PDA

View Full Version : Back pressure?



ade
03-07-03, 09:57 AM
took my car into a reliable garage I use (wish I used it when I had my engine 1st fitted!) and explained about my oil leaking from the breather pipe.

Car was serviced and runs fine but Ali (the mechanic) said he cant really sort the oil leaking from the breather pipe coz its caused by back pressure - and this means stripping the engine down to find out whats causing it. He thinks it more likely gonna be the piston rings coz its a little smokey when you 1st start it up - which later stops as the rings expand - but this then builds negative pressure in the lower part of the engine - forcing oil out the pipe. Can be recognised by trting to take the oil cap filler off when its been running for a while - its usually difficult coz the pressure is holding it in place.

Anyway - he says its a common thing with vauxhalls of this age and the engine on the whole will be fine - just need to keep a close eye on the oil - haynes also makes reference to the oil light coming on in older engines and not to worry unless travelling at speed. :?

Prob run her for a couple of months and then get thne piston rings done - in mean time better relocate the oil breather pipe - the amount that was coming out was getting onto my rear nearside wheel - dont fancy getting caught out and spinning. (aint forking out ?75 for a catch tank either - better find a suitable vessel to catch it in - anyone got a red bull can!)

:D

Dicko
03-07-03, 10:38 AM
ye if the engine is breathing heavy its usualy when presure is leaking past the rings. do the old compression test with/without a touch of gearbox oil when cold AnD when warm. will give you a good indication of how much pressure is getting past the rings at cold/hot

my sr was like this and i did 15k miles proper ragging its t1ts off and it was fine so i wouldnt worry :P