My fiat Uno 1.7 Diesel broke its timing belt during idling (at 45,000 Kms). I was in 1st Gear trying to park the vehicle when this happened. The engine stalled and would not start when cranked for 2 secs. Immediately i realized that its a timing belt failture.

After installing new belt I cranked the engine but it wont start. Is it a free wheeling engine or have i snapped / twisted a valve or two. I opened the valve cover and turned the engine and two exhaust valves i-e of 1st cylinder and the 2nd come out with a snap once the cam lobe has passed over em. Could it be sticking valves or bent valves? Besides this i dont hear any un usual sound when turning. Please HELP!

Do i need to overhaul the engine head? If possible please email me head over hauling section of repair manual for my model at [email protected] / [email protected]

In your view what other things should i check and notice.

Omer

probably bent valves, its only the 8v petrol f.i.r.e engines that are safe

Uno Diesel 1.7

Hi Again Omer,

Thanks again for posting up the thread .

Sorry for my delay, I’ve been chatting too much on MSN .

The only UK manual for the diesel Uno to my knowledge is the Porter manual, which has been out of print for some time now .

However, I hope this helps...

https://www.fiatforum.com/uno-technical/53603-uno-1-7-diesel-valve-settings.html?

https://www.fiatforum.com/showthread.php?t=27429 (post 3 and 4)
and
https://www.fiatforum.com/showthread.php?t=42467 (post 4 and 5)

Regards All,
Louie Bee

Thanks Dave and my new buddy Louie!

Now its time to get my hands dirty n start shopping for parts cuz im not giving up on my car just yet.

But Problems, Problems Problems.
First thing the timing belt. The OEM 168 teeth belt is not available anywhere in my country. I've bought n installed Mitsuba 168 teeth belt (Japanese) hoping the engine would start. Has anyone used Mitsuba before? Dont wanna snap another belt and ending up tearing the head apart again.

2nd thing. Im gonna do it myself on this weekend. If anyone has done it before then wht parts to change? I know ill be needing a set of new valves (all 8 of em), guides, oil seals and head gasket. I've been told that Diesel version head also uses removable valve seats?

Last but not least. The head gasket available here is made in Taiwan. The parts supplier says that it is slightly thinner than the OEM head gasket. So we are talking about more compression and with it more heat.

Will be needing lots of good luck and will post results of a Fiat Uno Diesel hybrid engine :devil: i.e with Japanese and Taiwanese parts!

First of all thank you FF for the links w/o which removing the head wouldnt have been possible.

I'd like to post my findings for the benefit of others!
1. Bent valves!
Bought a new set of valves, guides, oil seals. Took the head to a machine shop to set up the new set of valves at recommended valve clearances. Fiat recommends intake at 0.30mm and exhaust 0.4mm. The guy at the machine shop set up my head with slightly lower clearances i-e intake 0.25mm and exhaust 0.35. According to him the engine needs to be driven slowly for the first 1,000 kms, during this period clearances will automatically adjust.

2. I was able to find Guartinoauto head gasket. 2 notches - means it is 1.95mm. the one i took out of my engine had one notch (1.80mm). I guess 0.15mm wouldnt hurt the compression a great deal but it should run cooler.

3. Timing belt the culprit - Didnt wanna take a chance with Mitsuba (Japanese) timing belt and luckily i was able to find Dayco 168SHPN220H. The same belt is also recommended for Duna, Fiorino, Palio, Penny City Van, Strada Pickup for Turbo diesel and NA engines.

4. With the head removed I also got my injectors serviced and pressure adjusted to 140 bar. Fiat recommends 125 to 133 bars. Again - the service shop recommended slightly higher nozzle pressure that would come with in Fiat's recommendations during the first 500 kms! hope its true.

5. Cleaned the combustion chamber & block surface with the finnest waterproof emury / sanding paper to remove traces of old head gasket. shoving a piece of cloth in the cylinders is a good idea to avoid debri falling into the cylinders. These debri particles later deposit in the valve seats. Blowing air is a good option if you have a blower. Also cleaned pistons to remove loose carbon deposits.

My head is ready to be bolted on the block! which i'll accomplish tomorrow. However, there is one last question. Head Bolt Torque. 100 NM is it ? or less. Can anyone please advise?

Thanks once again.

Omer

sorry i dont know this one, if no one replies try pming oldschool, he has lots of info lying around in his head , he might know

Hi Again Omer,

Nice to see your getting on with the task in hand .

As outlined on my third link above, the porter Manual recommends 100NM on each bolt (page 23 https://www.fiatforum.com/attachment.php?attachmentid=8122&d=1129324982) in the sequence shown on page 97 (job 29-4 https://www.fiatforum.com/attachment.php?attachmentid=3845&d=1111935207) (Link 2 above) .

