New to polo's help help with engine gremlins

[dizzypolo]

Hi all,

Looking for some help, as I am very new to VAG cars and this is my first Polo.

I have had the car less than 1 week, and have been trying to workout the Gremlins, as it is a 2004,1.4 petrol With 74K on the clock, and the prevoius owner hadnt done hardly any miles in the last year. My car has service history going to about 50K however services after this is unknown.

I have already fixed quite a few problems already such as the 16V socket, Rear wiper wash leaking (Hose was loose), but the biggest SAGA so far started out as Juddering on acceleration, in adition to this the idle was rough and every 10-30 seconds it would misfire. After looking online it seemed that the throttle body is prone to getting clogged, and I removed the entire thing to clean it, and it was absolutely caked. This resolved most of the misfire, however the car was still alittle lumpy, espcially when moving and driving through 2000-2500 revs and trying to accelerate hard.

So the next culprit - I have changed the spark plugs, Using NGK plugs. After this all juddering and misfiring was much better, however initially driving it, didnt feel like it was 100%, After this I filled up I made a point to use Shell fuel instead of basic supermarket stuff.

However tonight the polo had a bit of a relapse. I took her onto the motorway and within 3 miles, after 3000rpm, the car struggled to go past 60Mph, the more I tried, the car seemed to shudder quite badly. Took the car back home, I let it go cold - and went for a drive again. This time there was no judder, car went upto 80-85mph, no issue, then when going on and off slip roads moved through past 3500rpm easy and very smoothly.

I now believe that the problem is one of the following.

1. Either a MAP sensor issue. Having looked on youtube, this is positioned near the oil dipstick. - I am to using some airflow cleaner, (I will goto motor factors tommrow for the cleaner. I cant use the Throttle body cleaner or wd40 ?? )

Or

2. Fuel related - I am hoping it may even be sediment from the prevoius fill ups before me, and it may be that blasting the car out - I did drive it hard, maybe has freed this up. Also I know I have put good fuel in. I think I may need to change the fuel filter - Which should be easy enough.

So the plan of attack is, Clean the MAP , then change fuel filter, only other thing I havent said is there are no fault codes on the engine coming up, even when the car started to badly shudder this evening. If the problem remains gone, I will also be carrying out a oil change, oil is alittle off brown but certainly not black, and also change oil filter at the same time. The air filter has been changed, and is clean as a whistle.

Ideally Id really like to keep this car, and so far impressed by everything else just this engine issues.

Can anyone else suggest anything else I can do to fix the gremlins in this car as its driving me potty. Any help is appreicated.

Will post some pics and progress of the car once these issues are fixed.

[bvs]

Do you know which type of engine is fitted ?It is usually a 3 letter code - ours is an AUB 1.4 16valve.

One possible problem at this time of year is intake/throttle body icing,there is an automatic actuator in the air inlet system which draws in warm air from the exhaust system to prevent intake/throttle body icing - I doubt this is your main problem but icing would clear after the engine is stopped and then the car would run ok for a while.
On our car - the engine oil always goes a weird brown colour between changes - same with a friends Polo with a similar engine.

[bvs]

Also would be a good idea to have a good look at all the Vacuum pipes - split or disconnected vac pipes can give similar symptoms.

[RUM4MO]

I would hope at that age the engine code is BBY.

You might not be seeing any engine fault codes logged as you are using a general basic OBD2/EOBD scan tool, I used to use a VAG specific cheap scan tool from Gendan, but it will have been withdrawn from the market now I'd guess as it didn't suit the comms for later VW Group cars - it could read the full extended range of engine fault codes and not just the short limited range of mandated emissions related codes.

The general advice is to spray the cleaner fluid indirectly into the MAP sensor and covering the open end with a finger etc shake it about dump the dirty fluid and repeat many times. You will find the MAP sensor at the driver's side end of the plastic inlet manifold it is secured by a single Torx headed screw and its rubber seals can be reused easily.

