I was thinking of adding an oil catch can to my 2005 XJR.

I have seen someone else with a pic of one attached to the full load breather.

My question is what about the part load breather? At light throttle is it not the part load breather that is used more than the full load breather.

So is it a waste of time just connecting an oil catch can to just one of the breathers?

The reason I wanted to do this was because of the carbon/oil deposit build up in my intercoolers as well as the throttle body etc.

When I replaced my super charger I spent a lot of time cleaning those items.

 

My oil catch can arrived today and I installed it with temporary hoses to the full load breather.

There was clearly visible oil inside the Norma connector going into the full load breather when I pulled it off. Enough to form at least one drip.

Hopefully it will help at least slow down the oil/carbon build up in the intercoolers which were absolutely filthy and clogged when I pulled them off
doing my supercharger swap about 1200 miles ago.

Will look at the part load breather another day. If I see oil there as well I will add another oil catch can however I am not expecting to see much if any oil there.

Will give an update when I have driven a few hundred miles as to whether I actually collect/catch any oil.

 

The full load breather is visible on the front of the rocker box RHS of car. Mushroom shaped.

The low load breather is towards the front top of the LHS rocker box.

The full load breather operates mainly under moderate to heavy load while the low load operates under low load as well as high load.

The low load pipe goes directly into the intake after the air filter and is a short inflexible pipe.

The high load pipe runs all the way back into the throttle body area and when I looked into mine there was oil in the pipe.

The Corvette oil catch can I think will be small enough to fit into a pipe I will use to replace the low load breather pipe and light enough just to hang on the pipe.

There is no space in that area for a large catch can which I do not think is needed there anyway.

 

252103791946 is the Ebay item # for the oil catch can I installed and

252305780630 is the Ebay item # for the Corvette oil catch can that I am waiting on.

If I do not collect oil in the 1st catch can then obviously I will have wasted my time but I
will be very surprised if I do not.

 

Corvette style oil catch can added to low load breather.

 

I have probably only driven about 200 miles since I fitted two oil catch cans because of SC issues.

In that short distance I can see about 1 cc of oil on the low load breather side.

On the high load breather side only enough to stain a cotton swab and thats stain not soak.

I was rather surprised at this finding.

The second pic shows what the elbow under the throttle body looked like at about 103,000 miles. Thats where the high load breather empties into thru that top hose going into the right side of the elbow.

Correction its the bottom hose thats the high load breather hose.

 

Thanks for the update. So was it worth it?

 

For the larger cumbersome can on the high load breather side noway was it worth it.

For the smaller "Corvette Style" unit absolutely.

I have actually ordered another "Corvette Style" unit and will replace the large oil catch can with that when it arrives.

The smaller device is much easier to locate, easy to see whats been caught, and very easy to empty.

Approx 1 cc of oil in about 200 miles on the low load breather side is I think quite significant.

The very significant carbon deposit build up in the elbow and in the charge coolers that I dealt with at 103,000 miles was a huge energy waster.

I believe the previous owner of my car just like me used 93 Octane fuel with at least the standard fuel system cleaners embedded.

 

Just some more thoughts on this.

Fuel does not enter the system until after the air has gone thru the throttle body, elbow, and charge coolers.

So it cannot contribute to the carbon build up. It has to be entirely due to oil from the crank case entering into the inlet system before the throttle body.

So my comments on fuel quality are irrelevant in this context. Keeping valves clean is another matter.

 

I have never seen any oil in the part load breather pipe , only the PCV valve pipe . The carbon you see in the intake is from the EGR not the breathers ,
you will only get oil in the PCV catch can after WOT runs .
i added a mishimoto baffled catch can to my PCV circuit as well for the same reason , after cleaning the TB , charge coolers and blower out , I couldn't bring my self to just assembling it with out revisions ! I have drained as mutch as 100-150mls from the catch can in just a month or two . so well worth fitting one ,
I also bypassed the EGR circuit as well , via avos's bypass thread method . My in take will sparkle for ever more .

 

I completely forgot about the EGR function.

 

Ok so I have studied Avos's EGR bypass thread and am interested in doing this mod.

I would start with a used EGR pipe as I want to be able to go back to the original set up if necessary.


How did you actually implement this mod Datsports?

 

i literally followed the instructions in the thread . . the big thing to watch out for is the pipe must be vacuum proof. (non collapsing ) and some orifice diameter tuning may be required to avoid the CEL . note well about the extended high idle it gives just after every time you load the engine it is noticeable . also it gives a softer initial deceleration so a few less pops and bangs out the back . and slightly delayed engine braking due to the air going through the EGR is oxygen filled , not inert as it should be.

 

This pic shows how much oil was in my oil catch can after approx 1,000 miles 900 of which was a round trip from MD to MA.

This is the high load breather side.

The oil catch can on the low side did catch oil because a pipe on the high side was blocked.

Since being unblocked the low side has not caught any oil.

 

Btw this is the mpg I saw on the return leg MA to MD. Quite a bit of driving in the 80-90 mph range with two stops. One stop to fill up and one stop because I misread the NJ exit off the Garden State Parkway!

 

Initially you indicated that the high load breather did not catch much oil at all, and the low load breather was doing most of the oil catching. Is this because of the "pipe on the high side that was blocked"?

Also just to confirm, do you mean by "pipe on the high side that was blocked" that the high load breather clogged with oil?

If so would you still recommend a big can on the high breather and a small can on the low breather?

 

Yes the high load breather pipe was partially blocked by a kink if I remember.

When corrected the smaller oil catch "can" on the low load breather side did not catch any more oil so I took that smaller catch can off as it served no purpose.

 

Hello Jackra_1.
Please forgive my ignorance, but I get how an oil catch can on the full load breather might be helpful (particularly on an XJR); however, (and here is where I may need correcting) does the part load breather not simply allow metered air INTO the crankcase (which is then subsequently drawn back out by way of the vacuum from the inlet via the full load breather, complete with blow-by product)? IF I have this right, surely there would be very little point in putting a catch can on the part load breather?
Or I could simply be wrong in my assumptions!

 

Kinda like a water pipe, long tube in, hole in top to draw air out, leaving the oil solids in the jar.

 

Yes you are correct.

On my initial foray into oil catch cans on my XJR I got a kink in one of the hoses on the high load breather which caused some oil to be discharged on the low load breather. After correcting that issue the low load breather oil can remained clean with no oil at all.

The kink was caused by a too soft tube that actually went flat with vacuum applied.