Check Engine Light is coming on every single day now after resetting-Anyone else?
11-11-2003 | 12:43 PM
#17
Burning Brakes
Joined: May 2001
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From: Hermosa Beach, CA
Steve:
Just curious. Did you ever check the secondary air injection check valve? Those cheap parts have a habit of rusting out and snapping off. On my 95, this was the case. I was able to hear the air blowing into the engine bay.
Could this cause the CEL to come on? I am not sure (Mine was ODBI). But before spending $5k, I would certainly take a look at a $42 part to make sure it is still there and operational.
I would be curious to see if the carbon buildup is a direct consequence of the check valve failing perhaps months earlier.
Just curious. Did you ever check the secondary air injection check valve? Those cheap parts have a habit of rusting out and snapping off. On my 95, this was the case. I was able to hear the air blowing into the engine bay.
Could this cause the CEL to come on? I am not sure (Mine was ODBI). But before spending $5k, I would certainly take a look at a $42 part to make sure it is still there and operational.
I would be curious to see if the carbon buildup is a direct consequence of the check valve failing perhaps months earlier.
11-11-2003 | 02:12 PM
#19
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From: Moraga, California
What ever happened to Mike J's solution of installing circuitry to fool the OBD software?
He was going to install it between the O2 sensors (here's the thread). I think he was following some circuitry someone else designed, but I can't find that link.
Anyway, what ever came of it?
Greg H.
(Valve job 7,000 miles ago
)
He was going to install it between the O2 sensors (here's the thread). I think he was following some circuitry someone else designed, but I can't find that link.
Anyway, what ever came of it?
Greg H.
(Valve job 7,000 miles ago
)
11-11-2003 | 02:25 PM
#20
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Joined: Aug 2001
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From: Wrightwood, CA
Steve,
Is your CEL problem related to the valve guide wear (i.e. high oil consumption), or is it something else? What is your consumption rate, anyway? I, too, am dreading the day when my light comes on. My consumption rate isn't the best right now so I now it's a matter of time before the CEL shows its ugly face.
Rich
Is your CEL problem related to the valve guide wear (i.e. high oil consumption), or is it something else? What is your consumption rate, anyway? I, too, am dreading the day when my light comes on. My consumption rate isn't the best right now so I now it's a matter of time before the CEL shows its ugly face.
Rich
11-11-2003 | 02:26 PM
#21
Race Director
Joined: Sep 2002
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Hi Steve,
Greg speaks words of wisdom. Unless you KNOW you will keep the car forever, you WILL have to spend the money to get this fixed (or discount the car by the same amount at sale time). So, the only real question is, do you fix it for yourself, or for the next owner?
It's like when you move, you fix the house up for sale, and then wonder why the heck you didn't fix/upgrade all those things for yourself.
Good luck,
Greg speaks words of wisdom. Unless you KNOW you will keep the car forever, you WILL have to spend the money to get this fixed (or discount the car by the same amount at sale time). So, the only real question is, do you fix it for yourself, or for the next owner?
It's like when you move, you fix the house up for sale, and then wonder why the heck you didn't fix/upgrade all those things for yourself.
Good luck,
11-11-2003 | 02:49 PM
#23
Racer
Joined: Jul 2003
Posts: 422
Likes: 1
From: E Cobb (N Atlanta) GA
After reading all the threads on the subject over the last several months (yes, I, too have the CEL illness), the consensus seems to support that the secondary air failure is due to the secondary air ports being clogged. This is not necessarily caused by increased oil consumption but possibly by driving style (ie. lugging in traffic) or use of inferior fuel.
I get over 2000 miles between quarts of oil, but have been victimized by the occational traffic jam and rare tank of off-brand gas (Chevron is used almost exclusively).
I can't know how concientious the previous owner was on these issues either.
Point is, the secondary air CEL can be cured without a valve/guide replacement. But since you've got to remove the heads to clean the clogged ports, you might as well do the valve job anyway.
If anyone has found a way to clear the ports without removing the heads, SPEAK UP!
One thread had an entry from a guy who's mechanic removed the exhaust manifold and cleaned the ports with a wire and some sort of solvent.
How about dumping (or spraying) something like Gumout in the secondary air pump inlet to clean the plumbing, like we used to do with carbeurators?
Actually, removing the bulb is not a bad solution. The vast majority of issues that could trip the CEL are emissions related, not mechanically threatening. Heck, what did we do to diagnose problems before OBDII?
JC
I get over 2000 miles between quarts of oil, but have been victimized by the occational traffic jam and rare tank of off-brand gas (Chevron is used almost exclusively).
I can't know how concientious the previous owner was on these issues either.
Point is, the secondary air CEL can be cured without a valve/guide replacement. But since you've got to remove the heads to clean the clogged ports, you might as well do the valve job anyway.
If anyone has found a way to clear the ports without removing the heads, SPEAK UP!
One thread had an entry from a guy who's mechanic removed the exhaust manifold and cleaned the ports with a wire and some sort of solvent.
How about dumping (or spraying) something like Gumout in the secondary air pump inlet to clean the plumbing, like we used to do with carbeurators?