Throttle body cleaning, did you manage to locate the EGR valve pipe connection point on the Throttle Body or on an interface plate at that area, and clear out the choked port that allows the EGR gases into the inlet manifold?

Edit:- split vac pipes include the brake servo pipe which has a one way valve fitted to it so that means 2 extra points for a possible cracked/split pipe.

[dizzypolo]

I would hope at that age the engine code is BBY.

You might not be seeing any engine fault codes logged as you are using a general basic OBD2/EOBD scan tool, I used to use a VAG specific cheap scan tool from Gendan, but it will have been withdrawn from the market now I'd guess as it didn't suit the comms for later VW Group cars - it could read the full extended range of engine fault codes and not just the short limited range of mandated emissions related codes.

The general advice is to spray the cleaner fluid indirectly into the MAP sensor and covering the open end with a finger etc shake it about dump the dirty fluid and repeat many times. You will find the MAP sensor at the driver's side end of the plastic inlet manifold it is secured by a single Torx headed screw and its rubber seals can be reused easily.

Throttle body cleaning, did you manage to locate the EGR valve pipe connection point on the Throttle Body or on an interface plate at that area, and clear out the choked port that allows the EGR gases into the inlet manifold?

Edit:- split vac pipes include the brake servo pipe which has a one way valve fitted to it so that means 2 extra points for a possible cracked/split pipe.

Thank you, I will double check the engine code, I am not sure as of yet.

Did some general maintenance on the car today, engine oil was really bad - prevoius owner said it has been changed, but from the state of it, the oil was at least 15,000 miles old, did oil filter at the same time. strangely the last owner actually changed the air filter, but never bothered with the oil change

My next area was going to just do the fuel filter, My guess that hasnt been changed from a few years. hoping this may help do steady things out too. This morning actually purchased some MAF cleaning spray, however doing the oil change took 2 hours, due to the horrid position of the filter, (hidden just behind the from near the radiator.

I do get a bit nervous unplugging sensors with the polo, as from what I have seen its very sensitive electronically, and I am alittle worried making anything worse. Today by 3pm it was far too windy for me to even think of braving this.

I dont personally own a scan tool, but prevoiusly when it misfired and the light came on, I had the AA plug in thier OBD tool. I am guessing that this is not a cheap one.

Fingers crosssed that all this work will pay off soon. Most of my outlay financially has been spent on tools.

Only other thing that might be an issue, and alittle alarming is I had to top up the coolant, on buying the car it was below the MIN mark, this morning it beeped to say it needed a top up. BUT hoping that this does not still happen. hopefully this is not going to be a sinister problem such as water pump seal or H/G which I doubt with a 74K engine.

Joints on all Pipes seem to be clean, Vacuum pipes are clips are all tight and clean. gave these a good look over ealier.

Not been a bad day all in all

[bvs]

If you are losing coolant - one place to check is down the rear of the radiator,you should be able to see the fan temp sensor (27mm ? or 29mm ? hex),if it is leaking - the rad will be stained around the sensor,I 'tweeked' mine up with a shortened open end spanner.But it is a plastic thread so it has to be done VERY carefully - I prob didnt even put a 1/16th turn on it - just enough to move it slightly.
There are of course many other possibilities !
When we got our Polo I bought a cheap VW compatible scan tool and it has worked ok so far.

[dizzypolo]

Any recommendation on scan tools?

Will check thoose things you have said.

Dont know is this works, but Ive heard you can use yellow glasses, a UV torch, and neon dye to follow any leaks in pipes. Sounds crazy! but an insanely cheap way to rule out leaks.

Engine is running so much better now, apart from this.

Only other niggle is the climate control is stuck on hot. Not a problem for me, as I like a warm car, and I will wind down windows if it gets too warm, so this is very low on priority.

Once the engine and coolant is A ok, I will be looking for ways to improve more styling aspects, but not going to be going over the top.

[RUM4MO]

The cabin air temperature will probably be the temperature flap motor assembly so I'd definitely forget that while the weather is cold.

