Excessive oil consumption - track only, street fine
08-06-2012, 12:15 AM
#1
Nordschleife Master
Thread Starter
Excessive oil consumption - track only, street fine
Alright got any ideas here?
Car burns through a BUNCH of oil on the track... 1/2qt. per 20 min session or so. At Road America in May I had to add a quart every 2 sessions (which worked out to not quite 80 miles). My Lemons car went through 2 quarts in 17+ hours of racing by comparison!
On the street, however, I go maybe through 1/2qt in almost 1000 miles, driving normally (occasional blasts up through 5500rpm in 2nd/3rd while merging or passing, etc. plus 1-2 autocrosses a month but otherwise fairly sane driving).
Head was fully rebuilt by the PO about 40k ago (have all the receipts, new seals, guides, and seats) and the plugs are clean (no gunk or oil residue). Compression pulls mid-high 130s across all 4 cylinders. AOS tube back to the intake is clear (so not full of oil as if I'd been sucking a bunch that way), boost tubes are all clean and dry (so it's not leaking at the compressor wheel seal). Car doesn't blow blue smoke at all - a good friend of mine played cat-and-mouse with me at my last DE, and she said my exhaust "stinks" and it blew a puff of grey smoke when we first pulled out on the track (so it's running a little rich, which is fine, I'd rather be rich and safe than lean and sorry) but said that cleared up after 1-2 straights. No blue smoke anywhere though.
My thoughts were that if it was a head issue (bad valve seals or something), the plugs would probably be pretty ugly. I'd think if it were rings, it would go through oil ALL the time.
The only real thought I had was possibly the seal on the hot side of the turbo? I bought it freshly rebuilt from a RL'er with 0 hours on it a little over 2 years ago and it certainly appeared to be fresh (housings fresh and painted, shaft nice and tight, etc). Sadly I hadn't DE'd my car before the new turbo so I don't know if the oil consumption changed after the turbo swap
I'd really like to find the source - and I'm hoping it's the turbo (gives me an excuse to upgrade) but I'd like to feel comfortable knowing that's the cause first. Otherwise I'll just pull the motor this winter and go through it w/fresh rings, hone, have the head re-done again, etc. Though that's $$$ and time I'd rather not spend if I don't have to.
Car is pretty much stock. Stock 26/6, stock block/head/pistons, etc. 160k on it but like I said, the head was redone 40k ago and I'm still showing good compression (though I'm fairly sure the rings are original). When I had the motor apart 2 years ago the bores looked to be in really nice shape. I'm running an M-Tune now but had the same oil consumption prior to installing the M-Tune. I generally shift by 5500rpm or so (just noise above that anyways with the stock turbo). I've got a Lindsey pan baffle and the Lindsey monster oil cooler. I've been running Motul 300V 15-50 oil.
Any other things I can check to try to narrow down the source?
Car burns through a BUNCH of oil on the track... 1/2qt. per 20 min session or so. At Road America in May I had to add a quart every 2 sessions (which worked out to not quite 80 miles). My Lemons car went through 2 quarts in 17+ hours of racing by comparison!
On the street, however, I go maybe through 1/2qt in almost 1000 miles, driving normally (occasional blasts up through 5500rpm in 2nd/3rd while merging or passing, etc. plus 1-2 autocrosses a month but otherwise fairly sane driving).
Head was fully rebuilt by the PO about 40k ago (have all the receipts, new seals, guides, and seats) and the plugs are clean (no gunk or oil residue). Compression pulls mid-high 130s across all 4 cylinders. AOS tube back to the intake is clear (so not full of oil as if I'd been sucking a bunch that way), boost tubes are all clean and dry (so it's not leaking at the compressor wheel seal). Car doesn't blow blue smoke at all - a good friend of mine played cat-and-mouse with me at my last DE, and she said my exhaust "stinks" and it blew a puff of grey smoke when we first pulled out on the track (so it's running a little rich, which is fine, I'd rather be rich and safe than lean and sorry) but said that cleared up after 1-2 straights. No blue smoke anywhere though.
My thoughts were that if it was a head issue (bad valve seals or something), the plugs would probably be pretty ugly. I'd think if it were rings, it would go through oil ALL the time.
The only real thought I had was possibly the seal on the hot side of the turbo? I bought it freshly rebuilt from a RL'er with 0 hours on it a little over 2 years ago and it certainly appeared to be fresh (housings fresh and painted, shaft nice and tight, etc). Sadly I hadn't DE'd my car before the new turbo so I don't know if the oil consumption changed after the turbo swap
I'd really like to find the source - and I'm hoping it's the turbo (gives me an excuse to upgrade) but I'd like to feel comfortable knowing that's the cause first. Otherwise I'll just pull the motor this winter and go through it w/fresh rings, hone, have the head re-done again, etc. Though that's $$$ and time I'd rather not spend if I don't have to.
Car is pretty much stock. Stock 26/6, stock block/head/pistons, etc. 160k on it but like I said, the head was redone 40k ago and I'm still showing good compression (though I'm fairly sure the rings are original). When I had the motor apart 2 years ago the bores looked to be in really nice shape. I'm running an M-Tune now but had the same oil consumption prior to installing the M-Tune. I generally shift by 5500rpm or so (just noise above that anyways with the stock turbo). I've got a Lindsey pan baffle and the Lindsey monster oil cooler. I've been running Motul 300V 15-50 oil.
