[Corsa B 1993-2000] Spark plugs black with some oil

[AKSport]

I have a 1996 1.4 16v corsa sport, I'm still learning to drive therefore the car is just sitting in my driveway. I go out every couple of days and start it up for a bit. I started noticing white smoke coming from the exhaust this only used to be on start up but now if I give the car more throttle it still blows out white smoke, white smoke not blue. I checked the plugs to see what they where like as I have new ones to replace them anyways but when I removed the plugs 3 out of 4 had some oil on them and all where black. If you even "dip" a new plug in it will come put with a slight bit of oil. Does anyone have any ideas? I thought it may be valve stem oil seals but hope it's not as bad I'm off for a week so would like to get it sorted in that time any replies would be appreciated.

[Brink]

Possibly careless filling and there's oil in the spark plug recesses? Can you clean them thoroughly when the spark plugs are out? Be careful nothing falls through to the cylinders of course. Make sure you clean the coil pack as well. Then see if there's still oil about when you stick the plugs back in. If you run it and the oil returns If it is then it might be the cam shaft cover gasket leaking possibly. However I don't know that much and there's a lot of very good vX engineers here that can give more accurate info.

[AKSport]

I haven't put any oil in since I got it, I have everything for a full service. But would rather get this problem sorted then service it. Do you know how I would go about cleaning the recesses? Thanks for the reply

[Alanco]

Hi AKSport,

Only a suggestion but I'd try and see if you can get hold of a compression tester and carry out a wet and dry compression test ( wet & dry ie - do the compression test as normal on each cylinder then squirt a small (small) amount of oil down each plug hole and repeat test, if compressions are sugnificantly higher on wet tests it would indicate rings letting by and could explain the black plugs and smoke.

Does smoke clear if car left running ?

If tests do point to rings, it dosn't always mean engine knackered, if the cars been laid up for a while the rings or oil control rings could just be jummed up and not sealing properly, there are oil additives on the market - search forte - which are designed to clean the crap out and allow the rings to move freely - Its worth doing before you consider ripping anything apart.

As far as cleaning the recesses, I'm not convinced this would cause your issue, only way I can see is jam a rag down each hole but as Brink says be careful not to push any crap down plug hole, blow holes out with air line before taking plugs out (wear eye protection)

Al

[Brink]

Oil can hang about in those recesses for a long long time. Just use a cloth and make a long thing taper then just twist it round in the recess a while. Until the bulk is gone you won't know if it's a historical issue or an ongoing one.

As mentioned just be careful about debris around the plug holes. Don't knock any in the cylinders. Wash the plugs in petrol and wipe off the coil pack with a moist rag with petrol so it's clean. Pop it all back together again and give it a run. If the oil returns you are likely to have a leak somewhere.

[Hardcore]

Seems like it might be valve steam oil seals.
Can you smell burning oil out the back when you start it?

What's the mileage on the engine and does it have any service history?

[Brink]

I am not so sure it's internal. The oil is at the top of the plugs above where they screw into the cylinder head. Unless they were loose and the olds been pushed back up the thread and coated the upper part I would investigate why they have oil there first? As I say. Not an expert, just doing lateral thinking.


just thinking though. White smoke is likely to be unburnt fuel? Does the engine sound as though it's misfiring?

[AKSport]

Hi AKSport,

Only a suggestion but I'd try and see if you can get hold of a compression tester and carry out a wet and dry compression test ( wet & dry ie - do the compression test as normal on each cylinder then squirt a small (small) amount of oil down each plug hole and repeat test, if compressions are sugnificantly higher on wet tests it would indicate rings letting by and could explain the black plugs and smoke.

Does smoke clear if car left running ?

If tests do point to rings, it dosn't always mean engine knackered, if the cars been laid up for a while the rings or oil control rings could just be jummed up and not sealing properly, there are oil additives on the market - search forte - which are designed to clean the crap out and allow the rings to move freely - Its worth doing before you consider ripping anything apart.

As far as cleaning the recesses, I'm not convinced this would cause your issue, only way I can see is jam a rag down each hole but as Brink says be careful not to push any crap down plug hole, blow holes out with air line before taking plugs out (wear eye protection)

Al

I will try and get hold of a compression tester and give that a go! Will clean the recesses later and fit the new plugs then take it for a run (learners insurance) and see how that goes! If this doesn't clear are we looking at valve stem oil seals? Thank you for the great reply!!

[Hardcore]

If the oil is external, then it wouldn't be able to reach the electrode on the plug and that electrode looks like it has cooked oil on it.
Likewise, it shouldn't cause smoking from external oil unless the HT lead was gunked up.

I only say as the X14XE & X16XE Sport engines are known for the valve stem oil seals to wear or harden after a while. The symptoms are the cylinders fill up with oil overnight as it drips by and causes rough running / burning oil on first start up.

It might not be this, but seems likely given symptoms.

[AKSport]

The plugs do look rather old to be honest, the oil is only on the threaded bit and the nut style bit, none has been found on the tip, could be rocker cover gasket then? But saying that why would it be blowing out white smoke, engine sounds 100% belt done at 60k supposedly. Car is now at 86k mark, was told it was owned by a man who works in vauxhall who had it all original and just in his garage til the fella I bought it of got hold of it and put the vx performance inlet on it and lowered it, car is soils body wise no rust underneath at all. But just want to get the engine sitting spot on before I pass my test

[Brink]

Hardcore know far more than I do lol. The oil could have transferred to the thread if you touched the sides of the recess as you pulled them out but to be honest I would consider hard cores answers more than mine.

[AKSport]

I have read the same, which has made me look further into just to make sure before the head starts to come off. How would I know if it's just the valve stem seals or If the piston ring is damaged as well?

[Hardcore]

Run the engine until the smoke clears and warmed up. (if it's in the cylinders this will make sure it's all burnt off)
Pull plugs then clean all around where the plugs go in until clear of oil.
Clean plugs in petrol until clear of oil as well.

Pull the plugs the next day, before starting the car and check where the oil is on them then.
If it's on the tips of the plugs then it's internal but if they're clean at the tops and oil further up probably just a gasket issue.

[AKSport]

That sounds the best idea to do before I start jumping to conclusions, thanks for the help boys will be back on tomorrow with the results!

[Alanco]

My logic (its probably flawed was)

If it clears its probably valve stem oil seals as they leak into the cylinder when not in use then it gets burnt off.

Compression test wet/dry will show if its rings

If its rocker gasket it would explain oil on nut but not on threads and not blackness of plugs.

I would see what its like with new (clean) plugs to work out if its in or out.

Again search forte as they also do an aditive designed to resoften valve stem oil seals etc which you add to the oil run then drop oil out and refil with fresh. worth a try before you go to the expense of ripping head off and NO I dont work for forte , but have used their stuff loads in the past with good results.

Al