Misfiring 991 997.1

[richardjjs1]

Please can someone help!!!. My porsche 911.997.1 2007, keeps misfiring, the garage has checked for bore score, changed the timing chain, replaced a bent valve, replaced the wiring loom, spark, plugs coil pack have all been changed, it's been going on for 3 years. I'm going crazy. Please help !!!

Where are you
Are you using a reputable Indy (or OPC)
Members on here will advise of their local indy. If its been going on for 3 years you should have tried a different on 2 years ago.
Is it actually a Indy that is known for Rear engined Porsches
Lots of thing - wondering what damage could have been caused bu a bent valve (And what caused it )
Where the correct Plugs and Coil packs fitted and TIGHT
Fuel Filter ?
Run a tank full of V Power through
Lots of thinks
Where are you going tomorrow
You can buy a Analyster yourself

If you wre in West London go to AMS Porsche, in Hertfordshire How much have you spend on FUEL over the last 3 years - Best it something really simple
I had a 986.1 Boxster son in law change the plugs and Packs (I always do my own maintenance) after 4 months it started occasional miss fires (Eventually turned out to be a loose coil pack )
Good Luck

 

[brian.pilgrim]

Any news on your car @brian.pilgrim

Yes hi red 997! You wouldn't believe it . Rsr porsche/ yonter asim has swapped my 3.8 engine for a 3.6. This came to light when 911 sbd, who are carrying out the work ordered the parts and none of them was compatible. I've reported it to the police, they seemed keen on the uptake. They went to yonter asims garage. It's been repossessed. All his mobile numbers are changed. The have downgraded the crime as a fraud. And told me if I want to pursue him I must do so through the civil courts. Now as things stand I'm looking for a 3.8 engine. They aren't cheap

 

[Red997C2Sport]

Yes hi red 997! You wouldn't believe it . Rsr porsche/ yonter asim has swapped my 3.8 engine for a 3.6. This came to light when 911 sbd, who are carrying out the work ordered the parts and none of them was compatible. I've reported it to the police, they seemed keen on the uptake. They went to yonter asims garage. It's been repossessed. All his mobile numbers are changed. The have downgraded the crime as a fraud. And told me if I want to pursue him I must do so through the civil courts. Now as things stand I'm looking for a 3.8 engine. They aren't cheap

That's horrendous!!! I wish you the best of luck with recovering what you can. I imagine there will be a long list of debtors. I guess an option is the get an engine with bore score and get it rebuilt. I know it's expensive but you'll remove the worry of future problems. My regular mechanic, Angus Archer of AMS Porsche, who I suggested up thread, has very sadly passed away. He was an absolute gentleman and would have been able to assist you but sadly the business the business is closed, at least temporarily. I'm now on the look out myself for another decent independent.

 

[brian.pilgrim]

Yes I heard rip Angus, I 911 sbd was due to pick up a engine from Angus last week. And was greeted with the sad news. Puts everything into prospective really. Life is so fragile

 

[Red997C2Sport]

Yes I heard rip Angus, I 911 sbd was due to pick up a engine from Angus last week. And was greeted with the sad news. Puts everything into prospective really. Life is so fragile

Exactly, so fragile.

 

[brian.pilgrim]

Any news on your car @brian.pilgrim

Hi Red 997. I've had to buy a 3.8 engine, which needs a total rebuild it's getting silly now. But I'm stuck in between a rock and a hard place. Hopefully it should all be sorted by mid June. Fingers crossed. Thanks for checking in!!

 

[richardjjs1]

Where are you
Are you using a reputable Indy (or OPC)
Members on here will advise of their local indy. If its been going on for 3 years you should have tried a different on 2 years ago.
Is it actually a Indy that is known for Rear engined Porsches
Lots of thing - wondering what damage could have been caused bu a bent valve (And what caused it )
Where the correct Plugs and Coil packs fitted and TIGHT
Fuel Filter ?
Run a tank full of V Power through
Lots of thinks
Where are you going tomorrow
You can buy a Analyster yourself

If you are in West London go to AMS Porsche, in Hertfordshire How much have you spend on FUEL over the last 3 years - Best it something really simple
I had a 986.1 Boxster son in law change the plugs and Packs (I always do my own maintenance) after 4 months it started occasional miss fires (Eventually turned out to be a loose coil pack )
Good Luck

Same here with my 987 Son in Law Fitted new Coil Packs - Occasional misfiring
Eventually blew the engine trying to clear the fault Sold the car to someone who wanted a project car to fit a A6 twin

He came back to me and said Yes it was a loose Coil pack despite me asking a qualified mechanic to check them He said it will not be that when I suggested it

So everyone ALWAYS check those coli packs Maybe tighten Maybe replace - it did not shpw up in checker

 

[Red997C2Sport]

without meaning to hijack the thread, I've just returned from 3K miles around Europe and the car started idling slightly rough, whilst I was on the final stages of the tour. Once back here, and I had put another 200 hundred miles or so on the car the idle is worse now.

My Foxwell scanner found a P0421 which is described as "warm up catalyst efficiency below threshold". I cleared the P0421 but the error came back and when I dug a little deeper I found a misfire on cyl 6. My plugs are only 18 months old so I'm intending to change all 6 coil packs, mainly as they're likely to be the next culprit, they're easy to replace (despite being hard to get to) and relatively inexpensive. The only downside is that on a gen 2 997 you need to remove the bumper, side silencers and the various heatshields

Fingers crossed it works.

 

[ianthow]

Same coils as 987.2 My 2010 Cayman S had one fail. Replaced all 3 on that bank. Kept the two good as spares. The other bank is still on its original fitment after 15 years and 93K.
Failure was on Cyl 4, a common fail on 987s because of poor engine bay cooling at that side.

 

[Red997C2Sport]

Same coils as 987.2 My 2010 Cayman S had one fail. Replaced all 3 on that bank. Kept the two good as spares. The other bank is still on its original fitment after 15 years and 93K.
Failure was on Cyl 4, a common fail on 987s because of poor engine bay cooling at that side.

Interesting you mention about engine cooling, on the Cayman. On my tour it was quite warm and I did long, often quite spirited, drives, so I guess it could have pushed a coil pack too much.

 

[ianthow]

Interesting you mention about engine cooling, on the Cayman. On my tour it was quite warm and I did long, often quite spirited, drives, so I guess it could have pushed a coil pack too much.

The 987 takes cooling air in from the right side air intake. The left side is induction air only. No 4 cylinder is front left of the mid mounted engine, close up against the front of the engine bay, so away from forced air circulation. I believe the 997 also only has a single engine bay cooling air fan in the rear lid, offset to the left. On 911s, cylinder 6 is the frontmost one on the right so it could well be that that coil is in a hot area of the engine bay. I would be tempted to change all on that bank and keep the old coils as spares (in the car if on a long hard trip!).

 

[Red997C2Sport]

The 987 takes cooling air in from the right side air intake. The left side is induction air only. No 4 cylinder is front left of the mid mounted engine, close up against the front of the engine bay, so away from forced air circulation. I believe the 997 also only has a single engine bay cooling air fan in the rear lid, offset to the left. On 911s, cylinder 6 is the frontmost one on the right so it could well be that that coil is in a hot area of the engine bay. I would be tempted to change all on that bank and keep the old coils as spares (in the car if on a long hard trip!).

That all makes sense, thanks. My car is back now so I will do both sides as I don't see any evidence in the paper of coil pack previously.