Your donations help keep this valuable resource free and growing. Thank you.
|
oil consumption |
Post Reply | Page 12> |
Author | |
johnnieboy
AMC Fan Joined: Jun/20/2021 Location: Ontario Status: Offline Points: 2 |
Post Options
Thanks(0)
Posted: Jun/20/2021 at 9:46am |
June 2020 i purchased a 72 Javelin SST . It was recently rebuilt form the ground up including new paint. I have gone on a few rolling car tours which were quite lengthy . When i got home i noticed it burned oil whereas i had to put a half quart if not a quart of oil in after each of these runs. There is no drips under the car at all , there may be a little coming out of the exhaust but i don't think it's an unusual amount as friends following had mentioned that it wasn't to noticeable. Just wondering if because it is a new rebuild it takes time for seals rings to set in ? We completely drained all the oil at the start of the season and put in the proper amount to monitor it . We put in PennGrade 10/40 as was suggested by the mechanic who works on Mopars at his work place and they put this oil in all of them as well he uses it on his own Mopars . Any reason for excessive oil burn Thx
|
|
BassBoat
AMC Addicted Joined: Aug/29/2008 Status: Offline Points: 1718 |
Post Options
Thanks(0)
|
It takes some time for things to break in. Normal Oil consumption on these old cars is a quart every thousand miles. I have also had AMC cars that took a long time for the oil to drain back to the pan. Check the oil after it sits overnight. If the oil consumption is more than a quart in 500 miles, don't worry about it until you have 3-4000 miles on the engine. If it doesn't get better then the rebuild is probably not first rate. In that case my advice would still be ignore it, put oil in it when it needs it, and enjoy it.
|
|
Trader
AMC Addicted Joined: May/15/2018 Location: Ontario Status: Offline Points: 6880 |
Post Options
Thanks(0)
|
My experience in the last few years is the machine shops do the "plateau finish" with 400 grit for moly rings. That may be fine for other makes, but AMC blocks need a little courser to get the rings to break in quicker. I've been getting them back and doing a very quick 220 grit and cleaning. That seems to seat the moly rings better. Just my experience of late.
|
|
billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
Post Options
Thanks(0)
|
It is so very easy to forget that in the 60s and 70s even the owner manuals said basically what you said - quart/1000 good, quart/500 don't panic (well, not those exact words...........) Anyone who worked in a gas station back in the 70s recalls the line almost every single customer uttered when the bell rang - "fill 'er up and check the oil". AMCs seem to be among the worst at the oil draining back - but they aren't the only ones. I've found I'm better off waiting an hour or so after running it even on my truck to check the oil. (then when I did, I found the dealership put too much oil in it after doing my free oil change because FCA decided to cut the oil capacity from 6 to 5 quarts for this vehicle and that model year and no one read the bloody bulletin) |
|
billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
Post Options
Thanks(0)
|
I think you hit one reason my SX4 4.0 will go 3,000 miles without the oil level dropping to the next line while the Javelin will go 500-700 and need a quart. I have to look at my records but believe I used standard rings in the SX4's 4.0 - I know I had moly in the Javelin 390. But then they are also very different engines........... |
|
troutwilly
AMC Addicted Joined: Sep/14/2007 Location: Carriere, MS Status: Offline Points: 992 |
Post Options
Thanks(0)
|
I don't know but sounds like the windage tray was eliminated during the rebuild. After you put a bunch more miles on it, if its still using oil, pull the carburetor and see if there's a nice coat of oil in the intake just below it. Pull some plugs, especially the rear ones, and see how oily they are. Sounds to me like the PCV is sucking oil that is splashing up on it. Been there, done that. Mine used 1 quart every hour on the highway at 60 mph until I installed the windage tray.
|
|
Bill O.
70 AMX |
|
billd
Moderator Group Forum Administrator Joined: Jun/27/2007 Location: Iowa Status: Offline Points: 30894 |
Post Options
Thanks(0)
|
Hope they used the valley cover type intake gasket........... if they didn't, and if there's no baffle on the bottom of the intake.
|
|
FSJunkie
AMC Addicted Joined: Jan/09/2011 Location: Flagstaff, AZ Status: Offline Points: 4742 |
Post Options
Thanks(0)
|
Piston rings have always seated very fast for me. So fast that I never noticed any increased oil consumption at first, if there was any.
Most of my engines used 1 quart every 3000 miles from the beginning and have stayed that way. It depends on the RPM you run the engine at. Oil consumption increases at higher RPM. Sometimes I've had the unfortunate experience of driving on modern interstate highways with a 3.55 axle ratio at 3500 RPM for thousands of miles on end an watching my oil consumption go up to 1 quart every 1000 miles. |
|
1955 Packard
1966 Marlin 1972 Wagoneer 1973 Ambassador 1977 Hornet 1982 Concord D/L 1984 Eagle Limited |
|
Ken_Parkman
AMC Addicted Joined: Jun/04/2009 Location: Ontario Status: Online Points: 1814 |
Post Options
Thanks(0)
|
X2 on the intake gasket and/or intake manifold baffle. The factory style intake gasket is part of the PCV baffle system, and along with the intake baffle separates oil from the PCV breather. Many rebuilds do not know this and do not get right.
|
|
BBO UK
AMC Nut Joined: Feb/17/2020 Location: UK Status: Offline Points: 288 |
Post Options
Thanks(0)
|
Got my Javelin cheap `coz the PCV was blocked and it smoked like an oil well fire, changed it and it ran cleaner, but intake had no baffle under it, removed due to ignorance by previous owner when he put a "race" manifold on it.
|
|
Post Reply | Page 12> |
Tweet
|
Forum Jump | Forum Permissions You cannot post new topics in this forum You cannot reply to topics in this forum You cannot delete your posts in this forum You cannot edit your posts in this forum You cannot create polls in this forum You cannot vote in polls in this forum |