71 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCH996 on track - watch that oil pressure!
Leading reported evidence
Fill right
Performed · outcome unconfirmed
No successful repair reported for this finding.
0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Leading evidence: 'Fill right' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'bent valve, perhaps caused by a broken rod' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Check debris' (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.
Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
Partial update - with a new oil pressure sending unit installed (which is a 5 minute job - so simple on a 996, and only a $40 part) my oil pressure now reaches 5 bar which it never used to.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
It was a fresh rebuild when installed before Laguna.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
Keep in mind I have a Motorspot Air Oil Seperator installed - so I wasn't too worried about filling it to top and testing it.
Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed
I installed the X51 on two cars and both still saw a wild oil pressure needle.
Discussions that performed work without a confirmed outcome
1
0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.
0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.
Performed · outcome unconfirmed · Original poster
Partial update - with a new oil pressure sending unit installed (which is a 5 minute job - so simple on a 996, and only a $40 part) my oil pressure now reaches 5 bar which it never used to.
Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.
71 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.
Rennlist: 1 discussions
0 evidence records excluded for query context · 1 excluded by outcome qualification · 0 adjusted by outcome qualification.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
I wouldn't call it fixed completely, but an easy improvement to make to your mantis pan.
Very cool! Fun video to watch, good cars, good action, good driving, and good video perspective.
Where's that at? We need to get some of us San Diego folks together for at least breakfast, if not for a morning or afternoon drive. Let's hook it up!
I'm surprised that you were running with the visor up.....I saw cherniack up ahead at the start but seemed to check out a bit. He IM'd me his video yesterday.
I got an X51 oil pan installed
http://www.vimeo.com/8023589
In my experience on Hoosier R6s the X51 pan alone doesn't fix the oil pressure drops. I installed the X51 on two cars and both still saw a wild oil pressure needle.
The porsche motorsport dual stage scavenge pump does fix it (impossible to locate) or the Accusump will intervene when pressure drops.
Great video? You'd think a guy in the business would have a better quality video!!
I needed the visor - the sun was rough through turn 2 and 9.
That video was from the Saturday race with the Porsche Owner's Club at Willow Springs last weekend.
Garrett that was a fun race to watch. Do you have a X51 oil pan?
The race went off late in the day with the sun low on the horizon into a few turns. Blinding actually hence the visor....
cool video... yes your pressure is jumping round quite a bit... what were your engine temps during that video?
does your oil pressure jump around like that on the first 3-5 laps? when the car is semi cold? I'd be willing to bet it doesn't... do you have the 3rd radiator installed... that does a lot for keeping down temps and keeping oil thicker longer so you don't experience pressure drops...
curious what your setup is...
nice vid!
Hi Guys.
Temps are not an issue - the needle is always just over the 180 mark regardless of whether it's 30 degrees or 100 degrees F out. I do have the third radiator kit, though. The oil pressure jumps around all the time - it's very easy to get it to do that, I can even drive on the street and jerk the car at speed and it will drop momentarily. The engine doesn't even need to be at the "just over 180" mark to have the drop occur. As for specs: the car is stock other than an M030 suspension, Nitto NT01 tires, Cobalt Friction race pads, Ate200 fluid, 0w-40 at the halfway mark, and runs with muffler bypasses and weighs 3200 with me in the car.
So I have the X51 oil pan on the way, and I will be interested to see if it makes any difference. It's so easy to reproduce, I will be able to report whether just the x51 pan does anything - other reports have said it does not. We'll see!
Garrett I have zero compression in number 3. I was hoping it was something simpler, but I checked compression today (zero) and leaked it (escape thru the intake). Most likely a bent valve, perhaps caused by a broken rod. It runs with a huge miss but no other noise. It's never been overrev'd, 20 track days since new. I'll know more Monday....
FWIW, I use 15-50 Mobil One and have in all my race motors. My 03' cup had 120 hours when I sold it and is still running stong 1 year later...
This is an 02 996 C2... so the 3.6 engine.
My "other car" has a 3.6 X51 and it's rock solid at 5-bar when doing the same maneuvers on the street with the same oil (0w-40). So, I'm hoping for big things from this $214 oil pan! If not, then I'll give thicker oil a try.
