Huge Smoke Screen From My Boxster At a Track Day
 

Today I went to my first track day since I got my Boxster (actually the first time I've been on track in nine years), and things didn't go well. The car seems to handle pretty well, and I'm pleased that after rebuilding the suspension (replacing every part except for rear toe-links) nothing fell off, but in long left-hand turns, the car smoked liked crazy.

The track I went to is The Ridge Motorsports Park in Shelton, Washington, and there are two very long-duration left handers there, so it was a real problem. The smoke was thick enough that the cars behind me were practically coming to a stop because they couldn't see through the cloud.

When I got the car, the AOS had just been changed, along with the intake manifold gaskets. The PO then changed the oil and over-filled it, so when you revved the car past 5,000 rpms it would lay down a thick smokescreen. I drained two quarts of oil out of the car and it has been fine ever since.

Well, fine as in no more smokescreen, but a CEL keeps coming on, then going off after a while. Sometimes the idle is erratic, and it sometimes stalls.

Yesterday I had topped the oil off to the top of the dipstick (after sitting overnight), so I thought maybe somehow the oil level was too high, and maybe it would burn enough off that the problem would go away, but it didn't. In fact, the last lap I did, the oil pressure warning came on in one turn briefly, which meant that the oil was burning off rapidly enough that the level was too low. I decided that was enough, so I packed up and went home.

What do you all think? Probably the AOS? I'm guessing that the diaphragm was damaged by the excess oil when I got the car, after doing a search and reading up on AOS problems. But what about the smoking during left-handers? Could the AOS also cause that?

Check the engine codes. See what they're coming up with. Once you do that you may have a better idea with what you're dealing with. Since you're suspecting the AOS, try disconnecting the intake tube from the throttle body and getting a look inside the intake manifold. If you see copious amounts of oil in there, then check the tubing from the AOS to the intake manifold. If that's full of oil, then you have yourself an AOS replacement incoming.

I blew a huge smoke bomb my first track day, I believe due to a combination of things:

• Oil was too full. I was new to the car, and overfilled the oil after reading the level improperly. The car needs to set level for a while, especially if it is cold.
• I went through a turn in 3rd gear, came out at redline and then shifted to 4th, that is when I blew my smoke bomb. I think the sustained near redline RPMS in what should have been a 4th gear turn combined with the oil overfill did it.
• During this, the CEL flashed a few times and the power dropped out, similar to the way it does when the TC engages. It turned out to be misfires on a few cylinders due to the oil ingestion.

When I got home I dropped the oil filter canister, and put a new oil filter + oil ring which dropped the oil level down to 2-3 bars below the top, which is where I like to run it. I have never blown a smoke bomb since, and also did not change out my AOS either, it was still good. I have done a lot of track days since and AOS still going strong.

This was at Roebling Road raceway which is mostly right hand sweepers but has 1 really high speed 90 degree left sweeper and one moderately left hand 170 degree turn. I didn't have any trouble with these and my 1 smoke bomb was on the straight immediately after exiting turn 9, a right hander.

There was a yellow base Boxster behind me at Sebring in January that blew a giant smoke bomb going through turn 1, a left hander, it looked like a mosquito truck. I didn't get a chance to talk with him to find out more details though.

Your AOS is probably still fine - if it had failed you would be blowing the smoke bomb 100% of the time the way I understand it.

You probably do have oil in your intake tubing as described by cornontherob - this oil is what caused your smoke bombs. If your AOS hasn't failed this oil will clear itself out, I didn't do any cleaning of anything after my smoke bomb.

Your CEL - the codes will give a clue as to the cause and solution, you can get them read at any auto parts store. They come and go, if the error condition doesn't repeat after a few drive cycles the light will go out and then come back if the error condition repeats.

Good luck with it - I was very nervous and hesitant to go back after my smoke bomb but it all turned out ok for me.

Steve

Yeah, I need to get the CEL codes read.

Before the track day started, my oil level was at the top/full line on the dash indicator. After pumping all the oil into the intake, it took about a quart and a half to get the indicator to read two lines from the full line this morning. Before I added a quart this morning, it was at the bottom/add line. I'm guessing it pumped around three quarts into the intake in about fifteen minutes of track time. The citizens that live near the Ridge can thank me for the low mosquito count this summer.

