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big oil leak

B

BVDP

Enthusiast
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16
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Belgium
Hey,

I have been following some threats here but have not posted a lot. I have a problem now so here I am.

Last winter I have rebuild my 850 cc engine. Engine out and open, new bearings, seals and gaskets, liners and pistons, oil pump, etc... Engine painted, a lot of parts coated,… Engine back in the car and complete fitted with cooling, oil, filters,.... When I try to start the engine it is no problem; starts immediately. The only problem is the engine starts to leak big time because the sealing of the oil filter is pressed out.

Any ideas what can be wrong? I suppose the oil pressure is high because the oil is trapped in the oil filter.

I have tried to find out how the oil finds its way in the engine. It is sucked up by the oil pump and goes from there to the oil filter. The oil comes in on the outside of the filter and goes through the filter and mounting tube to the engine. Anyone an idea how it goes further or am I missing something?


Regards, Bart
my beautifull but leaking engine:
2v91y50.jpg


2cwmr79.jpg



the pressed out seal:

50glms.jpg
 
Hallo Bart! -maybe obvious,but are you Sure the O-ring on oilfilter was properly seated before initial start?
otherwise you must have a Considerable pressure-build-up in there -R.
 
Yes, I have tried two new oil filters differerent brands, same result. I have also blown compressed air through the mounting tube of the oilfilter and heared a sissing sound so some channels must be open.
 
Hello Bart, has your oil filter got the M20x1,5 thread? I know there are 2 different threads available.

You're correct in saying that the oil goes into the filter through the small outside holes and then through the filter and back into the engine through the big centre hole.

The last filter that I bought had a piece of clear protective plastic over the little holes. Silly question, but did you also have it, and remove it?

When you tighten the oil filter did you lubricate the gasket first. It's to prevent the gasket from slipping out of place. Is it a good seal after tightening?
 
I have the 3/4 -16 thread. It is smaller as the M20. I am sure it is the right tread. If not, the filter would be pushed away, not the seal . Right?

I have lubricated the seal. No plastic to remove.

While building up the engine, I have lubricated all the bearings with Nulon Anti Seize Xtreme Pressure to prevent damage when the motor starts for the first time. It was recommended by the local car parts shop. If the Nulon is stuck in all the oil channels, they are blocked and the oil pressure would be high after the filter. Probably high enough to push the seal out with the new oil pump. As the oil pressure in the cam chamber would also be high, I think the oil would find a way around the camshaft seal. It is not a proper seal but a kind of mechanical through back. I do not see oil at all in that area. That’s the most likely hypothesis now, only the lack of the oil on the end of the camshaft does not fit in that story. All ideas are welcome.
 
i have a 1983 850cc and I take the metric thread.
3/4 inch is 19mm, a bit smaller.

Do you still have the old filter, perhaps put that on and see what happens.

Trying to follow your thoughts, if the oil seal gets pushed out, then won't the pressure be higher there, where the little holes are?That is before the filter and before the oil chambers. So maybe your oil filter is not screwing in far enough and clamping the gasket tight enough. How can the gasket get pushed out because it sits in a channel.

Beautiful clean engine you have!
 
I have been using the same brand of oil filter for years, Always the 3/4 thread. Don't ask why I am sure :-).

I have also measured the part of the thread that sticks out and the oil filter can go far enough on the tread. I have tried two oil filters (different brand), same result: gasket pushed out. You are right; the oil pressure will be higher before the filter. There will be a pressure drop because of the filter.

The only reason the gasket is pressed out seems to me a very high pressure. I will think about it and try to check. I am afraid I have to pull out and open the engine again though. It would be nice to have some ideas what to look for before I open it.

My car is a 1986. Yes clean motor. Wish it was dirty and running though :-)

Regards, Bart
 
Hello Bart and welcome to the forum,

Something is seriously blocking the oil from circulating and thus creating a massive pressure buildup...
One thing is sure the oilpump is working, and it should normally pump the oil outside-in trough the filter and then it should run trough the various oil channels to the crankshaft bearings, piston bearings, camshaft and rocker axle all simultaneously. At the end gravity takes over and the oil falls back to the sump.

