Technical Uno shooting oil!

[Nqo]

My Uno Mia (South Africa) 1400 1997 model, 4 Dr 5-speed is blowing oil like an angry volcano - first through the dipstick (It was pushing the dipstick out!), then when I added a piece of plastic paper to make the fit firm, it blows out the oil filler cap and shoots oil all over the place.
My local bush mechanic is stumped - he suspects the oil pump (we've cleaned the breather pipe, BUT NOT REPLACED IT - IT IS A BIT ON THE WORN OUT AND WHEEZY SIDE).

But then another, with a more formal training, suggests oil rings.

I've got a slight problem with both, thus my turning to this forum.

If it was indeed the former, then the oil pressure would surely be low? From reading on the net most oil pump failures for any car result in low oil pressure, and that of mine is certainly not low, it is VERY VERY high!

The latter - well - also from reading around, should also cause smoking - and that is not there - at least not notable. Can anyone PLEASE help?:bang:

I don't know if it's in any way related, but the carburretor leaks fuel a lot - one mechanic says it's the base or sitter or gasket or somesuch which needs attention and yet another reckons it might be overflooding somehow and then overflowing the excess fuel......

 

[Louie Bee]

Could be your piston rings on your way out, letting more air past than normal (excessive blow by gas). This air pressurises the sump and escapes through the easiest root. Plug one hole, then the pressure rises and pushes through the next weakest point.

I’d imagine that if this were the case, the Oil pressure would alos increase.

Are you sure the breather isn’t blocked as this may also cause the sump to pressurise.

 

[Steely]

Could be your piston rings on your way out, letting more air past than normal (excessive blow by gas). This air pressurises the sump and escapes through the easiest root. Plug one hole, then the pressure rises and pushes through the next weakest point.

I’d imagine that if this were the case, the Oil pressure would alos increase.

Are you sure the breather isn’t blocked as this may also cause the sump to pressurise.

yup sadly does sound like heavy engine breathing.. i had it happen on a rover engine.. compression test will rule out this!

 

[Nqo]

Tx 4 the advice - so if indeed it is Piston rings on their way out she would not smoke?

And the compression test - what deviance would i be seeking i.e. low or high compression?

Is the breather pipe supposed 2 b wheezy - when i blow through it it's kind of hard and there's a wheezing sound.......

Thanks much for the responses already.

Really great forum!

 

[alexGS]

I agree with your second adviser. A bad oil pump or other cause of high oil pressure will not pressurise the air above the oil sitting in the sump. A broken piston ring, or very worn rings, will. Note that high oil pressure and a pressurised crankcase (pushing out the dipstick) are not the same thing! The engine's oil under pressure circulates through the crankshaft, up to the head, and through the camshaft - losing pressure along the way through the bearings etc. and falling back down to the sump. The oil sitting in the sump is not pressurised. The air above this oil, however, IS being pressurised in your case, by the combustion pressure leaking past the ring(s).

Personally I think you have a broken compression ring yet the oil control ring is still functional - this may explain the lack of oil burning evident. It would be a good idea to do a compression test - the pressures should be about 160psi and more importantly within 10% of each other. Low compression means that the pressure is leaking away into the crankcase (past the piston rings).

As for the restriction in the breather pipe - there is supposed to be a 'flame trap' (a little wire-spiral thing) pushed into the pipe near the air cleaner. Push it out with a long stick from the engine-pot end, and clean it (petrol or other solvent). A blocked breather CAN cause this sort of problem, so it has to be worth another check first.

This is all pretty much exactly what the others have said above, sorry

Cheers,
-Alex

 

[Nqo]

You're a super star kind sir. Your explanation is concise yet comprehensive and comprehensible(?) ! Anyways, compression test it's going to be then - the flame trap was cleaned and unclogged, so broken ring it probably is.....

One last one (or two) - there is a major fuel leak at the base of the carburretor - it is not a drip kind of leak, but a stainy kind - all over the metal that is next to and beneath the carb (inlet manifold?).
It gets so bad that i the fumes are sometimes so intense inside the car that passengers beg to be let out, and this normally happens soon after stopping after a longish drive....

The other issue is my gearstick - it is all over the place and jumps out of 4th and sometimes doesn't want to get into 2nd. I actually thought of making it shorter somehow - hacksaw blade attack or such!

 

[alexGS]

Many thanks!