Using a UV light source, suitable glasses and UV dye is normally only used for refrigerant leaks, engine coolant leaks should become obvious due to the localised accumulation of dried out coolant concentrate.

Normal leak sites being the fan thermal switch on the radiator, waterpump shaft seal or heater matrix pipes.

Edit:- reaching in to change the oil filter just does not get any easier with time, I changed the filter on my wife's old 2002 Polo probably 12 times, and the filter on my daughter's 2009 Ibiza 4 times, unclipped some of the wiring makes it slightly easier, but I have this urge to fill the new filter with fresh oil before fitting it, now really does make life difficult! This job is probably very easy when the car is up on a hoist in a workshop though, reaching down from the top is challenging.

[dizzypolo]

so far the following is done.

- Oil and filter change air filter already clean

- Throttle body cleaned - Made a huge difference

- Today I cleaned the MAP sensor, this was hard to locate and awkward, however was caked, made even more difference.

- Lots little non engine related things are now sorted. 16 Volt socket now works.

- Hose on the rear washes now, was disconnected behind the passenger rear in the boot.

Still left for me to do.

- Jack up the rear and fix the rear suspsion arm dust cups, Look like black cups. No idead how these have come off.

- Providing on time will also be replacing the fuel filter.

- I ordered a new CAP for the coolant, I ve got a hunch this might be to blame, After parking up last night with a very hot engine there was very least psssst, when undoing the cap. However coolant hasnt moved today but only done 25 miles.

- There is a bit of trim missing from the rear washer jet, Will check with a local scrappie. She will also get a new wheel trim as one is missing.

Not going to be too bothered about the heater, as there is no way I am stripping down the dash.

Toying with the idea of finding someone to black out the windows, Id like to debadge it.

Image here shows the MAP sensor - Nice and clean




for me, this was an absolute pig to get too. (worse then the oil filter)

[bvs]

The V68 motor for the temp control is a fiddly job but does not require a full dash stripdown.
A few years ago KITT did a great thread/guide on here.

viewtopic.php?t=52145

[RUM4MO]

The rear suspension arm dust cover, do you not mean the "pipe covers" or dust covers for the rear shock absorbers? If so, they will be okay but it will be the bump stops that will have bio-degraded with time and these dust covers will have cut through them and dropped down still with a small section of hardened bump stop in them - so that means that you need to buy a pair of bump stops, I think that even ECP sells them.

[bvs]

Any recommendation on scan tools?

I got a cheapie (model U281) off ebay a few years ago - works fine - easy to use and will erase codes and will extinguish EML lights.
I am sure their are better/more modern ones available.

[dizzypolo]

The rear suspension arm dust cover, do you not mean the "pipe covers" or dust covers for the rear shock absorbers? If so, they will be okay but it will be the bump stops that will have bio-degraded with time and these dust covers will have cut through them and dropped down still with a small section of hardened bump stop in them - so that means that you need to buy a pair of bump stops, I think that even ECP sells them.

dust covers for the rear shock absorbers. They are black cups fitting over the rubbers.

[dizzypolo]

Thank you for the suggestion for the scan tool.

Fuel filter is now done. Head is absuluting still pounds from the smell of the fuel. Dispite purging the fuel beforehand.

This is what the old one looked like Looks almost 3 years old.



Coolant issue hasnt reared its head again and seems to be stable. If it does go down will be checking those sensors.

Last immiedate job is doing something with the dust covers on the shocks. At the moment they catch when going over 50.

Now that most of the more pressing jobs are done. I will be focusing the looks of interior of the car. Id like to fit a USB port above the cd player to charge devices, or route some usb cables out of the dashboard for mounting phone and dashcam. Then will be getting a damm good polishing.

Will post some actual pictures of before and after soon

[RUM4MO]

Well we traded in my wife’s Sept 2002 1.4 16V BBY petrol engine at 13 years and 105K miles and it was owned from new and never ever had its fuel filter changed!
I just never got round to changing it, VW Group do not suggest a change time/miles for these petrol filters.