204cab

Hello to everybody

I own a 2004 997 Carrera 2, so 3,6L, which has 65000 miles on the clock and was always serviced at Porsche dealer.

So... as quite many 996 but also 997... there is an engine breakdown! Nevertheless, I was suspecting not to have the IMS broken, as the car STARTS and DRIVES. OK, it has absolutely no power at all, and it is quite difficult to go beyond 40 mph. Also, there is no brake assistance at all, but I've been told it is connected to the problem (please confirm).

To go more into detail, I had a diagnostic on it and I had error codes for misfiring on cylinders on the right bank (cylinders 4, 5 and 6) but also sometimes on some cylinders of the left bank (nevertheless not so often, whereas right bank is always misfiring). I had an error code also for the right bank camshaft position sensor.

Sparks are (almost) new. Coils have been changed by new ones (Beru). Camshaft position sensor for the right bank of cylinder has been changed by a new one.

I have also noticed an oil leak at the cylinder 4 (on the exhaust pipe).

My opinion is that it is only the timing chain
My questions are:

1/ if the car starts and drives, does it mean that the IMS is NOT broken ? I would say so... but there is also the oil leak...

2/ In case the IMS is not broken, and it is only the timing chain:
is it possible to change the timing chain on the right bank of cylinders, without removing the engine from the car ? So saving labour cost...

3/
a/ If it is only the timing chain, how many hours do you think it is needed to change it ?
b/ If the IMS is broken, how many hours are needed in average to replace it ?


Many thanks to everybody!

mattyf

Although the engines are very similar, if this is a 996 car (pre 05) you might get better responses in the 996 forum.

204cab

I confirm it is a 997, one of the first ones (October 2004).

jhbrennan

Outside the US first model year of 997 was 2004. I'm guessing he's outside US.

AP997S

Model Year 2005 997's were available in the US in August 2004.

IslandS52

I had similar no power symptoms when my throttle body failed, but I am not sure what the diagnostic codes were at the time of failure. it was a simple $300 part replacement.

mattyf

Learn something new everyday. Sorry I couldn't be more helpful, but this sounds like a job for a competent shop. I don't think you want to go taking things apart based on internet advice.

BED997

I would contact your local Porsche club and get recommendations on local shops, and get the car towed flatbed there for a diagnosis.

Not sure I would drive it if it has problems at 40 mph and brake problems (assume you mean ABS???). Good luck.

Cloudspin

I'm no expert but I'm pretty sure the earliest 997s had M96 engines. I am an near expert on M96 engine failures though and strongly recommend you not drive it anymore until you have it checked by a dealer or reputable Indy. Those engines fail for a lot of other reasons than IMS bearing issues and it can easily cost $18 - 20k. I and several (3) friends have been down that road and only 1 was IMS related.

neanicu

Ok,first of all you need to find a very good technician to run a DIAGNOSTIC,unless you're one...
A good technician will have a place to start a proper diagnostic since the DME is telling him something(it's shouting : ' Something is wrong here ! ')
There are very good and knowledgeable folks here,but it is very hard to give a diagnostic over the internet to such a complex problem you're describing... You need to find EVIDENCE to your problem,not ASSUMPTIONS!
Since you've mentioned that the car has been serviced at the dealer its entire life,you've probably built some sort of relationship with them and if there's a good technician there,he'll be able to run such a diagnostic for you. How much can they charge for diagnostic only? I would guess 300-400$...but at least you'll know your problem and can have it fixed,if worth it,at a different cheaper shop...
Just to give you an idea,misfires are the most common and complex and require a diagnostic related to IGNITION,FUEL DELIVERY,AIR(VACUUM) and MECHANICAL. If you'd like to skip straight to the MECHANICAL diagnostic,I can tell you that a compression and leak down tests are MANDATORY for complete diagnostic.
Good luck!

204cab

First, thanks to everybody for the replies!

Indeed, it is a M96.05 engine.

I fully agree with you.

I conducted a diagnostic with the durametric tool.
Yes the car has been serviced at Porsche dealers through its entire life, but I bought it some months ago only... unfortunately with the problem already present (it was an auction... I haven't been told it has an engine damage... and I can't do anything - so from this side what is done is done, I can't do anything anymore).

I gave the car to a Porsche Specialist, but in a 2-month time he has the car he hasn't done almost anything... apart telling me that there is misfiring on the right bank (something I knew already and told him when asking him to look at the car) and that he needs 15 hours to remove and strip the engine in order to see what is wrong. I refuse to go directly to this without searching a bit more for the problem, and also I can't let him do it as he hasn't been, let's say "motivated".
It seems that he didn't checked the compressions, at least he hasn't told me he did.

I personnaly am in position to check compressions, the problem is that I am too far from the car, so it is not easy for me... or otherwise I should arrange another recovery, but very very costly this time!

In fact, the only question is: does anybody know if it possible to change the right bank timing chain, without removing the engine, and about how many hours of labour are needed for this ?

Macster

Regarding the question of changing a timing chain with the engine in the car, my WAG (FWIW) is probably not.

However, I think you are jumping the gun.

The symptoms/behavior do not read like they are timing chain related.

If a chain had failed the engine wouldn't run at all. Valves and pistons would be in opposition to one another.

If a timing chain tensioner/guide had failed I think the engine would have jumped time by now and be locked up.

Unless you see signs of a timing chain housing cracked or scary metal bits in the oil filter housing oil or filter element I'd drop chain problems down the list a few positions. If you find scary metal bits in the oil/filter then almost certainly you are faced with removing the engine and tearing it down to determine its state and effect repairs if the engine is repairable.

