Technical Punto 1.2 8v 2003 gentle misfiring/ shaking HELP 😫😫

[Msyogi]

Morning people! Another small update!

So I’ve asked few people to tell me what that knocking noise can be and after they hear that live almost 99% said it’s a piston pin! And that actually make sense because when engine it cold it’s running perfectly quiet and as soon as it reach normal running temperature maybe even few minutes after start knocking! It’s definitely not coming from the rocker cover gasket area, it’s coming from the very bottom or middle part of engine. Apparently pistons pins that’s the common problem on those cars??

I also thought that’s might be rod bearing shells but been told that if they poor the sound is different to what I’ve got.

I also take of belt and alternator just to make sure is not nothing to deal with that.

What you guys think?

 

[Mike1alike]

For your original problem, idle shaking, here is the solution:

Fiat Punto mk2/2b 1.2 8v (2004) - Rough idle, mostly on electric load | FIAT Punto (Mk2/2b)

Are the ECUs and body computers interchangeable between the 2 and 2b do you know? I didn`t know that. But since I cleand / replaced almost everything that could cause rough idle I`m also starting to think this might be an ECU issue. And also I start to think this is a common Punto 2b problem...

www.fiatforum.com

For the problem you've added up, considering it came along after you've flushed the engine, I rekon that you probably did clogged some of the tiny oil passages. You should flush the engine, but not using dedicated flush products, but the Romanian flushing method. That is adding about 1l diesel into the oil, after the engine is wormed up. And run the engine 10-15 mins. Than change the oil. I always use 10W40 on my Punto and it's good. And for the oil additive, I recommend one that is really really good, Liqui Moly MoS2.

 

[Ricardo Silva]

Mine does the same thing but under 2000rpm and only sometimes. This weekend did a 100km trip "Italian Style" because now the car is only used on short trips. 5500rpm at 2nd and 3rd gear on a few occasions. Already did some kms and no hesitation at under 2000rpm. Maybe italian tunup worked,

 

[GrandePunto PL]

Another thing to check (when you have "gentle misfiring/shaking") are camshaft lobes (measure the lifts). They can wear unevenly.