Hey John - total bummer - was that a brand new engine? How did you know, by the way? Will you do an autopsy, or just swap it? Sorry to hear, though it will be interesting to hear what happened. Another guy on here had a valve seat crumble away which could be what you're looking at.
the x51 has the complete oiling system for prevention of pressure loss... I have the x51 pan in my 3.4 and have seen a small reduction in pressure loss... there is still loss but if you look at the x51 pan and the way its designed... itreally prevents starvation on the main tube.... I noticed you are running at *half* the dipstick... you should really be filling it up right to the top of the stick.... others even use a deeper oil pan to store 1/2 more litre... so if your down half a litre already by leaving it filled to half your not really doing yourself any favors... also these engines run warm especially when tracking so a 50 weight oil is recommended for tracking... 5w50 works well for street and track... 0w40 is too thin for serious tracking..... and track oil is only good for about 10-12 hours of tracktime (if your engine doesn't burn any that is... )...
It was a fresh rebuild when installed before Laguna. I delivered it to the motor builder today and he'll take it apart Monday. Will update when I know....
I was just over the top of 6 and shifting into 4th when it just lost power. No loud noises, I thought I'd gone into 6th so I downshifted back to 3rd. but there was nothing there so I shut it off and coasted around to the pits. No metallic noises at all and none later when I drove it into the trailer. Oh and I was leading for the 3 Yoko slicks contingency. Oh well, I won on Saturday too but had Michellin Blues on.....
I think my mount was just not completely tightened down. I didn't realize until I got home and took the video off of the card.
That sucks about your car John, hopefully it's not so bad.
Bent intake valve in #3. The builder said I must have missed a downshift but that didn't happen. I'd man up if it did. Besides, no other valves were damaged so I'm guessing the spring or guide just bleeped up. It's being reapired though they have to take the case apart to check for debris and replace the oil pumps....
Now about that 3.6 I was offered. ...
For those interested, the x51 pan does not help stabilize the oil pressure at all, neither does running at max oil level.
I'll replace the pressure sending unit next... hopefully the pressure is fine, it's just reading funny.
Where did you go testing Garrett, what direction, and how far did it fall? I'm going to BW on Sat Jan 16 th for a open test date and I'll film my pressure gauge. The track is running CCW like we ran in November.
Also, 3 bar as mentioned by Pete above is still 45lbs. of pressure....
Running intermediate DE level or NASA level 2 on street tires, should I be concerned with the stock pan? I only run about 4-6 days per year at Mid-Ohio and sometimes Nelson Legdes.
iirc in addition to the deep oil pan, you should have the motorsports oiling kit (pump and other stuff ) installed to remedy the oil starvation problem.
From an oil control perspective the 3.4 and 3.6 have identical oil baffles in their pans. Porsche superseded the 3.4 part later to a 996 3.6 and then later to a 997 3.6 part #.
FWIW: I personally saw the same issue on my 3.4 another 3.4 and my new 3.6.
The x51 pan does help to control oil better than the stock one and is a good investment but the root cause of the pressure drop is related to there only being 2 scavenge pumps and their inability to return oil to the sump during high G situations.
This day in age and based on what we can/cannot get. If you want some additional insurance: Accusump
Accusump is made by Canton Race products (google is your friend).
Purely a bolt on solution that restores oil pressure for the split second that it is lost.
The key to putting it on your car is the Spin On Filter Adapter made by Jake Raby (Flat6 Innovations). Buy that part and bolt a kit on from Canton. Easy insurance for less than 1K. Pretty much the de facto solution amongst the Spec Boxster and Spec 996. Been in use by non dry sump racers for a while.
QUOTE=c70Pete;7192513]so what is the deal with Accusump... is it easily installed? does the engine have to come out...[/QUOTE]
[/QUOTE]
I don't think any of the POC Spec 996 guys have an accusump installed at this point and they've all been OK for the past couple years.... hope the record stays that way!
I can't see the video but any chance you are sucking air from some place else than the pick up? Could be your pump pushes enough to keep the pessure up but when backing off its much more evident due to the higher volume of air sucked in during higher revs.
Some day I have to learn all the particulars like how the crank case breaths and such. So many simple things that can all add up. I'm already starting to figure there is no spring loaded ball bearing to maintain pressure in the system.
that's great news... so the x51 pan on my new motor is doing something... my older 3.4 engine with many many miles on it that DIDN"T have x51 pan saw drops to 1.5 and 2 psi in super hard cornering not good... RIP.
I watched my pressure gauge while going thru the 18 degree banking at Cal Speedway at WOT in 6th gear and it hardly budged, certainly not below 4 bar but that's a left hander. The turn Garrett was going thru when his pressure jumped around is a right hander. I do have the X51 pan.....
