Oil leaking

Post by **muggwump** » Mon Jun 30, 2008 1:11 pm

Just bought a 1965 convertible. On the way home with it I noticed an oil smell and on getting home I looked underneath to find the whole of the length of the car from the gearbox back to be covered in oil?
It seemed to be coming out of the engine and gearbox drain plugs and also dripping from the splitpin dangeling from the little hole at the bottom of the gear box.
I tightend the engine and gearbox drain plugs but wasn't shure how far to go with them?? They could still be tightend up maybe a bit more.
Anyway my wife nipped out for 20 mins or so in the car and when see got back I checked underneath. Its as bad as before

Again the worst drip seems to be comng from that little hole with the split pin. I wouldn't of thought that oil should be in there

Any ideas, the car had been standing for arounf 6 months before I drove it. Also it had not long since had a few mods, 1340cc engine uprated alluminium radiator disc brakes, gas shockers etc etc...
It doesn't drip when its cold I don't think.

Post by **ColinP** » Mon Jun 30, 2008 1:24 pm

Hi,

The giggle pin (the split pin) is inserted to keep the drain hole clear.

Oil leaking from there is coming past the rear crank seal (not always oiltight) into the clutch bell housing - not good!

The oil drain plugs always benefit from a new copper washer (this takes up the slight irregularities in the plug/sump interface.

I also find it helps to clean all the muck & grit from the sealing surfaces before tightning the drain plugs.

Which enging block is it? - a standard 1098/848 A series - or a later one?
I think there's a difference in the rear seal.

Colin

Post by **muggwump** » Mon Jun 30, 2008 1:34 pm

Hi Colin,
The engine is from a midget 1275cc.
If it is oil leaking from the rear crank seal, then what does that signifiy and how big a job is it to put right

Post by **muggwump** » Mon Jun 30, 2008 2:32 pm

could it be a breather problem. I have noticed the car running quite hot. The temp gauge was at 90c and the inside of the car was very warm without the heater turned on. The heater control lever in the car was really warm.
How do I check for breather problems?

Post by **alex_holden** » Mon Jun 30, 2008 2:45 pm

90C is normal if you have an 88C thermostat fitted. If it creeps up to 100C or higher there could be a cooling problem.

You need to look at how the breather pipes are connected up (there are several different arrangements that will work, some better than others) and check that they are not bunged up with mayonnaise.

Post by **muggwump** » Mon Jun 30, 2008 2:54 pm

so is the rear oil seal a pig to change. I see ESM do a rear crank oil seal conversion for this engine. Anybody used that.

Post by **Stig** » Mon Jun 30, 2008 3:03 pm

muggwump wrote:so is the rear oil seal a pig to change. I see ESM do a rear crank oil seal conversion for this engine. Anybody used that.

Erm, there isn't really a seal there to change. Most worn engines will leak a little oil from the rear of the crank but if there's pressure in the crankcase due to poor breathing that can turn into a significant leak. Ideally the crankcase needs to have lower than ambient pressure by sucking out the fumes into the air intake/carb. Probably into the carb if it's a 1275, is there a pipe from the front timing cover?

Post by **muggwump** » Mon Jun 30, 2008 3:07 pm

I'll have a look for the pipe. What should I do with it to check it is clear?
The car has a very bad vibration through the prop shaft, could this vibration which I suppose is ultimatly effecting the crank, cause oil to leak out? Just a thought

Post by **Stig** » Mon Jun 30, 2008 3:35 pm

I occasionally pull the pipe off the carb and blow down that end (should feel easier with the oil filler cap removed). I've a feeling that the timing cover breather of the 1275 didn't fit with Minor pulleys or something - hopefully someone knowledgeable will enlighten us. I'm just wondering if it's been removed and there's not another breather fitted on the rocker cover etc. to do the job.

I doubt the vibration would affect the crank much - more likely to trash the gearbox first!

Post by **Packedup** » Mon Jun 30, 2008 4:55 pm

Stig28 wrote:I occasionally pull the pipe off the carb and blow down that end (should feel easier with the oil filler cap removed). I've a feeling that the timing cover breather of the 1275 didn't fit with Minor pulleys or something - hopefully someone knowledgeable will enlighten us. I'm just wondering if it's been removed and there's not another breather fitted on the rocker cover etc. to do the job.

The 1275 has a breather on the timing cover, that fouls on the fan. This can be overcome by cutting it down and welding a flate plate on, or by simply hitting it a lot with a hammer!

I've got a rocker cover with breather on my Midget as well as the timing cover one, and IIRC my 1275 Metro has the timing cover one as well as the one off the bellhousing/ transfer gears casing.

Two breathers always seem a better idea than one IMO.

Post by **muggwump** » Mon Jun 30, 2008 9:01 pm

This is my engine bay set up. Hopefully someone who knows what the're looking at will tell me what may be wrong.

