Hi guys,

Developed a problem with my octy :(...

Basically when the engine's cold, ignition on, fire up but it idles like a lumpy sod! There's a hissing noise coming from around the INLET manifold area (underneath). Once the car has idled for 5 minutes or so the hissing stops and the car idles fine and drives perfect (boosts to 20psi)

I removed the SAI and it did this before it was removed. The SAI just made it alot worse as the pump was split.

Wipped the inlet plastic cover off to have a nose around but couldn't see any split pipes.

My boost gauge reads -15 until the hissing stops then returns to normal -21 (vacumme)

Coils have been replaced last year under the skoda recall.

My question is, where is the cold start system? Is it prone to go faulty?

Any help would be much appreciated.

Coolant temp sensors are a known issue. Do you or any one near you have vagcom to check it?

If it is cts then get genuine vag one as cheapie ebay ones soon fail too.

I've scanned it with VAG com, No fault error apart from the SAI removal :(.

Did logs on the car also and it came back with the temperature working its way upto normal

There's a breather pipe under the inlet manifold that splits, quite hard to check properly.

Also did you cross reference the engine temp with the gauge temp?

When you remove that plastic cover there are 2 pipes Next to the dipstick tube that are prone to split, my money is on 1 of those. I had it with my vrs, they are hard to spot but if you run your hands over them you'll find your hissing I'm sure.