevoir evaporating all the fuel when the engine was hot. The thing is, it tends to get blocked after a while and you get not only poor hot starts (ie when you've stopped at a services on a long M Way journey) but you get a problem where the engine just dies about 15 minutes into a journey (ie, just after it's warmed up and the fuel in the internal resevoir has evaporated).

It took me ages to get to the bottom of this on my first Polo, but once the resevoir was bypassed, the cutting out stopped - and as long as the engine wasn't TOO hot after a short stop, it curiously didn't have too many hot start problems. REALLY cheap fix too (I paid a garage to do it - cost me a fiver!!!!) and far cheaper than a new carb!!

Think it was mainly the 2E3 carbs.............but worth mentioning as another problem finding route for dodgy carbs.............

Good to know. The other thing with these reservoirs is they're sometimes made of plastic too which gets brittle over time and can crack & leak and set your engine on fire. Either way, good reasons to do away with it.

.....NEED SOME KIND OF HELP 1.05ltr squareback polo......

Was in Nottingham earlier today and my car was spluttering and coughing. Managed to Limp it to a VW specialists in Radford Nottm and they were just shutting shop. However, they looked it over for me and said it was a blocked breather problem, oil was getting into my carb via the pipe. So just a get-me-home measure they disconnected the breather pipe 4 me, took oiled up airfilter out for me and i cleaned the carb and airbox and all was fine. I drove the 80odd miles home and just as i was pulling onto my road the coughing and spluttering happened again. I have replaced the dizzy,rotor arm, plugs, leads, coil, king lead, fuel filter and cleaned carb up and run redex through the system all before mot last month, so i know its not a problem with any off those items. could it be just a blockage in my breather system? The rubber thing that was recommended to replace ( also in the faq link) looks a ball ache to do. how do i clean the system out? is it all covered in faq link? I hoped my polo isnt foobared lol please let it be something trivial.

Nick

you can blow down the breather pipe to check that its blocked. Take the oil fill cap off and you should be able to feel the air coming out of there when you blow down the pipe. The best time to do this is just before an oil change as it sends it all back to the sump.

ah ha yes mine has gone known about it for ages i have filled it full of sealer and bit of duck tape in side lol works for now lol.

now i been trying to find where i acn buy the replacement panel as iv heard you can buy them any one know where???

if not i guss i will have to make the part my self.

Link doesnt work...

does now, link was of the type used on the old forum. I imagine the other internal links don't work either.

thought i'd add to this if i may, all the figures the blue temp sensor should show at different temperatures to help diagnose faulty ones as 'how do i know its faulty?' is a common question on these.. so....

temperature-----------------------resistance

0 degrees----------------------5000-6500 ohms
10 '' '' -----------------------3250-4250 ''
20 '' '' -----------------------2200-2800 ''
30 '' '' -----------------------1500-1950 ''
40 '' '' -----------------------1000-1400 ''
50 '' '' -----------------------725-925 ''
60 '' '' -----------------------540-675 ''
70 '' '' ------------------------380-480 ''
80 '' '' ------------------------275-375 ''
90 '' '' ------------------------220-280 ''
100 '' ------------------------170-220 ''

i dont know if i have posted in the right place as i am very new to all this. I've just passed my test and have a vw polo 1.3 M reg (1995) the problem is on frequent occasions she will not start, she doesnt even turn over, all i get is a very short and wuiet whirring noise. does anyone know what the problem could be i.e starting motor, ignition problem (as i need to turn key fairly hard).
i hope i can get some idea whats wrong so i can price things up as after xmas cash flow is dim.
many thanks leanne x

hey my horn keeps goin off when i turn left, is this a common.

Haha, not common but quite a simple fix. There must be a screw etc shorting out on the metal track behind the steering wheel. Just whip the wheel off and take a look to see what could be causing it.

HAHA, something similar used to happen on my mums old punto, when I brake the petrol gauge would drop to empty, and when I indicate the brakes lights would flash was pretty funny. But was just an earth strap that was not fitted correctly.

i dont supose you can sort a picture out of how they have bypassed the reservoir for me please? as I'm picking up a polo with this same problem next week.

cheers
gaz

Anyone know which wire you connect the air/fuel gauge too?

according to the haynes its a lilac one, but i have 2 white a brown & a black on the car side of the multiplug.

Thanks

when i start my car in the morning,
it starts the revs drop right down and usually cuts out
but i then start it again and its fine :
is this the auto choke ? or somthing else
ohh its a mk3 btw

thanks
Niall

Sorry to dig this up again, but how do you bypass it?

mine used to do the same! haha. any more and this may be common! lool

'Vague steering is ususlly caused by worn tie rod bushes. Also the bolt that supports the steering column can come loose (another mileage issue I think).'

Getting violent vibration and pulling to the left when accelerating after long periods of motorway driving, but stops after I turn hard right, is this likely to be a cause or more diff related?