mot emissions failure, head gasket?

[nathanpotato]

Hi I was wondering if you could help I have a 1996 golf mk3 1.6.
Basically my car first failed the mot on lots of stuff but one of these being the emissions that was thought of been due to the lambda sensor. Repairs were carried out including anew lambda sensor however it failed on emissions again, this time I was told it was due to the CAT.
So a new cat was bought however it still fails on CO emissions. This time they tell me they tried changing the timing and the spark plugs but can't get it to pass and think the head gasket has gone. At this point I'm pretty annoyed since I've already paid £260 for the previous work and now because it's the 10th day I would need to pay for a retest as well as the head gasket repair so I have just paid them and picked up the car with no MOT to have a think.
When I got the car back I noticed that the exhaust is blowing could this not be while it's failing the emissions? Also I'm planning on getting rid of the car so not sure if it's worth throwing more money at it any guesses on what I could get for it with no MOT? It's in pretty good condition with 97k on the clock.
Sorry for the long post any help would be great, Thanks

[trog_nfs]

are the hydrocarbons quite high as well?

Could be temperature sensor... Does it get up to 90 C ok?

[tweed]

Do you have to top up the oil say once a month?

[nathanpotato]

are the hydrocarbons quite high as well?

Could be temperature sensor... Does it get up to 90 C ok?

There at 66, no idea if that high but it passes on that it's just the CO at 0.73 and the Lambda at 1.063 that fails. Yeah the temp sensor seems fine it gets up to and stays around the middle

[nathanpotato]

Do you have to top up the oil say once a month?

I dont use it that much but probably top it up once every 6 months.

[tweed]

Do you have to top up the oil say once a month?

I dont use it that much but probably top it up once every 6 months.

How many miles do you do in 6 months and how much oil do you put in?

[shelaghmk3gti]

i love this thread...proper info not gti chat xx

[Rmachines]

What testing station are you going to just out of interest ?

[CJA321]

Normal ish reading for hydrocarbons is around 28 PPM.

High CO can can be a sign as low compression, however you would expect HC to be higher if that was the case.

High CO can also be a sign of poor spark, not as noticable as low compression but as combustion isnt quite complete CO will rise, but again you will see higher HC.

So id go with a compression test, check sensors, plugs(say they have done it but id put a new set in if not) check your water and oil for signs of contamination

[nathanpotato]

Sorry for the late reply I was extremely hungover yesterday! I probably only drove around 500 miles in the last 6 months and put in less than a litre of oil. The testing station as one in bodmin, cornwall called "spear garage services" just a local one.
They said they changed the plugs and changed the timing to see if this helps but no luck. One of the spark plugs was excessively oily which is why they think it might be the head gasket but they couldn't tell me if it was def the head gasket or not. They said the water is fine and the oil isn't creamy or anything. It has looked a little creamy in the past but i put this down to my short journeys.
Thanks for your replies.