Jump to content

Welcome to RennTech.org Community, Guest

There are many great features available to you once you register at RennTech.org
You are free to view posts here, but you must log in to reply to existing posts, or to start your own new topic. Like most online communities, there are costs involved to maintain a site like this - so we encourage our members to donate. All donations go to the costs operating and maintaining this site. We prefer that guests take part in our community and we offer a lot in return to those willing to join our corner of the Porsche world. This site is 99 percent member supported (less than 1 percent comes from advertising) - so please consider an annual donation to keep this site running.

Here are some of the features available - once you register at RennTech.org

  • View Classified Ads
  • DIY Tutorials
  • Porsche TSB Listings (limited)
  • VIN Decoder
  • Special Offers
  • OBD II P-Codes
  • Paint Codes
  • Registry
  • Videos System
  • View Reviews
  • and get rid of this welcome message

It takes just a few minutes to register, and it's FREE

Contributing Members also get these additional benefits:
(you become a Contributing Member by donating money to the operation of this site)

  • No ads - advertisements are removed
  • Access the Contributors Only Forum
  • Contributing Members Only Downloads
  • Send attachments with PMs
  • All image/file storage limits are substantially increased for all Contributing Members
  • Option Codes Lookup
  • VIN Option Lookups (limited)
porschedr

Newbie with engine missfire all 6 cylinders. Help!

Recommended Posts

Hello everyone, my name is Chris. I'm new to the site and this is my first posting; just wish it could be on a more positive note.

I managed to purchase my pride and joy; a 3.4L 996 (1998) with 49,000 miles from an independent dealer 2 months ago. Unfortunately, 2 days ago on starting the engine I noticed the CEL was on and the idle rough. I have had no problems with oil pressure, temperature and the oil level, fluid levels are all perfect. There is no evidence of oil/water contamination.

I purchased a diagnostic scanner that is recording a miss-fire in all 6 cylinders (PO300-306)

The car is still covered by the dealer warranty but I want to be armed with the likely underlying problem before I get into discussion with them.

I would be grateful for any help on this matter.

All the best, Chris Huston

Share this post


Link to post
Share on other sites

The car is of an age where the coils packs will be crakced and failing - you normally notice this more often than not in wet weather. It'd be unusual for all six to fail at once though, so it might be something else like a MAF sensor. I'm not sure whether this would bring up any other codes (i would guess it would). Get it back to the dealer and have them sort it .

Share this post


Link to post
Share on other sites

:welcome:

It could also be the wrong spark plugs if they were recently changed.

If your CEL is flashing (not solid) the car should not be driven as it will damage the cats.

Share this post


Link to post
Share on other sites

This site is great! :)

Thanks Loren and Percymon; I'm sure the information you have provided will be extremely helpful. Once I cleared the original faults (PO300-306) the ECL light went off but then returned (the idle remains rough); a subsequent diagnostic recorded missfires in cylinders 5 and 6? Fortunately so far there has been no flashing ECL.

I've always wanted a 911, but now I own one I'm starting to have regrets. The car has a beautiful appearance, is a pleasure to drive but I am starting to question the reliability of the early 996 models. My own personal experience coupled with some of the articles I have read raise serious concerns regarding the quality of the engine. Leaking engine seals and catastrophic cylinder head failures appear to be the order of the day. In my opinion it is unacceptable that owners who invest in a quality item and pay for expensive main dealer servicing should also have to purchase a warranty to insure against what appear to be design deficiencies.

What options do I have once the independent dealer warranty expires? Will Porsche cover a 1998 car with FPSH and low mileage, are there any quality independent warranties available in the UK?

All the best, Chris :renntech:

Share this post


Link to post
Share on other sites

Well, IMHO your car needs to be looked at.

It does not sound to me like you have a major problem (very few folks actually do).

As these cars age some of the plastic and rubber parts are going to deteriorate enough to need fixing - that is a fact of life on any 10 year old car.

You could have a cracked AOS bellows or cracked coil packs or some other intake leak. If you have a warranty now - take the car back and tell them that a CEL is unacceptable. If they are not qualified to find to the problem then they should take to someone that is - and they should pay for it - that is what the warranty is for.

Share this post


Link to post
Share on other sites
This site is great! :)

Thanks Loren and Percymon; I'm sure the information you have provided will be extremely helpful. Once I cleared the original faults (PO300-306) the ECL light went off but then returned (the idle remains rough); a subsequent diagnostic recorded missfires in cylinders 5 and 6? Fortunately so far there has been no flashing ECL.

I've always wanted a 911, but now I own one I'm starting to have regrets. The car has a beautiful appearance, is a pleasure to drive but I am starting to question the reliability of the early 996 models. My own personal experience coupled with some of the articles I have read raise serious concerns regarding the quality of the engine. Leaking engine seals and catastrophic cylinder head failures appear to be the order of the day. In my opinion it is unacceptable that owners who invest in a quality item and pay for expensive main dealer servicing should also have to purchase a warranty to insure against what appear to be design deficiencies.

What options do I have once the independent dealer warranty expires? Will Porsche cover a 1998 car with FPSH and low mileage, are there any quality independent warranties available in the UK?

