Dead end...please help! - 986 Forum

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).

mit6725 · 10-20-2008, 10:59 AM

Well I took Topless' advice on the idea of too much oil (might as well start with the least expensive problem). At lunch today my tech put it on the hoist and let the oil drain for 1/2 hour (which we did not the first time) and then refilled it. Our guess was it probably had about a half of a litre too much. We drove it for half an hour and it's perfect, all the codes were cleared and have not come back since. Thanks to everyone who helped, it's appreciated.
Tim

jmatta · 10-20-2008, 11:34 AM

These cars are really particular about the oil fill. I changed the oil in my '02 S this past weekend with the usual 0W40 Mobil 1. Drove the car to get to temp (180*), changed the filter and let the oil drain for half an hour. Put in 8 quarts, checked level (didn't even register on dipstick or dash). Added another half quart and ran back to operating temp; still didn't register on dash. Added remaining half quart (nine in total) and now I show second bar from the bottom on dash gauge. I will not add any more oil until I have a chance to drive the car a few miles and see where I sit then. Most likely will need another half quart, which is sitting on my shelf.

FTD · 10-20-2008, 12:14 PM

Quote:

Originally Posted by mit6725

Well I took Topless' advice on the idea of too much oil (might as well start with the least expensive problem). At lunch today my tech put it on the hoist and let the oil drain for 1/2 hour (which we did not the first time) and then refilled it. Our guess was it probably had about a half of a litre too much. We drove it for half an hour and it's perfect, all the codes were cleared and have not come back since. Thanks to everyone who helped, it's appreciated.
Tim

Very happy for you, especially that it was a simple solution. Wa hoooo!

E Kaplan · 10-20-2008, 03:26 PM

If you ever do need a Porsche mechanic in Orlando, try Redbone Garage. They specialize in only Porsche and their prices are reasonable. I used to have a 928S and had them do some work. If I lived in Orlando, that is where I would bring my car for service.

Eric

Topless · 10-20-2008, 03:34 PM

Quote:

Originally Posted by mit6725

Well I took Topless' advice on the idea of too much oil (might as well start with the least expensive problem). At lunch today my tech put it on the hoist and let the oil drain for 1/2 hour (which we did not the first time) and then refilled it. Our guess was it probably had about a half of a litre too much. We drove it for half an hour and it's perfect, all the codes were cleared and have not come back since. Thanks to everyone who helped, it's appreciated.
Tim

Tim,
I am glad you got it sorted out. These cars sure are fun to drive but they can be a little particular at service time. Cranky German cars. I use a method similar to jmatta's for oil change. A lot more hassle than my fleet of Toyotas.

mit6725 · 10-22-2008, 11:15 AM

Well if you read this thread earlier it appeared we fixed the problem...but, I guess not. Here's what's happening now....
After draining the oil we cleared the codes and the car ran very rough (almost like bad gas). I revved it for a while, drove it and after a while it smoothed out and drove great. All was well...the car was running like new and then the CEL came on again. I continued to drive it a bit and the car still was running perfect with the CEL on. I put it on my scan tool and I got 2 codes 1128 and 1130 (oxygen sensing adaptation area 2...rich threshold cylinders 1-3 and 4-6) and then I cleared the codes. After clearing the codes and restarting the car it chugged and spit, but after revving it and driving it a little it smoothed out again. This has occurred a few times since, driving great, CEL comes on, car still runs great with CEL on and then hook up the scan tool get the same codes, reset it, car chugs again for a while then runs great and it happens again. Is this possibly oil on the plugs? It can't be the MAS as that is an intake item. Any ideas?????

cas951 · 10-22-2008, 11:31 AM

Quote:

Originally Posted by mit6725

Well if you read this thread earlier it appeared we fixed the problem...but, I guess not. Here's what's happening now....
After draining the oil we cleared the codes and the car ran very rough (almost like bad gas). I revved it for a while, drove it and after a while it smoothed out and drove great. All was well...the car was running like new and then the CEL came on again. I continued to drive it a bit and the car still was running perfect with the CEL on. I put it on my scan tool and I got 2 codes 1128 and 1130 (oxygen sensing adaptation area 2...rich threshold cylinders 1-3 and 4-6) and then I cleared the codes. After clearing the codes and restarting the car it chugged and spit, but after revving it and driving it a little it smoothed out again. This has occurred a few times since, driving great, CEL comes on, car still runs great with CEL on and then hook up the scan tool get the same codes, reset it, car chugs again for a while then runs great and it happens again. Is this possibly oil on the plugs? It can't be the MAS as that is an intake item. Any ideas?????

Not sure if you read my first response to this thread. I ended up replacing the AOS to get this corrected. Are you having sny blue smoke issues when this is happening?

Topless · 10-22-2008, 04:02 PM

Yes,

When your car is run overfilled with oil it can damage the Air Oil Separator, then oil gets into the intake fouling the MAF, fouling the throttle body, fouling the plenum, and finally fouling the plugs. Think Exxon Valdez inside your intake.

The new codes you list tell us your car is running lean on both banks and the DME is trimming the mixture but has reached it's trimming limits. Often caused by a fouled MAF or damaged AOS.

Time to remove the intake and throttle body for inspection and a thorough cleaning. Clean or replace the MAF, inspect the AOS for damage, and replace parts as needed. Once she is running clean again the plugs will probably clean up too. There are good DIY for all of this on Renntech.org.

Sorry this turned into such a hassle. I also had to learn a few things the hard way on this car. Now I use the Bentley manual or print out the helpful DIY from other owners before diving into Porsche service waters. Good luck!