Oil spraying from breather filter on oil catch can

yabaiani
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Oil spraying from breather filter on oil catch can

Postby yabaiani » Thu Jan 20, 2022 10:48 am

When I drove my car, I opened the engine bay and saw oil had spit out of the breather filter on my catch can.

Any ideas on why this is happening? Can I add a PCV valve as shown in the picture to help stop this?

Image
host a pic


or here

Image

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jondee86
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Re: Oil spraying from breather filter on oil catch can

Postby jondee86 » Thu Jan 20, 2022 4:37 pm

If you have oil spitting out of the breather your catchcan is not working. This image
shows the basic requirements for an effective catchcan...

Image

The arrangements of the inlet and outlet can be changed. The outlet can either be
piped to the intake vacuum or vented to atmosphere but the basic design needs to
contain all of these elements..

1. The entry can be from the side or the top but it must turn downwards (if from the
side) and discharge about 3/4's of the way down the can. Incoming fumes expand and
make a U-turn allowing oil droplets to fall to the bottom of the can. Collected oil
should not be allowed to submerge the end of the inlet tube.
2. There must be a mesh layer with a large surface area for the finer oil particles to
condense on and drain back to the bottom of the can. A packing of coarse stainless
steel "pot scourer" type material is ideal, and you can have a deeper layer than shown
in the diagram for greater collection efficiency. Just make sure the filter has a low
resistance to flow i.e. held under a tap the water easily flows thru the layer.
3. The outlet tube should be raised above the top of the packing to prevent condensed
oil being being "vacuumed" off the top of the packing.

So long as the inlet to your existing can is directed away from the outlet, you can
probably get away with packing a few stainless scourers (the ones that look like they
are made of turnings from a lathe) into the bottom of the can. Your engine should not
be producing massive blowby :)

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

yabaiani
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Posts: 163
Joined: Sun Jan 13, 2013 8:28 am

Re: Oil spraying from breather filter on oil catch can

Postby yabaiani » Thu Jan 20, 2022 8:19 pm

jondee86 wrote:If you have oil spitting out of the breather your catchcan is not working. This image
shows the basic requirements for an effective catchcan...

Image

The arrangements of the inlet and outlet can be changed. The outlet can either be
piped to the intake vacuum or vented to atmosphere but the basic design needs to
contain all of these elements..

1. The entry can be from the side or the top but it must turn downwards (if from the
side) and discharge about 3/4's of the way down the can. Incoming fumes expand and
make a U-turn allowing oil droplets to fall to the bottom of the can. Collected oil
should not be allowed to submerge the end of the inlet tube.
2. There must be a mesh layer with a large surface area for the finer oil particles to
condense on and drain back to the bottom of the can. A packing of coarse stainless
steel "pot scourer" type material is ideal, and you can have a deeper layer than shown
in the diagram for greater collection efficiency. Just make sure the filter has a low
resistance to flow i.e. held under a tap the water easily flows thru the layer.
3. The outlet tube should be raised above the top of the packing to prevent condensed
oil being being "vacuumed" off the top of the packing.

So long as the inlet to your existing can is directed away from the outlet, you can
probably get away with packing a few stainless scourers (the ones that look like they
are made of turnings from a lathe) into the bottom of the can. Your engine should not
be producing massive blowby :)

Cheers... jondee86


Do you think it has anything to do with the fact that the engine has just been rebuilt and it only has maybe 30-50 miles on it so far?

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jondee86
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Re: Oil spraying from breather filter on oil catch can

Postby jondee86 » Thu Jan 20, 2022 10:22 pm

I am not about to tell you how to break in a new engine, but I will refer you to
this link... http://www.mototuneusa.com/break_in_secrets.htm

Everyone is an expert on how to break in a new engine and there are a thousand
different opinions that tell you that there method is the best. So up to you to choose
who you want to listen to. But for what it is worth I broke in a fully rebuilt 4AGE with
fresh bore and hone, new pistons and rings following the recommendations given by
Mototuneusa. It took about half an hour one evening to complete the break in
procedure and from then on I just drove it in my usual "spirited" fashion... no babying
at any stage.

The thing pulled like a tractor and never used any oil. IMHO bedding the rings in quickly
with lots of in-gear deceleration, together with steadily increasing load and engine
rpm's is the key to a happy engine. Extended idling and babying a new engine will lead
to cylinder glazing and rings that do not bed properly. You have probably seen videos of
race engine builders who put new engines on a dyno and push them up to full power after
a couple of lesser runs just to check the tuning. I think they know what they are doing :)

So no, your engine should not be blowing a bunch of oil out the cam cover vent. To see
if you really have a problem, take the hose off the catchcan and stick the end in an
empty wide mouth drink bottle. Zip tie the bottle and the hose to hold them in place,
and then go for a drive. See how much oil you collect.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

yabaiani
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Posts: 163
Joined: Sun Jan 13, 2013 8:28 am

Re: Oil spraying from breather filter on oil catch can

Postby yabaiani » Sat Jan 29, 2022 5:29 pm

So I removed the coil packs to check the the spark plugs and there was a bit of oil on the first 2 spark plugs…any idea why?

Image

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jondee86
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Re: Oil spraying from breather filter on oil catch can

Postby jondee86 » Sat Jan 29, 2022 9:32 pm

Little bit of oil ??? I guess that is a little bit in Texas :D Looks like someone might have had
an OOPS when filling the oil and spilled some. There looks lo be oil sitting around the cam
cover fixing nut beside the oil filler, and although oil can seep out of old seals the nut would
have to be real loose to let that amount of oil out.

The only other way you can get oil down there is if the cam cover gaskets are leaking, and
that should not happen if you installed new gaskets and snugged the covers down correctly.
If you have oil sitting on top of the cam cover flange both sides, that can only get there by
leaking down from the top.

Clean it up and see if it comes back.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.

yabaiani
Club4AG Enthusiast
Posts: 163
Joined: Sun Jan 13, 2013 8:28 am

Re: Oil spraying from breather filter on oil catch can

Postby yabaiani » Sun Jan 30, 2022 4:43 pm

jondee86 wrote:Little bit of oil ??? I guess that is a little bit in Texas :D Looks like someone might have had
an OOPS when filling the oil and spilled some. There looks lo be oil sitting around the cam
cover fixing nut beside the oil filler, and although oil can seep out of old seals the nut would
have to be real loose to let that amount of oil out.

The only other way you can get oil down there is if the cam cover gaskets are leaking, and
that should not happen if you installed new gaskets and snugged the covers down correctly.
If you have oil sitting on top of the cam cover flange both sides, that can only get there by
leaking down from the top.

Clean it up and see if it comes back.

Cheers... jondee86


I really hope its just that and nothing to do with how the engine was built and the piston rings are failing

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jondee86
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Re: Oil spraying from breather filter on oil catch can

Postby jondee86 » Sun Jan 30, 2022 11:57 pm

Here is a video showing the "normal" amount of blowby you should expect from
an idling smallport or bigport 4AGE engine in good condition...
https://www.youtube.com/watch?v=kZNlBJip518

Blowby increases with rpm, so if you have a a lot of blowby at idle you will likely
have way too much at high rpm.

A compression test would be a good idea.

Cheers... jondee86
The reasonable man adapts himself to the world; the unreasonable one
persists in trying to adapt the world to himself. Therefore, all progress
depends on the unreasonable man.