Oil leak - help!

[tbro]

You can tell if your valve stem seals are worn by checking to see if it blows blue smoke when you first start up when motor is cold. If seals are r/s oil sitting in the valve gear bypasses seal and goes into combustion chamber, thus blue smoke on start up. If thats the case you rearly have 3 choices, fix it, add oil thickner /thicker oil (not ideal)or check and top up oil every week and keep an eye on consumption.
Terry

[JBT]

Get a compression test to see if the rings are OK. It could be blow by.

[sabretooth]

Or even both.

Start with Terry's test, it's the easiest place to start.

[Hellmun]

Drop down a gear and keep the engine really laboured going down a steep hill. The vacuum created as the cylinders try and draw in air should drag oil in past the valves, either via worn valve guides or if the stem seals are leaking. If when you hit the bottom of the hill, you stomp the gas and make a very big cloud of smoke.... I would think valves would be the issue.

For pistons pull one sparkplug, disconnect the ignition system and open the throttle and crank it with a compression tester(if it's screw in you only need one person, hold in requires 2). Take down the value for each cylinder, then poor in a small amount of oil and repeat. If your compression goes up. You have blow-by from the pistons.

If you can't get a compression tester the piston rings should mean you get oil smoke any time and should be more prevalent under high revs. So just have a friend drive behind you and be a bit spirited. First time the smoke blown could be build-up but if it did it 2-3 times I'd assume oil is getting past the rings.

Replacing the valve stem seals means taking off the head, which means taking off every manifold, alternator etc. Draining all fluids and being prepared to systematically put it back together. It is quite a big job so I would be a bit more certain before completing it. Last time I did a head-gasket was due to the camira losing a head gasket (no idea how...but a head bolt came loose) and when I took the motor apart...the piston bores looked excellent and even the valve stems seemed fine. Reason the car blew smoke was the valves guides did look worn and I could see slop moving them in the valve. Wasn't worth the cost at the time (The valve regrind set + head-shave + Towing was over $500 which was quite a lot to a uni student 3-4 years ago).

Thicker oil will hurt economy a bit and you will need to be more diligent about looking after it, depends how much your car is worth to you and how you drive it. Personally if I was going that far... I'd go a bit past just putting it back together and look at either replacement pistons or getting some head-work done.

[adamjp]

Replacing the valve stem seals means taking off the head

No, it doesn't.

You can remove the camshafts, collets, valve springs and then the seals with the head still firmly bolted to the block. There is a couple of tools that will assist the task.

This tool can be bought from Repco for around $130.
http://www.lmperformance.com/1801/4.html

Unfortunately, if the head is pulled down properly, you may discover that you need new vavles (usually exhaust). So you need to balance fixing the problem for good at around $500 for a head rebuild, or fixing a symptom.