Technical Oil leak...

[AnthonyH]

My Grande Punto developed a metallic rattle which I went looking for today. I found the source of that problem, the oxygen sensor on the exhaust out/down pipe had come loose, it was easy tightening it up. But then I found a small oil leak. Its nothing major at this time, there is a small amount of oil just under the flywheel casing. See the picture, i've had an oil leak from there before which turned out to be the sump, but i'm also aware that the rear crankshaft oil seal is there. I've tried looking but I just can't see where the oil is coming from.

My question is; how do I check the rear crankshaft seal for a leak?

 

[AnthonyH]

I presume its not so easy...

 

[vexorg]

My question is; how do I check the rear crankshaft seal for a leak?

Gearbox off, flywheel off, then you can see it.

 

[AnthonyH]

Gearbox off, flywheel off, then you can see it.

And how common are rear crankshaft oil leaks in GPs? In comparison to other cars.

 

[rmjbn1]

My main rear seal failed on my 1.2 FIRE at around 100k miles / 17 years.

I'd suggest leaving it until clutch needs doing - on mine it contaminated the clutch causing it to slip.

If the oil has a strong smell it could be gearbox oil, the input shaft bearing and seal is famous for leaking.

 

[AnthonyH]

My main rear seal failed on my 1.2 FIRE at around 100k miles / 17 years.

I'd suggest leaving it until clutch needs doing - on mine it contaminated the clutch causing it to slip.

If the oil has a strong smell it could be gearbox oil, the input shaft bearing and seal is famous for leaking.

Ahhh, this 1.2 FIRE car is 88k miles and 16 years old. Its too small a leak and too big a job to do before the car has a serious problem and the clutch is currently OK.

I'll give the oil leak a sniff when its back with me. I've had a gearbox leak in a different car and the oil was dripping from the gearbox, whereas this leak is definitely only under the flywheel, and less than a teaspoon a week.

 

[GrandePunto PL]

First you clean everything well, then wait (watch) for the leak, pinpoint the source.
Look like you have just an axle leak (it's wet on the picture)...
Use cheap USB inspection camera/endoscope, put it into bell-housing (inspection rubber port), see if it's wet inside.

 

[AnthonyH]

First you clean everything well, then wait (watch) for the leak, pinpoint the source.
Look like you have just an axle leak (it's wet on the picture)...
Use cheap USB inspection camera/endoscope, put it into bell-housing (inspection rubber port), see if it's wet inside.

OK, i'll take a look through the inspection port with an inspection camera, fingers crossed. Thanks.

What do you mean by "an axle leak"?

 

[GrandePunto PL]

Have you seen Guides section?
https://www.fiatforum.com/guides/axle-shaft-oil-seal-replacement-1-4-8v.797/

 

[AnthonyH]

Have you seen Guides section?
https://www.fiatforum.com/guides/axle-shaft-oil-seal-replacement-1-4-8v.797/

I read the guide, its good. I'll investigate further tomorrow. Thanks.

 

[AnthonyH]

I looked for an axle leak but couldn't find one.

I opened the clutch inspection port and tried to use a camera, but there was so much metal in the way I couldn't get anywhere near the rear main oil seal. Is there some trick to looking deeper inside the clutch? The inspection port doesn't look terribly useful but it must exist for a purpose?

 

[AnthonyH]

In an irony I've found an axle leak, not on this car but my other one. It looks black and doesn't really have a strong smell, so I need to get the wheels off and clean it etc. It doesn't look like enough of a leak to fix. Maybe i'd need to top up the gearbox oil though.

 

[vexorg]

You have no hope of seeing a rear crank seal. Your only clue is engine oil from the flywheel area is the crank seal, gearbox oil will be the input shaft seal.
You'll know oil type by smell.

Bear in mind oil gets in weird places from leaks higher up.

 

[GrandePunto PL]

The inspection port doesn't look terribly useful but it must exist for a purpose?

Advice was to put the USB camera into the bell, deeper, so you can see the bearing and even more, bottom of the bell-housing (if There is a wet spot). You can see the operation of the clutch bearing. Pretty useful (not all cars have this feature).

The original purpose of the window was timing belt setup at TDC in older Fiats. Now we have locking tools (away from TDC). Is this all new to you?

 

[AnthonyH]

Advice was to put the USB camera into the bell, deeper, so you can see the bearing and even more, bottom of the bell-housing (if There is a wet spot). You can see the operation of the clutch bearing. Pretty useful (not all cars have this feature).

The original purpose of the window was timing belt setup at TDC in older Fiats. Now we have locking tools (away from TDC). Is this all new to you?
View attachment 450823

This is all new to me and I opened the bell housing rubber inspection port for the very first time in my life today. My picture shows the port, you can just about see some teeth on the left. The problem I had was that there was metal blocking me from putting the camera in any deeper. Maybe I should have taken it out of gear?

 

[vexorg]

The gear selection will have no effect on what you see in that port.

Maybe a small change if you press the clutch, given you are looking at the clutch and flywheel...

 

[AnthonyH]

I think I can ignore the oil leak until it gets worse or the clutch goes, so I'm leaving it be.

And I bought some gearbox oil to top up the transmission in the other car. The axle leak in that one is also too small to fix at this time but I don't know how long it's been leaking so it should get topped up.

 

[rmjbn1]

That's sensible.

I suspect gearbox oil is often overlooked - probably not helped by scheduled inspection only every 80k miles (according to the handbook for my 1.2 Panda), which is clearly nonsense.

I'm sure mine was low when I got it, now I remove the filler plug and top it up every year.

In your place I would keep oil levels topped up until you need a new clutch.

Then, when the box is off, replace a load of seals: crank main rear, driveshafts, and input shaft plus bearing.

Personally I have so little faith in the input shaft bearing in these boxes that I would change it every clutch.

You can stick a finger through that inspection port (engine OFF!), and feel the inside of the bell housing. It'll be filthy. Dry and sooty OK. Wet and oily something's leaking (give it a sniff).