In more detail. I have a thick pipe going from the carb to a cylinder on the right hand side of the block. When I disconnect that pipe and blow down it it seems clear. Just to the right of that pipe is a slightly thinner pipe comming off the carb. That one is not connected to anything and not blanked off. When I covered that up the engine died.
The rockercover has a blanked off breather on the top. When I tried connecting the unconnected pipe to that the engine wouldn't run.

The very thin pipe from the top of the distributor seems to have been cut and melted closed??

There is also a thin pipe coming off the top of the carb that has been blanked up?

Any ideas are very welcome. I was hoping that the oil leak through the rear of the crank into the bell housing would be just down to poor breathing but who knows. Maybe the rocker cover breather needs to be connected to the carb in some way too

Post by **simmitc** » Mon Jun 30, 2008 9:16 pm

Looks like a nice set-up. The bet pipe from the top of the rocker box (now sealed) used to go to the standard air filter. Your new arrangement uses another method - I will let the 1275 brigade comment further. As to the "improved" rear seal kit, don't touch it with a barge pole. Major engine out job and need specialist machinery to get bearing caps flush, then the seal runs against the flywheel boss - except 90% of cranks are outside the size tolerance, and the seal leaks more than the standard screw arrangement.

Post by **IslipMinor** » Mon Jun 30, 2008 9:25 pm

The crankcase ventilation looks as it should be. The 'thin' pipe is the carb vent and should not be connected to anything. Is the oil filler cap the vented type? It must be for the whole system to work.

If you take the oil filler cap off while the engine is idling, there should be a slight increase in speed, and definitely no smoke of anything coming out of it. If there is, the rings are not sealing properly.

Post by **muggwump** » Mon Jun 30, 2008 9:50 pm

How would I tell if the filler cap is a vented type?
Also if the engine speed does increase and there is no smoke or anything coming out then what could be the problem?

Post by **Willie** » Mon Jun 30, 2008 10:29 pm

The oil filler vented cap will have a metal gauze filter in it, i.e. it is the
INLET for air to get into the engine. You wash it in petrol every 12000
miles!

Post by **muggwump** » Tue Jul 01, 2008 3:43 pm

Ok so I've just been to try some of the ideas.
Firstly I checked the oil level. Now bearing in mind that the car has done about 200 miles with me since I picked it up and has been leaking oil over that time the level was showing just about full? I know that the car went for its MOT the day before I pickeed it up and the chap said that they had filled the oil as well. I don't suppose this could all be caused by an over full sump could it?

Anyway that aside, I brought the car up to operating temperature which would seem to be 90c on the gauge. The oil pressure started at 70 and gradually went down to 45 ish once up to temperature. A blip of the throttle sends the oil pressure up to 75 ish, I'm a bit of a novice at this so hopefully somebody can tell me if there is anything untoward in those figures.
I then took off the thick pipe at the carb end, the one that goes to the canister thingy on the side of the block. This made the engine cut out.

I started the car up again and let it run for a little while and removed the oil filler cap. There was no woosh of released pressure or fumes or any smoke but this made the engine slow slightly and tick over more erraticlly.
I inspected the cap and it is solid plastic, no metal gause or anything in it and I can't really see how air can get intothe rocker cover here if this is supposed to be the air inlet for the breather system.

I had wiped any drips from the bell housing and split pin before I started all this and inspected through out and at the end. There didn't seem to be anything coming out. Maybe it's something that happens when the car is moving??

Any futher thoughts on the above are very welcome.

Post by **Stig** » Tue Jul 01, 2008 3:57 pm

Are you really really sure about the cap not being vented? 'Cos it looks like a vented one in your picture. A vented cap has some barely visible slots around the outside at the top and a 10mm(?) hole in the plastic at the bottom which you can see the gauze through. I thought the non-vented ones were simpler and sort-of rounder looking.

Anyway, it sounds like the pipe to the carb is sucking if blocking/unblocking the hole for the filler cap changes the engine note. Sucking through a bit of resistance if taking the pipe of the carb stalls the engine (let's more air in and weakens the mixture).

Maybe it was over-filled with oil but it doesn't take much oil loss to make quite a mess. I'd suggest you keep an eye on it and measure the oil consumption over a few hundred miles.

Post by **muggwump** » Tue Jul 01, 2008 7:52 pm

Just been to carefully check the oil filler cap and it's deffinatley not a vented type.
Also now the car has cooled it has left a nice fresh oil pach from the split pin hole.

Post by **bmcecosse** » Thu Jul 03, 2008 11:45 pm

Cap is better NOT vented - the engine is sealed and any fumes passing the piston rings are sucked away into the carb. This minimises any leaks or nasty smells and works well. A series engines do tend to leak a bit of oil - don't worry too much about it! Your oil pressure sounds fine - although temperature is high for summer - but ideal for winter. I suggest a lower value thermostat - say 74 degrees for summer and keep the higher value one for winter.

Post by **Willie** » Fri Jul 04, 2008 7:57 pm

On the breather systems which should have the VENTED cap the engine revs SHOULD drop if you remove the cap, this proves that the system is working correctly so I suggest that you buy the vented cap pronto. You may then have to reset the mixture but,hopefully you will lessen your oil problems.