Actually, removing the bulb is not a bad solution. The vast majority of issues that could trip the CEL are emissions related, not mechanically threatening. Heck, what did we do to diagnose problems before OBDII?
JC
11-11-2003 | 04:31 PM
#25
Instructor
Joined: Feb 2003
Posts: 193
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From: Woodinville WA
Some of you have misunderstood the implications of clearing the check engine light and then going for an emissions test. Most states now connect to the OBD2 connector and scan for two conditions: 1) No fault codes present. and 2) a complete "drive cycle".
If you clear the codes you will be ok with number 1) but will fail because you have not completed a drive cycle and your vehicle is thus "not ready".
The drive cycle requirements are pretty extensive and if you do not follow the exact procedure will typically require 2-3 days of driving and at least two cold starts.
If your check engine light comes back on after one day, you are unlikely to ever pass emissions unless you get lucky and have it checked after your computer reports "ready" but before it detects a fault.
If you clear the codes you will be ok with number 1) but will fail because you have not completed a drive cycle and your vehicle is thus "not ready".
The drive cycle requirements are pretty extensive and if you do not follow the exact procedure will typically require 2-3 days of driving and at least two cold starts.
If your check engine light comes back on after one day, you are unlikely to ever pass emissions unless you get lucky and have it checked after your computer reports "ready" but before it detects a fault.
11-11-2003 | 04:45 PM
#26
Racer
Joined: Jul 2003
Posts: 422
Likes: 1
From: E Cobb (N Atlanta) GA
As written in detail in other threads, I've had success resetting the code, running through the detailed factory recommended readiness cycle (which takes less than 1/2 hour) and driving directly to the emissions check station.
We'll see how it goes again next year. In the meantime, may be pulling the bulb and periodically taking a code readout to be sure nothing "serious" is wrong.
We'll see how it goes again next year. In the meantime, may be pulling the bulb and periodically taking a code readout to be sure nothing "serious" is wrong.
11-11-2003 | 04:47 PM
#27
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From: North bay area
>the consensus seems to support that the secondary air failure is due to the secondary air ports being clogged. This is not necessarily caused by increased oil consumption but possibly by driving style (ie. lugging in traffic) or use of inferior fuel.
That's one possibility - just look at the inside of the ISV for an idea of how dirty things get. The other is that valve guides are worn - in which case you'll have a problem regardless of how you drive or how many times you dump gallons of techron in the tank. My car had the problem before I bought it, the previous owner shelved $4500 for a valve job and, pissed off, sold it. The CEL has not come back since. Better him than me ;-)
Good point about fixing it for yourself or for the next guy. If it were me and I knew it wasn't the valves, I would not bother fixing it. If on the other hand I was told the valve guides were worn, I would. I understand that people in california or other states that check do not have that luxury though ! Smog checks suck - that, registration fees and real estate price are a big part of me moving from california to Florida last year ! If I still ahd my old Sc i could even put SSI headers now, rats !!!
That's one possibility - just look at the inside of the ISV for an idea of how dirty things get. The other is that valve guides are worn - in which case you'll have a problem regardless of how you drive or how many times you dump gallons of techron in the tank. My car had the problem before I bought it, the previous owner shelved $4500 for a valve job and, pissed off, sold it. The CEL has not come back since. Better him than me ;-)
Good point about fixing it for yourself or for the next guy. If it were me and I knew it wasn't the valves, I would not bother fixing it. If on the other hand I was told the valve guides were worn, I would. I understand that people in california or other states that check do not have that luxury though ! Smog checks suck - that, registration fees and real estate price are a big part of me moving from california to Florida last year ! If I still ahd my old Sc i could even put SSI headers now, rats !!!
11-11-2003 | 04:48 PM
#28
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From: Orange County, CA
I recently had the Check Engine Light cleared at a local independent and immediately drove over (3 Miles) and got smog checked and it passed on the first try.
Therefore the drive cycle requirement is either not checked in Cali OR it cycled properly on the ride over. I am not sure which, but I can only tell you how it happened for me.
Therefore the drive cycle requirement is either not checked in Cali OR it cycled properly on the ride over. I am not sure which, but I can only tell you how it happened for me.
11-11-2003 | 04:57 PM
#29
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From: Moraga, California
That was the beauty of Mike's solution. It was going to fool the OBD into thinking the air injection was working.
Rich - The valve job solved the CEL problem and my car uses no oil to boot.
I didn't have the work done, the previous owner did. But he told me it was definitely a secondary air problem, not an oil consumption problem. The invoice says "Valve job due to carbon build up. Porsche to pay for half of labor and all of parts" (which included a new DMF).
On another note - I did get some CELs showing random misfires recently. I cleaned my ISV (which didn't look that dirty to me) and have had no problems since.
Greg H.
Rich - The valve job solved the CEL problem and my car uses no oil to boot.
I didn't have the work done, the previous owner did. But he told me it was definitely a secondary air problem, not an oil consumption problem. The invoice says "Valve job due to carbon build up. Porsche to pay for half of labor and all of parts" (which included a new DMF).
On another note - I did get some CELs showing random misfires recently. I cleaned my ISV (which didn't look that dirty to me) and have had no problems since.
Greg H.
