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Engine Problem - Misfire Cylinder 4, 5 and 6 - 997.2 (2010

calibra1010

Well-known member
Joined
4 Oct 2014
Messages
49
Hi,
I have a strange problem with my 997.2 (3.6 – 2010 model) . The car starts first time but the engine idle goes lumpy after a while on idle and at low speeds feels hesitant sometimes (noticeable). Ive scanned the car this morning using a PIWIS computer and is coming up wth a misfire on Cylinder 4, 5 and 6.

I am now scratching my head and am open to suggestions on what to do next. Could this be down to a bad O2 sensors?

Any help or advice would be much appreciated.
 
Re: Engine Problem - Misfire Cylinder 4, 5 and 6 - 997.2 (

could this be bad O2 sensors?
 
I had similar symptoms with mine (albeit I have a 997.1) and it turned out to be the camshaft solenoids.

Could be a number of things to be honest so a trip to your local Indy/OPC for a proper diagnosis would be my recommendation.

Demort is the Porsche fault finding wizard on here so he will probably be able to give better advice.

Good luck. :thumb:
 
I would get the coil packs checked out too.
 
FRZ 911 said:
I had similar symptoms with mine (albeit I have a 997.1) and it turned out to be the camshaft solenoids.

Could be a number of things to be honest so a trip to your local Indy/OPC for a proper diagnosis would be my recommendation.

Demort is the Porsche fault finding wizard on here so he will probably be able to give better advice.

Good luck. :thumb:

Yes Demont helped my out a couple of years back when I wiped out my cars settings playing with the PIWIS computer :eek:
 
I would lean towards it being the Hi lift solinoid for the tappets .. normally you have another fault code saying lambda sensors swopped but not always.

Your symptoms are similar to several members that have had this fault and indeed one i diagnosed last week at work.

The valve its self is about £100 and ill be generous and say 1 hours labour to replace .. it will take far longer for a garage to prove it than to just replace it so probably a cheaper option to replace it if only to eliminate it .

If not that .. hmm .. its something that effects every cylinder on that bank so .. air leak .. have to be pretty big and im not sure where on the mainifold would cause that but possible i guess .

Fuel pressure ? again possible if its the first bank that gets the supply but you would have issues at higher rpm .. this i assume is only upto 3k rpm and should drive fine after that .

Vario Cam .. possible again but i would expect some sort of fault code or pretty bad running .

Coils and lambda sensor are also possible but ...

I think i would start with the hi lift solinoid for that bank .


The Piwis fault turned out to be not too bad though and i remember it well :)
 
Hi Demont,

Ive had another tinker this afternoon with the PIWIS computer.

Below is the fault code results from PIWIS
http://my-star.co.uk/Photos/faultcode.JPG

Ive also read the actual values and also an O2 test (results below)

http://my-star.co.uk/Photos/o2test.JPG
http://my-star.co.uk/Photos/o2test1.JPG

Does this point towards O2 sensor or could it still be any of the others?

regards




Demort said:
I would lean towards it being the Hi lift solinoid for the tappets .. normally you have another fault code saying lambda sensors swopped but not always.

Your symptoms are similar to several members that have had this fault and indeed one i diagnosed last week at work.

The valve its self is about £100 and ill be generous and say 1 hours labour to replace .. it will take far longer for a garage to prove it than to just replace it so probably a cheaper option to replace it if only to eliminate it .

If not that .. hmm .. its something that effects every cylinder on that bank so .. air leak .. have to be pretty big and im not sure where on the mainifold would cause that but possible i guess .

Fuel pressure ? again possible if its the first bank that gets the supply but you would have issues at higher rpm .. this i assume is only upto 3k rpm and should drive fine after that .

Vario Cam .. possible again but i would expect some sort of fault code or pretty bad running .

Coils and lambda sensor are also possible but ...

I think i would start with the hi lift solinoid for that bank .


The Piwis fault turned out to be not too bad though and i remember it well :)
 
O2 sensor is possible but you have no fault code for that so its within limits and the high lift solinoid will cause mixture faults so its catch 22 as the readings your getting may well be the result of the solinoid .


You could leave the car running on idle for 20 mins .. then hold at 1500 rpm for a min and see if you get the lambda swopped fault code as that would prove it .

The only way im aware of to prove the solinoid is to swop them side to side .. the misfires will then switch to the other bank.


Downside of this is if the outer part of the solinoid is rusty as you wont get the seals you remove to reseal and will end up replaceing both sides .. it also takes a bit of labour to actually do this and as the valve is not that expensive then these days i just say replace it to prove or eliminate .

There are a few different things it could be .. im just going with what feels right to me from the description you have given .
 