Then go round and tighten the head bolts a further 90 degrees in the same order, and repeat a further 90 degrees. The head will now be torqued down .

Just a thought before you start. Are you using new head bolts? There is a discussion to consider here https://www.fiatforum.com/uno-technical/25235-cylinder-head-bolts.html?

Best of luck

Regards All,
Louie Bee.

Thanks louie. :worship: So one thing is confirmed. No im using the same head bolts cuz this is the first time the head has been removed. Read somewhere that the same bolts can be used 4 times over. 100 NM then 90 + 90. Phewww. Hope my internal torx socket (T60) will survive such forces.

but before that I have to cross another hurdle . The timing marks!. I have gone thru the porters manual (courtesy Louie Bee) n decided to install the timing belt with loose head bolts so in case the timing is wrong n valves come in contact with pistons the head would rise. Im doing everything right as per porter's but still the head rises. :bang: I have done head job on honda D16 vtec engines n its a piece of cake but fiat diesel is very tricky. The adjustable cam pulley is a real pain. I had marked the position before removing cam pulley from cam shaft. But with cam perfectly aligned as suggested by porter's and pistons at TDC when i turn the engine the valves come in contact with piston. A Gap forms between head n block confirming that things are not right. so before I tighten head bolts I need to be sure of TDC and cam position. In my vehicle there is a mark on flywheel as well for TDC. A small square rubber stopper on gearbox (below brake vacum pump) needs to be removed to see that mark. Accidentally saw this mark With crank pulley showing TDC this mark is also perfectly alligned with another mark on gear box. Secondly 1st n 4th piston move all the way out. So crank is at TDC but CAM.. arrrgh. :bang: If someone has done this before then please advise cuz i would prefer to wait n do things right the first time to avoid bending a few valves again.

Your welcome Omer !

Sorry I can’t be of further assistance . I’m yet to see a Diesel Uno

Maybe someone in the Fiorino section can help

I can say on the 1299 turbo engine I currently have in pieces, the cam pulley has a dowel for correct alignment to cam.

Kind Regards,
Louie Bee.

Another milestone achieved!

Head installed! Well through a refrence brought home a specialist to look at my engine. Seemed quite impressed with the parts I had managed to gather over the weeks and my tool box .

Anyway, he advised me to install the head and set crank a little before TDC. For all those newbies meaning to say the mark on the crank pulley is a little before TDC mark on the block (move crank pulley anticlockwise by 1.5mm before TDC mark on block). This also gave me almost half of an inch of clearance (1st and 4th cylinder moved inwards). Now head is installed with bolts at 73 foot lbs (100 Nm) torque + 90 + 90 in the order mentioned in porter's manual. Increased bolt torque in steps - 30 ft lbs, 60 ft lbs then 73 ft lbs. Finally 90 degress plus 90 degrees. Yeah my back does hurt . Its a lot of torque for a skinny guy like me .

He was a little short of time today and asked me to reinstall everything on the engine except the timing belt. Exhaust manifold plus exhaust downpipe, intake manifold, water pump pipes, thermostat unit, brake vacum unit, injectors, glow plugs etc etc. :idea: I had bought a dozen small polythene bags and had kept all parts and nuts, bolts, washers in em seperately. Also labeled each bag using a permanent marker. So putting everything back was very easy.

Now he has promised me that he will visit me tomorrow evening to do the timing himself which I will post for others (with pictures if someone can tell me how to insert em) who may wanna give it a shot.

Outaa curiosity what is the approx cost of a complete Fiat Uno 1.3 Litre gasoline turbo engine with ecu harness, gear box, engine mounts etc. in U.K?

Regards all

Omer

Excellent post Omer!

Being a 'skinny guy' myself, I can identify with the 'back hurts' comment, but can only point out that new head bolts reduce the tightening torque required, because they stretch more easily during those two 90-degree turns. Just for next time

Keeping parts in bags and labelling with permanent marker - now that is just TOO good I did that once, and haven't managed it for several years now - no time... I just grab more bolts from the collection. If working with a limited number of bolts and screws, it's a very good idea to keep 'em sorted like you have.

I'm still a little worried that at TDC there appears to be no clearance, but you have (as you know) done the right thing by winding the engine back a little from TDC. It sounds as though you have the cam timing off by approx. 90 degrees. Are there perhaps different marks? It sounds like that 'adjustable' cam pulley could be the root of the problem. I still think that the Porters manual that Louie posted is the best resource for this job.

So best of luck, you will now set the cam to the right position and gently turn the engine to TDC, time the injection pump, and the job will be complete... keep us updated!

-Alex

Hi everyone!
YO R RESPONSIBLE FOR IT ALEX.

