28k miles and ive been through 3 pairs of Densos on my EVT700, and now shes a 775... Motor is out because of a trans leak, ill most likely pull and change the plugs again... Never had a miss-fire, just change them often to prevent issues and she booooost like crazy

 

Which Densos? EVOMS told me they like the PK20 over the IK22 (platinum vs iridium).

 

Is there any data that supports their decision?
I spent considerable amount of time researching this, and a lot of tuners have different preferences when it comes to Spark Plugs (and Coils for that matter). But other than a nod and and a point, in one or another direction, I couldn't get at any thing else that would set their preference apart from the other.

Additionally, as mentioned, speaking to two different sources, outside the tuning circles, who see tuned cars (Porsche, and others like Ferrari and Lamborghini) come into their shops here in Canada, they see no discernible difference in life span from these tuner recommended plugs and the OEM.

Actually they lean towards the OEM saying that in most cases they do tend to outlast the "specialist plugs".

One thing is that there seems to be somewhat of a common thought/agreement that some specialist plugs do out perform (only on performance not longevity) on much higher HP cars 800+. But with such performance plugs their life span is considerably reduced.

Over all OEM seems to be the best choice, a perfect marriage between performance and longevity IMHO.
But, that said I encourage every one to go do the research and if you discover anything to the contrary, I'd be very curious to know!

 

I have been telling people for a while now that once you tune these cars and drive them hard they eat plugs. I was telling people that plugs are a maintenance item on these cars and should be done every 12-15,000 miles. Coils do not really last long either. I tell everyone that by 30,000 miles they are overdue. It's to bad that plugs are such a big job on these cars.

 

markski and Todd from protomorive , use the denso double platinums pk20pr-p8 and thats what i use on my 800 hp monster. no issues no complaints

 

How many miles do you have on them? My shop recommended Todd @ Protomotive for getting a new software if I wanted to De-Tune it a little.

 

With it being a maintenance item. How much are you guys paying for Labor & Parts?

 

pureporsche is it possible your plugs were never changed the first time?

 

So after about 2 months (less than 1400 km) since I replaced my plugs and coils for OEM I started to get a heavy misfire again. Just went through the ordeal again of having them replaced ($1200). I went with OEM's again but had the Porsche dealership flash my car back to stock until I could have a word with all parties involved.

Either the Tune is eating up the plugs (but find that hard to believe as a lot of folks on this board are running the same tune), or I got a bad set of plugs, or there may have been issues with the installer (Independent shop).

Attached are pictures of the plugs, as you can see the interior insulation (around the shaft) has been completely disintegrated. Only one plug actually has the insulation left. This is probably due to thermal expansion and contraction (shock) or detonation, which causes it to crack and disintegrate.

My problems span a little further than the plugs, so let me outline the situation for all:
1) installed the ECU tune
--- same day misfires start
2) Replaced the plugs and coils
--- same day the clutch starts to slip
3) replaced the clutch
--- then same day noticed the car is STILL not working fine
4) Take it back (flash it back to stock ECU) and find out the the turbo vanes were stuck and the actuators need to be replaced
--- fix the problems with the turbo's and then the misfires start again
5) Replaced the plugs for the second time in 1400 km

Any one have any opinion on why these went so fast? Or had similar symptoms on their plugs? Tune? Installation? bad plugs?

One guy I talked to said that as the vanes on the VTG's got stuck, this caused the actuators to pop off when the engine was trying to move them and probably built up a lot of back pressure in the exhaust. Also this may have also been a cause of very lean mixture going in which resulted in EXTREMELY hot temps in the combustion chamber that would have disintegrated the insulation.
I also got a CELL on the catalytic converter - which points to something like that?

 

wow that is a sign of serious heat damage/detonation. Unfortunately there are a number of things that you may find need attention:

1)the ceramic debris from the insulators went somewhere - possibly your combustion chambers and could scratch the cylinder walls. I would do an immediate oil change and send the oil for analysis. I would also consider doing a leakdown and compression test

2)your turbos are probably in need of a rebuild. VTG turbos are very sensitive to excessive EGT's and you may have damaged not only the bearing cartridge but the actual impellers

3)check your intercoolers for signs of aluminum debris/dust. That would be signs of the turbo impellers disintegrating. The intercoolers need a thorough cleaning with solvents and compressed air

 

...Just a follow up. Literally got off the phone with the Tuner. Had a long conversation and almost certain it's not the tune. We went over all the different symptoms and issues, and actually may have finally got to a solution/reason for all these problems... But that said, I have to run to the office, so will finish up detailing it out later today.

I find it rather interesting and looking forward to share it, in hopes it will save someone else considerable amount of problems.

 

Is the vane lubrication a regular maintenance item? All I know was there was an issue and got it into the dealer because of it.

 

It does all point toward the tune though unless you have a fuel pump/fuel delivery issue and its been leaning out under throttle. High combustion temps/detonation are the cause for the premature failure of the plugs. I agree with eclou you may well be looking at further damage within the engine as well. It's highly possible given the very short length of time it took to destroy the new plugs.
Btw how old is the exhaust? Whats the mileage? Did it have a tune prior to your ownership? Possibly your exhaust or cats are all choked up. Restrictions in exhaust flow will certainly cause abnormal combustion temps and an overfueling engine will eventually clog the cats ad muffler. The soot has to get caught on the way out. There really isn't a whole lot left here to look for that hasn't already been addressed in your recent maintenance. Be keen to hear the final wash up.

 

It all comes down to the turbos.
Apparently when the vanes got stuck they built up back pressure which threw the mixture off, which got exaggerated with the tune which demanded extra boost. And that is what ate the plugs up. Apparently the OEM plugs last 15,000 miles with this tune, tried and proven. One step colder plugs won't make much difference unless one is running a turbo upgrade package with the tune with around 700+ hp. Else you're not going to see much difference in life span.

Another contributing factor to this could have been a bad batch of fuel.

The car has 40k miles on it, exhaust has been on for some time, before my time (TechArt & 200 cell cats), and all work fine now. The car has never had a tune on it before I threw one on.

Regarding the plug disintegration, speaking with two different Porsche mechanics, both said that the insulation material around the center shaft is ceramic/porcelain, so it would not damage the combustion chambers, simply it would disintegrate into fine dust - not good, but not bad either.

SO far so good. Had her back for two days now and she's been purring like a kitten.
Tomorrow I'll be flashing her back with the Tune *gulp*. Let's hope it stays all good.

By the way, there are a lot of tuners that claim their tune can not be detected when flashed back to stock. If you like you can PM me and I'll let you know what tune it is.

The tune I have could not be detected with the PIWIS tool when it was flashed back to stock. People say that the there are two different time counters that may not match - however that requires a lot of digging, and don't think any Porsche mechanic would go to those intricate lengths to verify a "factory stock" program when they see it - which is what this one is when flashed back. The guys at Porsche could not tell and kind of confused them as I actually told them that there was a flash on the car - and they couldn't find anything. So there you have it - proof.
They flashed the car anyway with the PIWIS tool again, just to be absolutely sure they were diagnosing a stock car.

Regarding the turbo maintenance, any time you see abnormal boosts, check these suckers. It's my number one item to constantly check. Actually my mechanic just had another 997tt come in with strange noises/vibration coming from the exhaust - turns out he's VTG's are also causing problems. I think as this is the first gen with VTG's we can and should expect some growing pains with these components and take the necessary steps to make sure they run fine.

 

Glad everything worked out for you! It's been quite a battle to get everything sorted.