Engine sounds and feels rough

[8VGolfer]

Hi,

I have a 96 Golf GTi 2 litre 8V mark 3, and I was wondering if anyone knows why my engine sounds and feels rough.
The car was serviced last november. I had a new timing, alternator and steering belt added.
I have recently changed relay number 30 and 167 to sort the cutting out problem. Also i bought a can of ekotek power boost
to clean out the air intake. The car definately feels quicker.

However, the engine feels lumpy, if you know what i mean. Also you can hear a very faint whistling sound coming from the engine.
Does anyone have any ideas why the engine feels and sounds like it is not running very smooth.

thanks,

8VGolfer.

[mrwotto]

The whistling may be an air leak somewhere

[8VGolfer]

hi paul,

how's it going?

air leak. Do you think it would cause the lumpy rough feeling of the engine.

Where do i need to check?

[Overseer]

on my car there are 4 places to check.. they should be in similar positions on most cars


1.. check all air hoses from the air-box leading to the throttle body.. this is the most obvious pipe

2.. then check the brake servo feed.. this will come off the back of the manfold somewhere

3.. somewhere else on the manifold there may be a return type feed running back to the air box..
     there may be a valve here to regulate between 'inside' and 'outside' the engine (the ISV)

4.. at the front coming off the block is a fatter vacuum pipe. cant remember quite where it goes..
      this came directly out of the block underneath a coolant pipe that goes to the top of the radiator
      (and has a thinner feed running up to the expansion tank)


to get a good idea for your own car.. follow the pipes for the coolant system.. any larger pipes that arent part of the coolant
system will be part of the vacuum system.


in my case i've had 2 and 4 replaced.  along with a new ISV. (well a scrappy one)

4 was split really badly and wasnt noticed for ages.


i've heard that spraying wd40 around will help find leaks as the theory goes that when the wd40 is sucked in the engine stutters.. but in my experience it didnt work

[8VGolfer]

thanks overseer,

i will give it a try and let's hope the lumpy feel to the engine and the faint whistling go.

8VGolfer.