As you suggested brought CAM to its timing mark.... then slowly turned crank shaft to TDC . plz plz plz da da da dont hit the valves...

Next Aligned the markings of fuel pump and installed Dayco timing belt. Adjusted belt tension ... All appeared good. Turned the engine. All seemed well!

Connected negative terminal of battery. Heated glow plugs. Engine ready to fire. Errrr. and cranked!. Bangggggggggggg, turrrrr, hickup. Is it my car or am in a jet experiencing turbulence! After a few shakes, misfires that lasted almost half a minute it ........

RAN OKAY ! ! !

Cannot thank you guyz enough (especially Louie).

So this concludes my post. Timing belt failure in Fiat Uno diesel always leads to expensive head repairs. I didnt share one thing with you guyz! Actually at 45,000 Kms i did replace the timing belt. It was some cheap brand and it failed after 5,000Kms. So the lesson learnt here is never take a chance with cam timing belt otherwise you may end up paying 100 times more!

Correction - I made a typo in my previous reply. The head gasket im using is GUARNITAUTO (Made in Italy) 2 notches 1.95mm.

Regards all,

Omer

Great news. Louie was the most helpful here, as he collects obscure old documentation about the Uno Diesel. Probably comes naturally to him after he gets home from his work documenting diesel engines and parts!

I was worried when I saw that bold writing, thinking I would be responsible for more bent valves... but now we know it's OK at last!

That's a good brand for gaskets - that Guarnitauto (or whatever it is!) - it's the brand I use.

That timing belt failing after 5000km - that's inexcusable! Was there any sign of chafed edges etc.? That was very hard luck!

Might pay to recheck the belt tension in a week or so - to be on the safe side? And to make sure the belt isn't rubbing on something/running skewed (sometimes caused by a faulty tensioner).

Thanks,
-Alex

Hi Alex

Well after weeks of trouble looking for the right parts and doing research online allow me to use some humor, so i wrote it intentionally!

The edges of the broken belt are A okay. It simply broke into two pieces from the middle with nylon strands sticking out from both sides. Another area was half broken i pulled it apart myself (Grrrrrr :devil: ). I wonder who makes such belts? It has 802 FIAT 7565617 a696 printed over it but im certain it can't be an OEM Fiat belt. I couldn't find any signs of rubbing due to faulty tensioner pulley as even the text on the broken belt seemed new.

Nice tip dude. Will check belt tension in a weeks time.

I've finally figured how to attach pictures here. haha. so here are few picts of my car its engine n the broken belt. Notice the air filter outside on the side of the engine and yes i have painted the valve cover. Diesel is all about breathing freely so i've removed its standard air filter and replaced it with a high flowing one!

Regards,

Omer

That’s one lovely looking Uno you have there Omer!

Glad you managed to get her fixed up and back on the road :woot: ... you had me on the edge of the seat there .


I never knew the Diesel Uno has a silver firewall ... My MK2 turbo re-shell still has the black one from its 1.0 IE days.

Good to have a recommendation on gaskets too. I’m still to order a full kit for my MK1 Turbo. …Infact I’m still to have the head skimmed and the Turbo looked at .

How old is your Uno by the way?

Regards All,
Louie Bee.

Well Thanks Louie!

Having done 200 Kms with my repaired engine I still have one problem left. A strange chugging noise comes as i rev the engine and besides the engine isnt as smooth as it used to be. The only thing i could identify is tight valve clearance. Its sort of a chugging sound besides the normal engine sound that comes as i rev the engine..at idle there is no additional noise but when i rev it goes like chug chug chug chug n increases with rev's. 2ndly the engine used to have good torque and used to pull away nicely but now it seems to lag a bit and yes it vibrates more at idle. Last but not least it is producing more heat than it used to. Though in normal range but i know where that temp needle used to be.

Checked clearances today n found that the idiot head shop guy has configured the exhaust clearances all wrong. intakes clearances are 0.25mm to 0.3 mm (thats acceptable) but exhausts arrrggh one is 0.15mm and the rest at 0.20mm. (According to porter's Fiat recommends 0.3mm inlet and 0.4mm exhaust) could this be the cause of this weird noise? and lesser torque? and more heat? anyone?

Regards all,

Omer

Well - hard to say, but I would expect those symptoms to point more to the injector pump timing being one tooth off. Then again, I'm no diesel specialist.

Also, strange chugging noises are often air leaks - inlet manifold, or maybe at the exhaust manifold to downpipe join. Acceleration tends to rock the engine/transmission and aggravate any exhaust leak. I imagine that perhaps the exhaust pipes got shoved around a bit during the head removal/installation, so worth a second check.

