Mazda MX-3 1.8 V6 Engine Oil keeps Vanishing!

gravyuk · Post by **gravyuk** » November 13th, 2006, 3:10 pm

Im having problems with my Engine Oil level.
1) The car is not dropping any oil on to the road as i have monitored this.
2) I have changed the oil filter and oil and still the oil is Vanishing!
3) The level off oil seems to go under the low warning line on the dip stick.

Iv'e Never had the oil light come on but am worried about the engine going boom.

I keep filling the car up with oil about every 1500-2000 miles.
Im using 10W40 syn oil.

The engine is very clean and cannot see any signs off oil

Can anyone help with this problem ?

Tunes67 · Post by **Tunes67** » November 13th, 2006, 3:17 pm

How many miles are on your engine? If higher mileage (100,000 or more miles) you can try switching from the full synthetic oil to a 10W-30W conventional oil. Synthetic oils like to slip past rings and valve seals when they have gotten a bit of wear on them.. it wont hurt performance at all.. but will burn off in the combustion chamber. And just because you dont see any blue smoke does not mean you arent burning oil. Most decent condition catalytic converters will burn off excess oil residue well before it reaches the tail pipe. Your oil level is dropping slow enough that its probably just burning off oil that is getting past your rings & valve seals.

Tunes67

gravyuk · Post by **gravyuk** » November 13th, 2006, 3:24 pm

Milage is 106400 ive owned the car since about 95000.
Thanks for the reply will give that ago.

hharb · Post by **hharb** » November 13th, 2006, 3:51 pm

I'm having the same problem.. i always thought there was a leak somewhere. i guess i'm gonna try that on my next oil change and look for any improvment.

illapino · Post by **illapino** » November 14th, 2006, 7:13 pm

hmm.. title sounds familiar..

Vanished · Post by **Vanished** » November 14th, 2006, 8:30 pm

illapino wrote:hmm.. title sounds familiar..

hahaha i was gonna say.

http://www.mx-3.com/phpbb2/viewtopic.php?t=54212

good luck. I'd do a compression test to see if indeed the rings are shot. you can get one at any automotive place.

Tunes67 · Post by **Tunes67** » November 14th, 2006, 8:44 pm

I'd do a compression test to see if indeed the rings are shot.

A compression test will not.. I repeat WILL NOT tell you if your oil control rings are shot or not. Apparently there is a misconception about how piston rings are layed out and attached to a piston. There are usually 4 rings. The very top ring is your compression ring. The bottom 3 rings are your oil control rings. A compression test will only show how much compression any given cylinder generates. This is effected by the condition of the compression ring and the condition of the valves. If the valves are seating well and your compression ring is in good shape (assuming the cylinder wall is also in good shape) then you will have high compression in that cylinder. If the valves are not seating well or are damaged or if the compression ring or cylinder wall are worn or damaged.. you will not get good compression in that cylinder. A compression test is a decent indicator of overal cylinder condition.. but it is by no means a complete test. A leak down test will give you more accurate results and if you are considering boost.. a leak down test will usually give you a much more accurate result (I have been told its a must if your going to boost a engine with an indeterminate amount of mileage.. but that is out of my realm of experience to be truthful)

Also.. since I am dispelling a myth here lets dispell another one I see fairly often.. Valve guides and Valve seals will also NOT affect compression test results. There are 3 things a compression test can INDICATE.. but not prove. Cylinder wall condition, Compression ring condition and valve face/seat condition. And high compression numbers arent always as desireable as even compression numbers. Meaning.. if you blow 160 in all 6 cylinders.. this indicates that the engine has seen decent maintenance routines.. where as engines with values up and down the scale could indicate that the engine has had a poor history of oil changes. Or that oil changes werent done at consistent intervals. You can find more information on this topic by searching for burned valves.

Tunes67

hharb · Post by **hharb** » December 9th, 2006, 9:20 am

i switched to 10w-40w, and the problem seems to be gone, car is smoking more than ever before, but still runs the same and the oil is not vanishing anymore.. i'm not sure how is that going to affect my engine, but i'm hoping it won't be a problem since the car is still running normal

jschrauwen · Post by **jschrauwen** » December 9th, 2006, 11:46 am

hharb wrote:i switched to 10w-40w, and the problem seems to be gone, car is smoking more than ever before, but still runs the same and the oil is not vanishing anymore.. i'm not sure how is that going to affect my engine, but i'm hoping it won't be a problem since the car is still running normal

As Tunes mentioned previously, it appears that your valves are seating/sealing and the piston rings are sealing. You may have wear on the valve guides which in turn may have permitted the synthetic oil to slip by and eventually lower the overall sump level.

mxmaz · Post by **mxmaz** » December 9th, 2006, 12:48 pm

I bet the engine has always used conventional oil. Switching to synthetic oil on a high mileage engine will often result in what happened to you.