Polo 1.4 16v 1997 - Failed emissions test

[lennylegs]

Hi,

My polo has just failed the emissions test (twice now) and I'm after a bit of help please.

Driving home from work last week I noticed some smoke come from under the bonnet, pulled over and checked under the bonnet and there was oil everywhere. I'd checked the oil about two weeks ago and it was right in the middle of min/max, checked it then and it was in the middle of zero and min. Fab Dad came and towed me to the garage where the oil pressure sensor was found to be faulty. Sensor was replaced and oil topped up. I told them to keep it and do MOT as this was due 30th Aug anyway. Mot failures were - bulb, handbrake and emissions. First two sorted no prob, 3rd still unresolved.

First of all the lambda sensor was replaced, still failed. Then we were told it was the CAT, (had whole new exhaust from start to finish last August and mid section was replaced again last month as the garage that originally did the exhaust made errors) so took it back under warrenty to place that put on the CAT last year. They agreed the CAT had gone so replaced under warrenty and hooked it up to their emissions test to find out it still failed. They said disconnect the battery overnight then take it back. It's back in again and has failed again.
All I can remember is that it failed on the CM not the HC level.

Does anyone have any idea about what to look at next ? They say the head gasket is fine...... (have searched internet but come up with so many things to think about changing it's hard to know where to start!)

Thanks in advance
Lennylegs

Also best mention that in the last 6 months it has had - air filter, oil filter & change, sparks, ht leads (BUT not fuel filter)
And the the type of driving i do is poodle 3 miles to work and back weekdays, 20 miles and back on the motorway once a fortnight and a bit of town driving on the weekend.

[Paulpro]

I have a 2001 1.4 Polo which failed on its emission test last July 08. The car had only done just over 50K and had been serviced by VW meticulously since 2001. Initially, VW said that it was simply a spark plug problem so they changed a "coil pack" on what they thought was the offending plug. Of course it made no difference so they then decided to do a compression test. This showed that one of the valves was leaking - probably due to being burned out or similar. This meant taking the cylinder head off to repair the valve & also change the cambelt etc. at the same time. They talked me into having a completely refurbished c/head as they said thay there might/would always be a risk of the other valves going !!!!!.

The new head cured the problem but the whole episode cost me £1,350 for the service/MOT + repairs/labour etc. I hope your prob. isn't a valve then.

[VAGMAN54]

the readings off the failure sheet would be a good starting point,the one you got when it failed

[lennylegs]

Sorry for the late reply, have sorted car on that front it was a faulty lambda sensor. Mechanic was sure nothing else was wrong so rang up for another one, switched it over, hooked it up and it passed with flying colours!
However.... since then my car overheated.....

Car overheated driving in town traffic (not stuck in traffic, say 15mph ish). My other half limped it home stopping as soon as it reached 100 on the temp.
Spoke to mechanic who said to start by flushing the radiator (water tank was full of rust & gunk - no oil though). Dad & other half flushed it through and reverse flushed it then used a radiator cleaner on it so its now fairly clean - car still overheating. Blowers in car only kicking out cold air.

Next stop - changed the thermostat - no change.

Then called mobile mechanic who has changed water pump and cambelt (full cam kit done 15k ago so only paid for belt).

Now the car is not overheating, in fact all seems fine - however the blowers are getting really warm really quickly in the car. (they are quite happy to be on cold too) Not that I'm complaining here it's when things start going wrong you wonder what is next....

Could it be I'm not used to it warming up the car and having new pump/flushing really gunked up rad it making it more efficient?

I only have water in at the moment - need to go put coolant in the weekend - could that effect it?

Also - somehow (and i don't know how) the motor factor gave my dad the wrong thermostat and whilst trying to fit the new one they broke a bit of the cage that holds it in place so my car actually doesn't have a thermostat in at the moment. We will try to rectify this soon but mechanic has said its not the end of the world if it doesn't have one it will just take longer to warm up - but this doesn't fit in with the warm air in the car blowers?

Apologies for the lengthly post, but does it look like anything could be wrong or is just me worrying about the next thing going wrong?

Thanks!
(p.s mechanic checked car again and has said he's 100% sure head gasket is fine...)

[zollaf]

put a new thermostat in and your heater will be nice and hot once more.

[lennylegs]

Sorry I'm not explaining myself very well. The heater is warming up & getting hot - just much quicker and warmer than it has before ! I didn't know if I could attribute this to:

The car not having a thermostat in at the moment.
Only having water & no coolant in it at the moment.
The fact my water pump had obviously been on the way out and my rad def needed a clear out meaning for a while it's not been as effective as it should be and I'd just gotten used to the heat it kicks out.

Really I'm just worried that this sudden efficiency in the blowers warming up is something to worry about.

Drove car into work this morning (4 miles distance 30mph pretty much all the way) and she got up to about 75 degrees temp which seems about right to me. Sat in car park with engine running lightly tapping the accelerator and she crept up to 90 but refused to go over that so I guess she is ok. Just not used to the heat coming on so quickly in the car..... !

Cheers

[zollaf]

not having a thermostat will make the car not warm up properly and the heater to blow out luke warm air at best.