One last one (or two) - there is a major fuel leak at the base of the carburretor - it is not a drip kind of leak, but a stainy kind - all over the metal that is next to and beneath the carb (inlet manifold?).
It gets so bad that i the fumes are sometimes so intense inside the car that passengers beg to be let out, and this normally happens soon after stopping after a longish drive....

Yeah, you definitely should fix that!
Does it look like the carburettor has a rubber base that it bolts to? If so, you need to unbolt the carburettor from this rubber spacer block, then unbolt the rubber spacer block from the inlet manifold. It's a REALLY fiddly job and takes ages (I did it on a Tipo a few years back) because the bolts go into the manifold from underneath. You may need various 10mm sockets (short, long) and maybe a spanner or two.

But it's worth it to fix a leak, plus it will make the engine run better.

Of course, if the engine requires major overhaul anyway (new piston rings), you might as well fix this when you have the head off later (and drive with the windows open in the meantime).

The other issue is my gearstick - it is all over the place and jumps out of 4th and sometimes doesn't want to get into 2nd. I actually thought of making it shorter somehow - hacksaw blade attack or such!

Possibly - but first, replace the bushes or link rods!

There are two gearlever linkages used on the Uno. Most models up to the Mk2 have problems about halfway-down the gear lever where it fits into the U-shaped bracket of the linkage main rod (technically, the U-bracket is called a 'clevis' ) You will find if you take out the 10mm bolt that you can jam washers etc. in there to make it tighter. The better solution is a new bush kit - just ask for a gearlever bush kit at your parts dealer, should be pretty cheap and well worth it. Whether you fit all the other bushes is up to you - the gearlever clevis is the most important one, the others make incremental differences.

In the later Mk1 Uno Turbo and Mk2 Unos with the 1372cc engine, probably like yours, it's all different. The gearlever gets loose and makes a clanking noise, as though it's dragging a chain. There are not many bushes - most of the problems lie in two rods in the engine bay that run across the top of the gearbox, with balljoints at their ends. These rods may be completely worn out - and ready to fall off! Check them by trying to move them with your hand. Replacements may be a little expensive to buy, but you can make your own if you know where to buy 'rod ends' (balljoints that look like steering tie-rod ends) and M6 threaded bar + nuts. I know it would be much better if I had a picture - sorry I just can't find one.

In the later system that I'm describing, there is also a small diamond-shaped link located on top of the steering rack housing. This has three balljoints and may also be loose/worn out. You can only get to it from under the car, and replacement is fiddly but satisfying in the difference that it makes. Unfortunately it will be a case of buying the genuine part only.

I don't know which gear linkage is fitted to South African Unos - the earlier system I described is likely to be much cheaper to make - so it's a question of working out which you have first.

Cheers,
-Alex

 

[stepcaw]

I've got a similar problem with a Tipo that's squirting oil out of the petrol pump hole (underneath the pump). I had this problem years ago with a Uno and it was the flame retarder gauze that was completely gunged but not with this Tipo the breathers clear. It wouldn't be anything to do with the oil filter being blocked would it? The dipstick's not being forced out or any other leaks it just seems to be from the hole in the bottom of the petrol pump which I know from my Uno is easy escape route.

 

[alexGS]

I've got a similar problem with a Tipo that's squirting oil out of the petrol pump hole (underneath the pump). I had this problem years ago with a Uno and it was the flame retarder gauze that was completely gunged but not with this Tipo the breathers clear. It wouldn't be anything to do with the oil filter being blocked would it? The dipstick's not being forced out or any other leaks it just seems to be from the hole in the bottom of the petrol pump which I know from my Uno is easy escape route.

That fuel pump spacer is an old chestnut that I remember from my 128 days. There are two shapes of gasket - one for the inside, and one for the outside. If you put the inside one on the outside, there's a tiny hole left where the gasket is cut away to allow the pushrod to go through. The first thing I would do is take it off and check the gaskets I'm not sure how you'll go about getting a replacement gasket - might have to make it - but also check that the plastic spacer itself hasn't cracked.

-Alex

-Alex

 

[Chas Uno]

My 70SX leaks oil from around the dipstick and fuel pump area too. I assumed it was the dipstick rubber bung that has gone hard and isn't sealing properly, though I'm wondering if it may be the fuel pump gasket? Problem is finding a new gasket as the Fiat dealer is hopeless and can't find parts for my car on Eper