Pete, I'm sure you mean 1.5 to 2 bar?
I've seen it drop to 1.5-2 bar in my own C2 with a reman'd motor, as well as 3 others, including my current C2 (3.4).
I've also observed one car have no perceptible pressure difference w/an X51 installed, and no other modifications.
no I meant 3 bar....
I have x51 pan and use mobil 1 5W50 and in violent cornering... both right and left hand sweeper I have not seen below 3 bar... normal is above 4 bar...
1.5 - 2 bar your in trouble or you are low on oil OR... your engine temps are so hot that it has reduced your oil pressure because of high temperature... that's another thing the 996 needs is more cooling..... either through the 3rd rad or an external oil cooler..
... is it possible to mount an external oil cooler to the 996 engine to augment the one that is already there?
My experiences and opinions:
I am not convinced that it's a temperature issue, and I am not convinced that there's a problem either. There are tons of these cars running around, and it appears that dropping oil pressure is the norm not the exception. The data I have seen are from my own car(s) as well as instructing several students with C2s. I've certainly seen them below 2.5 bar on the gauge, in fact, other than a full X51 package car (not just pan), or the GT3/GT2/Turbo, I haven't been in a single C2 that doesn't drop to at least that level under sustained cornering.
interesting...
1. did the cars you observed <2.5 bar have x51 pan installed?
2. how hot were the engine temps when you made your observation?
3. did you check to see that these cars had full oil right to the top? 7 missing bars indicate 0.7 litres of oil are needed... and some people run with 6 bars... which means your down on oil... not good for the track...
reason I ask is because on the corners that make my pressure drop to 3 bar ... 3 bar is only reached when my needle moves past the 0 in 180... slightly past... so I'm running say 104-108 C (as observed on the AC display)
when my needle is pointing strait upward and my temps are normal... normal is 90-95 C I don't see 3 bar in these corners!!... so my conclusion from my observations is that
a) with a full oil compartment... filled right to the top... with no *empty bars* on the oil readout
b) normal temps 90-95 C
there is little pressure drop for the first 3 laps... when things start getting warm the oil gets thinner and I see 3 bar...
where is the OEM cooler located? is the cup car cooler an easy swap?
do you find you still get pressure drops with the increased oil cooling from the cup car cooler?
Pete,
Of all those, only one had an X51 pan. It belongs to a good friend of mine, I've driven/been in the car before and after the pan, did not notice a difference from the pan alone.
I did not check oil levels on any of them, though the two C2s I've had have been filled to the top marker. Only one car I'm familiar with has a third radiator (this is the car w/the x51 pan), the needle generally stays at the high side of the 0 on 180. Anyway, my cars only have the two factory radiators, and run a similar temperature, however for longer sessions I either turn the A/C off or start short shifting, thus I don't have experience with the temp getting too far over this.
This car (02 C2) has a third radiator and never has temp issues - once it warms up the needle never moves even during a 25-60 minute race in 100 degree heat or 40 degree F cold.
I have an x51 996 also, and its pressure is always pegged at 5 bar - never budges even on the same "test" route that triggers the C2 to drop pressure. Too bad that engine isn't in my track car. But I'm with Ahmet - I think a lot of engines would be destroyed if a catastrophic drop in pressure were happening this frequently. I did the x51 pan only because it wasn't that expensive, and I was hopeful it might make some difference.
that's surprising that a 3rd radiator doesn't make a difference in temp on your cars... hmmm
as far as the pan goes... I know it defintely does something cause engines were blowing @ sebring and the guys who came back with new engines and the pan had no more blowouts this was happening on 911 3.4 cayman 3.4 and 911 3.6 motors... so it does something... I'm not seeing 2.5 and I drove the **** out of the car around the corners... with sticky tyres... I'm going to a BFgoodrich R1 this summer and that is a lot sticker... I wonder how the pressures will run... I also wonder why I don't get the pressure drops on the first 3 laps when the engine is @ normal temperature... 90
in my opinion I believe heat is the culprit here... when my engine temp needle is pointing strait up - 90 - my idle pressure is about 1.5 bar - maybe a tad higher 1.6 bar...
when the temp needle is pointing beyond the 0 we are about 103-106 C and the idle oil pressure is 1 bar... sometimes @ 0.9 bar..... temp makes a difference even at idle... so its time for cooler oil or better oil that doesn't lose pressure when it heats up... I seriously think a cup car oil cooler is my next mod...
