Help Diagnosing Slew of CEL Codes

[-tWv-]

Originally Posted by blue62

when you get an O2 sensor aging code it is telling you that the sensor is responding slowly. Which is what they start to do as they get get older. eventually their response gets slow enough that the DME throws the code. Unlikely that the cats are causing the problem.

If the O2 sensors are new or recently replaced and you are getting O2 sensor aging codes.
I think there are other issues in play.
Were the codes present before they were replaced?
If so were the codes erased after they were replaced?
If they were replaced recently are you positive they are the right ones for the car.
If they were other than Bosch or Porsche (relabeled Bosch) in my mind things get iffy.
Is all the wiring to them and from them to the DME sound?
Are the connections sound?

I would fix the timing issue first.
In fact if it was me I would not drive or even start the car until the cam timing issue was resolved.
Then I would erase all codes and go from there. But that's me.

Still waiting for my BIL to send all the maintenance records but they put a ton of work into the car over the past few years and as far as I’m aware all parts were OEM. I don’t believe the codes were present prior to replacement, it was more of a preventative maintenance thing at that point but I’ll confirm.

The car has been driven a decent amount since the CEL came on with no major issues, but I’m not sure if the cam timing code was present initially. Definitely going to get the timing issue resolved first like you said and then start diagnosing everything else.

Is there any chance this could be a bad camshaft position sensor? Or does the code I have specifically relate to physical timing being off?

[blue62]

Originally Posted by -tWv-

Still waiting for my BIL to send all the maintenance records but they put a ton of work into the car over the past few years and as far as I’m aware all parts were OEM. I don’t believe the codes were present prior to replacement, it was more of a preventative maintenance thing at that point but I’ll confirm.

The car has been driven a decent amount since the CEL came on with no major issues, but I’m not sure if the cam timing code was present initially. Definitely going to get the timing issue resolved first like you said and then start diagnosing everything else.

Is there any chance this could be a bad camshaft position sensor? Or does the code I have specifically relate to physical timing being off?

I am not familiar with your ICARSOFT scanner brand.
But OBDII was standardized in 1996 so you don't need priority brand scanners to read OBDII codes.
Checking the codes with another scanner to prove your cam timing codes and other codes would not hurt.
Especially if the software is in the more common "P" code format.

Yes there is a possibility that the cam position sensor could be bad.
But I don' like to just change parts without confirmation that they are bad.

What I would do is have the codes read with a scanner that uses the more common "P" code format. Because that is what "I" am familiar with.
So I would have more confidence in my diagnosis.
Then if I got the cam timing code again I would check the timing by aliening the manufactures timing marks for the crank and camshafts. That way I would have physical proof of correct or incorrect crankshaft and camshaft timing.

If all timing marks fell in spec. then I would be looking at things like the cam and crank position sensors.

Setting up the timing marks so you can check them is a little bit of work but I think the only cash outlay is for the plastic plugs that you have to remove to see the timing marks.

[-tWv-]

Originally Posted by blue62

I am not familiar with your ICARSOFT scanner brand.
But OBDII was standardized in 1996 so you don't need priority brand scanners to read OBDII codes.
Checking the codes with another scanner to prove your cam timing codes and other codes would not hurt.
Especially if the software is in the more common "P" code format.

Yes there is a possibility that the cam position sensor could be bad.
But I don' like to just change parts without confirmation that they are bad.

What I would do is have the codes read with a scanner that uses the more common "P" code format. Because that is what "I" am familiar with.
So I would have more confidence in my diagnosis.
Then if I got the cam timing code again I would check the timing by aliening the manufactures timing marks for the crank and camshafts. That way I would have physical proof of correct or incorrect crankshaft and camshaft timing.

If all timing marks fell in spec. then I would be looking at things like the cam and crank position sensors.

Setting up the timing marks so you can check them is a little bit of work but I think the only cash outlay is for the plastic plugs that you have to remove to see the timing marks.

Thanks for the reply. Although this car is intended to be a project car, engine timing is a bit outside my wheelhouse. I am also a bit impatient and want to enjoy the summer weather with my new Boxster!

Have an appointment with a local mechanic on Wednesday to get a diagnosis. I’ll definitely report back as we make progress.

[blue62]

Originally Posted by -tWv-

Thanks for the reply. Although this car is intended to be a project car, engine timing is a bit outside my wheelhouse. I am also a bit impatient and want to enjoy the summer weather with my new Boxster!

Have an appointment with a local mechanic on Wednesday to get a diagnosis. I’ll definitely report back as we make progress.

Hope I have helped in some small way.
Yes do keep us posted.
Hope things turn out well for you.

