Last week my 84 fiero needed a head gasket. It was dumping coolant ou t of the expansion tank. I finished the job yesterday and drove it home from my shop just fine (about a half hour). Today I decided to take it for a bit further ride (about an hour or so) to see how its holding up. Now when I did the head gasket I put a new thermostat in and the heat quickly rose over normal and I didn't like that so I kept the thermostat out. When I got to the last two miles today the car started acting like it was overheating so I pulled over and checked the gauge (it only works with the engine off and the key on but that's an issue for another day). The gauge read above normal but out of the red zone. I got it home and checked everything, no loss of coolant anywhere and nothing out of the normal. What else could be causing it to overheat.
I have already changed the radiator cap, thermostat but it isn't in, and the water pump. I also have a new temp sensor for it but haven't installed it. I also flushed the system after I did the head gasket.
Last week my 84 fiero needed a head gasket. It was dumping coolant out of the expansion tank.
What made you suspect the head gasket needed replacement? Coolant dumping out of the expansion tank can occur for several reasons, including air in the system and the wrong (vented) rad cap being used. It's possible the same problem is now still occurring.
Originally posted by Patrick:
* Make sure rad cap is the proper one for Fiero use. The catalogs are wrong! You want a non-vented one, * Check that the overflow tank and the small hose to the rad are both in good shape. Otherwise air gets sucked in. * Ensure that coolant level in overflow tank is at the "Cold" level. * Position rear end of Fiero higher than the front. * Remove thermostat housing cap and thermostat... and then add coolant to thermostat housing with rad cap also removed until coolant runs out the top of the radiator. * Re-install rad cap.
* Continue to add coolant until you see the level come up to where the thermostat normally sits. * Put thermostat cap on and turn just barely enough to hold cap on. * Start engine and run for about 30 seconds. * Remove thermostat cap and check coolant level. * Repeat last four steps until coolant level no longer drops.
* Re-install thermostat and thermostat housing cap.
As long as there are no blockages anywhere in the cooling system and the water pump is circulating coolant, you should be good to go.
I tried everything else that could cause fluid to come out of the expansion tank and nothing fixed it. Pulled the head after finding coolant in the oil. I'm not losing coolant anymore and I know for sure that its not pushing into the overflow tank. It is flowing through the rad and none of the lines are crushed.
I've done those steps when I filled it and its still overheating. Not nearly as bad and the coolant level is staying the same. I'd say my gauge is just incorrect but for the last two miles it was acting as if it was overheating.
I drove the car to my shop today in 30 degree weather and wouldn't you know, it didn't overheat however it really didn't like the cold. It stalled at every stop sign and red light I came up to and I went through about half a tank on my 20 mile trip. I'm kind of at crunch time now since I need this car to be able to make it about 60 miles on Saturday morning. I'd say its the ecu temp sensor reading incorrectly except it runs fine when its warm out.
I think I figured out why its overheating. There's a blockage in one of the coolant pipes. I tried squeezing both rad hoses and all of them are hard. I'm not sure how the coolant is supposed to flow. Does it flow from the left of the rad to the right (super hose to lower hose) or right to left?
Yes it is. I checked them after a half hour of driving. I know they're going to get hard from the pressure but this was abnormally hard. Also don't know if I posted that my issue this morning with dying all the time was due to a new plug wire that had melted and was grounding out on the exhaust manifold...oops.