Please - Quick Oil cap / Blow-by test - AEL or AAT owners

Needs to get out more Joined: May 03, 2011 Posts: 119

Hi AEL or AAT owners !

Can you do very quick and safe test ?
With the engine idling, untight the oil cap, but let it be in place.

Two things can happen :

1- Does it “dance” ? (allow blow-by oil gases to pass through oil cap into atmosphere)

2- Is the oil cap sucked back into its place ? (you should feel vacuum if you try to lift the oil cap up).

Let me know, please ! Anyone with AEL or AAT...

Thanks !

Posted: Wed Nov 23, 2011 10:02 pm

AEL. It's a sucker. That's a good sign.
Just shy of 200k miles & still sucking! Very Happy

Needs to get out more Joined: May 03, 2011 Posts: 119

Mine sucks the oil cap back into its place. But i´ve heard the cap should " dance " , just like in the majority of the engines.

Funny, i´ve found a rubber membrane with a spring inside the valve cover (camshaft housing) in a small compartiment, that was damaged with a hole.
Replaced the part and I have a little more vacuum now.

Posted: Thu Nov 24, 2011 9:45 pm

AEL, 228K. It sucks and always has.

Failure to suck could be a problem with the vent system, doesn't have to be knackered rings. I've never figured how the vent system actually works but there seems to be some sort of vortex thing attached to the intercooler-manifold pipe.

Nick

Needs to get out more Joined: May 03, 2011 Posts: 119

So, it is normal to suck air from the oil cap...

Well, if it is a common thing, then I guess mine is OK !

Posted: Tue Nov 29, 2011 7:34 pm

I'm sure I've read on here that it's when they don't suck you need to worry on these engines......

Cheers

Nick

Needs to get out more Joined: May 03, 2011 Posts: 119

For instance, my 1.6 Ibiza TDi, it blows oil vapor out of the oil cap and apparently it is very normal. J
Just like what you see in any other youtube-like "blow-by" test video.

Very weird why the AAT or AEL engine suck and not blow these gases Smile

Posted: Thu Dec 01, 2011 8:53 pm

My AAT sucks - so I guess this is a good thing.. Smile

Needs to get out more Joined: May 03, 2011 Posts: 119

Ok, so this means that either all AAT or AEL are messed up, or, they´re just supposed to be this way, which is probably the right answer.

Thanks everyone for your input !

Bandwidth Buster Joined: Aug 12, 2006 Posts: 803

my ael sucks

Posted: Fri Dec 02, 2011 6:15 pm

I just wish I knew where the clever little gizmo that makes then suck is as I could do with one of my old Triumph 2.5PI - that blows and slobbers like an old steam train.....

Nick

Posted: Fri Dec 02, 2011 8:55 pm

Nice wording. Very Happy

In short, not sure, maybe some creative plumbing to bring the breather into the inlet manifold - that's how it's done on older petrol cars..

Posted: Fri Dec 02, 2011 9:36 pm

Yeah, I have created a breather system to replace the factory afterthought that is supposed to (and does) create a partial vacuum in the crankcase without hoovering up any oil. It fails to meet full expectation on the second point though..... more tweaking needed on the separation pot. Have to say that the breather arrangements did have remarkable effect on the various oil leaks which have mostly stopped.

Root problem is that the engine (rings/bores) is knackered, but as it still goes quite well and some ghetto valve stem seals have curbed the worst of the smokescreen effect, I can't bring myself to drag the engine out and mend it.

Nick

Needs to get out more Joined: May 03, 2011 Posts: 119

Hi,
Tried again today, it feels like it´s sucking good. I even hear a little "pss" when I lift the oil cap.

But then, I made the test of unplugging all tubes that come from the oil separator (near timiing belt cover), and it´s funny how I almost can´t feel or see any blow-by !?

I mean, where are the gases going ? Can´t they come up from the crank case to the oil separator ?

This is weird...there should be some smoke coming up to be recycled.

Posted: Mon Feb 11, 2013 12:09 pm

Hello ! I believe my problem is related to this topic: does anybody know the reason & function of that small hole (say 4 mm) into the crankcase cover, left side as you stand in front of the car, just between the 1st and the 2nd rubber hoses ? It's kind of tricky to notice it (at least for me) so be patient when looking for it. Can it be the way out for those gases ?

