Slant Six Forum
https://www.slantsix.org/forum/

Oil consumption: where to start
https://www.slantsix.org/forum/viewtopic.php?t=63993		 Page 1 of 1
Author:  pieranja [ Mon Aug 26, 2019 6:14 am ]
Post subject:  Oil consumption: where to start
My car starts to consume oil like I drink water after at a hot summer day. It's a 225 /6 from '67 that runs on LPG only. I'm using Shell Rimula R4 Multi 10W-30, a Heavy Duty Engine Oil.

Now the thing is: the engine itself looks pretty dry, there are no leaks visible. With the current rate of consumption, oil should be anywhere leaking from the engine. So I quess the oil leaves the engine as gas.

Another noticable thing is: the exhaust gases smell really terrible although not blue colored or otherwise strange colored.

What would be the most sensible order of tackling the oil consumption based on this information?

Greetz Henk-Jan
Author:  slantzilla [ Mon Aug 26, 2019 6:40 am ]
Post subject:  Re: Oil consumption: where to start
I seem to recall that LP is not real kind to valve guides.

How much oil is it actually using? Have you pulled the plugs to see if they look oily? Maybe do a compression check while the plugs are out.
Author:  Joshie225 [ Mon Aug 26, 2019 12:25 pm ]
Post subject:  Re: Oil consumption: where to start
Check the plugs as mentioned, but be aware you can burn/lose a surprising amount of oil and not foul the plugs. Replace the valve cover breather and PCV valve if not already done. Next I would pull the valve cover and see if the valve stem seals are intact. If the engine is original it's likely that they have disintegrated or are very hard and seal poorly. They are an umbrella seal, not a positive seal so the valve guides will receive some lubrication. If the guides and seals are in good shape then you have to look at the piston ring and cylinder condition.
Author:  Dart270 [ Tue Aug 27, 2019 5:36 am ]
Post subject:  Re: Oil consumption: where to start
It would be great to know how much oil is being lost. 1 L every 1000 km, or???

Best,
Lou
Author:  pieranja [ Tue Aug 27, 2019 11:54 pm ]
Post subject:  Re: Oil consumption: where to start
Quote:
It would be great to know how much oil is being lost. 1 L every 1000 km, or???

Best,
Lou
Lou,

I think it's something between 2 - 2.5 liters per 1000 km at the moment.
Author:  Dart270 [ Wed Aug 28, 2019 5:19 am ]
Post subject:  Re: Oil consumption: where to start
OK, that is quite substantial. I recommend checking the plugs and running a compression test (cranking cylinder pressure). Do that with the engine warm (normal operating temp).

Lou
Author:  pieranja [ Thu Aug 29, 2019 8:32 am ]
Post subject:  Re: Oil consumption: where to start
I assume that you guys refer to the spark plugs, not the spark tubes?
Author:  Joshie225 [ Thu Aug 29, 2019 8:38 am ]
Post subject:  Re: Oil consumption: where to start
Spark plugs are the only window into the combustion chamber we have without disassembling the engine. So when we mention checking the plugs we are looking for abnormal conditions. See this: https://www.hondaatvforums.net/forums/a ... k-plug.jpg
Author:  GregCon [ Thu Aug 29, 2019 2:19 pm ]
Post subject:  Re: Oil consumption: where to start
Memories...we used to have a 64 Valiant, 226/ 3 speed manual that consumed oil like crazy. It used so much we didn't usually even buy new oil for it...we'd just save used oil from other cars and pour it in the Valiant. Anyway, the engine was bone dry....didn't leak a drop. It also didn't smoke other than the smallest wisp out the tailpipe when you'd take off. But the oil was going somewhere, that's for sure...!
Author:  Rick Covalt [ Thu Aug 29, 2019 2:32 pm ]
Post subject:  Re: Oil consumption: where to start
Quote:
What would be the most sensible order of tackling the oil consumption based on this information
By a case of oil and add as needed. :D

You are talking 1qt every 300 miles. My truck use a quart every 500 miles and I never see smoke, not even on start up. I don't drive it more than 5000 miles a year so I just add oil. The only other real option is an overhaul, if you don't find an obvious place it is going. Good luck.
Author:  GregCon [ Thu Aug 29, 2019 2:39 pm ]
Post subject:  Re: Oil consumption: where to start
You don't say 'how' it started consuming oil...did it happen over night or over a few years or?

In any case, Rick is correct - just keep adding oil unless you want to do a full rebuild.

One 'possible' cause that is easy enough to fix are valve seals. Have you looked at them? If they hardened up then fell off, and your guides are sloppy, that will increase oil use.

Another is in rare cases the PCV valve can fail and you start sucking in LOTS of oil vapor...but usually when that happens the engine sees a big vacuum leak, too, and it runs poorly.
Author:  pieranja [ Fri Aug 30, 2019 12:22 am ]
Post subject:  Re: Oil consumption: where to start
The thing is, I only have the car in my posession for a year now, so I can't really tell when the oil consumption started. The car has served it's life as a hurst, so not a lot of mileage. No fast driving as well. Maybe the valve seals are gone, that could be true.

Anyway, I will check the sparks first and let you know what they tell me. Thx for the link Joshie225! Look's like there is somebody around who qualifies as a spark-whisperer.
Author:  mpgFanatic [ Sat Aug 31, 2019 12:15 am ]
Post subject:  Re: Oil consumption: where to start
Quote:
You are talking [about] 1qt every 300 miles. My truck use a quart every 500 miles and I never see smoke, not even on start up.
Sadly, I can confirm that burning 1 qt every 300 miles will not show much smoke at all. If you burn it in 200 miles (my old Duster) you'll see a little bit. If in 100 miles you'll see a fair amount. When my 65 Rambler burned a quart in 50 miles, there was a smoke screen behind the car every time I floored it to get up a hill. I'm embarrassed that I know this. Especially for the sake of the planet. What can I say, I was a young kid with no money. The good news is I sold that Rambler to a guy who wanted to restore it for his collection -- he had a 2 dr, a 4 dr, a wagon, and the only thing missing was the hardtop. That car probably would have been happy to pollute for many more years, but he promised not to let it.

To translate: at 1 or 2 liters per 1000km you won't see much smoke at all out the tailpipe. At 3L/1000km you'll see a little smoke. At 5-6L/1000km you'll see a fair amount. At 10-12L/1000km you'll be strangling birds.

- Erik
Page 1 of 1 All times are UTC-08:00
Powered by phpBB® Forum Software © phpBB Limited
https://www.phpbb.com/