Vacum/Air leak

Post Thu Oct 27, 2005 1:00 am

Ok heres one for you.............

On my old 320i, pre ICV valve thing, when i took off the oil filler cap while the engine was running, it would stuggle to idle, put the oil filler cap back on, sweet as a wurhters orignal. Now, my current 325i, 90 model. does not do this, does this indicate a air/vacum leak ?

As i am still having a over heating problem, i was checking for mayo on the cap at the time.

Post Thu Oct 27, 2005 1:02 am

the 90 model shud have an ICV no?

Post Thu Oct 27, 2005 1:06 am

318-is wrote:the 90 model shud have an ICV no?

Yes it has, soz.

would the ICV compensate for this ? As the engine revs do not drop then rise back to normal as the cap is taken off nor rise slightly as the cap is put back on.

Post Thu Oct 27, 2005 1:08 am

i would guess so mate

theres an old saying "if it aint broke, dont fix it"

basically if thers no symptoms of an airleak, e.g. erratic idling or lack of power, personally i wouldnt worry mate!

Post Thu Oct 27, 2005 1:10 am

i ask because the tube from the rocker cover to the TB is leaking, as it has stained my nice and clean rocker cover, if oil can get out, would air be getting in ?

Post Thu Oct 27, 2005 1:16 am

possibly, but i doubt this would cause your overheating problem

is a lot of oil coming out?

Post Thu Oct 27, 2005 9:37 am

318-is wrote:possibly, but i doubt this would cause your overheating problem

is a lot of oil coming out?

i know its not causing my over heating problem (which i think i have fixed now !), its just making a mess under the bonnet, there is not a lot of oil comming out, just enough to stain the area around where the breather pipe connects.

Looks like ive got to get a new one.... took of the pipe to clean it out, bloody thing is that hard it has split....Grrrrrrrrrr

Post Thu Oct 27, 2005 10:42 pm

kam-325i wrote:i ask because the tube from the rocker cover to the TB is leaking, as it has stained my nice and clean rocker cover, if oil can get out, would air be getting in ?

This is another of the many oil leaks that afflict the M20, albeit, a minor one.
Rubber goes hard and brittle with age and heat.
Unless its split wide open and splattering oil everywhere, then I doubt if its leaking enough air to upset the idle.