Sick chipped S2

[Craig]

Hi Guys

I'm having some problems with my '91 3b (Mihnea chipset). I hope someone can help me diagnose what's wrong.
1) Car started pinging at high boost recently in 3/4th gear; This was the only problem before the service.
2) Sent it for a service and checkup
3) after various tests, I get the car back and they tell me that the head gasket is blown causing the pinging??
4) After the service the car now has a bad missfire as well when cold to the point of cutting out after a cold start
5) On acceleration, the car hesitates especially obvious with small throttle openings
6) Fuel consumption is +/-15% worse than normal
7) When warm, the car feels much smoother, but still not going as it should

Any ideas on what could be wrong with my baby? Could the head gasket be the cause of all the above? I would appreciate any help.

Cheers
Craig

[Ski]

when my gasket was leaking i didnt loose performance and ran like it should if that helps

[quattronutter]

i would get a compression test done...

[Craig]

Done

That's been done. Compression is fine.

[quattronutter]

any signs of water in oil or oil in water?

[BRY]

Check :-
1) Fault codes - as on S2central or with VagCom.
2) the MAF - swap it with someone, if that's possible?
3) the lambda sensor - how long has it been in service?

[dan_b]

What petrol are you using?

[Craig]

Reply

1) I don't see any oil in the water or vice versa, but the car is using water even if it is very slowly. I have to top up once every 2/3 months (about a cup).
2) Petrol: I was using 97 leaded. After the problems started I tried using some 102 octane (mix so should have taken octane up to +/-99/100). The missfire was A LOT worse than before with the lower octane.
3) I'm pulling fault codes today, Maf was replaced last year (new). Lambda hasn't been replaced since I've owned it (last 2 years) - I have asked that this be checked today as well - would a lambda fault show as a fault code?

[dan_b]

Lambda should appear as a fault code, it did on mine, and was the cause of some poor running.

[iain1067]

I hope you meant unleaded fuel????? if it's pinging then maybe the knock sensors are faulty.

[Craig]

My car has always run on leaded fuel.

[SimonS4MTM]

Sounds to me like a head gasket or cracked head, misfire, slight loss of water!!!!

Most probably caused by running the car whilst pinking, causing over heating.

[Craig]

Okay more news. The error codes have been checked. I had three error codes.
1) idle switch - this error went away after a reset
2) ndc sensor error (air temp) - the sensor proved to be working properly. Looks like a wiring problem. They are still busy checking
3) oxygen sensor error (lambda?)- its ******ed and needs replacing. Is this a Bosch part? I thought I read somewhere that these can be ordered directly from Bosch. The stealers are crazy.

[BRY]

Okay more news. The error codes have been checked. I had three error codes.
1) idle switch - this error went away after a reset
2) ndc sensor error (air temp) - the sensor proved to be working properly. Looks like a wiring problem. They are still busy checking
3) oxygen sensor error (lambda?)- its ******ed and needs replacing. Is this a Bosch part? I thought I read somewhere that these can be ordered directly from Bosch. The stealers are crazy.

Cheaper than a head gasket then

[dan_b]

Oxygen sensor is the lambda sensor. I bought mine from VAGParts here in the UK, genuine Bosch one yes - easy job to fix, took me 5mins (no airbox to get in the way).