All the best, Chris :renntech:

Chris - as Loren says its probably just a little bit of wear n tear, and nothing major - i'm guessing you don't have the warranty currently ?

Find yourself a decent independent Porsche place - if you let me know your whereabouts i'm sure i'll be able to direct you somewhere for diagnostic help/rectification at half the cost of a OPC.

As to Porsche warranty - to qualify the car must be under 10 years old and under 100k miles - you'll need to have a 111 point inspection carried out by the OPC and any issues found recified. These don'ty have to be rectified by the dealer, but they might charge you for another inspection once the work is done if they don't do the remedial work. I think the inspection is about £150 nowadays. The warranty is £895 and includes breakdown and recovery within most of europe. Similar breakdown cover from AA or RAC would cost you around £180. The warranty doesn't cover everything, but will cover you for engine failures which is about the most costly occurence and the one you want the warranty for in the first place. Be carefuk to check though that it doesn't expire wih the cars tenth birthday. They may also be fussy about issuing the warranty if its not got a full service history !.

There are no ther independent warranties that offer anythign like the cover - most policies exclude Porsches due to the high repair costs !

The only other option worth looking at is via Hartech, a well respected independent in the North West - www.hartech.org . they offer a lifeplan service which equates to a monthly payment which covers servicing, parts and any other parts required (including wear n tear items) - it doesn't include labour charges for non service items, but their rate is half the OPCs. Maybe worth a read on their website.

Share this post


Link to post
Share on other sites

Whilst i would still recommend you take the car to be checked you could try swapping one of the coil packs from another cylinder to see if the fault moves around, or get yourself a new coilpack from eurocarparts for around £40. If you go either of these routes then check the sprak plugs while you're at it.

A firend of mine had to be recovered in wet weather about 18 months ago - his C2 was 4 years old at the time, the OPC replaced all 6 coil packs under warranty, as most were cracked on inspection.

Edited by percymon

Share this post


Link to post
Share on other sites

Once again, thanks for your advice :)

Sounds like obtaining a warranty for a Porsche 996 is an expensive must. After some research, I have found no companies other than Porsche who are willing to offer such a service, though many will cover other Porsche models, Aston Martin, Ferrari and even Maserati cars! Hartech offer a Lifetime Maintenance Plan but this does not cover the cost of parts in the case of an engine failure. Although Hartech do appear to currently have confidence in the early 996 engines they also state that 'if the frequency of failures became to common, we may have to limit our contribution to a more fair proportion'.

Is the lack of available warranties and the number of articles regarding 996 engine failures all indicative of a known and serious reliability issue?

As an owner of a 9yr old 996 I believe the additional running cost of £895 for a Porsche Warranty makes the car a great deal less desirable and I would expect an acceleration in depreciation.

The car is back at the dealers for repair under the warranty and I'll keep you informed of progress.

All the best, Chris :renntech:

Share this post


Link to post
Share on other sites

Dear Loren and Percymon,

Well the car went back to the independent dealer under warranty; they cleaned connections, replaced the coil packs, plugs and sensors all with no success. At this stage they handed it over to OPC; after one and a half hours diagnostic time the suggestion is that a faulty variocam solenoid/actuator may be responsible for the miss-fire, I am not sure which bank is affected. OPC have quoted a large bill; I am told around £1000 for parts and labour although I have not seen the report or quote.

The independent dealer and warranty provider has been v.honorable thus far so I'm keen to maintain good will and not have them sent on an expensive wild goose chase. Based on your knowledge of variocam systems is this a likely fault? Can this fault cause secondary damage to the engine/exhaust system?

I hoped to get the car up and running by the 14th as I've planned a driving holiday, looks like I'll be using the Merc S-class; not quite the same! :D

All the best, Chris :renntech:

Share this post


Link to post
Share on other sites

No VarioCam fault codes? That would be unusual - but I won't say impossible.

The key is if the actuator is replaced - and if the problem persists. For your sake I hope it does fix it.

Share this post


Link to post
Share on other sites

Cheers Loren, I'll let you know; just glad I have the dealer warranty. Once that expires if there are no further warranties available I'll just have to sell the car :( It's a shame because I always dreamed of owning a 911 and for the month it worked it was a joy!

Maybe I'll just have to save up again and get a newer model or a GT version ;)

Chris :)

:renntech:

Share this post


Link to post
Share on other sites

Hi Percymon and Loren, sorry about the delay with the update.

The variocam solenoid unit was the fault. Unfortunately, in the process of replacing the variocam actuator the exhaust manifold studs sheared and required an engineer to be called in. At the moment it is running perfectly, smooth idle, perfect power delivery and no warning lights or oil/coolant worries!

I have now spoken to too many Porsche owners and mechanics who have experienced unusually high failure rates with the 996 engines to believe it is just an internet scare. As for the warranty, there appears to be no option other than Hartech and I don't feel their cover is as comprehensive as I would require. I don't like it but I think I'll have to sell the car.

Before I do that I'll put a request on the board asking if anyone has any warranty suggestions.

All the best, Chris

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...

Important Information

We have placed cookies on your device to help make this website better. You can adjust your cookie settings, otherwise we'll assume you're okay to continue.