Oil breather issue

[pug rallye 0]

Hi all,

I have a question, I did a tarmac rally event just over a week ago in my 205 Rallye 1.4 and we broke down just before the start line of the fifth stage due to the car over fuelling, cutting out and not restarting. Eventually we managed to get it going again after we replaced the float valve in the carb, and that is when I noticed that oil was bubbling at the bottom of the oil catch can filter. As a result of this, the chap who was servicing with us said that we might need to get our engine looked at which got me slightly worried as we have had a lot of work done to the car (apart from the engine) and this was the last thing I wanted to hear at our first ever rally. However, after doing the next 2 stages I lifted the bonnet and I could no longer see any oil bubbling, but I am still worried that something is wrong and I am still wondering what was causing this and how to overcome it.

 

About the breather system: From the top of the rocker cover, there is a rubber hose with an 18mm inner diameter and a 25mm outer diameter that gets reduced to another hose with an 11mm inner diameter and a 16.5mm outer diameter that goes straight into the catch can.

 

Also, I am sorry for such a long winded way of asking this question, just thought I would include all the details I could think of.

 

Cheers

Edited October 18, 2022 by pug rallye

[soundguy 13]

Maybe he was suggesting there was excess crankcase pressure, which can be caused by worn piston rings, forcing oil out of places it shouldn't really come out of.

 

But I'm no mechanic/engine builder - someone else might have other info.

[pug rallye 0]

 

9 hours ago, soundguy said:

Maybe he was suggesting there was excess crankcase pressure, which can be caused by worn piston rings, forcing oil out of places it shouldn't really come out of.

 

But I'm no mechanic/engine builder - someone else might have other info.

Oh no, that sounds expensive. That also might be why the dipstick keeps popping out.

 

Thanks buddy.

[DamirGTI 342]

Aside from "guessing game" , perform both - compression test and leak down test , if it smokes/uses coolant do chemical block test too ..

 

If the oil and coolant levels are stable , hasn't overheated and there's no smoke nor unusual sound from the engine shouldn't worry about it .

 

You might've created some restriction within the crankcase by reducing the inner dia. of the breather system and that catch can setup (seals commonly like to "pop out" due to the increased crankcase pressure) or it might've been G force which shifted the oil up and around ... next time try it out with the breather in full size/dia. and venting directly into atmosphere without catch can (just don't tell anyone ! as it's pretty much illegal pollution wise nowadays) , try for testing purpose , see what happens .

 

D

[pug rallye 0]

5 hours ago, DamirGTI said:

Aside from "guessing game" , perform both - compression test and leak down test , if it smokes/uses coolant do chemical block test too ..

 

If the oil and coolant levels are stable , hasn't overheated and there's no smoke nor unusual sound from the engine shouldn't worry about it .

 

You might've created some restriction within the crankcase by reducing the inner dia. of the breather system and that catch can setup (seals commonly like to "pop out" due to the increased crankcase pressure) or it might've been G force which shifted the oil up and around ... next time try it out with the breather in full size/dia. and venting directly into atmosphere without catch can (just don't tell anyone ! as it's pretty much illegal pollution wise nowadays) , try for testing purpose , see what happens .

 

D

Thanks Damir, we have ran the car before with no breather system and it sprays oil on the underside of the bonnet. I will try and get that compression and leak down test done too, hopefully this week. Other than that, the car has never overheated, it does smoke a little and there is no unusual noise coming from the engine.

 

Cheers