I’m looking for technical help on: oily spark plugs and pistons
Hi, I’m a relative newbie NC 2006 1.8 owner. I’ve read many posts about excessive oil consumption and my 80k NC is no exception! I removed all spark plugs and they were all black and a little bit oily. I also put a camera down to look at each piston head and they were all similarly oily. There is no knocking, smooth drive and pulls like a train. Given all pistons look the same, I’m hoping that discounts rings and points to a common easier/less costly problem. Any suggestions would be appreciated…picture taken of top of the piston below…
Do a compression test first. If it’s fine, look at PCV valve replacement. The biggest problem that it may fail emissions on the next MOT NC PCV valve replacement.
Thanks Raymond. Passed it’s MOT last month without any issues, which was a surprise to me. I shall organise a compression test asap. I read that a PCV replacement isn’t so straightforward but hopefully that’s the root cause and nothing more serious.
In the owner’s manual, it does say up to 1 litre per 800 miles, so perhaps keep a note of the mileage against the oil consumption. Keep it topped up for now, and measure the oil level 5 minutes after switching off a warm engine to get a consistent reading. Look through the service history to see what oil she has in her
Might be an idea to put in some fuel system cleaner. It won’t address the excessive oil consumption problem, but it will clean things up a bit and in any case, it can’t hurt.
I am in St Albans also.
Thanks. I’m guessing the strip down option isn’t going to be worth the money. I’ve not had it long, so damage limitation is to try and get a year of fun out of it by trying different oil etc. and then cut my losses . Any idea what a strip down would cost if I went down that route?.more than a replacement I would guess
You have a year until the next MOT and its got to be worth trying things that would be more cost effective that a rebuilt engine, if that is the case. I would have a go with some of this. Bit more expensive than a normal oil change but it has probably got completely gummed up oil control rings and if this works, then it could save a rebuild .
I did look at this definitely something to add to the list before I concede! I put some STP stop smoke in today but caused more smoke and misfires , but suspect that’s a short term effect. Next up is Berryman’s B12 chemtool down each spark plug hole and leave to soak. Might free the rings up if stuck… easy to do and only a few quid so worth a try!
I had the oil changed on a service a month ago and have done around 300 miles and added approx 2 litres… didn’t check the guage after the service which wasn’t the smartest move but I’m monitoring now. Saying that it’s so difficult to get a clear read with the dip stick!
2 litres in 300 Miles? You should be leaving a cloud behind you. Up thread it’s suggested a litre every 800 miles as a maximum. Even that sounds excessive.
The dipstick Deano suggests is a very good idea too. I bought one and found I had over filled by some margin.
Old style or new style dipstick, dip the oil when the engine is cold, preferably left overnight. If it’s way over the max level then some needs taking out. About 3mm or so above the max is ok, I used to keep mine slightly above max👍
Good to have that over max level confirmed. I’ve been running mine overfilled near 3mm for 5k miles without blowing the main crank seal!
I did initially try to siphon out via the dipstick tunnel but couldn’t get tubing into the sump. Runs up against some sort of baffling by the feel of it.
Just covering their ■■■■? That’s a lot of oil in too few miles. My TT with a turbo is one litre for a thousand miles. That’s still outrageous. Do they get these figures from normal use? Of course not.
I was in denial for a while, but now resigned to having an engine rebuild rather than buy another and risk more issues. In discussions with refurb specialists recommended in the forums and not cheap, but can hopefully look forward to having a reliable engine providing I look after it!
. Any idea what a strip down would cost if I went down that route?.more than a replacement I would guess
