Oil Leaks

Post by **billlobban** » Wed Oct 07, 2009 5:29 pm

Pleased to say that Matilda the Minor passed her MOT with flying colours yesterday not an advisory to be seen. Went out for her first long run. Performance great - no problems at all. Unfortunately the oil consumption is horrendous. Doesnt appear to be burning any and doesnt appear to have the crankcase pressure mentioned elsewhere but is leaking like a sieve from the front of the timing cover and a little from the rear of the sump.
Question can I replace the timing cover seal without hauling the engine out - likewise the sump gaskets. If so any general advice

Post by **PSL184** » Wed Oct 07, 2009 5:39 pm

Yes, both can be done with engine in. You'll need rad out the way to get at the timing cover and car up on ramps to get to sump. The sump bolts are a bit awkward when you are lying on your back but not impossible.... When you fit the small gaskets into the half circle shapes in the sump you will have to cut them down because they are supplied too big - BUT - Leave them about a quarter inch high either side so that they get compressed when you tighten the sump up. You may also find it easier to soak them in water first (I'm assuming cork gaskets) and fix them in place with some grease whilst you tighten everything back up.

Post by **billlobban** » Wed Oct 07, 2009 6:52 pm

Thanks PLS I'll order the bits

Post by **RogerRust** » Wed Oct 07, 2009 7:21 pm

I doubt it's the sump gasket - much more likely to be the infamous scroll oil seal on the crankshaft where it exits the engine en route for the gearbox.

Post by **aupickup** » Wed Oct 07, 2009 7:22 pm

and a lot of that is down to engine breathing

Post by **bmcecosse** » Wed Oct 07, 2009 10:01 pm

I did wonder what the trail of oil along the street was - outside Aviemore Station this morning! And not a Minor to be seen - even though I walked the length and breadth of the village! Yes - you can change the gaskets and timing cover seal (remove radiator for that one) - but as hinted above - these leaks are often caused by crankcase pressure forcing the oil out. To check - hot engine - remove oil filler cap - rev up engine. Is there a plume of fume/smoke from the filler ?? To rectify - make sure breathers are clear - and connect one of them to the carb inlet, so it 'sucks' away all the fume! If that fails - overhaul or transplant required i'm afraid. Well done on that MOT. Maybe I should run my Trav up to Aviemore for it's MOT in future ?

Post by **billlobban** » Wed Oct 07, 2009 10:47 pm

Sorry I missed you BMC I was out coating the A9 between Aviemore and Inverness in 20/50. Hope you enjoyed your trip on the cho cho.
Will go over all of everyone's advice in the morning. The breather pipe from the rocker cover is connected to the air filter and there is another from the cam cover.
What should the cylinder pressure be on a 1098? as I would like to do a compression test.
I can thoroughly recommend Dulnain Bride Garage - rather old fashioned little place with people who like classic cars. Bit far to come just for an MOT though.

Post by **bmcecosse** » Wed Oct 07, 2009 11:16 pm

It's a great run up to Aviemore - although not sure my Trav would stand the hard thrashing to get past the artics on the short straights on the A9! Ideally - the pressures should be 160 psi or better - but 140 would be ok. Main thing is - they all should be much the same.

Post by **billlobban** » Thu Oct 08, 2009 12:54 pm

Compression test was 2 at 140 an 2 at 150. Both breathers are clear. When hot no smoke from the oil filler cap but there is quite a bit of pressure if I put my hand over the filler hole.
Flushed out the engine this morning and replaced with new 20/50. When hot there is a tiny drip from the bellhousing drain (got some sort of split-pin thing in it) but a continual drip, drip, drip from the timing cover front oil seal.
Looks like I might be going back to my childhood as its 40 years since I last rebuilt a 1098

Post by **bmcecosse** » Thu Oct 08, 2009 1:46 pm

billlobban wrote:Compression test was 2 at 140 an 2 at 150. Both breathers are clear. When hot no smoke from the oil filler cap but there is quite a bit of pressure if I put my hand over the filler hole.
Flushed out the engine this morning and replaced with new 20/50. When hot there is a tiny drip from the bellhousing drain (got some sort of split-pin thing in it) but a continual drip, drip, drip from the timing cover front oil seal.
Looks like I might be going back to my childhood as its 40 years since I last rebuilt a 1098

Compressions not too bad then - but obviously there is some bypass if you can feel 'pressure' on the oil filler ! The only answer is to make sure the carb can pull the fumes away - and burn them.

Post by **billlobban** » Thu Oct 08, 2009 2:47 pm

BMC the breather from the rocker cover is connected to the air filter is there anywhere to get a better vacuum.

Post by **bmcecosse** » Thu Oct 08, 2009 10:37 pm

Yes - very much better if directly to the carb - the later HS2 carbs have a brass tube on the side specifically for this. Connecting to the air filter casing - just spreads oily mess all over the filter! If you can't find a newer carb - then it is possible to make a hole in the aluminium mouting plate for the air filter - and put the breather pipe in there - at least then, it's not contaminating the filter. On a 'difficult' high power Mini engine I had recently - I used the servo take-off on the inlet manifold (servo not required on small cars like Mini/Minor!) - blocked it off with araldite - then drilled a 1/8" diameter hole in the araldite - and connected the breather to that. Completely solved all leakage problems, no more sore throat due to breathing in oily (carcinogenic!) fumes - and the oil consumption of the engine dropped dramatically - because oil was no longer being pushed up past the oil rings. It did make the already lumpy idling slightly more lumpy - otherwise - the engine ran every bit as well as before, and blue smoke after a period of idling was much reduced, although not eliminated.

Post by **billlobban** » Fri Oct 09, 2009 8:34 am

Thanks for all the info will report back with results

Post by **David53** » Sat Oct 10, 2009 4:05 am

I still have a slight oil leak at the rear, just a couple of drops after stopping. If I want to check the pressure in the engine are you saying I should feel no pressure at all placing my hand over the oil filler hole when running? My rocker cover tube goes into air filter (oil bath) and the crankcase breather is clear I'm sure.

I am actually wondering if when driving along if I am getting drips from the timing cover felt seal which are "blowing back" and hitting the plate at the rear, then dripping off when cooling. After my recent 900 mile run there was quite a bit of oil to wipe off the bottom of the gearbox and crossmember as well as some on the sump.....Front seal is going to be replaced with a leter Mini cover and rubber seal so I guess we will see.

Post by **bmcecosse** » Sat Oct 10, 2009 9:38 am

All that oil is excellent rust proofing -don't wipe it off!

Post by **David53** » Sat Oct 10, 2009 11:06 am

Ahh yes but after a run it was dripping from the surfaces and made me concerned about where parked - some people have very nice clean driveways!

Post by **bmcecosse** » Sat Oct 10, 2009 11:09 am

Yes - from time to time my wife does say we used to have one of them!

Post by **mike.perry** » Sat Oct 10, 2009 5:36 pm

"Chassis Lubrication"

Post by **billlobban** » Sat Oct 10, 2009 6:38 pm

In my case it was more like road lubrication I was just short of needing to apply for a licence to SEPA (Scottish Environmental Protection Agency) for the disposal of toxic waste

Post by **mike.perry** » Sat Oct 10, 2009 9:39 pm

You were recycling it. It came from the ground, you were returning it to the ground.