Hey everyone,
Been a constant lurker in the background of these forums but finally created an account to make a post in search of some advice for some issues I've been having.
Some important things to note:
The car was built to 3.6L spec with
LN engineering
"Nickies," Mahle pistons, LN thermostat, water pump and other components that I believe were sourced from LN.
The shop that did the rebuild was performed by Autohaus in Peapack, New Jersey
The rebuild was done around 48k miles, car now has approx 110k miles.
Rebuild was done prior to my purchase, 3 years 27k miles since purchased.
Was diagnosed with bore scoring prior to the rebuild
I'll try to provide as much detail as possible while still being concise.
Roughly one year after purchase I noticed a decent amount of oil consumption. Roughly 1qt per 1.5 gas tanks. I was also getting smoke on start up and occasionally on rev match down shifts or revving the engine. A local shop, R&D Automotive (Albany, NY), performed an oil change and inspection and said the rear main seal was most likely starting to go bad, no confirmation though. They said not to worry and to consider at at some point in the future.
Little by little I noticed the consumption issue getting worse and brought it back to R&D. They were to perform the 100k mile service and inspect the RMS again. At this point they said the RMS was fine but the Air Oil Separator was going bad. I decided to take the car back and replace the AOS myself.
I replaced the AOS with an aftermarket kit from FCP euro and the consumption issue seemed to go away, temporarily. After about 2 months I noticed the same symptoms, smoke on start up, similar if not higher oil consumption and an occasional smoke screen out of the exhaust when rev matching downshifts or revving the engine with the clutch engaged.
FCP sent me a new AOS which was a
Porsche
genuine unit and I installed that along with all new vacuum hoses to the AOS.
In replacing the vacuum hoses, I didn't reinstall the boots on the intake manifold properly and there was a noticeable vacuum leak, check engine light and other issues. I fixed the vacuum leak but the CEL still remained. The code was a misfire on cylinder 2. The spark plugs appeared as if they had never been changed so I replaced all of the spark plugs and the code went away and the car seemed back to normal. Other than a lot of smoke on first start up, which I attributed to excess oil from the AOS and other issues needing to be cleared out.
Test driving the car, things were operating as normal and I thought the issue was resolved. The
next
day, I started the car up, more smoke on start up which I figured would linger for a little while. I took it out for another test drive and after 5 minutes I was getting the same issue with smoke from the exhaust when downshifting. Then, when I revved the engine, there was a loud bang and the car shut off, not small pops out of the exhaust which would sometimes occur, if it was running rich. I was close to home so I coasted down my street. I tried restarting and got another check engine light. Similar misfire on cylinder 2.
At this point I replaced the coil packs, which appeared old but not in horrible shape, as well as another new set of spark plugs and noticed that there was another vacuum leak from the intake manifold, which I think either caused or occurred when the engine shut off. I fixed both and the car seemed okay but was still getting a lot of smoke and oil consumption. I took it for one drive for about 25 miles and it consumed about 1 quart in that range. Same symptoms as before and shortly after the check engine light came back on, now there are misfires on cylinders 1 and 2.
The 2nd set of spark plugs is also noticeably coated in carbon deposits/oil after only being in the car for a couple of days and only used in start ups and the drives mentioned here.
I've since sent in an oil analysis to Blackstone laboratories and am waiting on a result. I think the
next
step is a compression test.
I have not replaced the fuel injectors. I was able to test the fuel pump and that is working properly. At this point, after replacing the AOS twice, spark plugs and coils, I am not sure what could be causing these issues. Especially given the huge amount of oil consumption and the bizarre consumption with clutch engagement.
Any help or ideas you all have would be greatly appreciated! There is a part of me that wonders if I have been just overfilling and the engine has been burning off excess as the car seemed completely fine before changing the AOS and still isn't making any weird noises throughout the rev range. I was under the impression that I shouldn't have issues with bore scoring after these modifications but I am sure there could be other things that could cause these issues.