I would probably get those valve clearances adjusted, but as long as there is some clearance there really shouldn't be a problem. With 'performance' cams, you tend to run the clearances narrower to maximise the valve lift. My FIAT 128 used to run 0.15mm inlets/0.20mm exhausts. With standard cams, the profile is gentler so the valve gear is quieter even with wide clearances. I think they specify wider clearances for the newer engines, so that the percentage error is greater (gives more room for error in the adjustment, if you know what I mean?) I don't think the wider clearance serves much other purpose.

The reason there is a clearance at all is to allow for valve stem expansion with heat. But, as hinted before, this is a very small amount (perhaps 0.1mm, hard to say exactly). My engine certainly ran OK with the 0.15/0.20 clearances.

So I'd check the pump timing first. In fact, check the camshaft timing as well - just in case

Perhaps with the valve clearance, start by widening that single clearance (0.15mm) quite a bit, say to 0.40, and just see if that chugging noise changes. The more I think about it, the more I think that one cylinder would make a noticeable 'chug', whereas all four clearances being 'tight' would not do this. So, maybe 0.20mm is fine but the 0.15 is just a little too tight.

Just my thoughts - might pay to seek out the advice of that friend you had help from earlier and get his opinion?

-Alex

Appreciate your input Alex! It was a busy week at the bank so couldnt work on my car until this weekend!

I've tackled the air leaks (the easiest of em all). Removed Intake n exhaust manifold and noticed that the gasket was kinda pressed so applied heat resistant silicone gasket maker to cut out the possibility of any air leaking from exhausts or intake. Assembled everything back and noticed the engine became much quiter and smoother too - no more shakes! perhaps exhaust gasses was being re-circulated back into the intake since diesel Uno has exhausts and intake on the same side and both manifolds share the same gasket. This has also improved heat generation of the engine for obvious reasons! One cylinder still chugs but due to sealing of intake / exhaust the noise has reduced a great deal. The engine is overall running much smoother and with much better response. I guess exhaust gasses were being fed into the intake resulting in poor acceleration and power.


I've checked injection pump timing. It is spot on and engine starts instantaneously upon cranking. Dont even have to crank it hard. In diesel wrong injection timing results in hard starting. so pump timing has to be right!

Cam timing - before i experiment with the adjustable cam pulley i'd like to fix that 0.15mm exhaust clearance (my friend also advised me to fix this clearance first) perhaps it is too low for this engine and resulting in chugging. but errrrrrrrrr i don't have the fork tool to depress valve cup and remove the shim. Any tips on removing shim? w/o having to remove the camshaft.

Also checked timing belt for tension and any signs of wear! It seems it has loosened a bit but im not able to turn it 180 degrees between two pulleys. Max it goes is 90 degrees. So that is acceptable. Hey i'd like to have ur opinion on something. When i fired the engine with the cam belt cover off i could see that at a little higher rpm than idle the belt shakes a bit in the area between cam gear and injection pump but as i rev it higher things smooth out! Is this something to be worried about?


Regards all,

Omer

Hello everybody!

Seems like ppl have lost interest in this post but hey its a success story and valuable for the Diesel lovers!

Check out the last para of my last reply! Yeh tht was the culprit. Alex u were right, should have given more attention to timing. Discussed cam belt vibration issue with my friend and we both sat down and read thru the porter pages that Louie had provided. Well, we both came to the conclusion that there is no harm in checking it again so we opened up the top cam belt cover and fired the engine. Indeed the belt was vibrating. According to Porter's belt tension should be so tight that between the longest areas u should be able to twist it to a quarter turn using ur finger n thumb..thts abt 90 degrees. mine was going 90 quite easily so we put our heads together. Yes timing is critical for a diesel engine. perhaps it was loose enuff to put the cam off by half a tooth. errrrrr.

So we turned the crank clockwise in order to acheive tension on the front side of the belt (the area towards the left head lamp and yes the injection pump) n checked tension in the rear area i-e tension pulley area. It was loose. Adjusted tension pulley to achieve even tension in the front and rear sides. Cranked the engine and to my surprise the chugging disappeared! The engine is as smooth as it was ever. Im letting it run on closer valve clearances than recommended!

Thankyou guys and thankyou FF. I hope time spent writing this post and your valuable input will be of use to anyone who wants to attempt a Uno Diesel Head Job!

Regards All

Omer

Thanks for the update Omer...
It's very useful to have a success story as it builds our knowledge of when things WORK...

I don't know about losing interest - it's more a case of people here not knowing the Uno Diesel!

I didn't reply to the 'slack cambelt' question because I simply didn't know if it would be important or not - my Alfa V6 does exactly as you describe, but it has an automatic tensioner that allows the belt to lengthen as the engine 'grows' when hot. It also doesn't use the cambelt to drive an injection pump (as your diesel does).

So it's great that you found the problem and I hope your very-smart Uno continues to drive nicely for a long time to come...

-Alex