Question about Cars & Trucks
Your best bet have a qualified repair shop view scan data .
002 Fuel System Tests Start Here Rather then guessing and replacing a bunch of parts you don't need ? Do the cooling fans come on ? Testing to see if the engine coolant temp is overheating . By the time you get fedup with replacing parts for guess's on here ,have it tested . Unless you like making part stores rich.
Posted on Aug 04, 2017
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Posted on Jan 02, 2017
Sounds more like an ignition control or coolant flow problem. Or, a/c fan not coming on with a/c.
Getting the water pump question out of the way, the pump either works or not. If it leaks it will cause an overheat due to coolant loss on flat ground or grades...doesn't matter. If the pump bearing or seal is bad it will still pump, it will just be loose and noisy. Coolant flow through the radiator is also essential...I don't think you have a problem there because generally this happens with less maintained higher mile cars.
A bad map sensor can cause your problem because it changes both ignition timing and fuel mixture, either of which can cause very high temps in combustion chambers especially when under a load. Mass air flow sensor can also do this but usually will cause idle problems. If fan is not on with a/c if the remainder of your cooling system may be enough to maintain decent temp control but cannot do this under a load. A/C turned off removes some load and therefore allow you to get up hills. Operating marginally, you can be pushing some coolant out of the system at times without even knowing it.
Now, about your engine: These engines are in my opinion a very poor design to begin with. Even with the best maintenance and low miles, they don't handle temperatures well. at this point, I'd be concerned that after repeated overheats and near overheats, your head gaskets may have started to fail, even though they were not the cause of the problem.Keep that in mind.
Have the items I mentioned tested. If you finally have the problem solved I suggest you change the thermostat as well...Overheating makes them unreliable.
Posted on Jul 27, 2009
how many miles are on it? if you have over 70k the head bolts may have let loose and allowed the head gaskets to leak they all do it
Posted on Nov 30, 2009
The most common overheating problem with the Northstar engine is a blocked purge line. It's job is to purge air out of the cooling system.
There is a small diameter hose coming from near the top of the coolant tank,this is the purge line.
With the engine idling,pull the purge line from the tank,if there is no coolant flow from this small hose,it is blocked and this will cause overheating.If the hose is clear, check for blockage at the nipple on the tank.Or trace the hose back until you find the blockage.The hose goes in to the engine to a crossover and comes out the other side to near the thermostat housing,the blockage may be there.
Posted on Feb 25, 2010
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