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A FEW QUESTIONS FROM A NEW GUY

Discussion in '1973-1991 K5 Blazer | Truck | Suburban' started by IL84JIMMY, Sep 3, 2002.

  1. IL84JIMMY

    IL84JIMMY Registered Member

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    hey everyone, i just had a few ?'s about my truck. Lately, it has really been overheating,and gets pretty close to redline, i have to crank on the heater, and even then it doesnt lower too much. should i not drive it anywhere till i get it fixed, or will it be okay. also, i do a lot of highway driving, and not so much rock climbing(being from IL) and i was just wondering what anyone suggests to increase top end( 70 and i am at like 2 1/2 grand) adn gas mileage. is it going to be dealing with the gear ratio, or what are my options. it is a three speed with granny gear. just wondering what i could do. thanks for any help.
     
  2. NoSmog73

    NoSmog73 1/2 ton status

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    </font><blockquote><font class="small">In reply to:</font><hr />
    Lately, it has really been overheating,and gets pretty close to redline, i have to crank on the heater, and even then it doesnt lower too much.

    [/ QUOTE ]

    I would replace the termostat first...and while you are at it I would flush the whole cooling system while you have it apart...

    </font><blockquote><font class="small">In reply to:</font><hr />
    should i not drive it anywhere till i get it fixed, or will it be okay

    [/ QUOTE ]

    If it is getting that hot I would park it till you get the overheating problem fixed first..see above, The high heat could bust a radiator hose or worse while you are on the road..

    </font><blockquote><font class="small">In reply to:</font><hr />
    i do a lot of highway driving, and not so much rock climbing(being from IL) and i was just wondering what anyone suggests to increase top end( 70 and i am at like 2 1/2 grand) adn gas mileage. is it going to be dealing with the gear ratio, or what are my options. it is a three speed with granny gear. just wondering what i could do. thanks for any help.

    [/ QUOTE ]

    Well that is about right without an overdrive ( I and others are going like 2500-3000 rpm's @ 70...) so unless you want to get an overdrive then welcome to the world of the 8-14 mpg small block chevy world..Or you could do a gear swap to like 3.08's but that would just suck for the buck...LOL..mike
     
  3. zakk

    zakk 1/2 ton status

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    1. please fill out your profile as completely as you can. this will aid people like Mike and myself to know what you have and any year specific advice we might have.

    2. Water pump. replace it, thermostat, heater hoses, etc. It is not normal to have the heater on full blast in the summer.

    3. Headers, single plane manifold and custom curved distributor will help top end. but if you are doing 70 @ 2500 RPM's you really do not want to be doing or than that in a modified truck. Black Bear is a bear (pun intended) above 65 MPH.

    ad headers, dual plane mainifold, good distributor and coil for a decent bottom end truck, and a mild 4x4 cam if that is on the list to do.

    hope this helped...
     
  4. Blue85

    Blue85 Troll Premium Member

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    First, if you don't know that it's been done recently, empty the whole cooling system, use a cheap flush agent and then refill with new coolant. Put in a new thermostat while you're doing it.

    Check the fan clutch and make sure it has a some decent "drag" on it when your engine is warm (and not running, of course!) Any doubts, replace it. They are cheap, always wear out after a while and are critical to proper cooling. If you are overheating on the highway, this is probably not your only problem, though.

    If you still have cooling problems, you could have your radiator tested and/or change the water pump. That is pretty much everything in the cooling system.
     
  5. dyeager535

    dyeager535 1 ton status Premium Member

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    Have you checked (or do you still have) the cat converter?

    Do you notice any loss of power as it warms up or the faster you go, the harder it seems to be working (moreso than a normal vehicle?)

    I'm not saying remove or replace the converter, but problems at speed COULD be from the converter. Check it out.

    Definitely check your radiator out as well. I recently pulled my clutch fan off just to see how it ran without it, and at idle, it would climb to 210+ (didn't have time to see how high it would go) but as long as I didn't bog the engine down, no matter how slow I was going, the coolant never got over the t-stat temp of 195. Drove it around town/some traffic for two days. Waiting at stop lights was the only place I had problems. (and noticeably worse when it was 80-90* outside, vs 50-60* at night)

    Of course, I have no AC, a manual trans, and I know for a fact there is no junk blocking the cooling fins on the outside of the radiator. (bugs, rocks, etc). Radiator is a corroded (internally) two core with some unknown amount of antifreeze in it. (the coolant is green anyways lol)
     

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