Ignoring the chains/tensioners the symptoms/behavior can arise from a variety of things.

My first impression was the VarioCam Plus system is acting up that possibly one bank is not able to switch from low lift to high lift. Durametric might be able to provide with tests that you can use to check VarioCam Plus functionality.

There is also the issue of the plug/coil job. This has to be suspect unless you are sure the job was done right and the right parts were used. In some cases plugs and coils are touted as being identical replacements for whatever the factory has down for the engine but they are not.

Since you bought the car at an auction you know I assume nothing of its history.

How long has the car sat unused? Or used very little? Or run to death by every person who wanders onto the auction yard? (My experience with auction yards though is premium/performance car access is very restricted.)

What is the condition of the gasoline?

The fuel system overall? If the car has sat a long time the fuel system can be gummed up.

The air filter?

What condition is the battery in?

Any signs of rodent infestation.

Before I went to the expense of an engine R&R and tear down I'd want to eliminate other reasonably likely explanations for the engine's behavior.

It would appear though the mechanic you have selected is not up the challenge this car presents. Best bet is to cut your losses and find a top notch mechanic. But be prepared to pay.

204cab

What means WAG / FWIW ?

Indeed I'm going a bit too fast... but in final the Porsche Specialist wrote on the bill for the 2-hour work he did "timing chain broken on right bank of cylinders (4, 5, 6)" but OK it doesn't mean it is 100% sure that's this!

For the first part, chain fails for one side, I don't know if the engine would not run at all or not as "there is the other side" but at least there would be a very worrying noise! And of course fully agree with second part, pistons would have say "hello" to the valves. I'm wondering if the chain for the right bank can't have skip one (or maybe also two??) tooth ? So... no power, but engine still runs.

Most probably, indeed.

I have to recognize that I didn't think to check oil, neither asked the specialist... and he didn't suggest it neither.

I don't know... and don't have the car near me right now to be in position to check.

The coils have been changed first when I took the car, as I don't know whether they have been already changed or are the ones fitted at the factory when new. Of course the problem hasn't changed.

Correct, the only thing I have is the service book with Porsche dealers stamps, and corresponding dates and mileage. I have asked the Porsche dealers who carried the services but they are not allowed to at least tell me what has been done exactly, at least for the last service. I have just been informed of the dates and mileage of services done, so my service book is not a false one.

According to the low mileage accomplished since the last service and the date it has been done, I estimate the car was seating for approximately one year. Normally, but indeed I can't be 100% sure, it is not possible to run to death the car at the auction yard.

As level of gasoline was very low, I had to put some new, so unfortunately this possibiity can be rejected.

I agree, but I had and still have after replacement by a new one, camshaft position sensor fault... on the right bank.
Air filter is OK.
Battery, when I took the car was not so good. Of course it was the first thing which has been dealt with (replacement, and also after having charged it, it is OK).

Indeed this mechanic is not the best choice!
Unfortunately I fear that I will loss less by reselling it as is at the auction, than paying in order to repair it.

Macster

FYI...Uh, let me start over.

For your information, WAG is short hand for wild *** guess and FWIW is short hand for what its worth.

As for your other points questions....

If the tech believes/diagnoses the chain is broken then you either believe him or you don't.

I don't. And this is because there is no way I know of the engine would even turn over let alone run if a cam chain was broken.

Now a chain might have jumped/skipped time. If it goes one way the valves and pistons meet and all hell breaks loose.

The other way... the engine can run but poorly. Maybe the tech just didn't express himself clearly and and this is what he means by "timing chain broke..."?

A car sitting unused for a year is going to have bad gasoline. My sister's new Infiniti sat from late Jan of last year to the 1st week in July and while the engine fired up and ran the engine was flat. I was not familiar with the car and thought it was just well, a slug of an engine. I drove the car enough I had to fill up the tank and the change was remarkable. The fresh gasoline made a huge difference in the engine's performance.

In your car's case just adding a bit of gasoline may not suffice. The filter, lines, injectors may be partially blocked by gasoline residue. A complete overhaul of the fuel system from a tank drain/flush, new pump, fuel lines, filter, injector, etc. may not be called for but a portion of the preceding may be necessary.

You'll have to discuss this with your mechanic.

Next a car sitting a year is going to have a bad battery. While it may take a charge it probably has lost something (alot) and these cars with a weak battery and possibly a suspect alternator do not do well at all.

Reselling the car is an option. Given the circumstances you or you need someone who can go through the car step by step in an intelligent way to diagnose/resolve and repeat this process until every issue has been addressed to the point the engine and the car are working to an acceptable level.

Now I can't say for sure, but it may be the if the engine has suffered some serious internal problem the cost to put the engine right may be substantial.

Thus in my mind the possibility the engine has serious internal problems has to be addressed first before putting any money on say fixing the fuel system.

204cab

Thank you once more!

Fully agree with you, before putting any money it is important to determine whether there are internal problems to the engine, or maybe not.

Nevertheless I was looking carefully at all the documents I have, at this late hour here in Europe (2.35 am). And it seems that there was an error on the date of the last service, which has not been done in 2011, but in 2012 (according first to information on date and mileage of the services carried out that the Porsche dealer told me) and also the history of MOTs (technical check for roadworthiness of the vehicle, I don't know how you say it in US) which confirms the error on the year for the last service. Consequence is that the car was not seating for more than 1 year, but for 2 months at the date I bought it.

Nevertheless all your suggestions remain valid.

Main problem basically now is to decide whether to stop completely and give it to the auction, or having further checks by somebody else. I know that it is up to me to decide on this!