Engine fire reputation
Total production of the Pontiac Fiero over all 5 years was 370,168.[4] Regarding the number of cars which suffered an engine fire, we have the following two references, one from NHTSA and one from Pontiac Division."The National Highway Traffic Safety Administration...said it has received 148 complaints regarding [Pontiac Fieros catching fire] including reports of six injuries...Low levels of engine oil may cause a connecting rod to break; allowing oil to escape and come into contact with engine parts. The oil would catch on fire when it contacted the exhaust manifold or hot exhaust components...David Hudgens, a GM spokesman in Detroit... said, 'If you ran out of oil, and then that coupled with some aggressive driving perhaps, and maybe not changing the oil very often, you end up with a broken rod, and that's where the connecting rod came in, it is still the owners responsibility to check the oil.' "[5] "GM tests have shown that running these 1984 cars with low engine oil level can cause connecting rod failure which may lead to an engine compartment fire...Pontiac is aware of 260 fires attributable to the condition, along with ten reported minor injuries."[6] The larger of the two reported numbers of cars with fires (260), amounts to 0.07% of Fieros produced. The fires affected almost exclusively the 2.5 L engine, and mostly 1984 models. (Note that there may have been additional occurrences after the above reports were published.) The primary cause of engine fires was a batch of poorly cast connecting rods which failed when the oil level became too low. The faulty connecting rods were produced in GM's Saginaw plant. The theory is that the sports car styling attracted buyers who would drive the car hard, most notedly over-revving the engine. Another factor was the three quart oil capacity, and perhaps a leaky valve cover gasket which would allow the oil level to decline over time to a dangerously low level. If the proper oil level was not maintained, the bearings could seize, snapping the porous castings of the connecting rods resulting in punched holes in the engine block, thus spraying oil onto hot exhaust components where it could ignite. Most vehicles existing today have been serviced by GM during one of the safety recalls on the car. On the fire-related recall, shields and drip-trays were added to prevent leaking fluids from contacting hot surfaces. The presence of drip shields between the engine block and the exhaust manifold are a good clue that the car was retrofitted. The addition of the longer AC Delco PF51 oil filter and a re calibrated dipstick added extra oil capacity to the oiling system, and enabled running 4 quarts of oil in the crankcase instead of 3 quarts to help prevent oil starvation to the rods. Certain vehicles had their connecting rods or entire block replaced. Another theory is that some fires may have been due to the engine wiring harness being located in the center of the engine bay above the exhaust manifold, where the heat could theoretically melt and ignite the wiring. Also, the 1984 model had a magnesium grille over this area. In later models, this was improved to some degree with much better heat shielding wrapped around the wiring harness. A third cause of fires was due to the method used to cast the engine block and possibly overtorqued head bolts. Some engines developed cracks in the block that would leak coolant and/or oil, sometimes accompanied by broken head bolts directly above the crack. The leak would spray coolant or oil onto the hot catalytic converter and exhaust manifold located at the front of the engine compartment resulting in fire. This was the cause in several cases.
[edit] Cooling system issues
With the mid-mounted engine and long pipes carrying coolant to the front-mounted radiator, the Fiero was also prone to overheating if the cooling system had not been properly filled. Simply pouring coolant into the thermostat housing (on the engine) would leave an air bubble in the radiator, while adding coolant to the radiator would leave an air bubble in the engine's coolant passages. Proper procedure (filling the thermostat housing, then burping the bubble out of the radiator by cracking open radiator cap until coolant exits) must be followed in order to ensure an air-free cooling system.
A second problem has become common as more Fieros are being serviced by shops unfamiliar with their design. The under-body coolant tubes are positioned in such a way that a casual glance beneath the car will not suggest their fragility. As a result, many have been crushed by the shop lifts, resulting in a near complete lack of engine cooling. The age of the car means that even GM dealerships may be unaware of the proper jacking methods.
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