My question is that once it pumped all that oil out, and lowered the oil level in the sump, why did it keep smoking in the left handers? Does all the excess oil stay in the AOS for that long?

That sounds very odd, once the oil level is lowered I wouldn't expect to see any more smoke bombs.

Maybe it is the AOS, you say it smokes all the time over 5000 RPM?

A quick test for a bad AOS is to try and remove the oil cap when the engine is running. If it is very hard to remove, that is a sign of a bad/failing AOS.

Steve

It only smokes in the long left-handers; towards the end of the turn when it has been loaded to the left for a few seconds, and then for a few seconds once out of the turn (in other words, it takes a bit to burn off all the oil.). At all other times it doesn't smoke.

One of the turns is a second gear corner that is flat-out onto the main straight. You shift as the car is pretty much straightened out. I tried it in third gear a few times, and it didn't smoke then. The other turn where the problem was occurring is a third gear corner, I was probably at steady throttle at around 3500 - 4000 rpm. I didn't try second gear, as it too fast for second, and it would be lugging in fourth gear.

I can remove the oil cap with a little bit of resistance when the engine is running, but it isn't difficult.

I talked to a friend that races a Spec Boxster, and he told me that his smokes under hard braking (sometimes). That is a good James Bond strategy to open up some space ahead of your competitors in racing, but for a track days, it seems un-necessary. :)

After talking to him and mulling things over about this issue, I ordered a new AOS and a fancy stainless steel racing oil sump baffle from Pelican. I know the baffle probably won't affect the smoking, but it will reduce the chances of starving the pick-up of oil in the long left-hand turns.

Once the parts are installed and I do another track day, I'll update what is happening.

I've also had this problem twice now at the track. I've ordered that same baffle and changed my AOS. A new underdrive pulley should help with my power steering pump problems, and the new bleeder valve should stop my coolant from pissing all over the track! Here's hoping! :cool:

Please let us know if these measures help fix the issues!

Maybe the baffle will help the oil from sloshing up so high and getting whipped up and then into the AOS?

I hope so!

I overfilled my track boxster -- same issue.

Had a street Boxster that would do it on left handers until I replaced the AOS.

For my track boxster I added a 0.5L deep sump and a baffle kit.

I had not had any problems since I rectified my oil level.

I also have the under drive pully.

Mike

Great question. Maybe someone can chime in on this.

Seems that the best solution might be the motor sport aos. It's on my wish list but it's not cheap!

You need really good access to fit the Motorsport AOS. This mod helps:
https://i.kinja-img.com/gawker-media/image/upload/s--Jzg7MdMn--/c_scale,fl_progressive,q_80,w_800/fuaut6sy6rvlfipitxdq.jpg

Is that the F40 mod? I bet the Motorsport AOS is the least expensive part of that whole mod.

Yes, well spotted.
If only Porsche had copied this Ferrari to aid the engine/trans access!

Here is an update on my issue with the smoke bombs in left handers -

I installed the EBS Racing Oil Sump Baffle and the Brey-Krause Deep Sump Oil Pan Kit with the oil pick-up extension. I did NOT end up replacing the AOS because it never smokes in normal driving, and seems to have the proper amount of vacuum when opening the oil cap while the engine is running. Plus, I looked at the difficult access to the thing, and suddenly got lazy and skipped doing that.

I filled the oil to the third line below the top on the digital readout, Mobile 1 10-40.

Yesterday I went to another track day, this one at Pacific Raceways near Seattle. It has two long left-handers, and a tight left-handed hairpin.

My results? Bad! It is still smoking huge amounts when in a left hand turn under hard throttle and cornering. It was bad enough on the first lap that they red flagged the session because they thought I had blown my engine and oiled down the track! Very embarrassing, to say the least.

So I tried to drive around the problem, by running in a higher gear. It would still smoke, but not as bad. Then I tried essentially coasting through the turn in the higher gear, but then the low oil pressure light started to flicker. If I ran in the proper gear, but with higher revs but not really much throttle, then the oil pressure light stopped flickering, but it smoked more often. I even tried putting the clutch in a coasting through the turn (it didn't smoke!), but with other cars on the track, that wasn't an ideal solution.

