Help: 997 GT3 Oil Leak Via Oil Return Pump
Discussion
Hi all
Many of you have probably seen my heavily modified 997.1 GT3 in the Modified 997s thread and thank you all for the kind comments you have left.
I do however have a problem with the car and so reaching out for some help.
Basically, on two separate occasions (once driving home from work and once at the track) in the past two weeks I have suffered large and sudden loss of oil. Literally pouring out the bottom of the car. Luckily for me on both occasions I noticed immediately, as by chance the brakes also stopped working properly (scary on the track but luckily happened on a fast corner so I had time to slow it down). On both occasions I ended up losing about 3 litres of oil so still had 6 left and engine seems fine. Huge relief. First time we thought was a freak occurrence but now second time something is clearly wrong.
Apparently, the cause is the pump that takes oil from the cylinder head back to the tank is literally coming off and oil from the head is then spewing out. Since this pump also runs the vacumn for the brakes I am then losing all the assisted brake pressure. The weird thing is that the three (small M4) bolts holding this pump on are not snapping off, they are simply working themselves loose, presumably because of some severe vibrations?? The bolt threads remain in perfect condition.
I should add that whilst the car is heavily modified, then engine is not. It has not been opened and has not (yet) had an ECU remap. The only thing was that about 2 weeks ago the car did go to the Porsche main agent and have a newer version of the ECU software flashed, but surely this is just a coincidence? Engine over rev data is clean with tiny amount in bands 1-3 and nothing in 4-6.
We have removed the oil return pump and as you can see from the below images, there is some clear scoring on the inside so the bit that spins in the middle is clearly catching. But why? And would that be enough to loosen all the three bolts and to fire the pump off suddenly?
We have asked the Porsche main agent and other specialists but no one has been able to give us a clear answer yet. Any assistance would be massively appreciated. The oil leak is obviously a big concern but suddenly losing the brakes because of one pump and three M4 bolts is even more scary.
Many thanks in advance.
Peter
Many of you have probably seen my heavily modified 997.1 GT3 in the Modified 997s thread and thank you all for the kind comments you have left.
I do however have a problem with the car and so reaching out for some help.
Basically, on two separate occasions (once driving home from work and once at the track) in the past two weeks I have suffered large and sudden loss of oil. Literally pouring out the bottom of the car. Luckily for me on both occasions I noticed immediately, as by chance the brakes also stopped working properly (scary on the track but luckily happened on a fast corner so I had time to slow it down). On both occasions I ended up losing about 3 litres of oil so still had 6 left and engine seems fine. Huge relief. First time we thought was a freak occurrence but now second time something is clearly wrong.
Apparently, the cause is the pump that takes oil from the cylinder head back to the tank is literally coming off and oil from the head is then spewing out. Since this pump also runs the vacumn for the brakes I am then losing all the assisted brake pressure. The weird thing is that the three (small M4) bolts holding this pump on are not snapping off, they are simply working themselves loose, presumably because of some severe vibrations?? The bolt threads remain in perfect condition.
I should add that whilst the car is heavily modified, then engine is not. It has not been opened and has not (yet) had an ECU remap. The only thing was that about 2 weeks ago the car did go to the Porsche main agent and have a newer version of the ECU software flashed, but surely this is just a coincidence? Engine over rev data is clean with tiny amount in bands 1-3 and nothing in 4-6.
We have removed the oil return pump and as you can see from the below images, there is some clear scoring on the inside so the bit that spins in the middle is clearly catching. But why? And would that be enough to loosen all the three bolts and to fire the pump off suddenly?
We have asked the Porsche main agent and other specialists but no one has been able to give us a clear answer yet. Any assistance would be massively appreciated. The oil leak is obviously a big concern but suddenly losing the brakes because of one pump and three M4 bolts is even more scary.
Many thanks in advance.
Peter
ooid said:
Thank you very much. This is a massive help and I hadn't seen it. Also helpful to know that mine is not a one off isolated problem. The impact of the sudden loss of brake pressure and oil dump is a massive issue when you consider the vacumn pump is only held on my 3x M4 bolts and others have experienced the same problem of the bolts coming loose.Many thanks
Digga said:
HI, I don;t know the answer, but have you tried posting on either the 911uk or Rennsport forums to see if any of their tech gurus know?
Peculiar problem. I can only wonder about torque settings or Loctite?
Thanks Digga. Will definitely apply loctite when reinstalling and also new boltsPeculiar problem. I can only wonder about torque settings or Loctite?
Cunno said:
When you did the mods, did you change the engine gear box mounts to after market?
Hi Cunno, you read my mind from earlier this afternoon! Yes indeed. And also all suspensiom and transmission bushes to fairly hard Powerflex Black Series poly and the single mass flywheel. We were wondering if too much vibration is working them loose...M32GER said:
Cunno said:
When you did the mods, did you change the engine gear box mounts to after market?
Hi Cunno, you read my mind from earlier this afternoon! Yes indeed. And also all suspensiom and transmission bushes to fairly hard Powerflex Black Series poly and the single mass flywheel. We were wondering if too much vibration is working them loose...Could be the cause, when I first upgraded my gear box mounts with torque solutions 95A the vibration through the car was so bad I couldn't see out of the windscreen due to the vibration over 150 mph. Put softer 60A ones in all ok. I also run RSS engine mounts and aftermarket suspension and control arms all rose jointed, but not suffered this issue. my car is maintained by Matt at Fearnsport and not heard him mention this as an issue either. I'd look at your gear box mounts first and may be go with a softer option
http://www.tarett.com/items/996-997-991-products/9...
What engine mounts have you got?
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