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991.2 coil pack issues.

deMort

Well-known member
Joined
21 Mar 2015
Messages
11,244
Bit of a heads up here ..

I did my first major with plugs on one of these a month ago .. the bolts that held in the coil packs were heavily corroded .... i cleaned them off and applied a generous amount of ally grease to the bolts .

The single bolt that retains the coil pack basically goes through a metal tube of approx 1 inch ( 2.5 cms ) .. it's here it corrodes .

Had another one in today so my second one .. 5 bolts were ok .. but no.2 coil was corroded to the point it snapped the retaining bolt off.

Coil is now corroded to the head on what's left of this bolt .. plenty of levering , penetrating oil .. heat .. you name it and i got the coil off .. the bolt however is seized in place .

Not sure its going to come out to be honest as i have this to face tomorrow .

I have some pictures which ill upload later as i left the camera at work .

In short .. it's worth getting the coils removed and the bolt greased on each one imho.

Considering this is at 4 years old .. considering out of 2 cars i have had problems with each one then i'm a little concerned atm shall we say .

This is obviously just what i've seen but as always .. i say What i have seen .

Gen 2 991 only .
 
That's both interesting and scary considering the age of the cars.

My 991.2 is just over three years old with the warranty now extended.

Do you think the warranty will cover this work when and if it becomes evident at the four year service. It seems possible that a less skilled or diligent OPC technician could run up quite a bill if he had problems removing the coil packs.

Don't suppose the OPC would be interested in an inspection and a bit of preventative maintenance at three years old under warranty to save a bigger warranty bill later.
 
DeMort, looking forward to the pictures as I might have a go with some preventative work if I can get at it OK.
9E: Sorry, but VTG? (the turbos?) plus, where about is the corrosion and would a covering of '1000 degree' copper grease be any good as protection? Thanks.
 
Don't use copper grease om aluminium, it's ally grease you need. Copper grease actually causes more corrosion on ally/steel interfaces.
 
I am somewhat surprised that you have Turbo issues as well Ken , the coils are bad enough but Turbos as well .. :eek:

Considering the age then it should be covered under warranty but it would also fall under corrosion which isn't so i can't say .

What i found out today is there is a modified cam cover and the new coil i fitted seemed to have a bolt made of different material but cant say for sure.

Either way i found it strange that Porsche UK had both the cam cover and the coils in stock .. that strikes me as they know there is a problem.

It's all guess work though so imho only .

You can see where the corrosion has caused the coil to crack ..

This car was circa 25K miles .

the bolt when removed can be covered in ally grease to prevent future problems .. that's what i have done with both of the cars i've had issues with ..

access .. hmm .. a ramp is needed and small arms unless you want to remove the rear bumper and intercoolers .


Pictures as promised ...
 

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The problem with the turbos on 991 is contamination issues that cause the shaft to have more play that it should. Vtg should always have some play in the compressor side, but we are finding lots of them have excessive play. If left results in ultimately failure and risk around that.

Been doing a lot of hybrid upgrades on the latest 991.1 and 991.2 - we are seeing a lot of this now. Certainly not as common in early vtg cars although still exists.

You got to remember a lot of these turbos are close to 6 years old (991.1)
 

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de mort that is worrying indeed

do you think there is a lot more heat from the turbo charged engine that is accelerating the corrosion? those coil packs and bolts look like the same stuff on the 997 and 991.1 so from NA engines with potentially less heat

or maybe just crap engineering and more cost cutting/mass market approach from VW, sorry Porsche.
 
maldren said:
Don't use copper grease om aluminium, it's ally grease you need. Copper grease actually causes more corrosion on ally/steel interfaces.

Ok thanks. It'll have to withstand some heat though...EDIT, just found some "1100 degree" stuff.
 
I dont think its heat related .. more the design of the coil .. the sleeve in it is bigger than the bolt .. being horizontal as well i think water is getting inside of this sleeve and staying there and so corroding it .

The snapped coil bolt was no.2 so n/s/r .. our kerbs are n/s so its common for things to corrode much more on that side due to more water there .

Simple fix is just to remove the bolt slap a load of ally grease on it and then refit .
 
...how hard would it be for Porsche to specify decent quality fasteners ? In a few more years and the inevitable service skimping as cars pass through owners hands and these are going to be a bloody expensive nightmare to sort out !
 
Curious2 said:
That's both interesting and scary considering the age of the cars.

My 991.2 is just over three years old with the warranty now extended.

Do you think the warranty will cover this work when and if it becomes evident at the four year service. It seems possible that a less skilled or diligent OPC technician could run up quite a bill if he had problems removing the coil packs.

Don't suppose the OPC would be interested in an inspection and a bit of preventative maintenance at three years old under warranty to save a bigger warranty bill later.

I had mine sorted under warranty when the car went in for its 4 year service with 20k on it. They checked first with Porsche though as couldn't change spark plugs without removing coil packs and were worried about the extra work (and cost) caused if the bolts sheared.
 

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