Since the oil pressure warning was very concerning, I added another quart of oil, because I thought maybe I had burned off so much oil the four or five times it smoked that the oil level was low. The problem persisted with the oil pressure low light, though. Today I checked it after the car sat overnight, and it shows one line on the digital read-out! When I said that it was smoking a lot, I guess it really was!

Also, the brakes started to fade away, but that is another issue. I guess EBC Reds aren't suitable for track use.

That leaves me very frustrated! The handling is very good, the one series of corners that I could go through at speed nobody else was as quick from what I could see. It is fun to drive a car that you can steer with the throttle. But unless I find a track that runs clockwise, the car is unusable for track use.

At this point I'm pretty disillusioned with this dammed car. What really frosts me is that after spending over $500 on the Krey-Brause sump and EBS Racing Oil Sump Baffle, I have oil pressure problems in the turns (but that may be because the it burnt so much oil that the level was low). The tires I'm running are regular high-performance street tires, not R-compounds.

My step is to go ahead and replace the AOS, just because I don't have any other ideas. Anyone have any other suggestions?

It seems as if the oil is leaking past/over the baffles and starving the oil pick-up tubes ?
If one of the hinged baffles was hanging up ,this is exactly the result that would occur.
Others have reported some mods required to fit the EBS baffle and avoid this and other issues. Did you check this?
EBS Racing oil sump baffle issue - Rennlist Discussion Forums
http://986forum.com/forums/boxster-racing-forum/47090-x51-type-baffle-works-deep-sump-spacer-kit.html
You might investigate "horizontal baffle" also. Tarret/Pedro/Technosump have that as part of their deep sump kit. If positioned correctly, it is very effective.

I ran the newly installed ebs baffle with oil 2 bars low at Mont Tremblant last week. No smoke bombs. But then it's a clockwise track so YRMV.

The EBS baffle fit with no problem in the area that the original poster had to trim. In the three years since that was posted EBS probably changed it. That said, I did have to do some trimming with a Dremel along the bottom to get it to fit perfectly. Once I got it mounted on the sump plate properly, I did check to make sure the hinged plates moved without any interference.

I'll investigate the horizontal baffle.

Today I ponied up and paid an independent Porsche repair place to replace my AOS, and since I thought that was the last thing to try and fix the smoking issue, I signed up for a track day next Wednesday back at The Ridge. Since that track has a lot of really long left-handers, it should be a good test to see if the problem was solved.

While I was waiting at home for the Indy to call me when they were done with the car, I was doing some more research into AOS problems. I stumbled onto this very informative thread - http://986forum.com/forums/general-discussions/36949-oil-cloud-when-running-hard.html, and there is a lot of discussion about the scavenging pumps in the cylinder heads. I started wondering if my passenger side pump was weak, because it makes sense that if the pump isn't functioning correctly, you'll get the smoke bombs in left-handers. Think about it - the scavenge pump is in the rear of the passenger side head, so after blasting down a straight at high revs, there is hard braking, followed by hard cornering to the left. The oil can't get sucked out of the head and returned to the sump quickly enough, and the AOS sucks the oil into the intake. On the driver side head, the pump is in the front of the head, so it can return the oil back to the sump easily.

My thought was to swap the pump side-to-side, just to see if that would make any difference. When I looked at the passenger side pump, I saw that it wasn't indexed to the head correctly! The pump has 1-3 (passenger side), and 4-6 (driver side) that is stamped on it. The bank that the pump is mounted on should have the correct stamping on the pump facing the crankshaft. As you can see by the picture below, it was mounted wrong! (The driver's side pump was mounted properly). It is quite possible that this has been my problem all along.

I took the pump out and installed it correctly. It looks like the pump was removed at some time in the past, as the mounting bolts were a lot less grimy than the rest of the engine. Since I have no idea of the car's past, it is a mystery why the pump was removed.

Once I finished with the pump, I went for a test drive. There is a very steep hill in my neighborhood, so I went down it at redline (in first gear) for about five seconds, then braked very hard, and then went right back to full-throttle. Not quite the same as being at the track, but I figured if the pump weren't installed correctly, it might have smoked under those circumstances. It didn't smoke, so at least I didn't make things worse!

