1994 Rover 2 Series Wheres the oil going?

Hi there,

You need to do a leak down test as well, now you may have a faulty oil control ring, this won't affect the compression but it will allow some excess oil past and this will burn off at a constant but slow rate, putting a new head on the old block may increase the oil consumption, dose it puff smoke on cold start ups?

mark (mhpautos)

Thanks Mark for your reply.

I was considering a leakdown test but I assumed that if the compresssion wasn't down, a leakdown test wouldn't show bad oil control rings either, am I correct in assuming that, is there any sure what to find out how the oil is getting burned, and why arent the plugs wet considering the amount being lost

cold starts, as far as I know its not smoky but its hot here, 90 deg f approx, there is a slight amount of smoke when warm if you rev high but its very slight.

Thanks again.

Jon

Hi there.

if it's a blue smoke its oil, if a control ring is faulty you will burn small amounts of oil constantly, the plug wont foul as all the oil is being burnt, there is no real test for a faulty oil control ring, short of a visual inspection.

mark (mhpautos)

Sorry to keep asking, but could the fault just as likely be down to valve guides or stem seals as much as an oil control ring?
The pistons had new rings fitted about 30 000 miles ago and before it hardly used any oil.

I put a new head gasket on a few months ago to fix the common corner oil leak on these engines and changed the sump that was leaky too thinking this was were my oil was going because it was loosing a similar amount before I did that but it slowly uses more and more.
I did notice that the valve that wasn't fully closed did have some play in it but I didn't expose any others to see if they were the same.

Thanks again.

Have a great week

Jon.

Hi there,

the oil can be by passing the valve stem seals, when this happens you do get a blue plume on a cold engine stat up then the smoke clears, this is due to hot thin oil running past the seal and sitting in the valve this collection burns off with the first stat up and the smoke is quite visible, with running conditions there is not normally enough oil by passing to be that visible, also if the oil rings are a bit suspect, you may bet a puff when you back off the throttle at a higher speed as this is max engine vacuum and oil will by pass then.

mark (mhpautos)

Thanks for that, sound like a great test.
Will get someone to stand behind when the car is cold.

Thanks once more, you've been very kind and helpful.

Jon.

Hi there,

You welcome, let me know how you get on, good luck.
and thank you fore the vote and message.
mark (mhpautos)

Hi again.

You asked me to update you so here I am :)

I started the car this morning and I didnt notice any smoke, car started instantly as usual but no smoke that I could notice. So does it look like the worst then? I was really hoping it not to be piston related, that will be too expensive to repair :(
one thing I do remember was that when I removed spark plug number 4, smoke came slowly from the combustion chamber, dont know if thats relevant.

Thanks again

Jon

Hi there,

That smoke would just be some incomplete combustion gasses trapped in that cylinder when the engine shut down, go for a drive with some one behind you check for any smoke on acceleration and over run, (throttle off high road speed) see what that shows.

mark (mhpautos)

Ok, ill try to find someone to follow me... so you mean accelerate hardish and then fully let go of the accelerator and see when there is smoke and when there is not?
Ill have o find someone willing LOL,

Thanks again, I'll keep you posted.

Ps, what results mean what?

Jon :)

Hi there , when you back off the throttle at high engine speed, not high road speed, the engine creates a max vacuum condition, with this oil will by-pass rings if there is a problem, this is an indication of faulty oil control rings & general ring tension on the bore.

Mark (mhpautos)

Do i have to be driving to do this test or can the car be parked. Also, will this test differentiate between a faulty oil control ring and worn valve guides or seals.

Thanks again

Jon.

Hi there,
best to do this as a drive test, as i mentioned earlier with high vacuum oil will by pass rings and seals, but..... to be able to see the smoke sufficient oil must be burnt, now normally this will only be possible by oil by passing rings, as there is a bigger surface area for this to happen, you get the puff of smoke on start up as oil has had time to dribble past worn seals when the oil is hot and thin, this is burnt in one go, and faulty stem seals wont normally allow sufficient oil to by pass during normal operations to be that visible, so... oil puff on start up will be stem seals and guides, oil smoke driving and over run will be rings, this is the norm, but there can be exceptions to the rule but this would be unusual.

mark(mhpautos)

Hi Again!

Today I managed to get someone to drive behind me, i did about 5000rpm for a while in 2nd gear and then quickly took off my foot off the accelerator, flashing my hazards to the driver behind so he knew when to look, I also did the same in 1st, I did this about 6 or 7 times, so sign of smoke at all.
I checked again at start up this evening, still no smoke that I could see.
The only smoke I have managed to see so far is with the car in neutral and the engine being revved high, this is the only time i can see a slight amount of smoke, my oil is on minimum again after about 300 miles this time.

I don't see how I can ever find the problem.... its quite worrying thinking Im probably destroying my cat at the same time...

Hi there,

well i don't think that i have asked you what oil you are using? mineral or synth.

mark (mhpautos)

Hi!

Its synthetic 10w40

OK, do a oil change and use a flushing agent and go to a mineral oil, try a 10W-40 or 20W-50. this may help a lot.

Mark (mhpautos)

Hi again, thanks for that advice though this is this is the same oil I have always used in this engine, though changing as you say may help it loose less wherever its going.
I took off the breather tube to the camshaft housing that goes back to the air intake (just before the throttle)
There was no suction from the tube when i revved the engine, eliminating a blocked filter or intake, i put my finger over the tube from the camshaft housing and of it blows and sucks as expected but if i hold my finger on there it actually cause vacuum eventfully rather than trys to push my finger off. Is this the only ventilation tube from this engine or is there also one from below the cylinder head somewhere, I could not see one except for on the gearbox.
Inside the air intake just below the inlet from the crankshaft housing tube was just a tiny amount of thickened oil (less the a quarter of a teaspoon) in the rubber hose that joins to the airbox, that would seem to be about right. Air filter was very clean on top, no oil or any stickiness.
There was a drip of oil under the intake, just before the it joins to the big rubber separator that connects it to the throttle housing itself, i noticed that drip there before too, dont know if thats anything of importance?
Have a good week...

Jon