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THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHAOS replacement. Again.
Reported or suspected cause
first one la rose had done
Reported cause
No successful repair reported for this finding.
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Reported cause · Original poster
It was the first one La Rose had done so there was some learning for them in fitting it but no hearder than the regular AOS.
Leading evidence: 'first one la rose had done' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'first one la rose had done' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Install brombacher extended baffled sump' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.
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Performed · outcome unconfirmed · Original poster
FYI, I installed the Brombacher extended baffled sump on mine too.
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Performed · outcome unconfirmed · Original poster
It was replaced about 3 months ago when I put the baffeld sump in.
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Performed · outcome unconfirmed
Had it replaced ~5000km after my engine rebuild with a genuine Porsche item.
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Suggestion · Original poster
Just after buying my C4S I had the AOS replaced as I intended to track the car and while the clutch was being replaced, I figured it would be easier for the garage, and cheaper for me, to have it done at the same time.
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Suggestion · Original poster
Just after buying my C4S I had the AOS replaced as I intended to track the car and while the clutch was being replaced, I figured it would be easier for the garage, and cheaper for me, to have it done at the same time.
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11 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
911uk: 1 discussions
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Just after buying my C4S I had the AOS replaced as I intended to track the car and while the clutch was being replaced, I figured it would be easier for the garage, and cheaper for me, to have it done at the same time. A genuine Porsche one was fitted, it was fiddly but I was glad it was done.
Fast forward to the PCGB day at Silverstone GP track and I got black flagged due to throwing out a fair plume of smoke at 110mph on the start/finish straight. A quick chat with the gent from Parr onsite and we agreed that the AOS had gone. So that was less than 2 years, 2 track days and around 6,000 miles.
Quotes from Parr were £1,200 for AOS replacement or £3,500 for motorsport replacement, which I understand is a modified 997 unit. The latter requires the engine dropping out, which if course then becomes "while its out....". I got a 2nd quote of £750 from La Rose, my local independent, for the AOS replacement. Instead, I've bought the
UAOS
from the US, coming to £950 including shipping and taxes for the UAOS plus the oil drain via a new fill tube. La Rose have agreed to fit it for around £500 so I'll have a more robust, futureproofed solution that removes another one of our engines weak link. Hopefully I'll have the car back this week, ready for some more fun driving.
Now I just need to decide if I want to keep the car and keep investing in it....
pesky AOS, which is just one of those things
more of a question to the that part only last the time mileage you quoted ?
maybe worth getting an oil sample analysed or using a different oil ?
Good idea re. the oil. It was replaced about 3 months ago when I put the baffeld sump in. Its due a service in October so if I don't do it before I'll get it done then.
Re. the part, I'll ask the garage to take a look and confirm its the issue. Oil in the inlet would be a tell tale sign.
I had a similar experience, but with an aftermarket AOS. Had it replaced ~5000km after my engine rebuild with a genuine Porsche item. I believe the cost at the time, probably 3-4 years ago was around 1400€, but they did a bunch of other work like front diff seals, at the same time, so AOS was probably ~900€.
The UAOS is the only one to bother fitting. Expensive but cures the main issues! Do your oil return lines too if you havent already and run 50-60w oil. It'll solve just about all of the issues on track.
Just to close this, the UAOS went on last week. It was the first one La Rose had done so there was some learning for them in fitting it but no hearder than the regular AOS. The report was that there was oil in the intake so it had definitely failed. At least that was the cause rather than something else going wrong too! A spirited drive or two should clear the oil. The engine is now back to rude health.
One thing to note, I'd switched to the Millers Nanodrive 50w oil and feedback from Parr Racing was that this puts more load on the AOS, accelerating failure times. It definitely increased my oil pressure from <2 bar to around 2.2. After the UAOS install my oil pressure has dropped back to ~2 bar.
SimJen, I've got a X51 style baffled deeper sump and the M97 oil return tubes too. I'm not expecting any track oil issues from now on. Just in time for Brands Hatch next week.
Love Paddock Hill! Awesome test of the car. Long left hand bends is what causes the oil pickup issues though (from what I've read), so Paddock as a right hander should be fine. In my experience above, most corners caue issues for the AOS
Sorry to bring this back from the dead! I'm on the cusp of ordering the UAOS + a Hartech deep sump. Just picked up a 996 with no bore scoring and hope to keep her that way (at least for a bit!) how's it holding up for you?
I've phoned up La Rose for a quote, hopefully the X51 kit doesn't cause any additional problems with installation.
FYI, I installed the Brombacher extended baffled sump on mine too. I don't know how deep the Hartech one is but mone extends by 0.6l oil. If you're going to track the car, they're definitely both worthwhile mods.
What are the oil return lines? I've got a X51 sump, run 5W-50 and overfill and I still get some oil surge while I'm on track which is very annoying so keen to see if there are any additional fixes...
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