Hi Forum!

I've had the duty of looking after a Fiat Uno for some time......
All is well apart from a water leak which looks like its coming from the join/ gaps between the engine block and gearbox housing .

Any Uno owners experienced this before? Hopefully it's just another rubber pipe that's burst and nothing serious like a welsch plug....

Please someone point me in the right direction - thanx

Will be changing both outer CV joints later, so have a closer inspection then.

cheers

Is it a 999cc or 1108cc FIRE engine? If it is then its probably the frost plug. Look at the thread about the $120 Uno about 2/3rds down on the first page: https://www.fiatforum.com/uno/145226-120-47-24-uno-45-a.html One of the things we needed to fix on this was the frost plug. The part is cheap but you need to remove the gearbox and flywheel to get at it.

I cant think of anything else that it could be, but you might want to check theres no water coming from the thermostat (which is just below the distributor)

Welcome to the forum :wave:

As James said - my bet is the frost plug/core plug/Welsh plug, whatever you call it

On the bright side, it took James less than an hour to get the gearbox off and the flywheel removed.

-Alex

Yo Yo - thanx for the info! checked the link and viewed the dodgy welsch plug,will check whole cooling system before pulling the g/box off. Its an 1100 motor btw.



Also tried to avoid pulling the driveshaft completely out when changing the outer CV, but obviously the car had other ideas for me. Oil everywhere...... were can I fill up the g/box with oil (I assume it's g/box oil?!?) I have downloaded a pdf Uno Haynes manual, but it's missing a few chapters.


Your input is appreciated, not familiar with the Uno

Sounds like you've now drained the gearbox oil ready for removal... now you're part-way to having the gearbox off

The Uno was made from 1983 to the present date, so there are two possible gearboxes and even two different '1100' engine types: 1116cc and 1108cc. The 1108cc is a FIRE and looks very similar to the 999cc engine shown in James' project Uno thread, except the 1108cc has a blue air filter housing and cambelt cover, so that makes identification easy. The much-older 1116cc engine is a totally different design.

Is your gearbox the type from 1992 onwards (but not for certain countries)where you push down (or lift up, can't remember!) the gear lever knob to select reverse? If so, then it's standard gearbox oil (buy something labelled 'for five-speed manual transaxles', 75W80 is typical) and only about two litres.

If your gearbox allows the selection of reverse without pushing down/pulling up the gear lever, then the gearbox oil must be a non-EP type (no horrible smell). It takes about three litres. The best option is the proper FIAT ZC90 oil. Here in NZ we have something called Castrol VMX available, which does the job nicely.

-Alex

Cool - thanx for all the info - much appreciated! I've been considering pulling the gearbox off, but on closer inspection it looks like the water leak is coming from the water pump.....just where the pipe enters the pump.



In Uno language what does this indicate? split pipe, new gasket or replacement water pump - are there serviceable parts there?

So your correct about the oil - used Castrol vmx, which was recommended for a Fiat here in SA.

Hi There and welcome

That looks like the 903cc OHV but with the terrible distributor... the number of times I saw the inside of mine is unreal

If your engine is the 1108 Fire engine, there is an o-ring where the metal cross-pipe meet the back of the pump .

I replaced the one on mine and its a really easy job - no need to move the water pump,
just drain down the water,
clean up the joins - mainly the one where the pipe meets the pump,
remove the hoses(s) from the metal pipe,
undo the 1 bolt that fixes pipe to the block
and remove the pipe by twisting.
Fit new o-ring (about 50p IIR),

replace pipe,
replace bolt on bracket,
replace hoses,
flush cooling system and if your not sure that it's been done in the last year or so, also fill with NEW antifreeze (to protect your seals and gaskets especially the head gasket )

bleed system...

Jobs a good en

In Uno language, the problem is that the pipe to the water pump is made of steel. We all know what happens to things made of steel. You'll probably need to replace it, but at least that's an easy job as Louie describes - it's just that something tells me it will need more than just the O-ring replaced...

Your picture has confused me - where did you get it - as Louie says that's the 903cc engine and if yours looks like that, yours can't be the '1100'. Let us know which type of engine it is and how you get on with the repair.

-Alex

peanutville said:

Cool - thanx for all the info - much appreciated! I've been considering pulling the gearbox off, but on closer inspection it looks like the water leak is coming from the water pump.....just where the pipe enters the pump.

Click to expand...

That picture is of an 899cc engine, however, the FIRE engines have a pipe connecting into the waterpump in a similar place. My first 999cc FIRE had a leaking pipe in the same place, which turned out to be a worn 'o' ring. I replaced the 'o' ring between pipe and water pump and all was fine again

1986Uno45S said:

That picture is of an 899cc engine

Click to expand...

The Cinq 899 don't have a distributor or round air filter I'm with Alex on 903

Maybe he has an Uber bored out 903 :slayer:.

