Smokey VX - Blue Smoke at 6000rpm - Help

jimboharg · July 28, 2009

Hi there, I think this is my first post on here. I'm unfortunately having a problem with my NA VX220 which the guys on VX220.org can't really figure out. I've copied the below from VX220.org to see if you Z22SE experts can shed any light..
Obvious would be piston rings (and may still easily be this) but the problem literally just "appeared" about 500 miles ago and the comp test has come back fine (see below).
I've also just read up on oil pump pressure relief valves sticking and wondering if there is an easy way to check if mine is working ok (what should I look for if I remove it?)
I really hope you guys can help.....

"My compression tester turned up today and I've just done the test on all four cylinders - all 4 came back exactly the same at 15 bar
For those that haven't read my previous posts the car is blowing out blue smoke at around 6000rpm (2.2NA). It isn't displaying valve smoke behaviour as far as I can tell as it's fine on start up and no issues on overrun then acceleration or when sat idling and then acceleration.

I've disconnected the rocker breather pipe and taken the car for a 100 mile blast and it still blows smoke.
I've also blanked off the EGR - feels better at lower revs but still smokey
I cleaned out my original manifold and then broke it on refitting so fitted a second hand manifold but again cleaned this through with petrol - no difference.
The weird thing is that the car stopped smoking yesterday when come back from a spirited run out and was fine again this morning.
As I got nearer home today I gave it one last redline for good luck and the smoke started up again. I then tried a couple more times and the smoke is back.
Also the car smells slightly in the cabin after it has smoked- this clears after a few seconds.
I may have overfilled the oil after my last service by 0.5 to 1 litre (possibly) and the smell may have started around this time when approaching the redline.
I also noticed a bit of moisture on all the plug threads which looked a bit oily but don't know if this is usual - car had just been out for a run to warm up.
Please Please Please shed some light on this one for me - can it still be oil control rings if compression is testing as perfect?? Could it be something to do with the PCV in the inlet manifold? How can this be checked??"

Sjdickso · July 29, 2009

What oil are you using 5-30 fully synth?

How many miles has it done?

Have you done a oil consumption test to see how much oil it is burning over a perios of 500 miles?

At a guess it could be wear on the rings or valve guides.

jimboharg · July 29, 2009

I've been using 5W40 fully synth. I changed the engine last year after cam chain snapped on my original engine. Engine should have now done approx 62k.
Oil consumption over last 500 miles is probably just over 1/2 litre but I have spent alot of time trying to get it to produce the smoke ie the car has spent more time at high revs than it normally would so will get a better idea over next 500 miles.

Any idea why it seemed to stop smoking for a period of time? Can rings stick/unstick?

Sjdickso · July 30, 2009

May be worth doing a fresh oil change and filter and swapping to 10-40 semi oil.

Have you noticed that if you go down a very steep hill at load it smokes heavy at the bottom.

I am not sure why it would stop and start smoking. It is looking like piston rings / valve guides maybe.

jimboharg · July 30, 2009

What would the steep hill situation mean if it did do this? - I haven't noticed this but then I haven't been specifically looking.
It really only smokes right before the redline and at no other time as far as I can tell.

I've just spent the last few hours getting the piston out and re-oiled from the oil pump pressure relief valve. It was slightly stuck initially and was perfectly free when I'd finished. Wondered if this maybe was sticking and allowing the oil pressure to get too high? I'll find out on my next test run.

Could it be valve guides if the compression test was A-OK. I have read that full compression could still show if just an oil scraper ring has gone but would a dodgy valve guide not show on the compression test?

Sorry for all the questions!!

jimboharg · August 2, 2009

Just as an update. I've been out on a group run today with some other VX220s off the .org site. This means I've given the car plenty of abuse with someone behind me all the time. The car produces no smoke at all across all revs/accelerating/deccelerating unless I push the car to the redline.
However over the last 900 miles the car has used nearly 2 litres of oil. Admittedly most of this mileage has been pushing the car more than usual and lot of time testing the car to see exactly when it smokes and trying to eliminate causes.

So basically car is using oil and is only smoking under load past 6000rpm - Please someone put me out of my misery and give me the strongest possibility of what this could be out of rings, valve stems/seals, or even a PCV issue.

Sjdickso · August 2, 2009

I would say it is possibly the valve guides or rings.

jimboharg · August 2, 2009

But which is most likely and is there any way to work out which it is?
I understand that the compression rings can be fine even though oil rings aren't hence the good compression test results but still smoking.

Would worn valve guides not show up on a compression test?

vocky · August 3, 2009

valve guides usually cause smoke on start up, worn rings smoke most of the time, so it could be a blocked pcv system

have you still got the cam cover breather pipe connected to the air intake ?

jimboharg · August 4, 2009

I was hoping you'd be back soon! This is actually the engine I swapped at the end of last year with your help via vx220.org after the cam chain snapped.
I've taken the car out for a 100 mile spirited run with the rocker breather disconnected and kitchen roll taped over the end. Car smoked just as much with not much residue on the paper.
Is there anything I can check around the breather between cylinders 2 and 3? I have changed the inlet recently after snapping mine whilst cleaning it. No improvement with new manifold though.

vocky · August 5, 2009

is the small gasket still on the inlet manifold between 2+3, if thats missing it might cause a problem

edbutler · August 6, 2009

I always thought High RPM blue smoke is attributed to excessive blow-by from the piston rings. I just hope the bore isn't egged! Happened to one of my mates with a Honda VTEC. May be worth a punt and shouldnt be too hard if youve already had the pistons out!