Third Gen cooling issues? Solutions?

[1BADAIR]

yep. take a hose and wash the radiator/condensor. From the engine side forward

[shawnc16]

Gary to the rescue. Air deflector would be my first guess from experience.

[deeznuts94]

Thanks! That is my find of a lifetime, Its a 65 bonneville, I am the 3rd owner and I am huge into old school pontiacs. I like the GTO's but The big ones to me hold a special place, I grew up listening to my dad talk about his 65 2+2 and have always wanted one but they are too hard to come by

I have always loved the Pontiacs, old school Grand Prix's and the Bonnevilles. One day I will own one or a mid seventies coupe deville.

[deeznuts94]

have you thought about replacing the fan motor even thought it comes on and moves some air, it may not being working at 100% this was the case on my brothers car

Thanks for the idea Greg. I'm looking at a stock dual fan set up that Third Gen Ranch has. Mine is just a single. It seems to be working properly and pushing plenty of air though. The car only gets that warm on 85 plus degree days in traffic. I'm kind of stumped. I would think that if it had a bad radiator that it would run pretty hot all of the time.

[deeznuts94]

My 89 would run 220 nomally, these third gens were intended to run warm to meet emissions.

I don't pass 185 now with a low thrermostat and decent tune I flashed

Yeah I had an 89 back in the day with a 2.8 and the thing never moved off of 220.

[deeznuts94]

Start with the most simple thing before you start dishing out money.

Is it possible that you installed the stat upside down? That will cause similar problems.
Start there, then flush the system.
Might also be worth checking your fan sensor to make sure the fans coming on. Its in the passenger head just below the #6 plug.

Yeah this weekend I'm going to try a cooler thermostat and a new radiator cap. We will see what happens. Its supposed to cool off pretty good by the end of the week though.

[deeznuts94]

Is the black air deflector still attached to the bottom of the Radiator support?

It should look like this...


Is the cooling fins in the radiator plugged?

When was the last time you pulled the radiator and cleaned all the crap out from between it and the air conditioning condenser?
These cars are notorious for sucking crap(leaves, paper, etc.) in there and plugging up the cooling fin on the radiator and condenser.

Yep my deflector thingy is still there and we cleaned out a ton of leaves last summer. I figured flushing the radiator and getting all the crap out from the bottom of the radiator and condenser along with the thermostat would be the end of my issue. Not so much!

[deeznuts94]

New thermostat and radiator cap. Problem solved. On hot days it still runs about 3/4's of the gauge, but no more bubbling in the overflow bottle. I have been running it all week and back and forth to Superfest last weekend with no issues. Thanks for all the help, info, and suggestions.

[white1991rs]

Here's my set up, car runs cool as a cucumber.

[Gregs_gsxr]

are you running filters in both intakes?

[s8bayer]

Glad it worked, I did exactly the same thing after my engine rebuild. Wound up settling at a 185 thermo and I did get one of the $300 for a 3core aluminum radiator and two electric fans from ebay. it works great. I can run it just about as cool as I want. I got a jegs adjustable temp switch for the fans. I am going to now add a overall on/off switch to each fan. The dual fans run pretty high amps so you would turn them off a minute or two before you shut off the car. It is also a bit ruff on a hot restart because the fans try and come on right away while pushing the starter. My new Optima battery handles it fine though. Just plan for something like that on your engine rebuild and you should be in good shape.

(I would of course recommend buying more reputable american company radiator, but budgets a budget... I do think the one I got was from an american company, but I kinda wonder if it was actually made here)

New thermostat and radiator cap. Problem solved. On hot days it still runs about 3/4's of the gauge, but no more bubbling in the overflow bottle. I have been running it all week and back and forth to Superfest last weekend with no issues. Thanks for all the help, info, and suggestions.

[white1991rs]

Yes, I have the stock filter as well as 2 k & N's in the TPI intake. I intend on fabricating aluminum ram air boxes such as HAWKS and possibly removing the TPI air cleaner's baffles. People have asked me if it runs hot, supposedly the 305 was notorious for this but I have never had any problems with this set up, the stock set up or an running an open element filter.

[deeznuts94]

Drove the car today and almost overheated it. Got home and popped the hood and yep it was overheating, the coolant was bubbling again in the overflow bottle. I guess the new cap just increased the boiling point some. So for now I am in the market for a new radiator. Any suggestions?

[Msaone]

Running a 160 degree stat in my kids car (89 rs tbi) made a big difference.

[SOPES]

EBAY !