engine overheat on '88 blazer s-10 any ideas on how i can fix this?

 

Kinda lacking in details...

Anyway, the free thing to do is clean the radiator as bugs and other debris gets stuck on the front side of the radiator and limits the amount of air that can cool the fluid. The cheapest thing is to replace the thermostat and see if that helps. When you replace the thermostat, it would be advisable to flush the engine/rad out with new coolant. If it was running fine and all of the sudden it overheated, then I would have to lean towards the waterpump letting go. Also, you may want to check the fan clutch. I'm not sure if in '88 they had viscous clutches on the radiator fan, but if they did, it should be easier to move when the engine is cold than it is when the engine is hot.

 

My 87 does the same thing. When I got it 2 mths ago, I had to replace the water pump. It runs fine now at 55 mph, but when I reach 65mph + it will overheat after about 15 miles. I flushed the system and still did it. I took thermostat out and still did it. I even took out all the A/C componets(hoses, condencer, all of it) and it still does it. Now im outta ideas.

 

Have you cleaned the radiator where the air gets drawn through? Also, is all of your underbody cladding (esp. that which is behind the radiator, but infront of the firewall)? I say this because if it is not, then when you get going fast enough, if extra air is coming up from under the vehicle and pressurizing under the hood, the fan just doesn't have enough oomph (technical term) to pull the air through the radiator.

My dad's truck had this problem after he had a plow frame installed. The problem came from the fact that the factory splash sheilds/cladding could not be installed with the plow frame. We had to make up new sheetmetal sheilds to direct the air down and away from the engine compartment. This does 2 things, it keeps the air from pressurizing the engine compartment, plus, it also actually aids the fan in pulling air through the radiator by actually creating a vacuum in the engine compartment.

If everything is in working order, then it is quite possible that the radiator has some plugged tubes. You can either get it ultrasonically flushed/cleaned or buy a new radiator. It would probably be cheaper and better to just get a new radiator. Autozone shows 2 radiators for your '87. The standard 2 row rad is ~$150 and the upgraded 4 row is ~$210. Those are not bad prices at all especially when you are talking about an overheating vehicle that could seize up at any moment due to the extreme heat.

 

Some bitch, now that you say something it did happen after I pulled the splash sheald thing off(that goes under the radiator). an yes I have blown the bugs and stuff outta the rad. thanks swartlkk I will check that tomarrow.

 

a weak fan clutch will put on the side of the road quick. ive never heard of one causing a problem while riding down the road since you have forced air from your momentum going in the radiator. but his idea on positive pressure under the hood definateley makes sense cause if you pressurise under the hood it wouldnt matter much about how fast you are going, negative pressure is negative pressure. if your fan clutch is good you have to go with the rad. since you've already taken the therm. out