2ASeries484G

New Member
Had a problem with my 2a's 2.5NA where the furthest away tappet shaft fills up with oil as soon as the engine starts. Not long had the landy, have done 250 miles of short journeys in it no problem. I topped up the oil to the "full" level on the dipstick directly into the sump through a pipe that comes out the side (was thinking of the 2.25 oil filler and decided against putting it through the rocker cover hole for the breather cap). Drove fine for 20 miles home or so.
Next day I had it on the motorway, after climbing a big hill slightly faster than I should have, I could smell hot oil and the oil pressure warning light was flickering. Pulled over and lots of oil was dripping down the block onto the ground. The breather cap had popped off too, it was connected to a chassis lubrication bottle instead of the inlet manifold. drove further with the pipe off the cap after topping up the oil (the correct way this time) and found that oil had been coming out of the filler cap pipe, not necessarily the rocker cover gasket.
Made it the 100 miles or so slowly and the problem seemed to go away. Ran the landy a few days later and the same problem happened with oil coming out of the filler cap pipe.
There is some blowby I can feel when I take the cap off when the engine was running, the dipstick was also under pressure the first time I stopped on the motorway but this hasn't happened since.

With the rocker cover off, I can see the furthest back tappet shaft (No. 4 Exhaust) filling with oil quickly and then pouring all over the block. The pipe the feeds the rockers is clear and some oil also pumps through this.
Had the head off and the same problem occurs. I usually get no smoke when the engine's been running a few minutes and good power which suggests it's unlikely to be a piston ring.

Has anyone seen this problem before or have any idea what's causing it? Are there any inspection covers on the o/s of the block I can open to get access to the cam/tappet etc.
I'm working on the street at home so would rather not take the sump off if can avoid it.

TIA,
Adam
 
Had a problem with my 2a's 2.5NA where the furthest away tappet shaft fills up with oil as soon as the engine starts. Not long had the landy, have done 250 miles of short journeys in it no problem. I topped up the oil to the "full" level on the dipstick directly into the sump through a pipe that comes out the side (was thinking of the 2.25 oil filler and decided against putting it through the rocker cover hole for the breather cap). Drove fine for 20 miles home or so.
Next day I had it on the motorway, after climbing a big hill slightly faster than I should have, I could smell hot oil and the oil pressure warning light was flickering. Pulled over and lots of oil was dripping down the block onto the ground. The breather cap had popped off too, it was connected to a chassis lubrication bottle instead of the inlet manifold. drove further with the pipe off the cap after topping up the oil (the correct way this time) and found that oil had been coming out of the filler cap pipe, not necessarily the rocker cover gasket.
Made it the 100 miles or so slowly and the problem seemed to go away. Ran the landy a few days later and the same problem happened with oil coming out of the filler cap pipe.
There is some blowby I can feel when I take the cap off when the engine was running, the dipstick was also under pressure the first time I stopped on the motorway but this hasn't happened since.

With the rocker cover off, I can see the furthest back tappet shaft (No. 4 Exhaust) filling with oil quickly and then pouring all over the block. The pipe the feeds the rockers is clear and some oil also pumps through this.
Had the head off and the same problem occurs. I usually get no smoke when the engine's been running a few minutes and good power which suggests it's unlikely to be a piston ring.

Has anyone seen this problem before or have any idea what's causing it? Are there any inspection covers on the o/s of the block I can open to get access to the cam/tappet etc.
I'm working on the street at home so would rather not take the sump off if can avoid it.

TIA,
Adam
head oil supply is fed to rear of head by a transfer pipe, ive never heard of head cracking there so allowing oil to pump straight into the cam gallery,crankcase pressure could be piston ring /bore issue ,head gasket or valve not opening fully
 
Thanks jamesmartin. This problem still happens with the head off so that eliminates a few of your suggestions. I have ordered a compression tester so can check piston rings as a faulty compression ring may be pressurising the crankcase.
 
If you have excessive crank case pressure (which it sounds like you do) make sure you check the crank case ventilation system. The oil filler cap on my 3MB engine has a gauze infill that needs to be cleaned once in a while.

A compression test should help give an idea of engine health but as you've just bought the vehicle there could be a multitude of hacks / problems that have been "hidden"...
 
I think there may have been a problem with the ventilation through the rocker cover, this is the main crankcase ventilation for the 12J. Will try a compression test and pray I don't have to remove the head again to replace rings. You're absolutely right about bodges, found the steering relay had been bolted with M10 screw head roofing bolts instead of the correct 1/2" bolts.
 
To the best of my knowledge, the 2.5NA is the 12J, military version was 13J and the first turbo version was 19J.

I think the oil is coming through the rocker shaft slowly, I have had the shaft off and the rockers don't seem excessively worn. The oil's definitely coming up from tappet number 8 right at the back of the head. I've made a dropbox with videos of first the oil collecting at the back of the head, and second, with the rocker cover back on and oil filling the rocker box slowly.
https://www.dropbox.com/sh/odls4yo32r6hqsb/AACE1I-_J0AV9lsStd0m5eWMa?dl=0

My engine has had a chassis lubrication system implemented with a radiator header tank-type bottle at in the engine bay with a pipe from the inlet manifold, one into the chassis where there were grease nipple-like things which have since been cut off and a tube going from the box into the sump by a pipe that has been welded into the top of the O/S sump side.

After I removed the pipe going into the sump, oil started to spit out and the high oil level within the rocker box began to drop to just above the bottom lip of the rocker cover. This header tank had a radiator pressure cap on it which I have removed, hopefully the fumes can escape through the top whilst trapping some of the oil around the insides of the tank.

I did a compression test last week with the cylinders dry and got 300, 260, 350 and 380psi from cyl 1-4. The bores are in really good condition with hardly any step at the top so I was surprised at these results, the engine is also not smoky at all after 5 minutes or so of heating up. It may be then that the compression rings are failing in cyl 2 at least, and going the same way for cyl 1. I think sadly I'll need to remove the sump to investigate the oil pump and whether the pressure release valve is sticking in one position.
 
Tell us more about the chassis oiler. Some pics if possible. I think that could the cause of a lot of problems, if it were mine I think I'd junk it. Could be more trouble than its worth. I freind of mine restored an old Triumph "bathtub", it had all sorts of pipes on and didn't run properly until they were all in the bin, previous ower had fitted some kind of DIY pressure chain oiler/breather system.
Leave the head where it is for now, there is a rule of thumb for old diesels that more than 50 psi difference is trouble, and having had an engine with 100 psi difference it ran like a dog, yours has 120 but runs well so I'd suspect the readings before takeing anything apart just yet.
 

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