ChrisK

iTrader: (1)

I own 95 SC400 with about 84K miles on it. I got it about 1.5 years ago with 43K. From the beginning I noticed that my car uses about 1 quart of Mobil 1 5W-30 oil every 5k miles. I don't see any oil leaks. Is this normal? If not, how can I test where the problem is? Would the compression test be a good idea?

I believe once or twice, I've noticed the blue smoke after I stop completely, right after I "punch" the gas while driving.

Thanks,

PERRYinLA

I would not worry about it- that is well within the range of acceptable oil consumption of 5W-30, especially since you like to "punch" the gas!

It is actually the perfect consumption rate- if it consumed any more oil, you'd have to top off the crank case before your oil change, and if it consumed any less, you'd have an excuse to go further between oil changes! (But I'll bet you wouldn't risk that.)

Before you resort to the expense of a compression check (unless you are changing the plugs, anyway), you could run a cylinder balance test, pulling the wire to each plug and noticing the drop in idle RPMs - each pull should drop it by the same rate.

ChrisK

iTrader: (1)

Thanks PERRYinLA.

Lex Luthor

If it were me, i'd get that leakdown test, can't put a price on peace of mind, and if there's enough blue smoke that you can see it without being in back of the car, you have a blowby condition, however mild it may be. My SC4 has 71K and hasn't consumed a single drop of oil in 8 months, first conventional oil, then 5w30 M1, i've never seen a motor w/ 70K that was still that tight. I'm sure we all agree a qt every 5K is no big deal, but you've put 41K miles on this thing in 1 1/2 years, that's a whole whole lot, it's also 8qts of oil if that puts things into perspective for you. Where are you driving to with all that mileage? Disneyworld every weekend? Since I bought it, i've put only 4,000 miles on mine.
- Jon

ChrisK

iTrader: (1)

25 miles to work each way to begging with.

ChrisK

iTrader: (1)

By the way, my spark plugs are clean. I changed them twice and both times they didn't have oil on them.

Lex Luthor,

Wouldn't a blowby condition happend when I step on the gas? Keep in mind what happens in my car is actually opposite. When I step on the gas I'm fine, but afterwords when I stop then I think I see the blue smoke for a split second.

SCV8

Chris,I drive around 80mi every day to work and back;that's the main reason I bought my car.
I use about the same amount of oil,first noticed this when I was driving the car back from Texas,and it'd used a quart after driving 100mph all day for two or three days.
I the way I look at it is that there is less internal friction now than before.
I wouldn't wait until 100K+ to replace the plugs/wires,from what I've seen,they can stand to be replaced @80-90K.
If a leakdown test shows good all around,then maybe try the newer blend of Mobil,it's 0-W30(0-W40 also),works better in motors that've had conventional oil most of their lives.