[-tWv-]

Originally Posted by blue62

Hope I have helped in some small way.
Yes do keep us posted.
Hope things turn out well for you.

Originally Posted by blue62

Hope I have helped in some small way.
Yes do keep us posted.
Hope things turn out well for you.

So got the report back from the shop today. They took a look at the timing and everything looked good there from a mechanical perspective. Current diagnosis is there is an issue with the variable valve timing, specifically with the timing chain tensioner/actuator. Unfortunately that little part is incredibly expensive ($1300 on pelican parts) and about 10 hours of labor to get it put in. Total bill is just over $3k .....

I’m going to go through with the repair because his diagnosis matches with the symptoms I’m seeing. There are misfires on all 3 cylinders (1-3) but the engine starts and runs ok so not likely a spark plug or coil issue. It only really feels like it’s struggling in certain gears/rev ranges. Seems like the one cylinder bank is advancing/retarding timing without the other and causing it to run very poorly/low on power.

It’ll be done in the next couple weeks and I’ll report back. Really hoping this fixes the issue as I want to get out for a real drive on the Blue Ridge Parkway!

[-tWv-]

Originally Posted by blue62

Hope I have helped in some small way.
Yes do keep us posted.
Hope things turn out well for you.

Got the report back from the shop today. Looks like everything looks good from a mechanical perspective on the timing. Unfortunately, that means there’s some sort of deeper issue and the mechanic thinks it has to be the timing chain actuator/tensioner. This part alone is over $1200 and it’s about 10 hours of labor to put it in. Bill just over $3k ....

I’m going to go ahead with it because his analysis makes sense from what I’m feeling with the car. It starts and drives just fine so I don’t think I’m getting a consistent misfire. It seems like it occurs in specific gears/rev ranges and just feels like the car is very low on power. My assumption is this is occurring due to one cylinder bank advancing/retarding valve timing and the other not acting similarly. He’s going to work through getting to the cams and will report if there’s something simpler going on (ex: the plastic guides on the tensioner failed instead of the whole part).

Hopefully this is it and I can get out on the Blue Ridge Parkway in the next couple weeks. Wish me luck.

[blue62]

Originally Posted by -tWv-

Got the report back from the shop today. Looks like everything looks good from a mechanical perspective on the timing. Unfortunately, that means there’s some sort of deeper issue and the mechanic thinks it has to be the timing chain actuator/tensioner. Unfortunately this part alone is over $1200 and it’s about 10 hours of labor to put it in. Bill just over $3k ....

I’m going to go ahead with it because his analysis makes sense from what I’m feeling with the car. It starts and drives just fine so I don’t think I’m getting a consistent misfire. It seems like it occurs in specific gears/rev ranges and just feels like the car is very low on power. My assumption is this is occurring due to one cylinder bank advancing/retarding valve timing and the other not acting similarly. He’s going to work through getting to the cams and will report if there’s something simpler going on (ex: the plastic guides on the tensioner failed instead of the whole part).

Hopefully this is it and I can get out on the Blue Ridge Parkway in the next couple weeks. Wish me luck.

When your mechanic is talking about the timing chain tensioner/actuator (so you and I are on the same page). I am going to assume he means the Variocam actuators.
Did he test the function of the actuator??
I can test the function of mine with my Foxwell scanner.
I run the RPM's up to I think it is 1500 RPM and I watch the exhaust cams jump in advance by 25 degrees.
Or I go to the testing functions and actuate them with the scanner and The engine responds differently so I know if they are working or not.
Your mechanic should be able to verify if the actuators are functioning or not

As you stated:
There are wear pads on the actuators so if they are worn out the actuators can be fine and still not advance the cams properly.
Wear pads are cheap actuators expensive.

Hope this info is of some help.
Keep us posted with the out come.

[-tWv-]

Originally Posted by blue62

When your mechanic is talking about the timing chain tensioner/actuator (so you and I are on the same page). I am going to assume he means the Variocam actuators.
Did he test the function of the actuator??
I can test the function of mine with my Foxwell scanner.
I run the RPM's up to I think it is 1500 RPM and I watch the exhaust cams jump in advance by 25 degrees.
Or I go to the testing functions and actuate them with the scanner and The engine responds differently so I know if they are working or not.
Your mechanic should be able to verify if the actuators are functioning or not

As you stated:
There are wear pads on the actuators so if they are worn out the actuators can be fine and still not advance the cams properly.
Wear pads are cheap actuators expensive.

Hope this info is of some help.
Keep us posted with the out come.

You are correct, talking about the VarioCam actuator. He’s going to test the actuator function today and confirm there’s a cam position mismatch before moving further.