Any other things I can check to try to narrow down the source?
08-06-2012, 08:52 PM
#7
Rennlist Member
These cars really do like to gulp oil at the track, especially if you're living in the upper RPMs. How fast a track is it? At Summit Point out in WV (max speed of 135 for me; mostly 3rd and 4th gear screamer), I will go through 1 qt per day of track driving (4x 30min ea). This is roughly 160mi per day.
I do have a catch can and hardly see any goop in it after a hard weekend's work.
I do have a catch can and hardly see any goop in it after a hard weekend's work.
Trending Topics
08-06-2012, 09:20 PM
#8
Banned
I have owned a few 951's over the years and I have found that over time and mileage the engines begin to consume more oil. Probably a byproduct of blow-by through the rings. If the problem gets worse I would suggest a rebuild is in order. I have also observed that bad turbo bearings also yield oil consumption as well and most after market turbos tend to have blow through on the bearings. Simple because of the type of bearing they use. The oil pressure on our vehicles is quite high and likes to sneak past the bearing on the exhaust as well as the cold side.
08-06-2012, 10:58 PM
#10
Rennlist Member
Not unexpected for an engine w/ 160k miles on the rings and bores.
I used about 1 qt in 300 miles of racing last wknd (3 day event, 2 sprint races), on a relatively fresh rebuild.
I used about 1 qt in 300 miles of racing last wknd (3 day event, 2 sprint races), on a relatively fresh rebuild.
08-07-2012, 02:00 AM
#11
Drifting
I've got something similar on mine.
the engine was rebuilt with iron sleeves by the PO
about 5 years back -- but it sat for 18 months -- and
I'm told didn't have many hours on the car.
I'm blowing oil smoke out the exhaust on heavy acceleration.
nothing during normal driving. -- does not appear to have any
oil residue in intercooler. I do not have a catch can installed yet.
I pulled the intake to the cold side of the turbo -- and it seems to
have little or no play.
Mike
the engine was rebuilt with iron sleeves by the PO
about 5 years back -- but it sat for 18 months -- and
I'm told didn't have many hours on the car.
I'm blowing oil smoke out the exhaust on heavy acceleration.
nothing during normal driving. -- does not appear to have any
oil residue in intercooler. I do not have a catch can installed yet.
I pulled the intake to the cold side of the turbo -- and it seems to
have little or no play.
Mike
08-07-2012, 12:42 PM
#12
Nordschleife Master
Thread Starter
It seems "normal" is all over the board.
Like I said, my Lemons car barely uses any. It's got well over 100k on it. We found it in a field, no idea how hard of a life it's had. My buddy's Turbo Cup replica (xupkid2 here) barely uses any on a race or DE weekend, either... and he runs his car a lot harder than I run mine.
I know if I ran mine in the PCA Club Racing enduro (90 minutes) at Road America it'd probably blow up before the end of the race from oil starvation. Which tells me that most of the E- and F-class guys don't have the oil consumption issues I have either.
Well the catch can has been ordered. We'll see how much oil I collect per session in a few weeks.
Like I said, my Lemons car barely uses any. It's got well over 100k on it. We found it in a field, no idea how hard of a life it's had. My buddy's Turbo Cup replica (xupkid2 here) barely uses any on a race or DE weekend, either... and he runs his car a lot harder than I run mine.
I know if I ran mine in the PCA Club Racing enduro (90 minutes) at Road America it'd probably blow up before the end of the race from oil starvation. Which tells me that most of the E- and F-class guys don't have the oil consumption issues I have either.
Well the catch can has been ordered. We'll see how much oil I collect per session in a few weeks.
08-07-2012, 12:58 PM
#13
which one did you go with. I seem to need to top off 1/2 quart after every session. seems excessive. I might just stick the aos tube into a coke bottle to see what it collects first.
08-07-2012, 01:18 PM
#14
Nordschleife Master
Thread Starter
I ordered the Lindsey one (had an order pending for a new trans mount so just had them add it to the box). I also ordered the Moroso breather (http://www.jegs.com/i/Moroso/710/68781/10002/-1) since it was only $10. I figure if the fumes get bad (aka if/when the wife complains about the smell), I'll add it on.
Sounds like your consumption is about the same as mine. Burning that much 300V gets expensive on a long weekend!
Sounds like your consumption is about the same as mine.
Burning that much 300V gets expensive on a long weekend!
08-07-2012, 01:32 PM
#15
Drifting
I gave the same issue. I burn about a quart a day. I'll pour in 1/2 a qt during an enduro pitstop just to be safe.
I'm pretty sure mine is mostly blowby. My oil gets a gassy smell after a couple track weekends. 125k on the block and pistons so I know I'm overdue for a rebuild.
I'm pretty sure mine is mostly blowby. My oil gets a gassy smell after a couple track weekends. 125k on the block and pistons so I know I'm overdue for a rebuild.