cam shaft deviation 986 - 986 Forum - The Community for Porsche Boxster & Cayman Owners

barthol · 01-15-2016, 08:58 AM

Hi Forum

I have previous considered changing my IMS just due to the fact that the car has doe 150000km now
it is a 97 2,5 ltr boxster.
somewhere i read that before changing anything I should check the cam shaft deviation

today I connected a durametric v1.0 to the car and the live values from the car actually only contained Deviation for cam shaft 1 ( no 2 was simply not available???)
at Idle it showed steady -6.

is it correct that I only can see no1 and is -6 ok?
how much is it supposed to move and at what RPM?

BR
Barthol

jb92563 · 01-15-2016, 10:25 AM

You have 2 cam shafts so you should have 2 readings.

Perhaps V1 of Durametric is very limited in its reporting abilities.

Even the Chinese Durametric knock offs for $20 are using version 5 and
they do read both cams.

I have read that up to -6 is within spec. Outside of that and it will need some attention.

Normally you want slow changes in that reading as rapid changes indicates an impending failure.

I dont recall what the fix is to bring the deviation closer to zero. Chain Ramps? Chain tensioner?

I hope some others can fill in the info gaps for you.

My own 2001 S is also slightly either side of -6 deviation on one bank and around -4.5 on the other.

JFP in PA · 01-15-2016, 11:36 AM

Quote:

Originally Posted by barthol

Hi Forum

I have previous considered changing my IMS just due to the fact that the car has doe 150000km now
it is a 97 2,5 ltr boxster.
somewhere i read that before changing anything I should check the cam shaft deviation

today I connected a durametric v1.0 to the car and the live values from the car actually only contained Deviation for cam shaft 1 ( no 2 was simply not available???)
at Idle it showed steady -6.

is it correct that I only can see no1 and is -6 ok?
how much is it supposed to move and at what RPM?

BR
Barthol

Early ROW cars only reported one cam value as they used a different senor array.

In any case, your one cam is already at the limit value (assuming you drove the car around for at least 20 min. before checking as you will get errant values if you do not). If the value is real, you probably need to update the small tensioner paddles between the cams on your five chain motor.

I would also seriously plan on updating both your Durametric cable and software as the version you are on is woefully out of date (current version is 6.5.1.7).

barthol · 01-15-2016, 11:45 AM

hi

The car was definitely cold
it is stored in the garage and just had it idle for 10 minutes.

I guess that i will have to wait until I can drive it :-)

will the number change with increased rpm , and if yes is it gradually like the ignition advance

br
barthol

JFP in PA · 01-15-2016, 12:23 PM

You need to run it until it is fully warmed up and at road speeds for at least 20 min. before even looking at it. We get cars in all the time with claims of wild cam deviation values; we warm them up and they turn out to be fine.

Steve Tinker · 01-15-2016, 12:26 PM

barthol.....
1) The deviation value won't change - it remains steady regardless of engine revs.
2) Engine temps should be as per JFP says above - I use the oil temp on the Durametric to indicate +/- 80 deg C when I take the reading.
3) ROW cars like yours & mine only read camshaft #one deviations - don't ask why ???

barthol · 01-15-2016, 10:05 PM

Hi Steve,

I see that you have the LN bearing,
Is it just the Ceramic bearing , and did you install it yourself?

BR
Barthol

Steve Tinker · 01-16-2016, 01:54 PM

Yes I have a relatively early dual row bearing in my 2001 car, though looking at the build date (Feb 2001) the engine was probably built in 2000 before being shipped to Finland for final assembly.
I had the LN ceramic dual row bearing installed in 2010 which was probably one of the first in Australia I think - not many indies had even heard of IMS problems here then. I had it installed in Brisbane as there was (and still is) a question mark on my capabilities of removing the gearbox & installing the bearing on my own. Old age I guess, as I would have relished the challenge 20 years ago....

philou320 · 01-17-2016, 12:50 AM

A lot of car run with -6, it seems to be a very common value, if you want to improve it, change the
pads between the variocams you will gain and will run around -3.

barthol · 03-16-2016, 05:05 AM

Hi again,

Took the car out for a longer drive today with the durametric connected, and logged the date for the entire trip. Oil temp went to 79 deg c and the camshaft deviation never changed . It was -6.0 constantly .

I know this is the limit according to the manual. But what does it actually mean and indicate.
What would be the benefit of " correcting" it ( and how)
Car is running fine without any "strange " sounds
Only issue is that starting it after som days standing there will be a 2-4 sec rattle ( guess that it must be the chain?

BR
Kim

Steve Tinker · 03-16-2016, 01:53 PM

Kim,
Now you have a baseline on the deviation (-6 deg), I would just monitor it over the summer and check again before storage for your Danish winter sets in. To be really clinical, remove the sump and check for plastic debris from worn tensioners.
If the deviation numbers don't change & the sump is relatively clean, just accept it - after all, the deviations are at maximum, not over.

As for the chain rattle, you may find replacing the 3 x chain tensioners will improve the noise substantially - at least it did on my engine @ 105,000 km. The tensioners can be fitted without removing the engine, but you have to lock the crank & cams before removing each tensioner. About a 2 hour job total, and not too expensive for the parts.

barthol · 03-16-2016, 09:55 PM

Hi Steve,

Thanks a lot:-)
When you suggest changing the tensioneres I guess that you are "only" talking about the tensioners and not about the plastic pads, right?
Would I need to lock all 4 camshafts for changing the tensioners in order to be sure of the cams/ chains to stay in the right place?

Will changing the pads require the engine to be removed?

BR
Kim

Steve Tinker · 03-17-2016, 12:27 AM

The tensioner replacement is only to improve the startup "rattle" that you are experiencing. It won't (shouldn't) alter your camshaft deviations. You need to lock the crank and 1 camshaft relative to which tensioner you are replacing. Use the search function for details.

The plastic pad replacement is a whole different story which, (I believe), can be done with the engine in situ, but most experienced people say its quicker & easier by removing the engine.

PatM · 03-17-2016, 03:44 AM

Sorry to change the tread.
On the road to the 12 hours of Sebring.
Check engine light came on. 700 miles from home...
Engine sounds and runs great as usual normal engine coolant temp. Oil full and clean.
Anybody going to be at the Porsche Corral with a scan tool that can read my 2000 s Box
Maybe give me the name of an independent in the area. In Jax now heading to Lake Wales shortly.
Thanks for any info.
Patrick Morrison
2000 S

steved0x · 03-17-2016, 05:06 AM

Any autozone or auto parts store can read the code for you, and then you can look it up here or post the code and we can tell you what it means.

If you are in Jax, heading down south, are you taking 301 to cut across to 75 or are you going down past Daytona and then cutting down? i'm in Lake City, 1 hour west of Jax, but it is not on your way. An auto parts store is your best bet, or if you wait until you get down there, somebody will have an OBD-II reader.

Steve