P0506 fault code (IACV) and variocam issue......

[farmer boy]

Hi all, I have recently revived my old 996 after 18 months off - it has been sat in my shed with a cover over it.  All seemed well and after a new set of plugs and coils it was running very well apart from.....

 

1.   It would not tickover after a cold start in the mornings - fine once warmed up.

2.   Tickover is a bit lumpy - not a misfire just "hunts" a bit and is not smooth - drives fine.

 

I have cleaned the throttle body, MAF and IACV valve connections which improved things a bit with a higher tickover speed of about 900 rpm.

 

I then fired up the Durametric and (after updating the software) I find the following fault code - P0506 IACV.

 

Whilst I was playing with the software I tried to start and stop the variocam actuators.  Bank one appeared to be successful resulting in a reduction in revs and very lump tickover.  Bank 2 had no effect?

 

I assume bank 2 should do the same as bank 1?

 

I am giessing that this may be (from my reading on here) a problem with the electronic control of the variocam - a solenoid of some sort. 

 

Can anyone confirm my analysis and recommend how to fix it (DIY)?

 

Thanyou in a dvance.

[JFP in PA]

Hi all, I have recently revived my old 996 after 18 months off - it has been sat in my shed with a cover over it.  All seemed well and after a new set of plugs and coils it was running very well apart from.....

 

1.   It would not tickover after a cold start in the mornings - fine once warmed up.

2.   Tickover is a bit lumpy - not a misfire just "hunts" a bit and is not smooth - drives fine.

 

I have cleaned the throttle body, MAF and IACV valve connections which improved things a bit with a higher tickover speed of about 900 rpm.

 

I then fired up the Durametric and (after updating the software) I find the following fault code - P0506 IACV.

 

Whilst I was playing with the software I tried to start and stop the variocam actuators.  Bank one appeared to be successful resulting in a reduction in revs and very lump tickover.  Bank 2 had no effect?

 

I assume bank 2 should do the same as bank 1?

 

I am giessing that this may be (from my reading on here) a problem with the electronic control of the variocam - a solenoid of some sort. 

 

Can anyone confirm my analysis and recommend how to fix it (DIY)?

 

Thanyou in a dvance.

 

P0506 indicates that the idle air control valve may be sticking, causing the engine to idle too low.  If cleaning the IAC does not improve the situation (they usually suffer from a carbon build up), replace it.

 

Early ROW 996's can only trigger one bank's VarioCam actuators using the Durametric system.

[farmer boy]

Many thanks - I have ordered a new IACV... 

 

 

 

I had a quick look at it and it was badly "carboned up" and a quick clean with brake cleaner had no real affect.

 

Regarding the variocams - "Early ROW 996's can only trigger one bank's VarioCam actuators using the Durametric system".........

 

 

I assume that the Durametric and the car is behaving correctly?  ie only 1 bank will respond to the selections in the software and the poor idle is due to the IACV? 

 

Mine is a 1998 UK 996 with the latest vesrion of the Durametric software. 

[JFP in PA]

Many thanks - I have ordered a new IACV... 

 

 

 

I had a quick look at it and it was badly "carboned up" and a quick clean with brake cleaner had no real affect.

 

Regarding the variocams - "Early ROW 996's can only trigger one bank's VarioCam actuators using the Durametric system".........

 

 

I assume that the Durametric and the car is behaving correctly?  ie only 1 bank will respond to the selections in the software and the poor idle is due to the IACV? 

 

Mine is a 1998 UK 996 with the latest vesrion of the Durametric software. 

 

For future reference, you should only use product's designed for the purpose, like MAF cleaners such as the CRC product:

 

 

A lot of brake cleaners are chlorinated, which can damage critical components in some systems.

 

The Durametric system is functioning correctly; the ROW cars use and different DME software which responds differently than that found the North American cars.

[farmer boy]

Many thanks - much appreciated.

 

The new IACV was only £60 (Bosch) so I think it was sensible to replace it.  I will buy some proper sensor cleaner asap.  :)

Edited April 17, 2015 by farmer boy

[farmer boy]

JUst to confirm that the advise from JFP was bang on and a new IAC valve has resolved all issues.  Runs lovely now - Thankyou.

[JFP in PA]

Anytime, that is what we are here for.