1995 grand prix gtp coolant and no heat

I have a 1995 grand prix gtp with a 3400.the temp guage will climb to 210 then down to 150 it keeps going up and down while driveing. i also have no heat!!! can anyone help me

i would first check the UIM/LIM for leaks. see if you are low on coolant. this sounds more like a headgasket problem to me though...

Sounds like you have air trapped in your cooling system.
Try bleeding the air out. ;)

i have no coolant in the oil, and what is the UIM/LIM and where is it located. i tried to bleed the system and have had no luck

LIM = Lower Intake Manifold
UIM = Upper Intake Manifold

Put a plastic bag over your bleeder screw- does it blow up in 10 seconds? do the fumes smell like exhaust? - also does the system pressurize within 1 minute of running- normal engines- the radiator hoses stay soft until the engine coolant is hot- Engines that need a head gasket, the hoses are stiff almost immediately- if all this happens- sounds like your engine coolant system is being filled with exhaust gasses and this pressure shuts off the flow through the heater core- I have a '95 3.1 Olds Cutlass in the driveway right now that does this- I take off the heater hose and it flushes fine- start the engine- and I get "smoke signals" out of the heater return pipe- can't keep coolant in the radiator- it keeps burping out- system is under pressure even cold-- so these are all signs of a blown head gasket.....and it all starts with the "no heat" complaint...

You can do a compression test and see if the head gaskets are bad.

I've seen many GMs that are under pressure with in 1-2 minutes after start up.
Also a clogged heater core will cause simular issues with no heat , and or engine over heating. :2cents:

The one I just looked at ('95 3.1L) showed 3 cylinders at about 145 psi on compression check and 3 cylinders down around 115 psi-- so it can be borderline- although there is a significant difference in readings- I also flushed the heater core first- forwards and backwards- and when the hose was off- I could see the puffs of exhaust. I would consider all indicators- mostly the cold pressurization test----just my thoughts..

you wont ALWAYS have coolant in the oil if you have a bad headgasket. you could have an external leak. My old Grand Am that i had w/ the 3.1 had a bad headgasket w/ an external leak, and i would never see any leaks on the ground because it only leaked when it was running and there was pressure in the system.

i have changed the heag gasket noe it does not overheat and i have heat. Thank you for all of the help to everyone. i do have another problem though. my temp guage is all over the place. it will read from 150 then to 220 then bach to 150 it seems to go up and down with the throtle. at 60 mph it will read good take my foot off the gas and temp guage goes down

Probably an internal air pocket- the temperature sensor reads colant sometimes and steam at other times- steam is hotter than coolant- so the gage goes wild.. try bleeding the air at the bleeder screws just up from the thermostat on the same housing- this can happen after a coolant change- or major engine work like you had done....