There are a number of things wrong with what you're doing..
- You never told us the year of your car/engine - what was the engine before it became a 3.6L - the AOS changed between engine redesigns by
Porsche
, as did sump baffling
- It sounds as if you're doing a lot of cold starts without letting the engine get to operating temperature. That means you're dumping a lot of fuel into the cylinders and washing any oil on the wall of the cylinder away with the fuel - to be burned and perhaps cause at least part of the issue.
- Using a quart in 25 miles is massive oil consumption. The first thing I would do is a compression test and then a leak-down test on the engine. Make sure you haven't cracked a ring somehow. I see you're planning a compression test - it will be interesting what it says on cylinders 1 & 2. A big bang followed by engine shutoff is concerning.
- It sounds as if all the plugs are getting sooty at the same time - that's actually more or less normal the way you're running it - they never got hot enough and on a lean enough mixture to burn off the soot.
-
LN Engineering
claims injectors are good for 75,000 miles, the engine has around 62,000 miles since it was rebuilt - wonder if they replaced the injectors when they blew it out to 3.6L?
- When you check the oil level - is it under identical conditions in an identical location? A slight slant to the car can make it appear to need oil, when actually if's full. Park it on a level surface, do whatever is necessary to trigger your oil level gauge (it varies across years/model/iterations) and see what it looks like.
- BTW "clutch engaged" means your foot is off the pedal and the clutch is transmitting engine power to the transmission input shaft. A lot of people get it backwards - and that makes it difficult to understand what's being described. You said " revving the engine with the clutch engaged" and that would result in the car lurching forwards if it was also in gear. I think you meant revving the engine with the clutch disengaged (no power going to the transmission). Question - aside from tests, do you do this often? It's not considered a good thing for the engine.
That's my brain dump on this - it will require more investigation. Sounds like you don't mind getting your hands dirty, so let us know the results of the compression test, and if you do it - a leak-down test. These two tests may tell us a story.
Good luck, and
welcome to Planet-9, the Friendly Porsche Forums for Owners in Need of Assistance
Albany NY! I grew up there! I'm in CT now, but not that far away... welcome to the
Porsche
club and the area!
I don't know R&D Automotive, but they are probably pretty knowledgeable based on the website. That said, I know it's a drive, but I can HIGHLY recommend Musante Motorsports in Windsor, CT as well. Not that you need to go there, but just as an alternative, if you ever need it.
I don't have any newer advice beyond what Don said above... he's on the money, as usual!
Thanks for the thoughts, I appreciate it!
Car is a 2006. Don't know how I missed that in the original post.
Regarding the cold starts, that's not how I typically treat it but I think you're right. In trying to solve this problem that's all that's been happening because of the misfires and rough idle. Didn't want to drive it if I didn't have to.
I did drain the oil and only got 5.5 quarts out of it so about 2 quarts short. I also refilled to 7.5 qts and am getting 3 out of 4 bars filled on the electronic oil measurement so I can confirm I haven't been overfilling. As far as measurement, it's always been on the same surface when measured, level garage floor.
As for the "clutch engagement" I had no idea. Thanks for pointing that out, makes sense. You are correct, clutch was disengaged. I don't typically rev the engine unless matching revs while downshifting. This was something I was doing more recently as I was trying to figure out how/when the car was creating smoke.
I also did a compression test and compression was about 100psi lower on cylinder 1 than the rest of them. So all signs are pointing to repairs beyond my capabilities.
Had a great conversation with Brandon over at Slakker and I'm leaning toward sending it there for a rebuild.
Ha, small world. Thanks though, I appreciate the tip on the shop name. I'll give them a shout for another opinion.
Hi -
I ran into similar issues but with only a few thousand miles. My rings never seated. Seems the ones that were spec'd for the car were too hard for use with the Nickies. You might check to see which ring package was installed in your car. Mine was the XS set from JE Pistons. I hope this helps.
