Engine Breather Problem

[routerspouter]

Hi, I'm after some advice on my 2008 Astra H 1.8 estate. I have been getting puffs of smoke every 3 to 4 days of use. There is a clicking noise which I assumed was an EGR valve but after reading the Haynes manual, my particular engine (Z18XER) does not have one.There is a purge valve which connects to a charcoal canister for fuel vapers and if I understand it properly is separate to the engine breather. I had been told it was the cam cover breather that was faulty and I have replaced it with an after market part. This seemed to be better for a while but is now doing the same. The breather hose has oil in it and when I disconnected it with the engine running there is a lot of pressure blowing through it. I blew through the breather on the new part before I fitted it and the passed all the way through. I was also told there is a diaphragm in the breather which tends to whistle when it fails which mine never has done so I don't know if that refers to a different model or not. I would be grateful if someone could explain how this system is supposed to work exactly so I can get it sorted.

Thanks

Keith

[Vauxhall Owners Club]

When does the smoke appear and for how long....e.g. when starting up or under acceleration or deceleration ?

[routerspouter]

Hi thanks for the response. The smoke appears usually when I accelerate quickly but it will do it eventually even when I don't. I would say it seems to build up over about 5 days then releases it in one go and I can hear a kind of clicking noise as it does it. I am only doing about 20 miles a day, 10 to and from work and only really drive steady anyway. I have attached a link to a video that I managed to take (nearly braking my phone when it fell!) Sorry I gave up trying to rotate the vid! This is the worst it gets but you can see how bad it can be.

I am not sure if the breather is supposed to stop any oil getting into the inlet manifold or if it is just the way to divert the crankcase pressure. My previous 2 cars were the 2 previous models of what I have now. The F model I had no problems with apart from head gaskets, I think the breather was open to the atmosphere if I remember correctly.. The G model never seemed to get hot enough and the engine breather and cam cover used to choke up with whitish gunge. That went into the inlet manifold but had no problems other than the gunge.

I was going to keep the original cover when I changed it so I could examine the breather to see how it works but I ended up not doing unfortunately

https://drive.google.com/open?id=1Iw6jEqFG54QEl4XBFmDW1rss-UECX3Ng

[Vauxhall Owners Club]

Wow!  that is excessive.

Cannot say I have ever seen a breather issue produce anything at this level.

I would be looking at a cylinder fault and would be worth carrying out a cylinder leak down test which will determine the efficiency of the rings, valves, crankcase breather and manifolds.

[routerspouter]

If it was a cylinder fault, would it not be a continuous problem?

It was the clicking noise that is confusing me. It is like something is opening and letting the oil through which initially led to me thinking it may be an EGR valve, until I read the Z18XER engine does't have one. The purge valve is supposed to let fuel fumes which accumulate in the charcoal filter out into the inlet manifold.

If the oil is continuously passing through the system without having any effect, could this injection of fuel vapor when the purge valve opens, cause this problem?

I will look into your suggestion and thanks for the advice

regards

Keith

[Vauxhall Owners Club]

A cylinder leak down test would determine if there is any oil consumption via the cylinders, manifolds, breathers, rings, valves, etc.

It's a very quick and simple test and if it comes back clear then you would at least eliminate these areas.

[routerspouter]

HI, Managed to do  a leak down test but not to sure about the results. The compressor would only manage 20 PSI whereas the youtube vids use 100 PSI. Cylinders 3 and 4 were perfect while 1 and 2 were letting air out. The hissing was loudest through the spark plug ports so I thought that the hose might not be seated properly but after trying a couple of times it made no difference. The hissing could be heard through the air intake and slightly through the cam cover oil filler, loudest when checking cylinder one. When the pipe was connected we got a drop in pressure which sent the needle into the green on the pressure gauge. I turned the pressure back up to 20 PSI which put the pressure gauge needle on the edge of the yellow area on the gauge so relatively happy with that but not to sure how much difference the extra pressure would make if it was done at 100 PSI. Managed to do a bit of a compression test but the gauge had a bit of a dodgy pipe, this put cylinders 1 and 2 at 90 PSI and 3 and 4 at just over 100 PSI, so there does seem to be a bit of wear on 1 and 2. The plugs were a bit blackish and the pistons had a coating of soot on them, all 4 cylinders seemed about the same. Again not to sure just how this affects the smoke problem but I think I am going to get a genuine Vauxhall cam cover first and see what happens. Will let you know how I get on.

[Vauxhall Owners Club]

Thanks for the detailed feedback.

The fact that air is escaping through the air intake could be that the inlet valve is still slightly open due to lower pressure not completely at BDC which would naturally occur when the pressure is high and the piston is forced downwards. Alternatively, if you had some way of securing the crank at BDC then try again.

With the camcover emitting air, this again could be the piston at mid-bore which could have some ovality in the cylinder which is allowing air to escape past the rings.

Try a small amount of oil in the bores to recheck the compression test to see if it improves the reading on the low cylinders.

 

[routerspouter]

Thanks for the advice. I have bitten the bullet and fitted a genuine Vauxhall cam cover. Can't say I am overly confident as it looks pretty much exactly the same.

It let out a little bit of smoke after it was fitted but that may just be what had accumulated.

I took the breather apart on the cam cover I took off to try and see how it works but it isn't quite as simple a set up as I first thought, so I have put that theory on hold for now!

I haven't used my car much in the last couple of days but will see over the next few of days as I'm back at work. Will let you know what happens.

[Vauxhall Owners Club]

Would definitely be interested to hear how it works out, cheers

[routerspouter]

Hi, Well the new cam cover seems to have done the trick, not had a puff of smoke at all, but at a RRP of £220, I am glad I only paid £114 for it. Yes still a rip off for what was probably a faulty diaphragm and maybe spring though!

[Vauxhall Owners Club]

Great result, glad it all worked out okay.

Thanks for letting us know