Technical X19 Heat Gauge Issue

Currently reading:
Technical X19 Heat Gauge Issue

Turner Brown

New member
Joined
Jul 27, 2020
Messages
2
Points
1
I have a question for anyone who may have knowledge of the heat gauge operation on the X19. The events I am about to discuss happened in the late 70's and involved an X19. I knew a guy with a daughter that owned the X19. When her boyfriend was driving the car, he went around a 270 degree exit ramp as fast as he possibly could. The oil light came on and the result was the engine needing to be overhauled. They claimed that all of the oil went to one side of the oil pan where the oil pump could not pick it up. Rather than take the car to a Fiat dealer and pay their shop rate, he chose a local mechanic that had never worked on this kind of car. The daughter had went back to college a thousand miles away before the car was fixed and her dad asked me to deliver it to her. Before I got half way there, the engine blew up. I was keeping a close eye on the heat and oil pressure gauges and everything looked normal up to that point. When they tore the engine down, the pistons had holes burned in them so it obviously got very hot but the heat gauge never showed it. The dad accused me of continuing to drive the car after I knew it was hot which I did not. He did not believe that the heat gauge showed normal temperature. In a way, I can see why he felt the way he did but I know what the gauge showed. The reason why I am sharing this experience is to find out if anyone on this forum has any knowledge of the X19 having this type of issue where the heat gauge did not perform the way it should have. Any replies will be appreciated.
 
I can vaguely remember working in a Fiat main dealership 40 years ago...

I never encountered holes in pistons in an X1-9, or any other Fiat model.

Any that overheated usually just blew the cylinder head gasket, and that'll make you stop - due to loss of power and possibly loads of white smoke from the exhaust.
If the head gasket didn't blow, the pistons would 'pick-up' (i.e. start to seize) in the cylinder bores. Also, the crankshaft bearings could start to knock if the engine oil got really hot and possibly the camshaft bearing bores (the cam runs directly in the alloy cam housing) could also be damaged. But no holes in piston tops.

The temperature gauge in the X1-9 wasn't particularly accurate, it was more of a guide to coolant temperature. Iirc, it could read low, while in fact the engine was overheating, if the coolant level was very low. But, as described above, various things could then happen, but no holes in piston tops.

I also worked a lot on motorcycles, mainly air-cooled Japanese models. Now, these could hole pistons, especially the 2 stroke engines. However, the usual consequence of the engine overheating was piston seizure in the cylinders.

Holes in piston tops is nearly always due to pre-ignition, (possibly detonation?), incorrect ignition timing, excessive ignition timing advance, weak fuel mixture, or poor quality fuels.

If that engine had been properly repaired and road-tested, I doubt you would have had any problem. The original engine failure (at the hands of the 'boyfriend') I suggest may have been due to driving too hard with a low oil level - I've never heard of oil surge issues with the X1-9 in road going form
(i.e. not track use with 'sticky' tires). (Others may disagree).

Hth to give you peace of mind,

Al.
 
Back
Top