Birdstheword

ok , so so i have an 88 trans am with a 305 tbi in it and im having overheating problems . Well to start off first my car runs very hot , very close to 250 so i turn on the a/c and it will drop to around 180 . i checked my fan and it comes on around 230 but still the temp needle just keeps on rising , i check all my hoses and made sure they are all ok , put on a new water pump , i also bought a new coolant reservoir from hawks and put it on "because the old one had a crack in it " i did this because the coolant in the tank was bubbling and i thought it was because of the crack but no change , the car still over heats and i have this clicking sound when th car idles and when i give it gas , i think it could be my ignition time , or could i have a blown head gasket ? any help would be appreciated

HCR13

iTrader: (5)

have you flushed the system and filled it with the correct coolant?

WaltB_FB92

You might install a after market fan with additional blades some are noisy so
market carefully. I put one in my supped up V-305 and the temps dropped
over 10 degrees. A system flush might help as well.

Birdstheword

yes i have done a full system flush and refilled it with dexcool 50/50 but still my coolant bubles in my reservoir tank and the only way to keep my temp is by turning on my heat @ 150 if i do it too late my temp will reach 240-250 and so i have to shut my car off and let it cool . My fan works fine but i think its coming on too late like at 230 when it should be coming when it should come on at 190 , according most people on this forum .

WaltB_FB92

You may have a termostat that is opening up part way
try putting in another.

l_dis_travlr

"Clicking" is probably the fan relay, and not normal.
This relay turns on when an input signal (green wire, I believe)
is driven to ground by EITHER the temp sensor (connecting to
block ground) OR a circuit in the AC control switching to ground
when the compressor turns on.

I'm confused
turning on the ac lowers the temp (presumably activating the fan, as
above), but when the fan comes around 230 (also presumably, as above)
the temp keeps rising.

My suggestion is to fab a manual switch to control the fan, i.e. connect
one side to ground, the other to replace the (green?) switched ground
input at the relay. (Removing the (green) wire from the weather pack
may be tricky.) Considering everything else you've done, if manually
turning on the fan solve the problem, consider replacing the temp
sensor switch.

For what its worth, my formula was originally the same configuration as
yours, & it kept frying fan relay's. Turns out the fan motor was (barely)
operational, but degraded by excessive current draw. I never could (a)
find out what is the correct current draw for these motors, and (b) how
to measure that current in a DC circuit. Replacing the fan motor worked,
for the short time remaining before I tore out everything & started the
restoration. And in all my years of automotive maintenance, I have
NEVER seen a coolant reservoir cause overheating. The overall usefulness
of these appendages has, & will be debated, 'till the cows come home.

Good luck, & keep us posted.
We all like to know how the problems are eventually solved.

Birdstheword

so today i checked my coolant resrvoir tank .... , i filled it to "full when cold level" on saturday and today when i checked it it was waaaay below the full when hot or cold level , so , i might have a hose leaking somewhere " wich i doubt because saturday i check all my hoses and made sure they were ok " or i might have a blown gasket not sure ... any other opinions out there ???

Birdstheword

so , today i was reading on my haynes repair manual , what an EGR valve is , its operation , and the effects it has on the engine when it works and when it dosent , one of the effects was that when the EGR valve "diaphragm" or the solenoid dont work there tends to be more combustion in your engine therefore causing overheating , poor fuel economy and of course you wont pass your smog test , so i tested my EGR valve and the diaphragm was very hard to push up , it felt like it was "crusty" on the inside , so i purchased a new EGR valve today and will be installing it tomorrow after work . lets see what happens , will update ASAP .

Birdstheword

EGR valve did nothing , i bought a new thermostat , installed , and nothing , more than likely i have a blown head gasket ...

87tpiz28

iTrader: (2)

My 87 had tons of problems over heating. The previous owner removed the thermo. I installed a 180* and 16lb cap and now it runs 180 when driving but sitting at a light it will climb 220+ (and no bubbling). After a few WOT runs, the coolant tank starts filling up and bubbling, sometimes to the point of over filling but the temp is still around 180-190. Might be a slight head gasket leak for both of us that tends to create air bubbles in our cooling system.

Birdstheword

yes , i found that out today , my guess is that there's a tiny leak in the head gasket in wich pressure that the piston creates escapes through the leak in the gasket therefore loss of compression in engine, loss of power and pretty much boils your coolant therefore creating the bubbling effect that you see in coolant reservoir tank .

Birdstheword

CONFIRMED! , i have blown a head gasket , so i wll be replacing it this weekend , i bought a flepro gasket kit its around 80 dollars , not a bad price if they save your engine from becoming useless . So when it comes to your car over heating , start with the elimination process and save yourself money , instead of buying unnecessary replacement parts , start with your cooling system hoses , check for cracks and leaks , the move on to the bigger parts i.e radiator , waterpump and other cooling system essentials, also as i have learned , bubbles in coolant tank = more than likely a blown head gasket !