(T) Sudden diesel sound

Guys, first some background:

I bought a Barchetta '97 about 5 weeks ago. Having a look at the car and listening at the engine everything seemed fine. I drove back to my house, about 150km and she behaved very well. I've had her parked in my garage since then. When starting the engine today I heard the classic diesel sound after a couple of minutes. Have a look at this video... (by the way, how do I embed youtube videos?)

YouTube down for maintenance

I was told by the previous owner (and got a receipt) that he had changed the cam belt, water pump, oil filter, oil, and air filter just 800km ago. On the receipt it's stated "cam belt kit" (about €160). I'm not sure what's included in this kit...

Well, I guess my real question is: Can the variator go bad basically instantly? From what I've been reading in other threads this is something that gradually gets worse, but I've not heard the slightest sign of this before. Is there any other likely source of the sound I'm hearing?

I'm not sure if there's anything related to this, but my thermostat seems a bit strange.. The needle does move after a while, but never reaches any higher than about 1/4 of the scale...

Have a read of this...

http://www.fiatbarchetta.com/btech/variator.html

Variators on older B's (pre '99) get gummed up by carbon deposits on the vanes and jam in 'fast mode' ie camshaft advanced for max torque and high speed running. You'll hear the noise stop above approx 2500 rpm and start again when the revs fall off. This won't affect the performance but its deadly annoying...

From what you say it doesn't sound like your vendor had the variator changed..welcome to the club!

Later B's got a re-designed variator which isn't so prone to failing. What mileage has your machine done?

Temp gauge is reading normally. It sits somewhere between 3-4pm and only rises above half when idle in traffic. Good rule of thumb for car health is mpg. Should do 30-35mpg unless you either crawl in traffic all day or drive like a loon.

I guess you're right, but I thought that this was something that didn't just fall out of the sky, but rather came sneaking up behind you.

My milage is about 100 000 km and my last measured mpg (well, l/100km - come on guys ) is about 7,8 (if I've done my calculations right it should be about 30mpg) but the again the variator problems weren't there until this morning...

When I had my cambelt changed I decided to change the (absolutely silent) variator at the same time. Within two weeks it was as noisy as a very noisy thing. That was about two years ago. The noise comes and goes - some mornings when I start the engine it sounds like a London taxi, other mornings it's silent. It's actually got better over time.

yep... variator. same here... you start car and hear diesel sound when is above 2500... i found second handed 10.000km for 70€... reparation kit cost about 30€ (but will soon start to dieseling again).... new costs about 100€...

I found other Barchetta owners that claim that this problem could be greatly reduced by adding the RVS stuff, or using the STP oil treatment:

http://www.rvs-tec.com/English/index.htm

http://www.stp.com/oil_4cyl.php

I usually regard additives as fraud so it would be nice to hear if anyone else has any experience from these products...

I also found this rather cryptic message in the Facebook discussion forum:

----
solving problem the fase variator , my barchetta change oil 5w 30 new, level oil 10% more indicator mas level , on motor for 5 minutes or more, the problem is litle ugelli into varaiator and not fluid ald oil or oil more density. sory for bad language
----

I've asked this guy to explain himself ...

As the variator jams due to crud in the oil its a good idea to change the oil early. I've run my B on good quality semi-synthetic (engine is designed for semi-synth, fully synth is a waste of money in a low power mass market engine IMHO) and changed it every 5k miles (8300k to our friends in clogs) and never had any issues. Car had 55k on it before surgery and was sweet. Dyno tested immediately before conversion with 145hp at flywheel and 115 at the wheels. Rocket ship it ain't but it is a whole load of ultra reliable fun

Another cause of diesel knocking sound can be an over (normally) or under adjusted belt tensioner pulley. This results in the natural pull and tug of the cams going over the valves causing the tension bearing to 'knock' against it's end stops.

This knocking is worst at cold idle. Quieter at warm idle. At higher RPMs the sound tends to phase away (no pun intended).

As far as I can tell it is an uncommon problem and took me a while to diagnose on a Punto.