Optical TDI

Due to knocking noise on cold start up, the dealer is replacing both chain adjusters under CPO. If there anything else I should have them do while they are doing these? I'm not sure if this is one of those "while your doing this, do that" type of situation as I don't know what's involved.

ivangene

do you mean chain rail guides or chain actuators?

things to check....how much longer you have the CPO...that's about it IMO

15psi

This car only has 20K? If you really need new tensioners, I'd be looking at the IMS also. I'd be very very concerned about corrosion from water & acid in the oil while this engine sat for extended periods. There are 996s with 140k+ with original tensioners and no start up noise. (and original IMS)

At 2500 miles per year, it possibly sat alot and has a different set of concerns than those of us with 10k/year.

ivangene

as long as he is covered by cpo... why touch it ?

and Porsche sure as h&ll aint gonna pay to replace a part because it "might fail"
your only option is to smile, drink the free coffee and ask them what time you can pick up your car.

Drive it with a big ole smile

rb101

I would be concerned that the tensioners need to be replaced at 20K. How much longer is the CPO warranty?

Rick
99 996C4
87 944S

Optical TDI

CPO is in effect until November of 2011, so I have 1 yr and 4 months left. They said chain adjusters, but are going off of my recording of the sound. Parts are on order, so I'll know for sure when they finish the work.

Does the tranny get pulled for this job? If so, I'll look at the clutch. If not, then I'll wait just before CPO expires to do the clutch and IMS bearing.

The car had 13k on it last November and now about 21k. So I'm hoping that driving it more during the CPO period will surface more issues since it wasn't driven much prior.

Macster

Generally in these situations dealers don't have the freedom to throw new parts at the engine "while there".

Porsche is -- my second hand info -- pretty specific about what it will ok to replace or not replace. Anything obviously wrong or made wrong or compromised by some internal problem will be replaced.

But for instance if a broken valve spring replaced Porsche would not authorize the dealer to examine the bearings and possibly replace those as well absent any signs or symptoms pointing to the need to check the bearings.

However, if chain tensioners being replaced I'd want to be sure all chain guides were in good shape. If tensioners going bad the guides could have suffered some accelerated wear/tear as a direct result from any tensioner problems.

Also, I'd be very sure to inspect the driving and driven sprocket teeth for any wear and have these replaced.

Plus any VarioCam actuator hardware that might have been subject to more wear/tear from failing tensioners.

Sincerely,

Macster.

ivangene

well "chain adjusters" just doenst ring a bell...

I find it highly unlikely the rail guids are shot. Highly likely the tensioners are scored and not working and somewhat unlikely the actuators are out... is your car 3.4 or 3.6? (IIRC 02' is a 3.4)

so if it is tensioners they wont pull anything BUT the tensioners... there are no other parts to pull. If its actuators... woo doggie, bigger job... cam covers and cams off, and if its guides the same thing as the actuators... big job, going in deep in the heads (no head removal, but cams out)

make sure they look at the button on the IMS chain arm... its a silly plastic thing and has been know to frag.
(the black "button" on the top of the LNE part can be seen by looking directly into the tensioner hole for the IMS chain - staright up, you can feel it with your finger and use light to check for any cracks)

Optical TDI

My point was that I would pay for any parts that have been known to fail while the labor was being done. I certainly wouldn't expect Porsche to pay for a non-failed part.

Optical TDI

It's a 3.6. From what the service writer said, it's about a 3-4 hour job. I'll talk to the tech when I take the car back in when the parts arrive.

I'm surprised they are replacing these parts based on my recording of the start up noise, but am glad the dealer is good about addressing issues under the CPO.

2K7TTMIA

I would say bring the tech some bagels or donuts and coffee and he might do you a solid and go over any other items that could be R &R under CPO now or in the future...

ivangene

3-4 hours...?
BOTH chain adjusters?

wierd.
so you have 3 "chain adjusters
996.105.188.00
996.105.180.55 of 56
996.105.186.00

that's the only thing I can think of you could do in 3-4 hours... if you take lots of coffee breaks?

Macster

Well, over a large population of vehicles any of the parts exposed during this repair have been known to fail. Fortunately not very often. Not often enough to warrant replacing them as a precaution. There's a slight risk too replacing an existing part with a new one the new part could prove to be defective. The parts in the engine that are not acting up at least have been used enough that any chance a new part was bad has been eliminated. There's value in that fact.

Absent any signs of distress at the cam lobes (pitting perhaps) and absent any signs of any collateral damage from the failing chain tensioners -- such as the sprockets on the camshafts as I mentioned in previous post -- just taking care of the tensioners and the guides sufficient.

Of course, any signs of any oil leaks, seepages say from a spark plug tube, or a cam cover plug, etc., should be addressed. Not even sure I'd replace the AOS.

Sincerely,

Macster.

ivangene

I dont think the cam covers are coming off in 3-4 hours so there is not going to be any cam lobe inspection....

I am really curious what they are replacing and what caused them to think it needed to be replaced

soverystout

+1000 on that.

My CPO expires in 2/2011. I am trying to drive it as much as possible.
I've had the Oil pressure sensor and the RMS replaced to date. I had them throw in a clutch kit with the RMS that I bought from Suset.

My starter sounds terribly weak during a warm start up. I guess I have to wait for it to fail (and leave me stranded) before they will do anything.