Sudden increase oil usuage 98 S70 n/a, manual

Post by **Ocelot** » 22 Sep 2021, 13:02

Hey guys,

It's been awhile since my last topic and that's a good thing I guess

My S70 is running B E A U tifull, as well on LPG as on gasoline. But I noticed a sudden increase in oil usuage over the last few weeks/months. The car has been in my posession for about three years now and in the beginning the oil usuage was about a liter every 7000 to 9000 kilometers. After the LPG conversion that dropped a little bit, but not too much to a liter every 7000 kilometers. It stayed that way untill my last vacation into France. I filled her up just below the MAX sign on the dipstick and drove for about 2800 kilometers in two weeks. I came home and saw it was just above the MIN sign on the dipstick...

So... the motor doesn't have any external oil leaks. I've kept a piece of cardboard under the engine for a few days: nothing. Dry as can be. No stains, nada. I also did the glove test (PCV-system) after a long highway drive: it passes it. Also, no smoke out of the dipstick tube. I asked a friend to follow me in his car to see if there are any smoke plumes noticeable when driving behind me, he doesn't see any smoke coming from the exhaust.

Some more info: I always use Mann oilfilters and Castrol GTX 10W40 as that was the oil the car has been serviced with over the years, so I thought not to change that. 10W40 also seems like a good choice to me considering the mileage of the car (373.000 km). So I called my Volvo dealer and asked him what to do with this. The first step, they said, was to add a engine cleaner in the oil, let the engine run for a good 20-30 minutes, drain the oil, renew the filter and the oil. They also suggested to remove the spark plugs, drip some lubricant into the pistons to loosen up any possible stuck piston rings. Now I have to say that my friends mention my driving style as "captain slow", and it's true. I always drive in low revs, let the engine warm up, and I drive mostly on the highway. Could my slow drivingstyle also have something to do with this?

I hope to get some new insights from you guys. I would like to keep this baby running as long as I can

Post by **ZionXIX** » 22 Sep 2021, 20:44

I suppose it could be burning oil without leaving a james bond style smoke plume. Check the cylinders and plugs for oil like you planned. Being a manual NA you dont have to worry about a turbo or the oil cooler.

Post by **Ocelot** » 23 Sep 2021, 01:51

Thanks Zion, I'll do that and get back to you if I find out more!

Post by **scot850** » 23 Sep 2021, 11:50

Check the air cleaner and pipes. I had a 760 turbo that started using oil. I found oil in the air cleaner from the EVAP system. The dealer told me it was caused by valve blow buy. Having had the head re-built it returned. Turned out is was stuck oil rings in the pistons.

Neil.

Post by **Ocelot** » 24 Sep 2021, 02:20

scot850 wrote: ↑23 Sep 2021, 11:50 Check the air cleaner and pipes. I had a 760 turbo that started using oil. I found oil in the air cleaner from the EVAP system. The dealer told me it was caused by valve blow buy. Having had the head re-built it returned. Turned out is was stuck oil rings in the pistons.

Neil.

Yeah, stuck oil rings and/or piston rings is what my dealer is also thinking about. I'll check the airfilter house before I go to work!

Post by **Ocelot** » 05 Oct 2021, 03:25

Update:

I just checked the airfilter box and it's perfectly dry. Not a smudge of oil. I also checked the oil level and noticed it was in the middel between MIN and MAX. Thats strange, I thought, the oil was just serviced a couple of days ago. So I called the dealer and asked them about it. They told me they filled her up with the exact amount of 5,8 liters, a given for that engine. I asked them if there's a chance I have a wrong dipstick and badabim badaboom, there's a modification for the dipstick. I get that installed friday the 8th but IF I had been reading it all this time wrong... I've been overfilling the engine with 0,5 liter of oil everytime. Could something like that cause damage?

Post by **abscate** » 05 Oct 2021, 04:55

No. And one liter in 3000 KM isn’t really oil usage to worry about on a 20 year old car

Post by **RickHaleParker** » 06 Oct 2021, 08:03

1 liter in 3000 km is 1 quart per 2000 miles. The majority of manufacturers consider one quart of oil per 1,500 miles to be acceptable. Your not oil consumption is not excessive.

If I where to a guess at why your oil consumption is going up ... With the number you have on the odometer ... I would bet on Valve Stem Seal wear.

Post by **Ocelot** » 06 Oct 2021, 09:18

Thanks you guys for thinking with me. I know that the oil usuage of my Volvo at the moment isn't really that bad. It's the difference in usuage in a short window of time that concerns me, you know? First it was so, now it is such, et cetera. I'll keep a close eye on the dipstick because I have some long roadtrips ahead this weekend (France, Spain, and such). I'm also curious about the dipstick modification. If I can make some pics this coming friday, I'll post them here.