Exhaust Emissions Check Light Beetle 2.0

[juliedorman]

Any suggested or advice from anyone. I am a new Beetle owner year 2000 2 litre, I have had it about 6 months and have been pleased with it. About 2 weeks before Christmas I ran over a badger! the coolant light came on and the radiator was split and had to be replaced (my husband and mechanic friend did it). It was then fine and seemed to be running well. Last week the engine emissions check light came on, I took it to a vw & bmw specialist who did the checks and the emissions were poor and would not pass a MOT. They say that they do not think it is connected to me running over the badger as they could not see any sign of this (although I think it is a bit of a coincidence), they say that the first thing I should do is have the oxygen sensors replaced which will cost me about £300 and at the moment I am meant to be taking it in on Tuesday to have this done. The trouble is that they cannot say for sure this will resolve it as the ECU (I think this was the right terminology) runs the sensors and if the emissions are still not right I may have to have this replaced at huge expense! Before buying the beetle we had both our cars 'die' on us last summer and had to replace them both at the same time and had a lot of trouble and expense before they 'died', I really have had bad luck with cars. I am worried that I spend the £300 and it is still not right, feel very tempted to trade the car in for something else but would still lose out financially. One of my friends said, it it was them they would get the oxygen sensors done (which I believe is a common fault with the beetle), if it doesn't solve it get rid of it by trading it in. Any suggestions??

[Crasher]

The ECU will not be faulty in my experience so don’t let them worry you about that, I get a little irritated with people that waggle the finger at ECU’s, they are probably the most reliable component on modern cars. Didn’t they do a fault code read? The pre cat lambda (oxygen) sensor is a common fault on the Beetle with the 2.0 litre 8v engine and can just be faulty or its failure can be influenced by external factors such as a faulty coolant temperature sender, an air leak (split intake hose), faulty Air Mass Meter (also incorrectly referred to as a MAF) or a misfire from faulty plugs, leads or coil pack. The engines are also prone to burning oil which can damage the lambda sensor but I imagine you would have mentioned that. I would think the second lambda sensor behind the cat will be OK and the cat itself should survive and both normally come back to life after a good run. A genuine lambda sensor is £128 but they can be bought cheaper although the quality can be poor so make sure it is a good brand such as Bosch but there are other good makes as well. What is the engine code, AQY?

[juliedorman]

The ECU will not be faulty in my experience so don’t let them worry you about that, I get a little irritated with people that waggle the finger at ECU’s, they are probably the most reliable component on modern cars. Didn’t they do a fault code read? The pre cat lambda (oxygen) sensor is a common fault on the Beetle with the 2.0 litre 8v engine and can just be faulty or its failure can be influenced by external factors such as a faulty coolant temperature sender, an air leak (split intake hose), faulty Air Mass Meter (also incorrectly referred to as a MAF) or a misfire from faulty plugs, leads or coil pack. The engines are also prone to burning oil which can damage the lambda sensor but I imagine you would have mentioned that. I would think the second lambda sensor behind the cat will be OK and the cat itself should survive and both normally come back to life after a good run. A genuine lambda sensor is £128 but they can be bought cheaper although the quality can be poor so make sure it is a good brand such as Bosch but there are other good makes as well. What is the engine code, AQY?

Knowing nothing about the technical stuff I am not sure but they plugged the car into the computer thing and did the fault checks and a breakdown of the emissions that they said were all over the place. Not sure about the engine code. One thing you mention about fault coolant temperature is interesting as I had run over a badger two weeks before and the radiator had to be replaced also losing all its fluid and warning light coming on. My husband and a mechanic replaced the radiator and it all seemed to be running well again. They are getting the new oxygen sensor through the local vw dealer as they said the car would not accept any other makes. I am so worried as I previously had loads of bad luck with cars so am automatically very worried that the problem will escalate! Do you think losing the radiator and coolant would have damaged the sensors? and would there be a chance that I will replace them and whatever made them faulty would make them faulty again, say it was something to do with the damage running over the badger made to the radiator?

[Crasher]

Loosing coolant could damage the engine, never mind any sensors but it can cause the coolant temperature sensor to play up. These are cheap and take a few minutes to fit. Knowing the results of a fault code read would be very helpful, why is it that garages don’t routinely give the customers the fault code report, we do.

That the engine will not accept anything other than a genuine sensor is male bovine rectal emissions, if you get my meaning but I also like to use a genuine VW lambda sensor if the customer will pay for it, if not there are others I will happily use.

As I said, lambda sensor failure is common on these so a new lambda sensor and fault code clear is a good step and lets see what happens after that.

[juliedorman]

I did find your response reassuring! if only the mechanic had a more reassuring manner! Got it back today and it has sorted it out and all running to correct levels. Cost me £312 which I paid cash and asked for best cash price! Is that normal level of cost? Will never know if the collision with the badger contributed or just very bad luck as normal (with cars). Car has done just under 60,000 miles (x reg), so will have to get cam belt done soon as VW recommend it is checked at this level, but if they are looking at it may as well replace it. Do you think the two litre beetles are good cars, my first beetle and bought on a bit of a spur of the moment. It is costing me a lot more in petrol of course. Also how long is the life of the oxygen sensors in the 2 litre beetle if it is a common fault? Thanks for all your help.
Julie

[Crasher]

The interval on the timing belt is as high as 110,000 miles according to VW (I never take a petrol past 80K though) BUT it MUST also been done at five year intervals, so yours is about four years overdue! The water pump must also be replaced at the same as must the coolant and the correct VAG specification G12 or G12+ type coolant used. The 2 litre Beetle is a good car, the only real gripe I have over them is that the engine is a bit rough compared to the 1.8 20 valve turbo. The 2 litre is very prone to lambda sensor failure, in fact in around 2000 it was the subject of a recall on the Beetle.