Code 1539

[RICK3452]

My car keeps coming up with code 1539 "99" 996. I did buy a scanner and have cleared it a few times to see if it continues, and it does. Is it a big job to replace the cam adjuster? any chance in "upsetting" something else? Thanks much...

Rick

[JimB]

Rick,

I know way more about cam adjuster problems that I want to. It was the biggest problem to overcome when I swapped a 3.6L X51 into my 99.

If your cam timing adjuster is actually bad it will be obvious. Put the car in a gear where is won't accelerate too fast. Floor it and see what happens around 5800 rpms. If your cams don't switch, you will loose 50 or 60 hp. It should be obvious.

Assuming that the car accelerates fine, you probably have a sensor problem. That's good news. There is a sensor on each side that reads a little disk on the end of one of the cams. I can't remember if it's intake or exhaust. I would guess that it is giving a bad reading. Just a guess though.

Good luck,

Jim

[RICK3452]

Jim thanks so much for the info. The car has no-loss in power and runs great except for a low-idle when hot.

Thanks again...

Rick

Rick,

I know way more about cam adjuster problems that I want to.  It was the biggest problem to overcome when I swapped a 3.6L X51 into my 99. 

If your cam timing adjuster is actually bad it will be obvious.  Put the car in a gear where is won't accelerate too fast.  Floor it and see what happens around 5800 rpms.  If your cams don't switch, you will loose 50 or 60 hp.  It should be obvious. 

Assuming that the car accelerates fine, you probably have a sensor problem.  That's good news.  There is a sensor on each side that reads a little disk on the end of one of the cams.  I can't remember if it's intake or exhaust.  I would guess that it is giving a bad reading.  Just a guess though. 

Good luck,

Jim

<{POST_SNAPBACK}>

[iflyjets4u]

I tried what you suggested, in second and third gears, but I don't feel like the "afterburners" kicked in. Is there a chance that the power change could happen smoothly?

I'm curious because I seem to have developed an oil leak on the right hand side, near where the sensor is.

Lastly, is there any other way to tell if the cam "switches"?

Thanks

[umn]

...

Lastly, is there any other way to tell if the cam "switches"?

...

Well, the proper way to do it is with a Porsche System Tester:

You let the car idle. Then you use the PST to switch the timing on one bank. The idle should change and become lumpy. You change it back, and it becomes smooth again.

Then you do the same with the other bank.

It's worth checking out, because if one bank runs on early and one on late under high load, the cylinder head can overheat. The cam position hall sensor is important in this context too, because the DME compares the signals from the crankshaft sensor and the camshaft sensors to determine if the timing is set to "early" or "late".

Cheers,

Uwe

Edited June 1, 2005 by umn