94 Blazer overheats

[454cid]

Woke up too late to go look at it on Saturday, but got over there today. Chassis and body look good for Michigan. The passenger side fender, near the door, is rusting, which was the only obvious rot I saw. However, the engine was troublesome. First thing I did was take the radiator cap off. Very rusty, and the coolant was super low. That kind of explains the overheating.... gotta have coolant to cool. The front of the engine was wet, all down the front and the frame, so I'm thinking a badly leaking pump. Not great, but the engine could still be fine. I couldn't get it started, Though. The battery was dead, and even with cables on it, it wouldn't turn over fast enough to fire. I could see someone had been into the ground, but the positive was super corroded, so it's likely the power just wasn't getting to the starter. When turning, I could hear some sort of scraping, but it didn't sound internal, to me... the serpentine system needed attention, by the looks of it.

I'll pass. It would make a good project, but is more of one than I'm looking for.

 

[Supercharged111]

Woke up too late to go look at it on Saturday, but got over there today. Chassis and body look good for Michigan. The passenger side fender, near the door, is rusting, which was the only obvious rot I saw. However, the engine was troublesome. First thing I did was take the radiator cap off. Very rusty, and the coolant was super low. That kind of explains the overheating.... gotta have coolant to cool. The front of the engine was wet, all down the front and the frame, so I'm thinking a badly leaking pump. Not great, but the engine could still be fine. I couldn't get it started, Though. The battery was dead, and even with cables on it, it wouldn't turn over fast enough to fire. I could see someone had been into the ground, but the positive was super corroded, so it's likely the power just wasn't getting to the starter. When turning, I could hear some sort of scraping, but it didn't sound internal, to me... the serpentine system needed attention, by the looks of it.

I'll pass. It would make a good project, but is more of one than I'm looking for.

Sounds like a dirt cheap truck to me.

 

[movietvet]

Woke up too late to go look at it on Saturday, but got over there today. Chassis and body look good for Michigan. The passenger side fender, near the door, is rusting, which was the only obvious rot I saw. However, the engine was troublesome. First thing I did was take the radiator cap off. Very rusty, and the coolant was super low. That kind of explains the overheating.... gotta have coolant to cool. The front of the engine was wet, all down the front and the frame, so I'm thinking a badly leaking pump. Not great, but the engine could still be fine. I couldn't get it started, Though. The battery was dead, and even with cables on it, it wouldn't turn over fast enough to fire. I could see someone had been into the ground, but the positive was super corroded, so it's likely the power just wasn't getting to the starter. When turning, I could hear some sort of scraping, but it didn't sound internal, to me... the serpentine system needed attention, by the looks of it.

I'll pass. It would make a good project, but is more of one than I'm looking for.

IMO, biggest worry is the rust in the cooling system. I worked on an American Legion member's 91 K2500 5.7 for a leaking water pump and the system was full of rust. The cap and thermostat were loaded and both a full rust color. The bolts holding the thermostat housing to the intake were so rusted from being in the coolant under the intake, that they pulled a small amount of threads with them, when removed. The radiator was loaded. She replaced all of it and was pretty happy till I told her that the rust is attacking the head gaskets and would soon win the battle. She is aware of the ramifications but still drives it sparingly. She has put no more than 200 miles on the truck since the work done a year ago. I would also assume that the freeze/welch plugs are barely hanging on.

 

[454cid]

The radiator was loaded. She replaced all of it and was pretty happy till I told her that the rust is attacking the head gaskets and would soon win the battle. She is aware of the ramifications but still drives it sparingly. She has put no more than 200 miles on the truck since the work done a year ago. I would also assume that the freeze/welch plugs are barely hanging on.

I guess I'm not seeing how the rust would affect the head gaskets after the fact.

You mentioned the thermostat bolts. Do those go into water on the small block?

 

[movietvet]

I guess I'm not seeing how the rust would affect the head gaskets after the fact.

You mentioned the thermostat bolts. Do those go into water on the small block?

When you pull the thermostat housing on the 91 K2500 5.7, that I worked on, when you remove the thermostat and reach in, you can feel the bottom of the bolt hole. The bolt threads are immersed in the coolant, except for the threads of bolt that is in the intake above it. The rust builds in the entire cooling system and you saw it yourself on the Blazer. That rust will eat away at the edges of the head gasket where coolant passes thru the head gasket. Eventually the rust will eat thru if it already has a foothold on the gasket edges. If is not too bad and the system is flushed thoroughly, it can be ok. I have pulled head gaskets off that were eaten by rust but it takes some time. These are pics of what I pulled out of that same truck:

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[movietvet]

The bolts look better than they did because of me cleaning with a wire brush.

 

[HotWheelsBurban]

When you pull the thermostat housing on the 91 K2500 5.7, that I worked on, when you remove the thermostat and reach in, you can feel the bottom of the bolt hole. The bolt threads are immersed in the coolant, except for the threads of bolt that is in the intake above it. The rust builds in the entire cooling system and you saw it yourself on the Blazer. That rust will eat away at the edges of the head gasket where coolant passes thru the head gasket. Eventually the rust will eat thru if it already has a foothold on the gasket edges. If is not too bad and the system is flushed thoroughly, it can be ok. I have pulled head gaskets off that were eaten by rust but it takes some time. These are pics of what I pulled out of that same truck:

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Yecch.... nasty stuff in your cooling system!

 

[movietvet]

Yecch.... nasty stuff in your cooling system!

Not my girl's truck cooling system. Her's is a 1990 and the one I worked on is a 1991.

 

[HotWheelsBurban]

Not my girl's truck cooling system. Her's is a 1990 and the one I worked on is a 1991.

I figured y'all's was better cared for; that truck needs some attention.

 

[movietvet]

I figured y'all's was better cared for; that truck needs some attention.

It is owned by the wife of a fellow American Legion member and he just passed away. She owns a 2005 Tahoe LS as well. I do the work now on both but the rust opening on the truck was the first time I had touched that truck. It is blue and silver and is a regular cab with a long bed and about 210k miles. Is the 6 lug 2500.