Hi guys newbie on here and to Punto's so be patient (I'm a landrover nut but the missus has a mk1 punto) I also have no "comma" key on my laptop so excuse the poor punctuation.

A few days ago her car started to run rough. A quick diagnosis showed it wasnt firing on the cylinder nearest the drivers side (dont know if this is 1 or 4 !!) As her cambelt tensioner had been squealing and she was hitting 70k miles I suggested to give her a full service i.e cambelt; water pump; plugs; leads filters and oil. I popped plugs in the other day to keep her running till this thursday when I planned to do the rest.

Today she was driving and engine temp light came on she nursed it home very slowly. When I had a look it had clearly overheated so I took into changing the belt and water pump (which was perfect) and new leads etc. After popping it all back together I ran the engine and there was some smoke wisping up from the back left handside of the head after removing a plastic bracket I could see that it was coming from a plastic housing that appears to hold a temperature sensor and connects onto the pipes going to the heater matrix. Does anyone know the official name for this or where I'd find a part number before I go ringing around looking for a replacement ?

I had planned to post a picture but as I'm a newbie and havn't posted 5 times yet I'm not allowed share a url yet

Also the car seems to be smoking a little bit do you think I may have the timing slightly off ? And to add another mystery I checked the all the HT leads using a timing light; first 2 from left to right were running perfect second 2 were intermittent and showed no light when the engine revved up ??

Any suggestions greatly received

Thomas

is this a mk2

car overheated due to not enough coolant inside, did you find out where it leaks already
did headgasket pop?

It's a Mk1.

Small leak the back of the head from plasting housing where water temp sensor is fitted. I picked up a new housing today so will fit it tonight if I have time.

foxfiat said:

A quick diagnosis showed it wasnt firing on the cylinder nearest the drivers side (dont know if this is 1 or 4 !!)

Click to expand...

well as for plug numbers, just so you know..
1 is belt end of the engine and 4 is gearbox end.

so if looking at the engine from front of car they go - 1 2 3 4
and looking at the coils from front of car, starting at the back and moving toward the front they go - 4 1 3 2 (its marked on the coil pack holder anyway)

foxfiat said:

After popping it all back together I ran the engine and there was some smoke wisping up from the back left handside of the head after removing a plastic bracket I could see that it was coming from a plastic housing that appears to hold a temperature sensor and connects onto the pipes going to the heater matrix. Does anyone know the official name for this or where I'd find a part number before I go ringing around looking for a replacement ?

Click to expand...

Not sure what you mean this leak is, which side is the left side? belt end? gearbox end? and leaking from between what parts? the head and the block? I think if you make a few more posts and post a pic it would help alot. In anycase, recommend you compression test it, wet & dry test.

foxfiat said:

Also the car seems to be smoking a little bit do you think I may have the timing slightly off ? And to add another mystery I checked the all the HT leads using a timing light; first 2 from left to right were running perfect second 2 were intermittent and showed no light when the engine revved up ??

Click to expand...

Well for timing, just put your timing light away, not much use on these really - just use the timing marks...

you should have the mark on the cam pully in line with the mark on the cylinder head



And for the crank line up the mark on the crank with the notch on engine



Then get your belt and start at the cam pulley, wrap it down the front around the waterpump and then crank - keep it as tight as you can down this bit and have the slack up the back and round the tensioner.

Then tension up the belt, you can use a bar put in from above and push it backward to it pushes the tensioner, or how i do it is use a pair of circlip pliers on the holes on the tensioner and twist with one hand to tighten up the belt and do up the securing bolt with the other hand.

then check the belt is not slack or super tight. check the timing marks are still lined up bang on. Then before you put the alternator pulley back on turn the car over so the engine has done 2-3 full rotations (it won't fire up cause the crank sensor need the alternator pulley on in order for the plugs to fire and fuel to be injected). Recheck the timing marks and belt tension - if either pulley is out at all undo tensioner and start again.

And after all that stick the alternator pulley and belt back on ensuring the little pip on the crank pulley is in the little hole on the alternator pulley.

foxfiat said:

It's a Mk1.

Small leak the back of the head from plasting housing where water temp sensor is fitted. I picked up a new housing today so will fit it tonight if I have time.

Click to expand...

A small leak of what? From what you are saying i think you mean water from the thermostat but not 100% sure.

I reckoned everything was lined up as should be using the marks you have illustrated turned it over by hand least 4 times and all seemed to be good. It just seems be running a bit more smoky than it did before so I wondered maybe I was a tooth out somewhere ?

I only used the timing light as my gf wanted to know what it was; but confused as to why leads 3&4 were very intermittant and showed no spark when rpm increased whereas 1&2 were running beautifully.

I only checked compression dry in cylinders 1&4 so far as they were the easiest both were round the 180psi/12.5 bar mark; will check the others when I get home.

The leak was from between the plastic coolat temp sensor housing and the head the bulkhead side of cylinder 4. Picked up a new housing today.

Generally Fiat coils share leads 1 and 4, 2 and 3 so if the coil fails partially you may lose sparks to 2 cylinders.

Compression test will show a head gasket failure...

Yeah the fact that its cylinders 3&4 means that both coils must be dodgy, but surely if the coil was dodgy it would affect both leads off that coil ?

On a side note I'd love to meet the Italian p**** who decided that the coolant temp sensor housing neede to be clipped into the intake manifold !! WHY WHY WHY !!

why, the sensor is easily accessible and swapped on nearly all the engine variations. What engine exactly have you got?

Its a 1.2 8v 188 engine. The coolant temp sensor housing is held in place with 2 bolts and also it clips into the intake manifold. The only way I could release this clip was to take the manifold off as the onky place to getba screwdriver in was on the fce of the manifold that bolts to the head ! unless I was being TERRIBLY dumb and missed something obvious !


Here you can see the housing beside the manifold and the slot for releasing the clip !!

so this is a mk2 then... mk1 is 176, mk2 is 188. Colour of the car points towards a mk2 rather than a mk1 as well

The mk1 never had the plastic style inlet anyway - and the only mpi one with a FIRE engine was the P75 and that has a metal manifold as well.

I never really messed with these ones although they are mostly the same bar bar the inlet and wiring/ecu setup.. I would expect the connector on the loom is the type with the wire clip thing in - and you don't have to take that clip out to undo the connector you just press them in and then you can pull the connector apart. Certainly never heard of anyone taking the manifold off to remove the connector before!!