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Hey everybody, i just got my 72 malibu. It needs a tune up and alot of work. It was over heating really bad so first i took the radiator(original) to the shop so i wouldnt have to worry about that. Had 20% restriction and a little rust. Replaced the radiator hoses and removed intake valve to find no thermostat and rusted intake walls. i power washed what i could out and flushed the dirty water out. It runs better now but still blocked up. Could the narrower passage ways cause over heating in the water pump and intake manifold? Im a 19 year old noob and im learning as much as i can. any adivice would help . what else should i look for or check. everything is stock.
 

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Ben,
There could be a bunch of reasons why. If you look above your post you will see a "Search" (third button in from the right), type in overheating and hit go. Tons of stuff that may help you out.

Mark
 

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Like Mark said...There could be a bunch of reasons why it would run hot...
My experience was running a cheap reman water pump.It would take about 10min of driving to hit 210-220 degrees. I put on an Edelbrock w-pump and now it barely makes 185. Besides my blower my water pump was the best thing I ever spent money on.
 

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Ben,

If it was overheating without a thermostat, you have other issues. BTW, that's called the thermostat housing. An intake valve is something else but we get the picture:thumbsup: Make sure you don't have a leaking head gasket. Check for bubbles in the water at the filler neck while it's running. This would be after it's been refilled and run for a while and topped off so all the trapped air has had time to escape. BE CAREFUL. You can get burned very badly messing with a hot running car's radiator.

If you think the block is clogged up with crap, run a flushing solutoin through it. Easily obtainable from any parts store. Follow the direction on the bottle. It does sound like a new WP is in order. If you aren't running a performance build, any good brand of WP will do. NAPA's are OK. I'd consider a new one over rebuilt. Auto Zone will give you life time warranty on a new one.

If things still are getting hot, consider a new or radiator or having your's rodded. I'd go with a new since it's not that much more usually. Lastly, you could pull the intake and have it boiled at an engine machine shop. That will remove the crap in it and open all the passages.

So, going from cheapest solution to the biggest pain or most expensive:

- Have cap tested or just replace it with a 16lb cap.
- Flush the system
- replace water pump and hoses.
- replace radiator
- remove and have intake boiled and reinstall.

JMHO

BTW - What engine are you running and do you have a shroud???

/herb
 

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Ben,

If it was overheating without a thermostat, you have other issues. Check for bubbles in the water at the filler neck while it's running. This would be after it's been refilled and run for a while and topped off so all the trapped air has had time to escape.
/herb
Not entirely true. Depending upon your system, not having a thermostat can cause overheatin as well. This is due to the fact that the coolant does not have adequate time to stay in radiator to cool off sufficently. A hint to all you guys that are replacing your thermostats, if you drill a 1/8" hole in the thermostat about 1/4" from the spring pearch on the thermostat this will allow all air to escape with minimal water movement. A lot of european car companies are doing it at the factory level, this bypasses the possibility of vapor lock, burning yourself, overflows and overheated engines.
 

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Discussion Starter · #6 ·
Thanks for the help so far. Herb, I did have the radiator roded and they treated a little rust in it with an acid solution. Flushedit with watewr til the water came out clear and clean, Replaced hoses and reinstalled everything with no leaks. I didnt remove the water pump though which would have made alot of sense while i had everything off. I'll Check it and most likely replace it. Right now i am just trying to get a healthy running car and turn it into my first performance project later as i learn the ropes but i think you guys figured that out.

Would it be wise to go ahead and buy a good performance water pump so i dont have to buy another one later?

"BTW - What engine are you running and do you have a shroud???"
-herb


It has a stock 350 ci engine and yes it has a shroud. WHen i first got it looked like it had been bleeding oil on itself for a while. The head gaskets and intake manifold gaskets need replacing but im waiting to take them off till tuesday. Someone is coming to look at the engine and give me some help. since it has been running more the crap in the engine has been loosing up and it runs better. i used those oil treatments to help break it down and flushed the oil out and replaced with clean oil.

I also could hear a fast clicking noise toward the back of the engine on the passenger side when i first got it. I thought maybe the hydraulic lifters were sticking and the rocker arms where making that noise. does that sound right. You really cant here it anymore but at first it was pretty noticable. like i said im a noob and am trying to learn about engines. Im fascinated by these old cars and reallly bringing these engines to life.

thats all i can think of, thanks for any help.
 

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Not entirely true. Depending upon your system, not having a thermostat can cause overheatin as well. This is due to the fact that the coolant does not have adequate time to stay in radiator to cool off sufficently. A hint to all you guys that are replacing your thermostats, if you drill a 1/8" hole in the thermostat about 1/4" from the spring pearch on the thermostat this will allow all air to escape with minimal water movement. A lot of european car companies are doing it at the factory level, this bypasses the possibility of vapor lock, burning yourself, overflows and overheated engines.

Running without a t-stat will also o cause the water to cavitate (sp:confused:) inside the stat housing, causing the water (coolant) to foam, making the motor run hot..

The first thing I would do, is to make sure you have a good 180* stat in there, and make sure it's installed right side up ;) .. Also check your timing, it can also have a drastic effect on engine temps..
 

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The first thing I would do, is to make sure you have a good 180* stat in there, and make sure it's installed right side up ;) .. Also check your timing, it can also have a drastic effect on engine temps..

Right side up is spring towards the motor. ;)

How long does it take before over heating?

You'll have problems long before you ever block up an intake. Usually rad or heater core will tell you first that you have a problem, and then you'll have rust in the block also, I would do like mentioned earlier check timing and flush it, but after you do get to stop over heating, don't run straight water, use anything that inhibits rust and lube the water pump.

I have never had to run anything but stock type water pumps, on a street car, built street, race car, or in town, or alot of cross country driving. It's just whats worked for me! new or good used, but not a rebuilt.

Just my .02 worth.

Pat
 

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In my case, previous owner had taken off clutch fan and replaced it with a 15 inch flex fan and removed the thermostat. Ran really cold so I replaced the thermostat and it started running warm. Finally figured out through this forum and other sources on the web that the fan should be 18- 19 inches in diameter. Changed to an 18 inch flex fan and operating temperature stabilized to 180-190 degrees on a hot Illinois July day. In process of changing to clutch fan because it runs quieter. Rather hear the exhaust than fan at 60 mph any day. This site and some other ones on the web are invaluable as a source of information.


KEEP TINKERING, HOW DO YOU THINK THE MAJORITY OF US OLD GEAR HEADS LEARNED ?

TED
;)
 

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if there is that much crap in your coolingsystem, it might be a good idea to take out the drain plugs on the bottom of the block, right above the oil pan. if they are stock (which they probably are) they will be the 9/16" plug on either side of the bottom of the block.
they will be a bear to get out- use a good 6 point socket and a breaker bar to crack them loose. don't bother with any sort of penetrating oil- it won't help at all. then, once they are out, you might need to stick a screwdriver up in there to loosen up the crud that accumulates in the bottom of the block- which is the lowest point of the entire cooling system. keep running water thru it until it comes out clean.
 

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overheating without a thermostat has more to do with coolant pressure differences in the block than coolantspeed.I know people have said that for years but i've read some engineering articles on coolant dynamics that adressed that.
 
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