Burning oil like a navy destroyer
08-21-2009, 01:58 PM
#31
Rennlist Member
To put your consumption in perspective, if you averaged 20 mpg (gas) and burned a quart every 400 miles, that is an 80:1 gas/oil ratio. 2-strokes are 40:1 or so and have an obvious oil vapor out the tailpipe. Your cat would be dripping oil by now if it were burning that much. Are you absolutely sure you don't have a leak?
08-21-2009, 02:01 PM
#32
Rainman
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i dont religiously keep track of mpg but on my trip to san jose i averaged 29mpg each way.
maybe there is a fat leak somewhere....
well, when i go to swap oil coolers i now have new seals on the way for the AOS, oil cooler gasket, oprv rings, and the front crank seal. with a fresh ~7 qts ill see how it fares after a week or so.
maybe there is a fat leak somewhere....
well, when i go to swap oil coolers i now have new seals on the way for the AOS, oil cooler gasket, oprv rings, and the front crank seal. with a fresh ~7 qts ill see how it fares after a week or so.
08-22-2009, 07:28 PM
#33
Rennlist Member
Just because you know there is oil in the intake tract doesn't mean that you can rule out the rings. If you are getting excessive blowby, the crank case will be pressurized more than it should be, which would explain why you are getting a bunch of fumes escaping when you open the oil-fill cap and why a bunch of oil is being pushed/pulled into the intake tract.
As long as you don't do crazy revving until after the engine is warmed up and has sufficient oil flow, there shouldn't be any issue with it. However, were the parts not all up to temp or something then you could have created some issue with premature wear in the cylinders causing the blowby.
My car has a decent amount of blow by currently, which is causing me to loose oil into the intake and turbo. I use a quart of oil every gas tank, which on highway driving is 500mi. Of course my car now has over 100k on the stock bottom end and I know that there is a decent lip worn into the cylinders, so I've just come to accept it with the age of the car. It has gotten worse since my last oil change when I went with a lower viscosity oil. On the 951's you can get a lot of oil loss through the turbo if the vent hose between the aos and intake is clogged, but since you don't have a turbo to lose the oil through the possibility of having a clogged aos hose isn't something you need to worry about.
As long as you don't do crazy revving until after the engine is warmed up and has sufficient oil flow, there shouldn't be any issue with it. However, were the parts not all up to temp or something then you could have created some issue with premature wear in the cylinders causing the blowby.
My car has a decent amount of blow by currently, which is causing me to loose oil into the intake and turbo. I use a quart of oil every gas tank, which on highway driving is 500mi. Of course my car now has over 100k on the stock bottom end and I know that there is a decent lip worn into the cylinders, so I've just come to accept it with the age of the car. It has gotten worse since my last oil change when I went with a lower viscosity oil. On the 951's you can get a lot of oil loss through the turbo if the vent hose between the aos and intake is clogged, but since you don't have a turbo to lose the oil through the possibility of having a clogged aos hose isn't something you need to worry about.
08-22-2009, 11:28 PM
#34
Rainman
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I havent opened the oil cap with the engine running, only after its shut off and I've checked the dipstick and decided that it needs more which may take a minute or two after shutoff.
Like I said I drive the hell out of it but only once its warm. until its at the middle mark it doesnt pass 2000rpm
Like I said I drive the hell out of it but only once its warm. until its at the middle mark it doesnt pass 2000rpm
08-22-2009, 11:30 PM
#35
Rennlist Member
(Edit: nope, it's 6.3)
Last edited by 944Ross; 08-23-2009 at 12:36 AM.
08-23-2009, 06:26 AM
#38
Three Wheelin'
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Over the past few weeks I really seem to be going through alot of oil. I changed the oil and filter in mid September and put 6.5 qts in the pan (had a case of 12, 6 ended up in the trash and the 7th was put in the back of the car, with 5 left in the case) and since then I have put in probably 3 qts. I did make a long trip recently, driving from San Diego to San Jose and back (~900 miles) and while I was up there probably another 500 miles of cruising around the Bay Area. Almost all the miles driven were on the highway. I drive my car hard normally but on the highway the vast majority of the time was around 3000rpm in 5th on light throttle.
