oil cloud when running hard - Page 3 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Jake Raby · 09-25-2012, 07:38 PM

Is the pic of the scavenge pump taken on bank 1 or bank 2 of the engine? Its not totally clear.
Have you taken the scavenge pump apart? It is symmetrical and the body can be assembled out of phase and still fit, but have this symptom.

healthservices · 09-25-2012, 08:24 PM

Quote:

Originally Posted by Steve Tinker

HS
If I'm reading this right, your valve cover (cambox) is over full of oil, so that means its filling OK from the main oil pump but not being pumped out by the cylinder head oil pump.

Before pulling engines wouldn't it be prudent to test the pump output on the bench (or even swapping / comparing pumps with the other cylinder) and if OK, pressurize the pump discharge port in the head to make sure that there is no blockage downstream of the pump.
Even oil from a hand operated oil can should be able to create enough pressure to see if the oil discharges into the sump.....

Quote:

Originally Posted by Jake Raby

Is the pic of the scavenge pump taken on bank 1 or bank 2 of the engine? Its not totally clear.
Have you taken the scavenge pump apart? It is symmetrical and the body can be assembled out of phase and still fit, but have this symptom.

Thanks Jake and Steve for responding, This is on the passenger side head on a Boxster. I have taken the pump apart twice and it is phased correctly on the plates. When I hand turn the pump clock wise when looking at the pump shaft it pumps out of the correct port in a bath of oil. The valve cover 'oil pickup port' is clear. I removed the oil pan again and blew air into the presure port and air freely comes out of the Drivers side swirl pot.

healthservices · 09-25-2012, 08:33 PM

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healthservices · 09-25-2012, 08:34 PM

This is the way it sits in the head. passenger valve cover on the right and the crank to the left.

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healthservices · 09-25-2012, 08:44 PM

Steve what I would love to do is to pressurize the main oil galley and see where the oil is spilling out of the head, without the valve cover on, the oil would come out of the cam jornals

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healthservices · 09-26-2012, 10:29 AM

Just so I can put the thing together with a change I will swap the two pumps (of course clocking them correctly) and see if the pump is to blame.

healthservices · 09-26-2012, 04:02 PM

So I pull the front sump pump and....

No oil in the valve cover...

Not even when I insert a dipstick in there!

healthservices · 09-26-2012, 04:58 PM

This is what I see...

After I put everything together, which will be a while I will put 9 quarts of oil in. After running for 10 or so minutes to warm up, the oil level should not change more than a 1/2 quart (I'll give this one whole quart) if it does differ more than that then one of the valve covers is full of oil again.

Is that is good assumption?

Steve Tinker · 09-26-2012, 09:44 PM

HS....
That sounds a fair enough assumption.
Did you swap over the two pumps - your posts don't say exactly if you did?
I'm still not convinced that you haven't got a faulty or inefficient scavenge pump in the oil filled head / valve cover. Seeing that Porsche use identical cylinder heads (just reversed), the two scavenge pumps should be identical (can anyone confirm this) and certainly if havn't already, swapping them over at no $$ cost would identify a pumping problem.

BYprodriver · 09-26-2012, 10:00 PM

Quote:

Originally Posted by Steve Tinker

HS....
That sounds a fair enough assumption.
Did you swap over the two pumps - your posts don't say exactly if you did?
I'm still not convinced that you haven't got a faulty or inefficient scavenge pump in the oil filled head / valve cover. Seeing that Porsche use identical cylinder heads (just reversed), the two scavenge pumps should be identical (can anyone confirm this) and certainly if havn't already, swapping them over at no $$ cost would identify a pumping problem.

The scavenge pumps are identical. (same part# either side)
Pumps have to be installed correctly to scavenge properly. Thats why I asked about the odd camshaft plug in 1 of the pics, looks like someone had worked on the head previously & altered orientation of a scavenge pump.

Steve Tinker · 09-27-2012, 01:01 AM

My point exactly. If the valve cover / cambox is flooded with oil, then the oil return to the sump is not happening.
In the "old days" on a V or in line configeration engine, the valve cover was semi-pressurised with oil & then gravity did its job of returning the oil to the sump. But on a horizontally opposed engine layout, gravity doesn't play a big part unless specifically designed oil return tubes are built into the design.
Over pressurisation / filling of valve covers and camboxes can cause all sorts of problems from simple oil leaks to blown valve stem guides, not to mention loss of crankcase oil capacity which I suspect may be happening to HS's engine......

healthservices · 09-27-2012, 07:27 AM

Oil pick up has been check and solvent runs freely out this.

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healthservices · 09-27-2012, 07:34 AM

I replaced the swirlpots. Strange the right head would drain in the left swirl pot and vice a versa. I blew air in the oil return pressure port and it appears to get out into the oil pa. Ok

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healthservices · 09-27-2012, 07:39 AM

The opening does seem kind of small for the oil return with only one small hole for return. I can see that if there is a port plug missing how it can overwhelm the pump.

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peterbrown77 · 10-01-2012, 05:59 AM

The suspense of this thread is killing me... I check every morning to see what the hell it was.

srad34 · 12-29-2012, 01:32 AM

Did you get this issue sorted. I have a similar oil cloud going on under hard acceleration. It just started one day. I replaced my aos with a new OE 4 months back, not been into the inlet to take a look just yet as the weather here is awful (UK)....
I was thinking to vent the AOS into a filter, rather than back into the inlet to test it.

Cheers

healthservices · 01-07-2013, 09:24 AM

Boy is it possible for me to forget about this thread? Yeah I did! It was the pump. Dunno why because the pump worked well just pumping by hand. But moving the pump from one side to the other reduced the amount of smoke significantly.

Steve Tinker · 01-07-2013, 07:22 PM

HS - are you saying that the smoking problem has been remedied by swapping over scavenge pumps from one head to the other?
Just curious......

Heiko · 01-08-2013, 03:48 AM

Swapping the pumps is only a test and doesnt remedy the fix for the damaged pump! If swapping the pump reduces the smoke under load then the pump that originally came from the right side needs to be replaced.
The problem is that the right side extractor pump sits at the rear with its vent hole directly above; and the left pump is at the front. So when you accellerate hard (and even worse if you accelerate and turn left at the same time) the oil flows to the rear of the head rapidly... if the pump is weak or not functioning 100%, it cant return the oil to the sump fast enough and it gets sucked into the AOS through the above vent.
Under normal driving, people braking hard and reving high RPM's isnt likely, which is why on the left side the chances of oil getting sucked into the front vent is less likely. Now having said that... If you track your car you'll probably find that you will have no choice but to install a bigger AOS unit to handle the extra oil or even go to the extreeme and install better oil return pumps.
H

healthservices · 01-08-2013, 09:11 AM

I'm saying what Heiko said the right pump was the issue. I tend to not replace parts just to replace parts that's why I swapped pumps to see it the right pump was the issue. it did not have enough pumping capacity. Yes, a new pump is in the car.

On to the next issue!