On engine rebuild and especially the crankshaft and piston bearings I would never use any form of paste such as that Nulon Anti Seize Xtreme Pressure product just plain engine oil is sufficient for the older Ventoux, Billancourt and Cleon engines. Remember in the early days they didn't use such a product as it didn't exist at all in those days, and I've never seen any recommendation in any MR, RTA or Haynes manual for such a product.

Maybe a small test with compressed air coupled on the oil filter thread might give you an insight...

But I assume the engine has to be re-opened completely again, checked for any blockages in all the oil channels, all the bearings have to be checked and cleaned as they are critical and make part out of the oil circulating circuit, as well as the camshaft and rocker axle.....
 
I did connect compressed air to the oil filter mounting tube. I could hear the air comming out some where but not a lot of it.
Used the nulon because I knew it would take me weeks/months to rebuild the engine and I was afraid common oil would leak out the bearings in the period between mounting and starting. Not a good idea it seems afterwards.
I will start to pull out the engine. Seems the only option left to be sure no damage is done to the motor. I will keep on posting here.

Regards, Bart
 
I know this might sound daft but I don’t suppose you have left another filter seal on the engine therefore have two seals on it !!
 
I like the way everyone is trying to help me :-). Never thought of this one but sure it is bare metal.
 
jt8o7n.jpg


2j1skl1.jpg


The engine is out. Seen the first picture before :-)
Oil is on the cam shaft and I think more as left over after filling. I also see the nulon. Not good.

regards, Bart
 
Yeah darn it..... you can clearly see the Nulon has forced its way through the rocker axle oil channel :(
So other channels are surely affected as well as the thin bearing channels...
Don't know about the distribution chain tensioner on Billancourt engines, I'm used to Cleon engines and they have an oil channel towards the acting hydraulic tensioner.

Take the engine apart (again ;)) but be sure to keep the piston liners fixated so the thin paper seals won't break...
Good luck with the re-rebuild Bart and please keep us informed on the progress with the pictures accordingly.
Cheers, Joop
 
I have connected a pressure meter to the motor. Result:

new pump gives more than 6 bar ( the needle is been round so more than 6 bar), the old one between 3 and 4 bar. Should be 1 bar or so. Something seems to block the oil circulation. The pressure is building up in half a minute.
Tomorrow evening dismantling the crankshaft, cam shaft and rocker shaft.

2udywy9.jpg
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BVDP....thank you.....

Sorry to hear you have trouble with already refurbished engine.
You want best for it and it backfires to you!
 
petak said:
What is nulon?
Click to expand...
@ Hrvoje,
Extreme Pressure Anti-Seize Lubricant
Nulon Extreme Pressure Anti-Seize Lubricant is a complex bentone based lubricating paste containing a high percentage of polytetrafluoroethylene (PTFE). Nulon L90 provides extremely high film strength and adhesion, protecting against initial start-up damage of machinery even after long periods of lay-up. Nulon L90 provides long-term lubrication of components that are otherwise difficult or impossible to lubricate after initial assembly. Most chemicals, solvents and corrosive agents do not affect Nulon L90. L90 does not dry or harden with age and offers performance over a wide temperature range. L90 protects exposed components against rust during lay-up. L90 permits more even torque pressures and faster breakouts of threads, joints, flanges and gaskets.​
Source: http://www.nuloneurope.com/en/products/53-lubricants/129-extreme-pressure-anti-seize-lubricant
 
On most engines the oil pressure is limited by a pressure release valve with a spring. Normally it is hidden behind some big bolt head on the block near the oil filter. I don't know about the R4 engine; but 3 or 4 bar gauge pressure is typical before the spring releases the pressure. More likely that than a blockage elsewhere.
 
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