Oil smell?

[sodafeld1]

I keep my 2h, 1988 hj75 pretty clean in the engine bay. It has 280,000km, non turbo. I have been chasing an oil smell when driving. I think I have got any oil weeps eliminated.
Have noticed after a long drive, descending downhill the smell is strongest, perhaps from oil pressure pushing out without throttle.
More noticeable, it also seems with a 15w-40 oil, than my usual 20w-60 mineral oil.

There is little to no engine oil loss, compression feels good. I haven't done a leak down test but I can go up a fairly steep hill in third at 2000rpm. Happy with that.
New injectors and glows, not much visible smoke.
My engine oil filler sucks a little with a sheet of paper on top of the filler hole, doesn't blow out.

It leads me to think that my valve seals may need replacing?

Is it recommended to put some sort of filter between the oil vent hose and inlet manifold? If so, what sort of set up? If it did not restrict air flow it would eliminate oil entering that side of the engine.

 

[Gimme a 60]

I’m not sure if “compression feels good” is a thing. I would do a compression test, because maybe your down one cylinder.

Maybe PCV if it has one?

 

[sodafeld1]

Hmm, interesting. I get 10km per liter which seems pretty good. Doesn't run rough which I would imagine would happen with a cylinder missing..wouldn't it run rough with a cylinder missing?
But, yes worth doing a compression test. Leak down too.

No pcv, runs straight from valve cover to inlet manifold. Wondering if some sort of oil breather is worthwhile to install.

 

[sodafeld1]

Oh gosh, the more I look about, I think the valve seals are ok for a bit longer, no blue smoke, no oil loss. I change oil at the drop of a hat.

I should change my power steer hoses and I also recently put a transfer to transmission bypass hose which are two factors. I do not have even one drip underneath after a 500km drive just yesterday, runs well.
It could even be the transfer valve..could even be a bit of grease flung from a driveshaft to somewhere hot. Probably being anal.

Shall do the compression test for the heck of it.

 

[Gimme a 60]

Yea doing the compression test might be worth it. I should do one on my 3B but I’m a little scared to see the results.

If you smell oil, go the the exhaust when it’s warmed up and give it a good sniff?

On my Toyota pickup it burns up to 1 quart every 1000km. Not sure why, but it has 400,000 km on it so…. Anyways, I can smell it all the time, it’s annoying, but it doesn’t have any blue smoke, even if I give er the beans. I have tracked it down to the engine because I can directly smell the oil at the exhaust.

Good luck, I’m just trying to help to the best of my knowledge.

 

[sodafeld1]

I get the impression it is from the engine bay itself, wouldn't know if I didn't have the window down.
I thought it was the oil filter seal, but have cleaned that up and tightened, no leaks, looks ok.

When I was younger I had a bj40, she was dirty, stinky and neglected, didn't worry then.

Could be a number of things, steering pump hoses for example or secondary fuel filter lines.
Funny thing is I am not loosing fluids anywhere it seems..but it wouldn't take much to make a smell where it is hot. Just have to keep honing her, did the steer pump seals last month. I'll end up replacing everything eventually.

The local car wash has a hot wash now which is helpful.

 

[Gimme a 60]

Maybe you spilt oil when you did a oil change and it trapped somewhere hot?

 

[sodafeld1]

replaced steer transmission hoses, (Using transmission hose by the meter, you can pre shape the curves with wire inside and then submerge in hot water, then cold. Pull out wire, Holds it's shape, 1/2 price than ome, I needed two, another one for the other troopy) no leaks. Tighty bum I am.

Now I think it maybe the valve cover rubber gasket,I replaced that recently too, needs to be nipped up every now and then it seems, if new.

 

[sodafeld1]

Well, my sad news after a compression test is that my 5th cylinder has greater than 10% less compression. It is an ebay compression tester so the numbers are probably not accurate but at least it appears to be consistent readings. I get 450 psi in all cylinders but only 400 psi in 5th. I put a drop of oil in the 5th glow hole and psi went back to 450psi like the others. No need to check the valve seals for now as far as I can see, unless she makes it to another rocker gap check.

I chipped the head in the 5th injector port awhile back,10-20k kms ago, whilst changing injectors. A chip must have scored the cylinder or damaged the rings. I was hoping and wishing I had managed to blow the chip out at the time, but obviously not. Alas.

Unusual thing is that I don't have smoky exhaust at any stage, start up, running slow or cruising on the highway. There is zero oil consumption too. I put that too very clean engine oil I guess, everything else has ultra love and care. No smoky exhaust yet anyway, just some black carbon on the exhaust tip. I can only guess that the oil smell is the first sign from pressurized oil gas in the chamber?

Luckily, I have nearly completed rebuilding a second 2h which was going to go into another troopy I am building. Expensive mistake chipping the injector port. But I have to accept being self taught from here, manuals and trial and error, that learning costs in one way or another.

May as well do the clutch plate at the same time. I started to rebuild the engine firstly, off the wrecked troopy, as that was the fun and interesting bit, compared to the chassis frame rot, especially in the rain we have had.

So, I guess, I shall go back to the 20w-60, avoid 10w-40, and drive her until too ugly. She still runs a treat, can go up a steep hill in 3rd gear at 2000rpm, no smoke, the oil cap sucks at idle, and sounds ace with extractors/headers.. just the pending oil gas smell for now.

The smell is likely to be oil finding it's way down the 5th cylinder and mixing with the combustion gasses, expanding and smelling when the engine is at running temp. Bit embarrassing to admit my stuff up, but worth sharing as warning and educational purposes.

Can folks recommend any snake oils to prolong my inevitable engine changeover?
I see risolene has a thickening oil additive called risolene 4,6,8...?

Alas