[gr_diver]

Hello all!
My 1.6S Ascona (1900), consumes oil, about 400ml/1000km. By taking a look at the plugs, I can see that the 1st cylinder burns the most oil , the 2nd is burning less, the 3d burns even less, and the 4th burns NO oil at all.
This "progressiveness" struck my attention. Should I suspect a blown head gasket?
The engine does NOT consume coolant, nor there is oil leakage in the radiator.
Thanks in advance!

 

[baz]

i would think its valve stem oil seals going if any thing but is there any smoke from the exhaust?

 

[gr_diver]

Oh yes, I forgot to mention that smoke comes out from the tailpipe at mid and high rmp (above 3000rpm), especially during shifting to higher gear . But I can't say it's color correctly, as it can only be seen at night, when closely followed (less than 5m) by other cars that have their headlights on. Looks grey, but can't say if it is any "blueish"...
In addition the engine produces internal fumes (but not tailpipe emissions).

 

[baz]

try starting the engine and then take the oil filler cap of and you will hear an sharp increase in sound (a deep rumble ) put the palm of the hand over the hole if you feel a lot of pressure then it will be worn piston rings
if its just a bit then it will be the stem seals
try cleaning the oil breather pipes so that the engine crank case is breathing as it should this may help for a while

 

[hrcollinsjr]

BAZ is probably correct about the valve seals leaking. Most of them can be easily replaced without removing the head. An air compressor to supply air, an adapter for the spark plug hole, a valve spring compressor, and seals and you're good to go. When replacing seals on each cyl. bring the piston up so that both valves are closed, the compressed air keeps the valves from dropping into the cyl. The rear valves are a pain to get to because they are under the cowl. Alternative method if you don't have air is to take enough cord to fill the combustion chamber and insert it into the cyl. and bring the piston up so the cord holds the valves. LEAVE SOME OF THE CORD STICKING OUT FOR RETRIEVAL! I haven't tried this method.

Wouldn't hurt to do the easy stuff first that BAZ suggested like cleaning the mesh inside of the top of the valve cover.

HTH,
Harold

 

[gr_diver]

Ok guys, thank you very much!
I will try baz's method to see whether it is a valve seal problem... Most propably I will take it to a shop to have the repair done, but I wanted to know what the most possible cause, so as not to have something fixed by a "genius" mechanic (although the one that repairs my car is a very good one), and then realize that it was not fixed correctly...

Thanks again!

 

[MikeyOne]

Alternative to a compressor

My neighbor is a boat mechanic and showed me a trick to hold a valve up in a pinch. Remove the spark plug, rotate the engine until the piston is at the bottom and starting up for compression, then stuff a length of thick cotton rope into the plug hole. (leave the end hanging out) Hand crank the engine until the piston is topped (or feels restricted). The rope is now pressing the valves up and the springs/seals can be removed without dropping.

When done just back the piston back down and pull the rope out.

Anyone ever seen the 'Bush Mechanic' show on Discovery channel? Ingenuity is amazing sometimes.

 

[gr_diver]

Hello again!

I did the test that baz recommended! I did it with the engine cold (on fast-idle) because I was afraid of getting my hand burnt by hot fumes - oil drips.
Well, when I used the palm of my hand to seal the oil-filler hole, I could barely feel any pressure (if any at all) forcing my hand up. So I guess that it is the valve-stem seals that leak oil in the cylinders.

(BAZ, when I opened the oil-filler I heard that deep rumble you mentioned. Is this an indication of something, of is it just normal "internal" engine sound?)

I was wondering, can leaking valve-stem seals somehow explain the "progressiveness" of the amount of oil leaking in the cylinders, being the most in #1 to none in #4? Or is it just random that they wore in that order?

Well, propably next month I will have the cylinder head inspected. I know my valves will also need adjusting, as I have started to hear a very slight ticking, propably from valves of #3.

 

[jeff denton]

The "progressiveness" you're seeing is something I've noticed in tearing down three heads, only I see more lifter wear in the rear than the front, again in a progressive order.
I think it's because of the way the head is fed oil, it all comes through that tiny passage at the front, so there must be less oil at the rear by the time so much bleeds around the cam bearings and lifters.
So you have more oil dripping off the rockers at the front than the rear.
And I feel the valve stem seals are your problem as suggested, but bet that your guides are worn too.
The oil system in the head really irritated me, that's why I came up with my external "oil header" that feeds each cam bearing. I don't know if it works better or not, but in theory it should, and it looks kinda trick...