Oil Catch Can - Ford Forums - Mustang Forum, Ford Trucks, Ford Focus and Ford Cars

MR AUII · 09-21-2004, 23:45

What are these and what are they for?

EDXR8 · 09-22-2004, 02:44

An oil catch can sits between the pcv valve and the air intake pipe. Basically, some of the cylinder gasses escape past the piston rings (blow-by), and preasurises the sump. In older cars this just escapes out the rocker cover breather but that causes pollution so on modern cars it is recycled back into the air intake via the pcv system. The problem is that this blow-by also has a fine mist of oil which can cause problems. The oil catch can alows the oil to be trapped in the can while the gasses to continue back into the intake as normal.

ebxr8240 · 09-22-2004, 07:14

They are used mainly on turbo or forced induction as the venting to inlet cannot be used as it presuris's crankcase and blows oil seals etc..So a catch can is used then its vented to blower inlet..Btw oil in blown engines causes detonation...The pcv can generally stay as there is a oneway valve built into them...

outback_ute · 09-22-2004, 19:54

Or in a racing car they are required to catch any oil that might come out the rocker/cam cover breather, so that it does not get onto the track. They have to be a specified size (refer to the CAMS manual - think it is 2 or 3 litres depending on engine size).

MR AUII · 09-22-2004, 23:45

thanks for that.