93 taurus wife's car 3.8 the headgasket went out and i changed that the when i took it for the testdrive i had no heat and the gauge was floting from cold to hot within seconds so theres air in the system right? no that's not it i got all the air out and car was great till i shut it down and alot of the coolent went into the overflow and would not come back down. it's not smoking, and there is no fluid in the oil and the car run's good i changed the thermostat still no luck what do you think it could be water pump was changed 2 years ago and no sign of that being the problem.
help please

 

It sounds like you have no coolant flow from the block to the head or you may have the inlet manifold blanks in wrong if it is a V8, I don't know the engine in that car. This is not uncommon after a head gasket change out.

 

Oh!

Same problem for me.

Yesterday, I finished my 2.8 V6 head and int. manif. gasket change, I took it for test and the temp. gauge was from cold to hot within seconds, then how did you got all the air out?.


Thanks for the reply.


Denis V.

 

Hi It sounds very weird the temperature guage would go up so fast, but I guess it came down when the engine cooled and is not a faulty guage.

Is it a V6 Chevy? I never worked on one of those, but I think it is like a V8, unless some one says it is not.

To get all the air out takes a few heating and cooling cycles, and you must have a good condition or new radiator cap. The reservior has to be well filled and regularly checked.

What I do before starting, - and making sure no one will start the engine while my hand is under the hood - is have the radiator cap off and squeeze the bottom hose to pump the water a bit. That will get quite a lot of air out.

Also a lot of air is trapped in the top hose of the V8 where it goes above the radiator level, that can be reduced a bit by squeezing it down, then putting the radiator cap on. But it doesn't help much.

Air will also be in the heater circuit.

After that just be sure the engine does not get too hot before you shut it down, and let it cool to suck coolant in to replace the air which gets pushed out the radiator cap over a few heating and cooling times.

 

Oh, thanks a lot!.

The last Sunday, I squeezed the bottom hose and I heard: "glo,glo,glo,glo..."

The engine ran until "normal hot (110 º C)" and shut it down. Only 3, 4 times.

I noted the big difference with the simultaneous scanner reader (31º C). Cause is the 2 temperature sensors in 2 different places: One for ECM and the other for dashboard temp. gauge. For this reason, I thought: "Some is bad here" and the engine was off until new information. (it's a canadian Chevrolet Celebrity Wagon Eurosport).

Thanks, I'll run new tests tomorrow.

Denis V.

 

Overheating and loss of oil pressure are the big issues with an engine, so I always fit additional guages. If possible I use non electric.

This way I always have some way of seeing faults regardless of what the stock guages show. Old stock guages are unreliable anyway, and new stock guages are set up to lie to the driver to make them feel happy and not bother the dealer until the engine is either wrecked or really in trouble.