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[mkaminski100]

Can you please advice me if emission test values, listed below, will make the 2.2 Omega pass the MOT?
CO % - 0.44
HC ppm – 118
O2 % 14.5
Lambda – 1.019

I’m concerned about CO, but don’t know if it’s still acceptable.
What do you think might be the reason? Is it because crack on the exhaust manifold, or is it because engine is burning oil?

[Marks DTM Calib]

Think HC maximum is 100.....so thats probably a fail.

Is it getting upto temp?

A hole in the manifold wont help as this can draw air in and affect the mixture readings.

[mkaminski100]

Yes, it is getting up to temp.I bought this car to save it from scrapyard and sell in pieces and have few spare parts for my Omega, but then I found it very economical and comfy. It had a spapped cambelt and previous owner fixed it in Vx, but it's stil burning oil. There might be few threads about this engine. He was adviced to chenge oil rings in the piston but I wanted to start from stem seals, as I cant find them on the bill from VX. I chenged oil and is smoking less (only when accelerating really hard). It might be a valve seals, valve guide or a oil rings. Valve seals are easiest to change (will not take the head off)
So I aassume that these readings are from oil burned in the cylinder.
If it's too expensive to pass the MOT I will have to strip it, but would try to fix it before.
I want to add some sealant on the manifold to "fix" it just to do the MOT (I will have to replace it but just dont have enough time at the moment).
If it's just a valve seal, then I can chenge it, but if thats a ring, then don't think it's worth to touch it. In my experience, usually when oil ring fails (break) it scratches cylinder and this way compression drops. There is a high comporession in this engine (almost the same in all cylinders) so I assume it's a head's failure.

BTW - I had a great difficulity to take old seals out. Is there any good way to do it without damaging them? Just dont want to damage anything else .

[Marks DTM Calib]

So its had a cambelt failure....

Ok, points to note.

1) Following this, you can get cracked valve guides from the bent valves.

2) Its generaly not the rings that crack or break, they can get crimped by the valve impact into the ring grooves, this might not affect compression massively (because there are two compression rings on each piston) but can up oil consumption.

[mkaminski100]

Only 2 exhaust valves hit the piston so I assume that there wasn’t a big impact, but who knows.
If it’s an oil ring and it’s crimped, then I need to change a piston. New is expensive, second hand is a good idea, but both will not fit properly into the cylinder as this would have to be skimmed and fitted with oversized piston and rings. But it’s too expensive.
I mentioned valve guides, as this might be a reason as well and changing seals will not cure the problem. Second hand head costs about £100-120 so it’s worth to do it and have a spare one.
I could take the camshaft out but I don’t have any tool to unlock the valve spring. Would have to make one. Don’t want to take the head off, so I would try to check the valve seals and replace it.

Is there any way to check if the oil rings are crimped without taking all of them out?
There are two good ways of fixing it:
1.      “New” head.
2.      “New” pistons.
How can I find which to replace?

In some engines it’s possible to take a part of the piston from the bottom. Then I would be able to check if that’s a ring or not, without taking the head out. Is it possible in these engines?

[jules]

HC is 200ppm
CO is 0.30%

The Hundy failed last year on Emissions, was up at around 1.8%, couldn't believe it cos it's always been well under.

turned out to be a combination of the fuel in the tank which was nearly a year old and the tester hadn't brought the car up to full operating temp.

Took it to another garage in the end who did the job properly.

Have you given the car a ragging recently ? Might help

[lee4206]

was the engine upto normal running temp when the test was taking as if the cat wasnt hot enough it would give higher readings. its not excessively high so i wouldnt have thought it was that serious.  it is possible that if it has been burning oil it could have damaged the cat or the lamda sensor.

[magnul]

As lamda>1 it implies exess air, whereas high CO and HC should mean excess fuel, it recommend trying a dirty fix of the manifold.

[mkaminski100]

Engine temp when test was done, was ca 90 degrees and I am sure that the lambda is in “closed” mode.
Both Lambdas are working, but don’t know if working properly. Can you please tell me proper values for these sensors?  
I also consider catalytic converted damage due to excessive oil (previous owner did few thousand miles after the head was fixed).
I compared this test with my X20XEV emission test and it’s a fraction of what I have in this one. CO 0.03-0.07, HC ca 30-40.
I think, I will have to replace converter as well.
I will check lambda sensor today and find out if it’s covered with burned oil. If it is, I will try to find a second hand head, piston (only one was hit) and catalytic converter. I will put some repair “glue” on the manifold to find out if it helps.
Do you know if anybody has it in reasonable price?

[Kevin Wood]

If it’s an oil ring and it’s crimped, then I need to change a piston. New is expensive, second hand is a good idea, but both will not fit properly into the cylinder as this would have to be skimmed and fitted with oversized piston and rings. But it’s too expensive.

To do a repair on a budget you won't need to worry about a rebore unless the crimped ring has damaged the bore, so a 2nd hand piston will fit with no problems. Just give the bore a hone and fit a 2nd hand piston with new rings, checking the ring gap. It might be worth checking if the pistons are classed in different sizes on this engine so you can find one of the right size.

However, I'd try to find out if ring seal is the issue first. See if you have a weaker compression on the cylinder that had the valve damage, and if it improves with a drop of oil in the bore. Either that or try a leakdown test. Have a look for any evidence of oil staining on the valve stems too.

Sounds like the head needs to come off anyway, so it is a good opportunity to fix the manifold leak, change all the stem seals and check the valve guides for damage and see if the piston ring has been crimped.

It looks like the cat is still working, at least partially, so I would hazard a guess that once the engine is healthy and it's had a run the emissions will recover.

Kevin