Coolant backup in '94 Pontiac Grand Am

Once it

If you could clarify what you mean by this...

I had a similar problem on a '90 Bonneville, and I think the answer is pretty universal: The cooling system won't fill completely just by gravity. There will be cavities in the block, etc, where it just won't flow on its own. You can fill the system as full as you'd like, and the engine will get quite hot or even overheat a bit (if you let it).

On the Bonneville, what I do after draining the cooling system for whatever reason, is to fill the system as much as it will take, fill the reservoir overfull, and run the engine until the radiator fan comes on.

I shut off the car and let it cool down. As it cools, it 'inhales' coolant from the reservoir. At first, it'll be quite a bit. I refill the reservoir again and repeat. Usually, by the 2nd time, I'll start getting heat inside the car, which means the coolant is getting where it needs to be.

In fewer words, the cooling system won't fill until it gets hot and cools back down, inhaling from the reservoir as it does.

Try that.

RB

Fill the radiator as full as you can first!

Here is GM's filling procedure.

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1. Refill the cooling system with GM Goodwrench=AE DEX-COOL=AE or Havoline= =AE=20 DEX-COOL=AE. To ensure sufficient engine cooling, freezing and corrosion=20 protection, maintain the protection level at -37=B0C (-34=B0F) lower. Use a= =20 solution that is no more than 70 percent antifreeze.=20

1. Place the heater and A/C control in any A/C mode except Max and the=20 temperature in the highest setting.=20

2. Allow the engine to continue idling until the lower radiator to=20 coolant pump hose is hot.=20

1. Cycle the engine speed up to about 3000 rpm and back to idle five=20 times. Slowly open the bleed valve on the rear of the thermostat housing=20 for approximately 15 seconds to expel any trapped air in the cooling=20 system.=20

2. After the air has been expelled, fill the radiator. Install the=20 radiator pressure cap, making sure the arrows on the cap line up with=20 the coolant recovery tube.=20

1. Allow the engine to cool to outside temperature. Check the coolant=20 level in the reservoir.=20

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Thanks for the tips guys. For some reason, GM decided to omit the bleed screw from the thermostat housing on my 95 Grand Am 2.3L. So I combined the following steps with a couple of suggestions from the radiator shop I bought the radiator from.

1. Filled the cooling system up again

1. turned on A/C normal at full heat setting

2. warm up engine, cycle the idle

1. pulled the upper most resevoir bottle run-off line. nailed the throttle a few times. (shop guy says this helps release some air)

2. replaced the removed line. took it on the street and nailed the throttle again (like you used to for those thunderbirds to get the air out).

1. now I have heat in the vent again and the engine stays below the mid point of the temp guage

thanks again and happy new year.

DM

are you sure there is not a cap on the radiator? there must be one someplace! if not splice into a heater hose with a flush kit, hook your garden hose onto it and let it run for about 20 minutes with the drain c*ck open

Yup, no radiator cap. You can only fill it via the cap on the resevoir bottle. The radiator itself only has the upper and lower hose connections, a small overflow hose at the very top and the obligatory trans cooler connections (why must the lower one always rust out and break when I'm removing them???). That's it, no radiator top cap (would be nice though). I think my 2.2L Sunfire is the same way IIRC.

Thanks for the splice tip. I found if I remove the very top small overflow line, it does the same thing.

Best wishes, DM

B.C

There are many cars on the road that do not have a radiator cap on the radiator. I had an 89 Chevy Cavalier convertible, Z-24, 2.8V6 that had the pressure cap on the overflow bottle.

I believe a Caprice I rented in Albany, NY in 1993 had the pressure cap on the overflow bottle.

My car has the radiator cap where it belongs, thankfully.

========= Harryface =========

For one, its a pressurized system so you will get no flow if the fill bottle cap is off. It will just bubble out. You need to let it cool down, fill the fill bottle to the fill line, close the cap on the fill bottle. Run the car for a few minutes to warm up the car, then let the car cool for a hour or so , then remove the cap and see if the level is still correct. If not top off to the fill line again. Run car again and repeat till the fill level is at the proper line when cold. If you truely have air, it needs to be burped elsewhere.