Dead end...please help! - 986 Forum - The Community for Porsche Boxster & Cayman Owners

mit6725 · 10-17-2008, 02:00 PM

To start with this is my first post and any help would be greatly appreciated.I have a 1999 Boxster 986 with the 2.5 litre 5 speed manual that I purchased in June of 2008 and has been a joy to own...until now! Last Thursday I brought my car into my dealership (I am a General Manager of a car dealership...another brand) to get it checked out before winter. My technician did an oil change, checked the anti-freeze and changed the air filter. I purchased the OEM oil filter and air filter from Suncoast (great price and service) as I live in Ontario and the closest Porsche dealer is 3 hours away. The air filter that was in the car was a very dirty K&N unit of which we replaced with the factory paper unit. Otherwise everything was normal and basic. I drove the car Thursday night and all day Friday and was thrilled as the car seemed to have much more get up and go which I assumed was due to a nice clean air filter. On the Saturday morning I filled the car with super unleaded fuel and tightened the new gas cap (replaced in July at a Porsche dealership due to a campaign) with many clicks as required and drove a short distance to work. Later in the day I was heading out of town and as I started on the highway the CEL came on (not flashing) so I went home (while taking it home it seemed to be running great) parked the car in the garage and took my other one on the trip. On Monday I drove the car to work (ran great) for my tech to check. He put on our scan tool and a P1128 code came up which we cleared. The car was still running great. That night as I drove it home from work it started to run rough and the CEL came back on. So the next morning I decided to bring back to work for my tech to look at again and as I started to drive the CEL started to flash so I turned around and brought it home. Later in the afternoon my tech and I drove over to my garage to see what was up with the car. He removed the MAS and cleaned it (visually it looked great...nice and clean, no issues). Then hooked up the scan tool and ran the diagnostics. It was running very rough as it was in the morning and the night before. The codes were P1319, P1313, P1315, P0300, P0301 and P0303. He was befuddled how changing an air filter and doing an oil change to a car that was running great could alter it so drastically. It makes no sense. We left the car as it was with my tech going home for the weekend to investigate on the internet and see it he can find an answer. Sorry for writing a book but I thought to get the right help you need the whole story. Any help would be great...Thanks.

tboyer · 10-17-2008, 02:23 PM

I would clean throttle body, lots of info on how-to all over this forum and others. If that doesn't work, I'd replace the MAF, see Mike Focke's FAQ for instructions.

10-17-2008, 03:07 PM

I'd get the code values to validate the MAF replacement, the Bentley book has them.

husker boxster · 10-17-2008, 03:46 PM

Did your tech add any antifreeze when he checked it? If so, what kind of antifreeze did your tech use? Porsche's require phosphate-free antifreeze. Your garden variety antifreezes like Prestone contain phosphates and if used in a Porsche will turn into a gell. Better check this out.

Topless · 10-17-2008, 05:01 PM

Check your oil level. Those are misfire codes and could be caused by overfilling the oil and fouling the plugs. These cars are very sensitive to overfilling. Do not drive it with a flashing CEL as engine damage could result.

mit6725 · 10-19-2008, 06:39 AM

Thanks to everyone for the advice. This whole thing blows my mind...car's running perfect, do an oil change, change the air filter and you end up with this????????? Makes no sense.

10-19-2008, 08:25 AM

Given Topless's advise it could make perfect sense. There is a very remote chance removal of the air filter allowed debris to reach the MAF.

FrayAdjacent · 10-19-2008, 01:25 PM

I'd ask the tech how much oil he put in. 9.5 quarts is a lot, and, given many other cars don't use near that much, it could have been underfilled.

Other than that, there are resources to find what those codes are. A quick test for the MAF would be to unplug it. If the engine runs better, you have a bad MAF.

RandallNeighbour · 10-19-2008, 03:20 PM

codes are found on this page on my site:

http://www.iwantaporsche.net/BoxsterCheckEngineLightCodes.htm

cas951 · 10-19-2008, 06:57 PM

Quote:

Originally Posted by mit6725

Thanks to everyone for the advice. This whole thing blows my mind...car's running perfect, do an oil change, change the air filter and you end up with this????????? Makes no sense.

I had similar symptoms. Can ran great till I did an oil change. Filled the oil till it was full from the dipstick and the oil level sensor from the dash. It took 9.5 quarts. AFter awhile the car started to leak oil on the right side valve cover gasket. Then it started to run rough when cold. It ran fine while it was warmed up. Then it started to run really rough when cold and eventaully I started to have smoke at start up. I ended up replacing the AOS. Once replaced it ran like a champ.

My take is your oil is overfilled and may have rujined your AOS. I drained my oil and I now keep my oil level only at 1/2 full at the dipstick and the dash sensor level.

Brucelee · 10-20-2008, 06:46 AM

Between the owners manual and the dipstick, the oil issue should be sorted out quit nicely.

My bet is on both the MAF and an O2 sensor. Perhaps throttle body crap too!

Lets see how this turns out.

Good luck..

Lil bastard · 10-20-2008, 07:09 AM

There is no truly accurate way to measure the oil using either the dipstick or the dash gauge.

The only way to measure it accurately is to measure what came out and replace only that amount (be sure to include the oil in the cannister and filter).

This is because in '99, Porsche, in response to some bearing starvation issues, revised (increased) the oil capacity in TSB: Boxster 2/99 1 1701.

In this TSB, they revised the oil capacity from: 8.25ltr. (8.7USqts.) to: 8.75Ltr. (9.24USQts.) - w/ filter. An increase of slightly more than 0.5 USQt.

But, they never revised the dipstick or the sending unit for the dash gauge, making both of these invalid. If you fill to the full mark on the dipstick or gauge, according to this TSB, you are underfilled.

The biggest reason people overfill these cars is that they either do not have the car level when draining, or they do not allow 20-30 min. time for all the oil to drain out (or both).