surging and severe knock when pulling away, the knock is intermittent

[Trevor Ashman]

I have an intermittent surging on acceleration and the car tries to stall pulling away from standing starts. It also so has an associated knock with the pulling away aspect been to the garage but the don’t know. I have checked the air intake pipewear. I intend to clean the MAS, if this doesn’t work then change the MAS. Any more clues please

[Trevor]

Hi Trevor....welcome to the Forum

It could possibly be a vacuum leak as this causes similar symptoms.

If you carry out an exhaust gas check (any MOT approved garage should be able to carry out a Pre-MOT gas test) and look for Oxygen (O2) levels above zero which suggest a leak in the intake or exhaust.
Also, Hydrocarbons (HC) which should be very low (almost zero) which suggests that there is an ignition problem if high.

Let us know how you get on with it.

Cheers,  Trevor