Check your sending units conections. Two wires so I'm thinking if somebody put teflon tape on the sensor when screwing it in that it might not matter. Hopefully you are getting a bad connection, heated wires failing or such. Would be nice if it's just sensor reading related meaning bad info was being displayed. Wires will flap around during G's and change a loose or dirty connections state. Inspecting and cleaning the connections and their wires is what I'd try. Good luck.
Partial update - with a new oil pressure sending unit installed (which is a 5 minute job - so simple on a 996, and only a $40 part) my oil pressure now reaches 5 bar which it never used to. The max oil pressure I ever registered at cold idle or acceleration was 4 with the old 94000 mile unit. I haven't had a chance to check the pressure dropping yet.
Sorry, since I'm considering replacing my Mantis 1.2 Litre deep sump oil pan with an x51 oil pan, I was hoping to see a video of someone on track with an x-51 oil pan.
Maybe I should create a new post then?
Any Updates?
I have the exact same issue in my 997.1 with a Mantis Deep Sump. No pressure drop in left handers, drops to about 2.5 bar in right handers.
I saw the same oil pressure drops with my Mantis 1.2 L deep sump, so I built a mockup of our sump, installed the mantis into it, put water in it, then sloshed it around to see what I could see. Water is good here because when engine oil is super hot on the track it's viscosity is closer to water.. plus it's clear - consider it a worst case - viscosity scenario.
My apologies for the video quality.
take 1:
You Tube
take 2:
You Tube
modification of the windage tray - test:
You Tube
Porsche
996 986 997.1 987.1
Mantis Deep Sump Oil Pan with holes plugged where clearances allowed. I used m6 bolts with nylon locking nuts and heavy duty thread lock to reduce oil bypassing the baffle during long hard cornering (on street tires).
After doing all this - and refilling the engine oil - I also noticed that in order to get a consistent engine oil level on my dipstick - I had to wait about 3 minutes after the last oil put in. I filled it to the top notch. Keep in mind I have a Motorspot Air Oil Seperator installed - so I wasn't too worried about filling it to top and testing it.
I tested it by waiting until my engine oil pressure indicated the oil was fully warmed up (at least for street driving), and doing circles in a back parking lot with my RPMS above 4000 rpm until my tires were squealing (street tires - 235 and 295 width in the back, 300 or so compound). This test would normally have shown oil pressure fluctuations easily with the 1.2 L mantis deep sump as originally installed. After installing the bolts, and filling it to the top notch - as per my past picture above, the oil pressure did not fluctuate nearly as quickly. I wouldn't call it fixed completely, but an easy improvement to make to your mantis pan.
If you haven't already done it, you should get the upgraded oil pressure relief valve and spring. Easy to change out while doing an oil change or installing your X51 pan. Just another precaution.
thanks for posting! For those of us who use their 996 as a DD too, there's no reason why we couldn't build a box around the accusump, and maybe even a tray underneath. Could me made of aluminum sheet and "L" extrusion from the hardware store, etc. that way groceries and luggage wouldn't damage anything.
Krombacher,
I think that is a very good test! It's not completely scientific, but it I would think it would explain what you are seeing.
What I think you should do is show this to the guy who touts the mantis tray. He says it's better than anything out there and looking at this, I'm not so sure now.
Is that the stock baffle you are using, or the X51. Sorry if that was stated somewhere in this thread, but it's pretty long to look at every single post.
Just some thoughts.
Mike
Does the Mantis not come with an extension pickup? Could that be the problem?
Also, have you looked at the ln engineering one? I do think adding a space is stupid and kind of weird and for just the spacer, that kit is a little expensive.
I went to mantis's website, It does appear to include an extension for the pickup.
However, looking at the windage tray compared to LN engineering's, the mantis has holes in it, where the LN engineering does not. According to the pics anyway.
Now, if that makes a difference, I don't have any idea.
I do have a question, and maybe Hella-Buggin can answer this one.
When you say it drops to 2.5, at what RPM is that?
If it is anything over 3500RPM, that's not very good. Of course, that's better than 0.
Mike
Thanks for the vids of the sump experiment. The thing that gets me though is that the pressure is rock solid on left turns. The pick up tube is centrally located so why would it make such a difference which direction the turn is.
This is a source reference. Confirm exact model applicability in the original material.
