my car just started to over heat, i have a brand new thermostat in the car, new coolent, new intake manifold, the fan stays on all the time, when i drive long distants it over heats, in the mourning i take the raditor cap off. and start the car, i see the coolent moving around, so im thinking the raditor is blocked of something, what do u all think, thanks chris

 

probaly wont hurt to have the cooling system flushed.

 

its been done, been flushed times 3 times 2 by me, once by my dad

 

you have a air pocket in system. Leave cap off and run car filling radiator as system pumps.

check thermostat in pot of boiling water on stove to see if it opens. if not, replace thermostat.

POZ

 

i let it run for 20 minutes with no cap, and no more air bubbles, and i just put a new one on, i have 2 thermostat and i keep changing them and same problem

 

O.k does this happen only on trips but not at idle?What I mean is you can let the car sit and run without driving and does not overheat?I work at a gm dealership and I have seen an air pocket cause what you are talking about.Did you have the heater on full so coolant will go through the heater core completely?If not try this,also I have seen a bad head gasket cause this.I hope it is not this but at the dealership we have a special tool that will tell if combustion gases are getting into the coolant system.

 

If it's airbound you can sometimes correct the problem by jacking up the frt end to about 15 degrees and make sure the radiator cap is the highest point in the cooling system to make sure it is not airbound. you did say it has a new intake, is it an aftermarket intake with different coolant routing

 

i have no heater core, it not a bad gasket, i checked the oil and no coolent in the oil, and i had the intake manifold, it i let me run for a while, it will over heat, it i get on the gas, really hard it will over heat really fast, my dad is a mechanic, but my dad just lost his wife to cancer, and i dont want to really bother him right now, it was over heating when i had the stock intake manifold, when i had the intake maifold off, there was no coolent in the oil. i think the raditor is blocked

 

i just ran the car for 20 minutes i didnt see no more air bubbles, i will try it tommorrow and see what happens, but im thinking on waiting for my dad

 

First I'm sorry to hear about your Dad's loss(I'm guessing this may have not been your Mom).

When you take the radiator cap off and see the water moving that's good because it's flowing thru the system.Not saying you couldn't have a blockage.What pressure cap are you using?

On the thermostat if you drill 4 (1/8") holes through it.This acts as a vent after you do the main purge.Jacking the front up is a good idea and having the heater on is a must(not just the temp set to heat but the actual fan on to open the control valve to the heater core - you may even have to flush agagin).One suggestion on the thermostat,get one of the fail safe type where if it goes out it does so in the open position.Also what temp thermostat are you using(personally I use 180*F thermostat - factory calls for 195*F)?

Also is your undercar airdam still in place and in good shape?On an F-body this is critical to highway use(anything above 45mph).

Also take a look at this tech article https://www.thirdgen.org/overheating

 

dont have a heater core, the other owner took it outk, when the cap is off i see the coolent moving, im not running a thermostat, it dont fit in my car, because of an after guage, i will try again with a 180, im just scared of snaping a bolt, and its good the airdam

 

Try running with the AC on--see if the temp drops--also replace the radiator cap with a new one expressly for your motor.

Good luck

 

I noticed you said it heated up when you drove the car for a while, by any chance have you put a lower gear in the car, like say a 4:11 or 4:56. The reason I say this is because I had this problem a long time ago. The problem is that the engine was turning higher and the coolant is passing through the radiator so quick it dosent have time to cool. I just put a larger pully on to slow down the flow and it solved my problem. Good luck.

 

It could be possible to check for a blocked radiator by measuring the amount of fluid that is drained from the full radiator . You would have to know how much it is supposed to hold.Just a shot.

 

when i changed the radaitor it stop overheating, so i think it was blocked

 

and the timing was to far advanced, thanks for all ur help