Hi Demont,

Thanks for the info. Are the solenoids easily accessible (ie could DIY mechanic like me do it) or is it more involved.

also is this the solenoid
https://www.amazon.co.uk/ACTUATOR-TAPPET-Porsche-Boxster-Cayman/dp/B00UFTJ8QI

or this if the above link don't work

http://www.design911.co.uk/fu/prod127690/Porsche-Actuator-VVS-Tappet-9A110530803-9A110530802/





Demort said:
O2 sensor is possible but you have no fault code for that so its within limits and the high lift solinoid will cause mixture faults so its catch 22 as the readings your getting may well be the result of the solinoid .


You could leave the car running on idle for 20 mins .. then hold at 1500 rpm for a min and see if you get the lambda swopped fault code as that would prove it .

The only way im aware of to prove the solinoid is to swop them side to side .. the misfires will then switch to the other bank.


Downside of this is if the outer part of the solinoid is rusty as you wont get the seals you remove to reseal and will end up replaceing both sides .. it also takes a bit of labour to actually do this and as the valve is not that expensive then these days i just say replace it to prove or eliminate .

There are a few different things it could be .. im just going with what feels right to me from the description you have given .
 
Not your car but it gives you some info on replaceing it ..

http://www.pelicanparts.com/techart...09-ENGINE-Valve_Lift_Solenoid_Replacement.htm

You dont remove the items listed .. just jack it up and do from underneath .


Basically its the one in the middle of the head .

Difficult parts of the job .. access but thats not too bad .

You have to pull it hard to remove or do what i do which is move the seal back a bit then lever it out on the seal with a screwdriver.

Make sure the new one pushes fully home .. its almost a click as it seats as if it doesnt it will cause issues .

Also bear in mine that this is just my opinion .. with out the lambda code then i cant say for sure this is the fault .. its just my hunch so a garage looking at the car is Always going to be better than me giveing advise :)


Link looks like the vario cam solinoid .. you want the Hi lift or tappet solinoid .

EDIT

Actually the gen 2 looks different from the gen 1 solinoid as per this link with part number .

http://www.deroure.com/partinfo.asp?MAK=3&MDL=27&TBL=2987&SMA=0&SMO=0&ST=&SC=0&PBID=102232
 
Thank Demont,

Its worth a punt and I may have a go. I will have a look underneath my car.
On the 997.2 do heat shields or anything else need removing as I
i think the make or break is access and if anything needs removing as Cats and mufflers are nearby and i know space is tight. I have ramps so I can get the car up and have a look underneath.

Demort said:
Not your car but it gives you some info on replaceing it ..

http://www.pelicanparts.com/techart...09-ENGINE-Valve_Lift_Solenoid_Replacement.htm

You dont remove the items listed .. just jack it up and do from underneath .


Basically its the one in the middle of the head .

Difficult parts of the job .. access but thats not too bad .

You have to pull it hard to remove or do what i do which is move the seal back a bit then lever it out on the seal with a screwdriver.

Make sure the new one pushes fully home .. its almost a click as it seats as if it doesnt it will cause issues .

Also bear in mine that this is just my opinion .. with out the lambda code then i cant say for sure this is the fault .. its just my hunch so a garage looking at the car is Always going to be better than me giveing advise :)


Link looks like the vario cam solinoid .. you want the Hi lift or tappet solinoid .

EDIT

Actually the gen 2 looks different from the gen 1 solinoid as per this link with part number .

http://www.deroure.com/partinfo.asp?MAK=3&MDL=27&TBL=2987&SMA=0&SMO=0&ST=&SC=0&PBID=102232
 
Ive not yet actually done a gen 2 .. done gen 1 , 996 and 991 so far so im thinking !

The exhaust is different but as the solinoid is in the center of the head then the exhaust shouldn,t be a problem , heat shield off for the spark plugs then its x2 T30 i expect ( early cars are 4mm allen ) on the solinoid bracket , either pull the solinoid or move back the metal seal and use that as a lever point to extract it .. new one just pushes in .

Jack it up and have a look .. youll soon see if your happy to continue :)
 
Hi

Had a look and car needs the backboxes removing to access the area (same procedure as replacing spark plugs). I might leave it to my local Indi to do the work as it is outside of my skill set and abilities. Once again thank you demort for the advice


Demort said:
Ive not yet actually done a gen 2 .. done gen 1 , 996 and 991 so far so im thinking !

The exhaust is different but as the solinoid is in the center of the head then the exhaust shouldn,t be a problem , heat shield off for the spark plugs then its x2 T30 i expect ( early cars are 4mm allen ) on the solinoid bracket , either pull the solinoid or move back the metal seal and use that as a lever point to extract it .. new one just pushes in .

Jack it up and have a look .. youll soon see if your happy to continue :)
 
Demort said:
The only way im aware of to prove the solinoid is to swop them side to side .. the misfires will then switch to the other bank.

You can prove solinoids are moving at least electrically. You will need a scope and an amps clamp plus a code reader to carry out an actuator test to do it though. I proved a mates variable cam actuator was pig on his 996 Turbo about a year ago using this method. Unfortunately the equipment is beyond most DIYers
 

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