Posted: Mon Feb 11, 2013 12:23 pm

I doubt the hole is for venting crank-case gasses- they're usually routed back into the intake so they get burnt - as they're all part of the emission control system. You'd also get a constant dribble of oil from that hole if it is vented.

I was unaware of the existance of a hole there - I'll check when it's light and see if I got one too (might explain my filthy engine)

Needs to get out more Joined: May 03, 2011 Posts: 119

Funny, never saw that hole in mine. The 3 pipes, yes, they´re there.
Will check when i have light.

Posted: Tue Feb 12, 2013 7:56 am

Funny it is, indeed. I noticed that small hall while replacing (for the 2nd time!) the cover gasket, hoping to solve the oily mess on that side of the motor block. I do hope that the problem is solved now.
On the other hand, yesterday I tried a boost leak test on my engine, i.e. I put a cap with a bike valve onto the big hose that goes into the air intake. Guess what, the only smoke I saw coming out was through that small hole we were talking about ! Is that normal ? to loose air pressure ? I wonder what could go wrong if I block this hole ? And yes, my AEL is still a "sucker"...
One thing more: I removed the oil separator and cleaned it. When opening it, I only saw a steel ball at the lower end, acting like a valve. But no wire mesh or something alike to help condensate the fumes. Is that OK ? The previous owner worked on it before so I can not be sure if he "forgot" to put back everything inside. Mention should be made that I started this job with the separator consequent to an intriguing oil consumption. Indeed, the top cap of the separator was blown off.

Posted: Thu Feb 14, 2013 11:24 am

I have that small hole too. Somebody had put a screw in it.
And... mine was a sucker, I'm not sure yet what has happened, but nowadays it is a blower.

Needs to get out more Joined: May 03, 2011 Posts: 119

Your engine is a blower ? How ?

Mine sucks air to inside when I open the oil cap.

I am going to check that hole this weekend. And IF I have the time, I´d like to clean the oil separator, but it is time consuming because of the lower pipe connected to it. It has got a bracelet hard to take apart.

Posted: Fri Feb 22, 2013 1:25 pm

Needs to get out more Joined: May 03, 2011 Posts: 119

Needs to get out more Joined: May 03, 2011 Posts: 119

Well, i´ve been looking at my engine this weekend. The pipe that blows the gases is the one nearest to the firewall. There are not too many gases coming out, but there are some. Just normal.

The tiny hole, i´ve seen it. Don´t know what it is for. Can only check if removing the valve cover which will be done in a few months to stop a leak.

The thing that surprised me the most was that my intake manifold pipe was clean without the smallest pint of oil. Weird. Blow-by gases are sucked in the compressor side of turbo and sent to intercooler and then to intake. However... nothing.
Even inside the intake manifold, I can only feel and dirt my fingers with a little soot. No oil whatsoever.

Is this normal ?? I remember in my Audi A4 AFN 1.9 TDI 110hp, that there was oil in this areas. Just a little, but there was. And oil comsumption was normal. Rolling Eyes

As a few of you know, I have some oil consumption. Can this be related ?

How are your intake pipes ??? Idea

Posted: Tue Mar 19, 2013 6:22 pm

My intake pipes have a little oil in them. But the engine doesn't really use oil - maybe 300mls in 6000 miles.

Nick

Needs to get out more Joined: May 03, 2011 Posts: 119

How weird...this is against everything i´ve learned !

Mine is using about 1 liter every 3000/4000km. And my intake pipe is absolutely dry. Even the intake manifold just has soot. Dry soot.

I need to check my intercooler...

Posted: Thu Apr 04, 2013 1:01 pm

Needs to get out more Joined: May 03, 2011 Posts: 119

I have deleted EGR now with a blank plate and electronically via vag.com and a new chip program.

But it wasn´t deleted before. The soot is just dry, like the exhaust pipe. I mean, there is not that wet paste we usually see in an intake manifold. Even the boost pipe that connectes to the manifold has no oil.
This is weird, because blow-by gases of oil from CCV should go there.

In my last A4, I had a film of oil in the intake pipes, which is normal and acceptable. Rolling Eyes

Needs to get out more Joined: May 03, 2011 Posts: 119

Guys... how is your "IC - to - intake manifold" pipe ? Do you have oil in it ?

I haven´t any, which is not normal. I should have the oil coming from crankcase blow-by.