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87 tbi blazer running hot

I

isaac

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hi everyone i just have a little issue with my blazer. it is running around 225 degrees in town and on the freeway. i have changed the radiator, temp sensor, fan clutch, antifreeze flush/fill, and 195 thermostat. i cant figure it out. the last thing i changed this morning was the fan clutch. so my question is how do i tell if the fan clutch is working correctly? i turned off the blazer when it was at 225 and i could spin the fan no problem. is 225 temp too hot for normal operating temp? i know i am not a paying member but i have been a little broke latley any help will be appreciated.

thx
isaac
 
225* is not right. You don't need a fan at cruise, so it should be running at the rated thermostat temp. Idle/around town is where you check fan operation. If the fan isn't working but the rest of the cooling system is in good working order, you would overheat in town while steady cruise would keep temperature at thermostat temp.

How do you know it is 225*? If the temp hasn't changed with all you've done, I'd be a little suspect of the gauge if you haven't checked the temp out with another instrument.

225* probably won't hurt anything, but it's higher than it should be.
 
Check the lower radiator hose. A worn out lower radiator hose can squeeze closed under acceleration because the coolant is being pulled through (as opposed to pushed for upper radiator hose), thus closing off the flow of coolant.
 
that is a good point i am thinking that the gauge could be off... i havent checked it with any other gauge. as for the lower radiator hose i changed it with all the other hoses when i did the radiator swap. but thanks for the resonse. i am not over heating at idle or in town just gets a little hotter then normal on freeway? its just staying at 225... thanks again guys. will check the gauge.
 
So the temperature stays steady regardless of how it is being driven (city, highway, under load, etc...)?

As said above, the cooling fan doesn't come into effect while cruising on the highway so if it was defective than you would have a temperature spike when in town (slow speed, stopped at a light, etc...). However there should be a decent amount of resistance to spinning the fan by hand when the engine is that warm.
 
yes sir the temp stays constant except on the freeway it gets a little highter but then goes back down. there is very little fan resistance when i shut the engine off after it comes up to temp.
 
Bad gauge, mine did the same thing.I put in a mechanical gauge and it read about 190,when the factory one read about 225.
 
so i checked the timing and it is 4 degrees before 0. will this cause my truck to run hot also? i havent changed the timing because i didnt have a crows foot to get to the bolt that holds down the distributor. any input would be apprecitated.
 
Wow sounds like my 91 camaro @ things i havent heard on here check your radiator cap! if it is bound up and will not let the radiator vent into the overflow resivuar it will cause overheating also have you checked your water pump? open everything up and start the truck, watch in the radiator if you have a thermomiret you can insert in there and not loose that is great. now just grab a beer and a smoke and a chair and watch around 195 you should see a big drop in the radiator and see fluid start sirculating rapidly and see your true in radiator fluid level. this process also helpes it there is a air pocket in the system. hope this helps.:D
 
yep new radiator cap i forgot to mention. i have done the opening up the cap let it flow watching the coolant flow looks good? putting a thermometer to check the tem sounds like a good idea. the only thing i havent changed on the cooling syste is the water pump but it seems good no noises or play in the bearing... i am going to try to set the timing and see if that helps... thanks
 
did you check it with the brown wire unplugged? tbi sets its own timing once thats plugged in. I like to run 8 on them anyway.
 
"stock" base timing is 0* for the TBI trucks IIRC, and you'd think 4* wouldn't affect temperature as yours has, but it won't hurt to adjust it either way and see if problem changes.
 
one other thing do you still have the fan shroud on there? believe it or not it can make a little differance, as for timing bont forget to disabli the electronic advance wire on the passenger side before you re set or the computer will just re ste it back.
 
unplugged the little brown wire when i checked timing as stated on the sticker on engine bay. i have a fan shroud. another thing that i noticed was when it gets up to temp i shut off the engine and the fan stays spinning for about a couple rotations... thinking the fan clutch could be bad too....
 
pretty obvious one but I didn't see anyone ask it... have you checked your anitfreeze fluid concentration?
 
i am located in albuquerque nm. antifreeze concentration? i mixed it 50/50.
 
where did you buy the t-stat at?

it SHOULD stay cool even with new stock radiator, but i have always put "heavy duty cooling" radiators in my vehicles out here in the heat, and i know you have similar weather as i do here in Phoenix.

always install a heavy duty fan clutch, and i have never had any cooling issues with this, always runs right near the t-stat setting.

from what you are saying about your fan clutch, it sounds to me like you bought the standard, generic clutch.

50/50 mix out here is fine too.

are you running air conditioning while you are driving?
 
225* freeway/city means it's not a fan issue. Fan problem would only be evident in town., not cruising unloaded.

Antifreeze isn't a good coolant (sorry if that bursts anyones bubble) the least amount of antifreeze you can get away with is the best, however antifreeze concentration is not your issue either, if it's 50/50.
 
4xcrazy said:
where did you buy the t-stat at?

it SHOULD stay cool even with new stock radiator, but i have always put "heavy duty cooling" radiators in my vehicles out here in the heat, and i know you have similar weather as i do here in Phoenix.

always install a heavy duty fan clutch, and i have never had any cooling issues with this, always runs right near the t-stat setting.

from what you are saying about your fan clutch, it sounds to me like you bought the standard, generic clutch.

50/50 mix out here is fine too.

are you running air conditioning while you are driving?
Click to expand...

got the stat from napa. and it has been hot out here upper 90's everyday. you hit the nail on the head el chepo fan clutch i think i will take it back to auto zone and get the hevy duty fanclutch. yep i had ac on when i was driving thinking another reason for the engine to be hotter then normal.
 
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