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[mkaminski100]

I bought an Omega 2.2 that was going to be scrapped. Cambelt snapped last year. After that it was fixed by Vx dealer and since then the engine is burning oil. Because it drives fine, I am getting 40MPG instead of 30MPG (my estate) and has got 81.000 miles, I think about fixing it and keep it. The only problem is that every mechanic wants at least £1000 for labour to fix it as it's a "time consuming work" (read: I don’t want to do it and will charge you extra). I can do it, but want to know if it's worth to start this job (after few days work might find that it's not worth to repair it).
I checked sparkplugs yesterday. Three are white and clean and fourth has got white, burnt coating on it. . Black/blue smoke comes out of the pipe only when reved. No smoke on idle or soft accelerating. I checked the compression as well and it's ca 14 bars in all cylinders so not bad. I think that it might be a piston ring, valve seal or head gasket. I could take the head off, but if it's a piston ring I would have to take the piston out, and I am afraid that the piston or cylinder might be damaged. So I might finish with engine in pieces which is not worth to fix...
If it's not worth to fix it, then I will have to sell it for parts but I want to sell it to my friend in Poland so I don’t want to start repairing if I'm not sure if it's worth.
What do you think it might be and is there any reasonable way to check it without taking the head of. I know that some garages have bore scope to check the cylinder through the sparkplug hole, but I cannot find any at the moment.
I know that the easiest way would be to replace whole engine but only quote I got was £500 + p/p.
I was told that it takes 1l a month. According to my calculations it needs 1l per ca 1000miles. Oil is very dark and dense. I know that I should change it but if it's a sticked piston ring will it help to undo it?
Air is blowing from the oil cap. I took the rubber pipe that is comming from crankshaft box to the rocker cover and it's blowing from both holes. I think that a little bit of fumes is comming from the cranshaft box.

What do you suggest?

[Marks DTM Calib]

If the cambelt snapped then its possible that the top piston ring has been crimped........so it would be a new piston and rings which is not so bad.

[mkaminski100]

Mark - the mechanik said it's the worst scenario, so it would cost a lot. They all complain about taking the head of, so the best way would be to do it myselft. I just hava a parking place so it would be quite difficult job. Second think is that I cant check if thats not the head fault (seal). Is there any way to find out?
Do I have to take the engine out to relaese the piston as the mechanic said? I was doing the same thing in Astra1.4 and we took oil sump and undo the connexcting rod  from the crankshaft and pushed the piston up.
Second mechanic said that he needs to replace all walve seals and it would be better to replace all rings. I think that its not wored just dameged so only damaged parts should be replaced.
I am also affraid that the cylinder might be damaged and need to be skimmed - this might cost a lot...

[mkaminski100]

There’s some more.
I disconnected the pipe between crankshaft box and rocker cover and found that some fumes (hard to see) are coming from the crankshaft box. It’s blowing from this pipe as well. It’s not blowing that much from rocker cover.
When reved to 3000-4000 I found that it’s not blowing more and there’s no more fumes (would say it’s less)
I closed the rocker cover nozzle (for oil filter) and opened oil cap – it wasn’t blowing that much as from crankshaft.
I also checked the pressure on hot engine
First pot is from cambelt:
1. 16.6 kg/cm2 = 235 psi = 1.62 MPa
2. 16.0 kg/cm2 = 230 psi = 1.58 MPa
3. 16.9 kg/cm2 = 241 psi = 1.66 MPa
4. 17.0 kg/cm2 = 243 psi = 1.67 MPa

Sparkplugs – third is more black than others. It looks like it was sprayed with oil, but I can only see small black dots on ceramic.  Rest is white.

I also checked the pistons through the spark plug hole, 1, 2 and 4 are black and 3 is cleaner with black peeling pieces. There is something like oil – it’s on the side of the top where the 4th pot is.

Would that be a 1st compression ring?
Could it be an oil ring? If this would be the reason, would the pressure be lower?
Or valve seals or the valve runner, bent when the valve was hit by a piston?

[mkaminski100]

Finally, some progress…
Engine head is out, same as pistons. What I found;
- no sign of broken head gasket
- 2 nd piston hit the inlet valves, not like I suspected 3 rd. 3 rd is untouched.
- only 3rd cylinder is full of unburned oil (around valves, spark plug hole and on the piston lid). Hard, black (on exhaust piston its white like concrete) thing.
- inlet manifold and inlet valves area is clean
- exhaust is full of burned oil (hard and soft) only from 3rd cylinder. Others are as normal.
- no signs of fumes coming through stem seals.
- all 4 both bores are untouched. No signs of damage. First machining is still visible
- 2 and 3 piston are untouched. No scratches.
- 3 rd has more burned oil on one side but both were black on sides, same as on top.
- pressure rings can be turned without any problem. These are not broken.
- Oil rings. These had a lot of burned oil on these “waves” same as in the groove, underneath the ring. There was more under and in 3rd piston oil ring. All 4 holes were not clogged. After cleaning it looks like 3rd piston oil ring has more wear (it doesn’t expand that much).

There are several suspects:
1.Stem seals or guides – if from inlet than there wouldn’t be any gases in oil. Oil was changed 100 miles ago and it’s black and greasy. If It would be from exhaust, then there wouldn’t be that much oil in 3 rd cylinder. Oil would be burned through the breathers.
2.Rings – is it possible  that from the hit oil ring in 3 rd piston was moved it different position in wchich it was wearing fast and wasn’t cleaning all oil? This way oil was in contact with hot gases and was burning and pushing ring even more? Would be because of poor quality oil or rare oil change?

I will attach some photos today, but could you please give some guidance if it’s good to clean all pistons and replace all rings as well as connecting rods bearings?

[Martin_1962]

For what they cost I would fit new rings and con rod bearings.

not sure if you need to rehone or not - any sign of bore wear or lips in the bore - if there is may not be safe to rering

[mkaminski100]

Thanks for your help
Usually, wore bores are clean (shiny) or have vertical scratches. These are not shiny, and have the first machining marks (going from the top to bottom like here http://images.hondatuningmagazine.com/images/0702ht_18_z+budget_type_r_engine+ring_gap.jpg )
No lips visible. Only small ring or black burned oil and petrol but after cleaning, surface is even.

What is the best to clean pistons (petrol, ON, white spirit) I know that I will heva to clean piston groves before fitting new rings, but what if I want to leave them? (I wouldnt' - it's just a theoretical question)

[Martin_1962]

I'd use whatevers to hand and a broken ring to clean the slots, might be worth polishing the crowns, (yes I have done this before) to clean them.

Petrol meths white spirit - whatever is to hand

[Big_Roger]

Hi,
Now that you have it dismantled this far, as suggested by Martin, I would re ring all pistons, BUT use a stepped top ring. At 81000 there must be some wear, even if as you say, you cannot see any lip.
Clean the pistons and all the grooves.
I would also replace big end bearings as have been disturbed.

Roger

[mkaminski100]

Where I can buy rings and bearings? What's the cost?