Sorry to confuse the topic..... I just grabbed the pic from the Haynes manual to illustrate where the water leak originated from & to identify a solution

On closer inspection of the pic I uploaded..... it's def not the same motor as the one in the 1100 Uno Mia - I have the rectangular air intake box and the spark plugs are at funny angles located on the back of the engine facing the driver & the distributor on the right hand side of the head (opposite side from the cambelt) It's a standard standard boring Uno, with no performance enhancement parts....unlike my mk2 gti golf

Hopefully its just the o-ring

Thanx

Louie Bee said:

The Cinq 899 don't have a distributor or round air filter I'm with Alex on 903

Maybe he has an Uber bored out 903 :slayer:.

Click to expand...

I meant 903, honest!

Well, 903 or 899, it's still the old ohv lump

peanutville said:

Sorry to confuse the topic..... I just grabbed the pic from the Haynes manual to illustrate where the water leak originated from & to identify a solution

On closer inspection of the pic I uploaded..... it's def not the same motor as the one in the 1100 Uno Mia - I have the rectangular air intake box and the spark plugs are at funny angles located on the back of the engine facing the driver & the distributor on the right hand side of the head (opposite side from the cambelt) It's a standard standard boring Uno, with no performance enhancement parts....unlike my mk2 gti golf

Hopefully its just the o-ring

Thanx

Click to expand...

You have a FIRE engine going by that description. You can remove the coolant pipe by undoing the bolt around the middle of the pipe and then sliding it out. The 'o' ring fits on the end that goes into the water pump housing.

Good luck

Found the offender & promptly removed!
Good old section of steel pipe - easy to remove as you mentioned



& pic of motor to avoid any confusion....

IT'S STILL LEAKING!!!!!!

I was correct all along - it is leaking from below the gearbox where it bolts on to the engine - Must be that bloody welch plug leaking too..... only does it when the engine is at operating temperature.

Off with the box when I'm next in the mood - anything Uno related I need to be aware off while I'm removing the box? (Special tools/ any DIY tips for this model?) Done the procedure on a few vehicles.

Top tips are appreciated!!

thanx

Chris
Cape Town

Hang in there Chris...
With a rust hole like that, that pipe was obviously causing trouble, so you haven't wasted any time so far! (Funny how I knew it would be more than just the O-ring that needed to be replaced )

I believe it's easier to take both the driveshafts out of the gearbox if you're working by yourself. Leaving both driveshafts on the gearbox seems appealing but their angles will make removal of the gearbox difficult and refitting very clumsy, plus you risk damaging the diff casing if you force the driveshafts at the wrong angle.

Leaving the right-hand-shaft attached to the hub, and refitting the gearbox over it, seems like a good idea but is difficult in practice and needs two people. The driveshaft inner joints have to fit through a three-sector-shaped hole in the diff casing AND then engage in the differential. It's much easier to do this after the gearbox is refitted. Therefore, start by removing both driveshafts. This also drains the remainder of the gearbox oil.

There's no need to undo the bottom balljoints - you can swivel the hub far enough to remove the driveshaft if you undo the two strut bolts (easy) and the steering tie-rod end (fairly easy) plus remove the brake caliper (easy) and tie it onto the suspension strut so it doesn't fall off...

Don't forget to remove the tin plate from under the gearbox, next to the engine sump, which has a nut/stud near the inner driveshaft joint as well as the three bolts underneath (the gearchange linkage comes off easily at the same time).

Your Uno has a hydraulic clutch, so unbolt the whole bracket from the transmission - a few bolts - don't try to remove the slave cylinder from the bracket (probably rusted-in) and don't bother to undo the fluid hose as it may be difficult to bleed the system later (better not to interfere with something that's working...)

Take a critical look at the clutch itself, since you have to take it off to remove the flywheel. If the radial grooves in the friction lining are nearly gone, it'd be silly not to replace it. The release bearing commonly wears the spring fingers so it's usually best to replace all three, unless you're not expecting the car to live much longer.

Actually replacing the core plug/Welsch plug is very easy. It's shaped like a paint tin lid (has a flange around the edge) so make sure you get the genuine part rather than a standard core plug.

All in all, the job is not that difficult and a chance to fix any other wear items along the way - e.g. the clutch, the CV boots...

Let us know how you go,
-Alex

COOL - thanx for the informative technical details - familiar with the job then?

Will paste info into word doc & use for reference during job.....

Thanx again - the leak is not too bad, but would rather get everything done 100% anyway. Put it this way - the leaks not going to get any better!!

cheers

Chris

Ended up being a blown head gasket, not a leaky welsch plug after all!

peanutville said:

Ended up being a blown head gasket, not a leaky welsch plug after all!

Click to expand...

Oh - sorry about that

That's really unusual to have a coolant leak to the outside as a result of the head gasket failing. In fact, I've never seen it before Usually if the head gasket fails, it's around the cylinders (due to the combustion pressure) - and lets coolant into the cylinders. So, thanks for the report!

-Alex

Oops! At least a FIRE head gasket is fairly easy to change. Sounds like your engine will be quite well sorted after all this