The real test will happen next week at the track, but I'm excited that I found something that could be the root of the trouble! I'll check back and let everyone know if the issue has been fixed.




http://986forum.com/forums/uploads02...1473382887.jpg

The Prime Suspect in identifying the cause was ..........guess whoo....yup Jake !
"The pumps are also installed incorrectly in their bores or the body is disassembled and phased incorrectly into the housing."
"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. "
Here is a reason why the mistake may have occurred -I stumbled into it when I rebuilt my engine. I was fanatical about marking everything with a paint pen. Both scavenge pumps look identical - but they are not -quite Unless you have studied the long Post by Insight on Timing as if your life depended on it ,you could easily miss it as a noob. I did but luckily caught myself.
This is a good example of the standard of work required on these cars. If you think it is "just nuts & bolts-like any other car" ,you'll fail.
Kudos to Jake and Racer Boy for doing the research.Thanks for Posting this because we tend to fixate on the AOS and X51 baffles for symptoms like this smoking.
See pge 7 photos, Post 91 scroll down for the exact photo required here:
http://rennlist.com/forums/996-forum/672370-engine-rebuild-part-3-the-finale-7.html
See Waynes comments alongside Fig 25 here:
http://www.pelicanparts.com/techarticles/Boxster_Tech/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner/16-ENGINE-Camshaft_Swap_and_Chain_Tensioner.htm
and
http://www.pelicanparts.com/techarticles/Boxster_Tech/Disc163/BoxsterTech-163.htm

Good find. Indexed as it was the discharge port was no longer positioned correctly. I had started thinking along this line after reading your posts. I have attached your thread to patssie's thread about AOS hope you don't mind. Today I searched scavenge pumps and apparently this is not uncommon.

Good catch, I hope that fixes it!

As promised, here is the update after doing a track day today. It didn't smoke! Looks like indexing the scavenging pump correctly solved the issue. Phew!

I really thrashed the thing today, and it ran just great without any issue. I guess I won't sell the damned thing after all, and I've even started to allow myself to like the car a little bit. But just a little! ;)

It turns out the $99 for the set of rotors from China don't work well at the track, warping enough to cause severe juddering, and the pads faded badly, so I had to ease out of the gas way before the turns and brake early. Despite that, I was able to reel in a 2002 911 (he eventually spun, no doubt from me pressuring him :rolleyes:), and a new 911 blasted past me down the straight, but I was quicker in the turns, despite the huge tires that car has. So I feel pretty good about things. Not having to worry about the smoking allowed me to focus on my driving and learning the track, so that was fun!

My daughter lives nearby, so she came out and I gave her a ride for one session. She felt very nauseous afterwards, so that was a positive as well; if I made my kid sick, I must be doing something right!

That will be my last track day this year, so over the winter I throw some decent rotors and EBC Yellows at the car, and I'll start looking for some M030 roll bars. But I'm really happy to have a car that functions as it should on track!

Great news!!!

JayG has had some success with the Meyle rotors which are very affordable, and I think at this point he has had some track days on them and can report how they did. Meyle makes good stuff, I have some of their suspension parts on my car and have been happy with them.


Always a bonus :) Reeling in the more powerful cars is always a lot of fun :)

RacerBoy, you may want to try the Pagid Yellows instead with new rotors
these will squeal like pigs but will stop you and will not fade ;)

M030 roll bar
Suggest you also Search for "Lower Stress Bar" or Pedro bar . There is a $10 diy version also
Zimmerman rotors + Pagid?

Fantastic to hear the smoke bomb issue is resolved. I admire your persistence. A lot of folks would have said "screw it" and put the car on Craigslist.

I had the pleasure of being on track in a 911 with a Boxster in hot pursuit. I would pull away fast on the straight, only to have him squeeze by me in the turns. We both thought we were pretty cool until an off-duty Skip Barber instructor absolutely SMOKED both of us in his spec Miata. We might as well have been driving golf carts. :o

Way to go in finding (and fixing) the root cause of this issue! It sounded like it was pretty aggravating. Congrats, and thanks for sharing!