Technical Fiat 500 1972 overheating?

[cinquecento72]

Hi,

I have a completely stock 500L from 1972. Today I decided to head out on the Italian highway (30C outside) and I was doing about 80-90km/h on average while in 4th gear for about 45-50 mins? Then we ended up a long straight part with quite a good incline so the car started slowing down to almost 50km/h forcing me to change down to third, as we got up on top of the hill I started to feel the engine struggle (like it lost power) and some white smoke puffing out in the rear view mirror. I let go of the throttle and tried to get back into 4th gear (as we were about to head down the hill on the other side) to give the engine some slack however the car just seemed to not gain any power so I put it into neutral and it died immediately.
We rolled to a halt on the side of the highway and I open the engine bay with quite a lot of smoke surrounding it (the engine was crazy hot) so I let it cool for maybe 20 mins (so I could touch the engine head without burning myself) and tried to start it again but it wouldn't start although the starter cranked around fine.
I call the tow truck and they show up 30 mins later and tow us to the nearest garage and as they were towing the car up on the back of the truck some oil came out from what seemed like the transmission (?). 15 minutes later we end up at the garage and the car starts up just fine but they told me that a mechanic would look at it tomorrow just to be sure.

Any ideas on what could have happened? Also at what speeds can I drive for quite some time without the engine overheating? I thought I would be fine on the highway due to the high speed since it is air cooled.

Any help would be greatly appreciated!

 

[Bounding Bambino]

Ive driven a 500 hard in approx 30c weather and they do run warm, but they can handle the heat (ive done full throttle 90km/h for atleast 40min a few times to no issue). In your case it sounds like you have a serious cooling issue. Which could be a few things.

1-Airflow obstruction, as you said the car is bone stock. So you could be having issues with the thermostat deflector valve on the passenger side of the engine. They typically fail open, but the design is very basic and the flap can stick and open fully. I would dedicate efforts looking into ensuring that the system is fully functioning, or removed (if you dont need cabin heat at all).

2- I would also check and see that fan intake is clear and free-flowing. Ensure the dynamo belt is tight and in good condition. There is also a small air deflector on the bottom oil pan that allows some of the blower fan air to flow over the bottom of the factory pan, these can get plugged and would be best to ensure it is clear.

3- What weight oil are you using. These aircooled engines like a thick quality oil such as 20w-50, especially important in warm climates.

 

[gordinir8]

Little cat can handle heat and you can drive all day long with 70-80 kilometres but try not to maintain the same speed at hills. Engine gets difficult to start when hot most of times is because valves need adjustment. When hot you can't touch the right aft fender more than a few seconds so don't worry about it, oil temp gets more than 100 Celsius. smoke indicates oil leak probably. I highly recommend to change oil pan and put and aluminium ABARTH style. It holds a litter more of oil and helps temperature a little.