Hello Fiat forum,
Hope all are well.
Am new owner of a restored 500 L with a 650 engine, and car ran fine until I took it to a local specialist whom adjusted the valves as engine was getting very hot, too fast (this now resolved it seems) however two new issues arose and not sure they are related to the 'valve adjustment' or a new issue.
Two new issues are:
1. Upon starting from cold, there's a whirr and bang/ or one big knock coming when the engine kicks in.
2. Now occasionally it just starts, or doesn't. It has an electric starter motor and never had any issues until, the garage did the valve adjustment.

Any advice I'd be grateful, I'm cautious to take it back to the garage without knowing a bit more of what I'm dealing with first.

Many thanks,
Bomboloni 500L

Welcome to the FIAT forums BOMBOLONI, I can't help you with this, but I'm sure someone will be along soon that can.

Good luck

If it's a metal on metal "bang" then that could be a coincidental starter motor problem and not related to the valve works.

If it's an explosion "bang" then that may be a back fire, which would be caused by a valve clearance problem (typically inlet valves not closing fully).

The second would also explain why the car seems more difficult to start. The valve clearances need to be checked, for your precise 650cc motor. The garage may have thought it was a 500, or they may have picked settings for a 650cc of a different spec' to yours. It was around a long time... so plenty of scope for different clearances to have been used by Fiat.

If our engine runs hot and the valve clearances are okay, check the timing. You may just have too much advance. That may have been the cause of your original problem.. I'd hope the garage checked it before they adjusted the valve clearances, particularly if they thought your valve clearances were wrong based on the spec's for a different 650cc.

If your timing is spot on and your clearances are correct you can run the engine slightl cooler by changing the spark plugs for colder/harder ones... but this can't compensate for the wrong timing/valve clearances, so get those sorted out first.


Ralf S.