Squirting oil out of engine

[seaandmoor]

Hi all,
I've trawled the forum but I'm still puzzled! 1973 +2 running fine and last parked in garage 2 weeks ago.
Went to it to-day and started fine.
Off down the road about 5 miles and slight 'tinking' noise then hot oil everywhere.
Lifted bonnet to find it gushing out of the dipstick hole and onto the fanbelt. The whole of the engine bay is a complete mess. Oil pressure is fine and I haven't overfilled it.
Now I know you are going to tell me badly worn bores/pistons and leaking down into the crankcase causing pressure to expell the oil. However, this has been rebuilt in the last three years and since done about 6000 miles. Also whilst setting up the Dellortos on the rolling road the compressions were only been tested 4 months ago and ranged between 170 and 176.
Can anyone suggest how and why am I suddenly getting this problem please? Thanks

[RotoFlexible]

Is it still running OK after the "tinking" and commencement of the gusher? I expect you are reluctant to run it hard with oil spewing out. Maybe the "tinking" was an internal failure that pressurized the sump very quickly. You could also check the breather vent although it is hard to imagine how this could fail so completely and quickly.

I am recalling a recently reported engine failure that filled the sump with water, making it appear that the oil level had risen dramatically.

Just speculation...

[john.p.clegg]

Could be the oil level has been raised by water or petrol leaking into the sump???

John

[neilsjuke]

Do a compression test first

[Frank Howard]

Broken fuel pump diaphragm causing fuel to fill up the crank case. I wouldn't smoke while near the car.

[rgh0]

If oil level still normal and you have not filled the sump with petrol or water then the potential is for a dropped valve or something to have holed or cracked piston and be creating huge blowby presurising the sump. A compression and or leak down test will then tell you what the bad news is.

Rohan

[seaandmoor]

Thanks for quick replies.
It was dark when it happened.
To-day I pushed car out of the garage to have a closer look - what a mess in the engine bay!
First sprayed 'gunk' over everything, left it in sunshine and hosed everything down to get rid of oil and left to dry in sunshine.

Meantime checked Dellortos - fine. (didn't notice a significant fuel loss either)

Breather doesn't go into the airbox as oil vapour used to clog it (and got fumes inside the car) - breather pipe goes into catch can - pipe all clear.

Next checked oil level - just below the top mark.
Before reading replies I had been thinking that any fuel or water in the engine would've vapourised on heating up and the resulting pressure causing oil to be expelled past the dipstick. Oil appeared to be clean after recent change with no sign of emulsion or petrol smell, so I discounted that.
I went to sleep thinking a broken piston ring but this morning thought unlikely as I remembered last time a ring went I had clouds of smoke out the exhaust.

Eventually I plucked up the courage to start it.... no 'tinking' and (with some protection spread over everything to avoid another clean up operation) no oil gushing out of the dipstick hole.
Why last night and not this morning? ? ?
Rohan is so often correct on these things and pressure is usually caused by escape from the combustion chamber so compression test again to see if a cylinder is down although it doesn't feel it.

Is it possible for fuel or water to drain into the engine whilst in the garage for two weeks?
Thanks for help on this - much appreciated.

[seaandmoor]

Just an update on this.
Got the pressures tested... range 171-175
Hasn't happened on the subsequent outing so I'm still puzzled and a little worried as to what caused this but my only option seems to be to wait for it to happen again - consistently, otherwise I'm just boxing at shadows.
Thanks for the thoughts and advice though.

[rgh0]

mmmmmmm - mysterious

The good news is that you appear to have no serious engine damage with the good compressions.

I can only imagine that some how the dip stick came loose allowing oil to come out and the tinkling noise you heard was the loose dip stick. When you stopped the engine the dip stick dropped back into place.

I use a spring from the alterator bracket to the top of the dip stick to positively hold it in place in my Elan as I have had them come loose in competition but not normally a problem in a road engine.

cheers
Rohan

[seaandmoor]

Aaaaaah Rohan,
You are a star. As it happens the roads round this part of UK are twisty and bouncy and I had been wondering if it was possible for the dipstick to rattle out but discounted it - BUT you have had the same experience by the sounds of it. I'm relieved.
I was thinking of taping round the neck of the stick to make it a tighter fit when inserted but I was worried that the tape may slide down the stick into my sump and cause a worse problem. Or that it would make it airtight which wouldn't be a good idea either.
Your solution - a retaining spring Brilliant, I'll get one tomorrow!
Thanks

[robertverhey]

Hi
In my case I stopped oil misting up the dipstick tube with a spark plug lead cover (the long sort). This is a neat fit over the stick itself (the small end) and the tube (the fat end). But I doubt that it would stop a gusher, which indicates something seriously awry.

Robert

[M.J.S]

Your solution - a retaining spring Brilliant, I'll get one tomorrow!
Thanks[/quote]


Always used retaining springs on the dipsticks of my rally Minis - amazing how much oil can pour through a dipstick hole when you land dirty side up.

Mark.