I_FLY_LOW

iTrader: (2)

^^ and that would be mine dude just check your oil....and keep it up to level

loccomoffo

There is no linear relationship between degrees of oil level and degree of engine damage. You need at least enough oil to keep the oil pump pumping as much oil as it’s designed to pump. When there isn't enough oil provided to the bearings they will simply run metal on metal and undergo accelerated wear. The most noticeable wear will happen in the con rod big end bearing which will start slapping. Bearings in the engine rely on there being enough oil in the bearing gap within a correct viscosity range.

Less oil in the sump means that it is circulated more frequently thus its exposed to higher temps more often and it is this which is the oils worst enemy. Heat oxidises engine oil thus breaking it down and thickening it up.

Synthetic oils like the one you use are much better at resisting this oxidation at higher temps thus they don’t need to be changed as often. Personally I use mineral oil and change it twice as often as this also gets rid of particulates in the oil which also damage the bearing surfaces (the filter doesn’t stop all of them).

Look after your oil level and change out period and your car will love you for it. My little 1.6L 4cyl car ran for 250,000miles (400,000km) on the original engine when I sold it 2 months ago and it was still running strong, all due to good oil maintenance.

If you want to read more, this’d be a good place to start:

Lube oil
http://en.wikipedia.org/wiki/Motor_oil

Hydrodynamic lubrication
http://webphysics.davidson.edu/facul...ubrication.htm

Enemies of lube oil
http://www.upmpg.com/lubricationnews..._deteriorates/

PS. just to stir , motors run on electricity, engines on heat

redmomatt

Thanks for the response and the great information. I will definitely look after it better.

In your opinion, would you think that I did permanent damage to my engine, or just perhaps accelerated its wear so that it would not last as long overall?

NW OBS

iTrader: (2)

It's impossible to read an Impreza dip stick any way! It is a very vague idea of level at best! Just make sure there is some in there!

loccomoffo

Don't stress about it, as long as there was some oil left in there, all will be fine

It sounds like you change the oil out frequently enough so thats good, and definatelly the best way to keep wear to a minimum.

I remember my girlfriend once ran her engine dry of oil, she was wondering why the engine was reading soooo hot . After that even when i filled it with very heavy oil the engie had a very loud slap from the con rod big end bearings.

HJC

How's your car running now? I know this is an old thread but I came across it looking for rod bearings threads.

Don't mean to worry you but I ran my WRX's oil down so low there was none on the dipstick! Plus smoke was coming out of the tube! Worse was I was driving HARD before checking too. I put a little less than 2 quarts in. Ran fine after that.

Then......10,000 miles later, rod bearing went. Got the tick of death. Don't know if that's what lead up to it.

dub81

iTrader: (39)

Whoa!! Thats living on the edge!!

laters,
walter

redmomatt

Just wanted to say thanks again and let everyone know that the car is still running ok. It's got about 73K miles on it and no problems yet. I'm certainly glad I've always used a high quality synthetic.

On a related note, I was wondering what standard oil consumption is for the NA engine. I've heard from various people that these engines have a reputation for burning a fair amount of oil. I've heard too that it's because these engines have pretty tight tolerences, and when cold they tend not to seal as well? This would fit with my perception that the engine startup noises are worse in the winter (until engine is at temp) and that I also burn more oil when it's cold.

Just wondering. Thanks.

loccomoffo

if the tolerances are tight then theyll also be tight when cold. my ´95 1.6L doesnt burn any oil and its done 160,000miles. if your car does lose oil then its either leaking somewhere or its getting past the piston rings as the rings or cylinder are worn. a compression test will lead you to this problem of a simple rev to see if you have blue smoke coming out the exhaust.

redmomatt

Thanks for the info. I checked the exahust, but didn't notice any apparent blue smoke. I think I will do a compression test, but also noticed some oily residue inside the tail pipe.

Is there a reason then, why I would have greater oil consumption in the winter than in the summer? Also, engine noises (before warming to temp) are also louder in the winter. Is this just because the engine oil is thicker and doesn't get to the parts as quickly?

Thanks again.