What would cause my car to burn so much oil? There are no visible oil leaks. I know the Porsche spec is 1 qt every 1000km (620 miles) but I am still well above that. My engine was fully rebuilt in 2006, all new bearings, rings, gaskets, every seal imagineable.
In searching I saw some stuff about bad AOS seals, could these be causing an excess amount of oil to be put into my intake and burned?
What would cause my car to burn so much oil? There are no visible oil leaks. I know the Porsche spec is 1 qt every 1000km (620 miles) but I am still well above that. My engine was fully rebuilt in 2006, all new bearings, rings, gaskets, every seal imagineable.
In searching I saw some stuff about bad AOS seals, could these be causing an excess amount of oil to be put into my intake and burned?
08-23-2009, 02:41 PM
#40
Racer
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Hey, Spencer, I'm pretty sure you know more about these cars than I do, but there is a possibility you *may* be overfilling it. The last 944 (early) I owned actually came with an owner's manual, which I actually read (I know, violation of the rules in the Manly Manual), but one of the surprises I found in the owner's manual (and it really threw me for a loop, which is why I remember it) was that one of the maintenance procedures was for checking the oil (doh!), and it stated that to get an accurate reading on the dipstick, it was necessary to wait 15 minutes (!!!) after shutdown...Just for the hell of it, I checked it once about a minute after shutdown, and then again 15 minutes later, and sure enough, it showed about a 1/2 quart difference. Must be some tiny oil passages in the cam/lifter galleries...
08-23-2009, 02:58 PM
#41
Rainman
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oh thats interesting. i never got a manual with my car, i had to dig one out of a parts car lying in a field lol
what i usually do is drain oil/filter, put new filter on, fill to 6 qts, run it for a little while, then check the oil level again once the fresh stuff has had a chance to warm up and it usually needs another qt or so.
ill have to try this next time.
what i usually do is drain oil/filter, put new filter on, fill to 6 qts, run it for a little while, then check the oil level again once the fresh stuff has had a chance to warm up and it usually needs another qt or so.
ill have to try this next time.
08-23-2009, 04:32 PM
#42
Nordschleife Master
Hey, Spencer, I'm pretty sure you know more about these cars than I do, but there is a possibility you *may* be overfilling it. The last 944 (early) I owned actually came with an owner's manual, which I actually read (I know, violation of the rules in the Manly Manual), but one of the surprises I found in the owner's manual (and it really threw me for a loop, which is why I remember it) was that one of the maintenance procedures was for checking the oil (doh!), and it stated that to get an accurate reading on the dipstick, it was necessary to wait 15 minutes (!!!) after shutdown...Just for the hell of it, I checked it once about a minute after shutdown, and then again 15 minutes later, and sure enough, it showed about a 1/2 quart difference. Must be some tiny oil passages in the cam/lifter galleries...
I've read the same thing in my manual, but its something I've always done anyway. I think its pretty common practice to wait 15/20 min to check oil on a warm engine.
Some of the Chrysler engines hold almost an entire quart in the engine after its shut off. The dipstick sits on the low mark for 20min.
01-26-2012, 01:03 AM
#44
Pro
i think my a o s seals are gone also >.< little bit of oil in the air filter box, and it eats oil about the same as yours 
grrr its a pain in the *** when this stuff happens right after you had that all apart and could have fixed it right there if you would have known about it >.< haha
grrr its a pain in the *** when this stuff happens right after you had that all apart and could have fixed it right there if you would have known about it >.< haha
01-26-2012, 01:17 AM
#45
Nordschleife Master
+1
This was a good thread....with no conclusion.
My oil usage has gone up significantly since I posted in this thread initially. I went from 1qt every 5,000mi. to 1qt every 2500. Balance shaft seals, and the front seal on mine are toast......still loses nothing like you said you engine was losing oil though.
WTF did you find!?!?!
This was a good thread....with no conclusion.
My oil usage has gone up significantly since I posted in this thread initially. I went from 1qt every 5,000mi. to 1qt every 2500. Balance shaft seals, and the front seal on mine are toast......still loses nothing like you said you engine was losing oil though.
WTF did you find!?!?!