dallasboats

My car went into the shop and indicated a failed cam sensor. The code was cleared and I went on my way. I then had the car at an indy shop that replaced plugs and code 1531 popped up on their generic tool. They think it's the actuator for the cam variable system. My car is a '99. Could this be the same code or problem and the generic tool is just not reporting correctly? Thanks for your thoughts............

Loren

P1531 Camshaft Adjustment, Bank 1
Actuator triggered, no active position.
Potential causes:
- Open circuit in triggering wire.
- Open circuit in B+ supply.
- Actuator faulty.

99firehawk

on a 99 thats a pretty invasive procedure, make sure they know what they are doing before you authorize the work. real easy to screw up.....................

Paul Conquest

I picked up a 1999 996 with 100,000 miles on it for a track car, and it had the same code. I changed the cam sensor, but the code came right back. I had a bunch of other intermittent codes caused by vacuum leaks and a bad coil pack, so I was getting multiple codes. When the other issues were all corrected, the cam adjustment code kept recurring. In the end, I found that cam timing was way off on one bank. Retiming the cams corrected the problem.

Timing cams on is a pretty involved proceedure requiring some rather expensive tools to hold the crank and cams in perfect relation to one another while the cam gear is adjusted. If you also have to remove the actuators, the cams will have to come right out which involves more jigs to hold the cams in place when the cam covers are removed (half of each cam journal is an integral part of the cam cover casting so you need the proper tools to avoid damaging the cam cover).

You can check the cam timing without removing the cam covers (or exhaust system, chain tensioners, oil pumps, etc.) which would save a ton of work if one or both banks are not actually out of time. The proceedure is to lock the crank at TDC, remove the inspection plugs on the end of all 4 cams and insert the timing tool. The Porsche tool is expensive but you can buy a knock-off tool made by Sir Tools (p/n P253) for under $200 that works just fine, and which Pelican sells as well. One bank should be in perfect time, the other 180 degrees out (in perfect time if you rotate the engine 180 degrees and lock the crank again). Now that I've done it once and know what to look for, I think I could probably check the cam timing in 2-3 hours and $22 worth of cam end plugs from Pelican (the car has 6 but you really only need to remove 4 to check the timing). Find a good shop that knows what they are looking for and they can potentially save you a ton of dough.

dallasboats

Thanks for the input. Hopefully I'll know more on Monday. I just think it's odd that it showed the sensor and now it may be showing something different.

Tbred911

my car had this code as well... but after driving for a day it went off... then the CEL came back two weeks later and same code... again I drove for 1-2 days and the CEL went off again... is it possible something is "sticking" intermittently and correcting itself and when it sticks it causes a CEL in these situations?

99firehawk

I would try an oil chnage with some additive and see what happens
sounds like a sticky acuatotr

Tbred911

funny you mention that... the 2nd time the CEL lit up the car had sat for about a week so that may be it... in any case I"m running 0W40 mobil 1 and the CEL hasn't come on again...

my friend had this as well except he was getting a flat spot in power between 5500-6500 rpm and it was very noticeable...no power loss in my case... not yet anyways...

dallasboats

I'm getting the flat spot at the range your freinds car was, what did he do and how was it resolved. I'm on the thicker oil now but was going to switch back to the 0w and change the sensor............... Hmmmm...

99firehawk

the sensor isnt that easy to change you need to pull the cams inorder to change it

1999Porsche911

The cam sensor is easy to change and is external to the engine. It is not likely the cause of your problem as it only reporting a problem. You wouldn't throw out your home smoke detector just because it propely reported that there was a fire, would you?

Tbred911

all I know is he changed the cam sensor and that is not a small job... probably 7 hours labour??

as far as my car goes the CEL didn't come on again so it's probably an intermittent stick or electrical problem... the last two times it came on it went off within a day of driving and no power loss....

now if your feeling the power loss it's definitely time to replace the sensor.. I wish I could tell you more about this problem and what it means but your best bet is to find a shop that has done this and is intimately familiar with the symptoms and causes ...

1999Porsche911

Replacing the sensor is only about an hour job, with smoke and coffee break. He may have replaced the actuator for you which is more involved and you must enter the engine to do so.

Tbred911

thx for correcting me there... actuator vs. sensor... GOT IT! big difference... in dallasboats case it sounds like the actuator needs replacement since he is experiencing power loss... I was speaking to my mechanic today and he has seen this problem on MY 2002 996s... it's not just common to 99's...

99firehawk

2002 996 is about an hour job to change the acuator, vario plus cars are really easy
its the 3.4 cars that you have to pull the cams