Running rough

[Flat6speed]

My 2000 2.7 manual is running rough.  Hooked up my Durametric software and here is what I found. I cant imagine all three banks going bad at the same time.  I plan to pull the plugs, replace the secondary O2 sensors, oil change and a lot of other things that are due.  I did order a replacement spark plug coil in case that is the issue.  What are your thoughts?

[Loren]

Clear the codes take the car for a short drive (at least 10 minutes) - then recheck the fault codes.

[txhokie4life]

One of the common things of all 3 cylinders is the cam.

 

the chain could have jumped a tooth, the cam sprocket lock bolts slip, or the chain tensioner is weak or failing, or the vario cam tensioner is failing, but I don’t think that would give you the misfire codes.

 

I can’t remember if this is a 5 chain engine, but the cam sprocket for one chain could have slipped on the ims.

 

it could also be a failed/failing ims bearing.

 

I believe it is possible to have a AOS fail and only dump oil on one side of the intakes, I forget where the AOS feeds back into the intake.  You would have a good bit of oily blue smoke 

 

I would check compression on cylinders 4,5,6 

 

I think you can check the cam timing for the two banks and see what the delta is with the durametric

 

mike

Edited November 30, 2021 by txhokie4life

[Flat6speed]

I did clear the codes and drive car briefly and what's above is what I got for codes.  The CEL was flashing.  IMS bearing was replaced with LN Engineering bearing about 50K ago. Its running rough and has lost some power.  I'm about to pull the plugs.  Now I'm thinking you might be right about the cam tensioner jumping a tooth.  How much work is this?  I'm fairly handy but I've never torn into this engine before.  

[mikefocke]

The LN bearing is probably not one of the life-of-the-car type ("The Solution") but has a replacement interval recommended. So just because it has been replaced don't assume it is good.

 

Not suggesting that is the cause....

[txhokie4life]

8 hours ago, Flat6speed said:

I did clear the codes and drive car briefly and what's above is what I got for codes.  The CEL was flashing.  IMS bearing was replaced with LN Engineering bearing about 50K ago. Its running rough and has lost some power.  I'm about to pull the plugs.  Now I'm thinking you might be right about the cam tensioner jumping a tooth.  How much work is this?  I'm fairly handy but I've never torn into this engine before.  

blinking cel is definitely a bad sign

if you had the cam alignment tool

you could pop the green cam covers and check to see if the engine is still in time.

at tdc, the cam notch is vertical.

you might be able to tell without the tool, not sure.

 

if it’s not, you’ve likely bent some valves.

 

The 5 chain design had press fit gears on the IMS tube.  In some cases the gear rotated.

if the cam is out of alignment, 

fixing this depends on the root cause.

 

mike

 

mike

 

 

[JFP in PA]

18 minutes ago, txhokie4life said:

blinking cel is definitely a bad sign

if you had the cam alignment tool

you could pop the green cam covers and check to see if the engine is still in time.

at tdc, the cam notch is vertical.

you might be able to tell without the tool, not sure.

 

if it’s not, you’ve likely bent some valves.

 

The 5 chain design had press fit gears on the IMS tube.  In some cases the gear rotated.

if the cam is out of alignment, 

fixing this depends on the root cause.

 

mike

 

mike

 

 

 

Interesting thinking, but as he has the Durametric software, he could just ask it to check the cam deviation values; if they are +/- 6 degrees, he is good to go on cam timing 😉

[JFP in PA]

2 hours ago, mikefocke said:

The LN bearing is probably not one of the life-of-the-car type ("The Solution") but has a replacement interval recommended. So just because it has been replaced don't assume it is good.

 

Not suggesting that is the cause....

Realistically, LN ceramic hybrid IMS retrofits should be good out to around 75K miles.  Again, checking cam deviation values and the oil filter for metal grit being present would also confirm the IMS status.

