Mk1 Golf (S3)


Registered User
Jul 18, 2015
Reaction score
North East
Hi everyone. New to the forum. I've just bought a Mk1 Golf with a 1.8 S3 engine. I know very little about cars so would appreciate some help. The car was running horrible when it did actually drive, seemed to jolt and bunny hop a lot, and do nothing when I put my foot down for 300bhp car. I took the Map Sensor out as someone told me it could be that and the car seemed to run better. However, it was a brand new genuine sensor. As I was taking it out I noticed the air filter had a huge rip in so is going to need replacing. I then noticed than it had lots of oil on it. The oil breather filter has actually had a hole blown through it and oil coming out and on to the filter. So I'm thinking the air filter could have maybe been sucking in air and dmaged the sensor. I'm going to buy a new oil breather filter and a new air filter, can anyone help me on what to buy? A picture here to show the engine bay


Thanks very much. Can I just ask the reason for the ones you have said? Any particular reasons for them ones and not others?

Also, do I need the oil breather filter? And do you know why theres a huge hole on it facing the air filter?

Thanks again
...and avoid foam filters... untreated they don't filter fine particles... they need to be oiled to do that... once oiled though the oil tends to coat the MAF and this kills them quickly...

The also have a habit of degrading over time and bits of foam break off and end up in the turbo... never a good thing

You should put some sort of cover over the ECU too (I can see it in the scuttle in the right of the picture)... it won't like water ingress which can happen especially as open as that one is...

As for the oil breather... ideally you should consider a catch can as the PCV looks pretty much deleted on yours anyway... you can then either vent back to the TIP or vent using a filter on the can

Ah right brilliant I'll get that red one ordered, thanks.

I'll get the ECU covered as soon as possible, good observation.


The hole is where the blue arrow is pointing.. I'm guessing the oil comes up the black pipe (green arrow) and is meant to turn left? I don't know what stopping it from going right into the oil breather filter and maybe thats whats caused the hole?

Sorry for my lack on knowledge, wheres the pvc on the photo? Can you send me a link to a catch can too if I need one!

Jesus I hate cars already I've only had it a week!!!
Last edited by a moderator:
S2000 filter mod, cheap and good dry filtration, £12 at euros at the moment.
I bet it's a proper little rocket, if you can stop the front wheels spinning all the power away, I know someone with a mk1 GTI with the same conversion, he has 225/300 bhp switchable boost, he virtually never uses the 300, because it's an absolute animal.
I know Erikn89nl thats the scary part!! Thats good thank you, looks a bit out of my ability at the minute though.

Ye ayfreetee but bit of a shame, just wheelspins like mad in every gear, even 4th!!

So is the PCV system I have set up at the moment just a waist of space? From what I can work out (which isn't much) is the pipe (green arrow) comes from the crank case breather/oil filter housing and then comes up, goes left into the cam cover breather and any vapours is meant to pass right into the oil breather and vent to atmosphere? Is this correct?

So if I bought a catch can, what would be going where? And where is my PCV valve?
oily vapour air comes from crankcase and from cam cover and currently vents to air through the filter.
on OE it goes via hockey puck valve (PCV) back into intake and gets burned.
you can fit a catch can where the filter is to catch the condensed oil, then vent to air through filter.
oily vapour air comes from crankcase and from cam cover and currently vents to air through the filter.

So the oily vapour comes from both of the connected pipes and hits that oil breather filter? When i've looked, there is liquid oil coming out the side of the breather filter (hole has been burnt in) and is spraying on my air filter? Do you know why I'm getting oil coming from there if its only meant to be vapour?
If the pcv is deleted need a catch can to catch the oil and the breather filter vents the vapours to atmosphere instead of venting it back into the turbo intake pipe via the hockey puck like on a standard car ..

ur resulting in oil coming out of the breather filter due to no where for the oil to go hence the requirement of a catch can on a pcv deleted engine