OK, so I've been running my catch oil catch can in my AJ16 engine for almost 10,000 miles and I decided to see what I've caught.

Water?!?! Well, lots of water and some...oil, maybe?

I've posted pictures. I will ***-U-ME that I'm capturing condensate, is that a fair guess? I've posted pics of the extremely watery substance as well as the routing of the catch can.

Any input would be appreciated.

The hose from the catch can to the intake elbow is clean as a whistle, no oily residue at all, so I believe it is doing its job.

The hose from the camcover to the catch can was wet and somewhat oily.

 

Yes, condensation. Almost certainly nothing to be worried about


Cheers

DD

 

Yes, condensation (a by-product of combustion) that would normally be boiled off and sent out the exhaust pipe as the engine reaches normal operating temperature.

The catch can is short circuiting that process.

 

Thank you. I wasn't expecting so much water to be collected.

I believe the next time I clean my throttle body, it will be the very last. I think the can will prevent oil from ever reaching the butterfly plate or TPS ever again.

 

My 95 VDP 6cyl does the same thing. I don't use my car in the winter but cold weather seems to catch more water/ crap, especially short drives. I can really say the catch can was a worth while investment for me.

 

My view is that condensation is "created" in at least two areas in an IC system.


1. The exhaust pipes and mufflers. Hot gases on cold metal. And, they rust from inside to outside. Some counsel drilling a really small hole at the low point, usually a muffler.


2. In the crankcase. Hot oils on tin, steel or alloy. And blow by from the combustion chamber. In olden days, dealt with by "road draft" tubes to vent to the atmosphere.
Then came PVC. Positive vented crankcase. The fumes are drawn off and fed to the engine to be burned.


I am surprised that a sophisticated engine like these have what we old guys used to term as "snot cans".


But, I agree, no angst, here, the catch can is doing it's job.


Carl

 

Sorta, but not really. The water vapour is created in one spot and one spot only- the combustion chamber. No combustion, no vapour.

Where this vapour condenses again is a different matter. One way or another it must be vented from the vehicle fully.


But they don't. People are adding them believing there's a problem that needs to be solved but without considering the side effects. In this case, the can is acting as a condenser for the water vapour created during the combustion process. Normally the vapour would stay in suspension and go harmlessly out the exhaust.

 

The shorter distances driven, the more water will condense resulting in loads of emulsion...

Easy way out: don't drive a short distamce in a large engine. The more metal, the mkre condensation. A V12 will have more condensation inside than a 3 cylinder...

 

What are the unintended side effects? I can deal with emptying a can of water every once in a while.

The problem I'm trying to solve is keeping the throttle body and TPS clean. I believe I have solved that problem. The hose between the can and intake elbow looks brand new on the inside. The hose I replaced had a very oily interior which wreaks havoc with the throttle body on these engines.

 

OK, so I moved the can this past summer over to the front of the car, just behind the passengers side headlight, and now I am catching tons of water. I can fill up the whole can in a month!

I guess moving the can to a colder part of the engine bay has increased its ability to capture condensate?

I think I got into a little bit of trouble because the can was full and the engine had nowhere to dump the excess pressure....except probably through the camcover gaskets. I fully expect to see some oil in my spark plug wells...

 

Well I thought I would add some more to the tale.

The catch can works great, and in the cold winter it did so great that it filled up with condensate. So what happens when the can gets full? The camcover blows the seals. That's right. I had oil in 5 of six plugs, and probably a bit in Plug #6 as well (the one that looked the most dry)

I've replaced the seals. I've also added an electric valve to the can! I can now drain the darn thing from inside the car! I bought a 1/2 inch barbed hose gravity feed 12v DC plastic nylon solenoid valve! I ran the wires back into the cabin and fit a switch in the blank next to the emergency lights button.

Now I'll drain the darn thing daily if I want. No more busted seals.

This certainly has become a project.

I am now planning on removing the mesh and riveted shield in the camcover itself so there can be no blockage in the camcover itself. I'm thinking that mesh trapped in the top of that camcover will eventually become blocked.

 

HMM, where do you dump the residue from the can??