[Flat6speed]

Well thank you for everyone's input!  I guess I will have to hook up the Durametric again.  Does anyone know how I go about checking the cam  timing? 

[JFP in PA]

23 minutes ago, Flat6speed said:

Well thank you for everyone's input!  I guess I will have to hook up the Durametric again.  Does anyone know how I go about checking the cam  timing? 

 

First, drive the car for a few min. to make sure it is fully warmed up, then follow this video:

 

How to check cam timing with the Durametric software

[Silver_TT]

Using software to check the cam timing (also called "phase position" with some VW/Audi engines) is a quick and easy way to check without even getting your hands dirty. I used this method on an Audi 2.0T last summer to save the engine before it completely destroyed the head with no warning.  Upon taking the timing cover off and seeing the timing chain "stretch" and tensioner extension (almost completely out of the housing), I could see that the software deviation value was right on the money.  The 2.0T actually has a little "peep hole" that you can use to look at the tensioner extension but I don't even bother with that and just check my deviations periodically (every oil change I check it and record it).

 

As JFP said, be sure to check on a hot engine as the value can deteriorate significantly.  On my engine it was almost a full degree with the old worn chain.... on the new chain it still differs, just not as much as one would expect.

[Flat6speed]

Thank you guys!  I will check it out and let you know what I find.

[Flat6speed]

OK, here is what I got on the cam shaft deviation.  I contacted my local indy and he said I have some serios decisions to think about if the cam has slipped a tooth.  The cost of the repair probably exceeds the value of the car especially being it needs a new top.  I'm not sure what to do.   One thing for sure is I will have a Boxster in my garage one way or another.  If I decide to unload this one then I will probably be looking at a 2005 model.  I've seen them for as little as $15K.  What are your guys thoughts? Should I save this car or should I sell it and buy a newer one?

 

[Silver_TT]

I would see if it can be saved.  If you didn't bend any valves then you can replace the chains, tensioners, and all plastic guides.  A simple compression test should answer that question I would think.

[JFP in PA]

53 minutes ago, Flat6speed said:

OK, here is what I got on the cam shaft deviation.  I contacted my local indy and he said I have some serios decisions to think about if the cam has slipped a tooth.  The cost of the repair probably exceeds the value of the car especially being it needs a new top.  I'm not sure what to do.   One thing for sure is I will have a Boxster in my garage one way or another.  If I decide to unload this one then I will probably be looking at a 2005 model.  I've seen them for as little as $15K.  What are your guys thoughts? Should I save this car or should I sell it and buy a newer one?

 

 

As yours is a five-chain engine, I would be willing to bet that the biggest part of the deviation values comes from worn chain pads located between the two cams on each head.  This is a very common problem, but fortunately the fix is cheap parts wise, but does require some labor to get at them. I don't remember how many of these we swapped out over the years, but it was quite a few.

 

 

 

[Flat6speed]

What should I see during a compression test? Does this mean dropping the motor to replace the parts?  And how do I find the part list and the cost of the parts?

[Flat6speed]

I'm guessing an oil change is first to look for metal?  

[Silver_TT]

If the valves aren't bent, when they seat they form a nice seal.  When the engine is out of the car and they are closed if you're getting a good seal you can literally do a "water test" and dump some water down in and will hold -- that's how well they seal up.  If they are bent the air (or water) will just leak right by...

 

For parts I would go to Sunset Porsche.  They are one of the largest dealers in the country and sell OE parts and have full access to Porsche (and Audi) dealer information.  That's who I used to do my timing job.  You can give them your VIN and they can tell you every part for the job.  I would do the whole thing while you're in there if you go that route -- chains, tensioners, all guides.  Doesn't make sense to do anything short of everything while you're in there (although at least with the tensioners they are serviceable outside the engine).

[Silver_TT]

21 minutes ago, Flat6speed said:

I'm guessing an oil change is first to look for metal?  

 

Or maybe bits of plastic from the pads/guides.