hear is the wright up for the gm coolant cleaner its the same stuff as the oxalic acid and washing soda http://members.shaw.ca/betterthanyou...xcoolflush.htm

any one want to chime in about this ill probably do it this coming up week end

 

well i did it first i flushed it with prestone radiator flush then i back flushed with water for like 7 mins after it ran clear from the block plugs then i filled back up with the oxalic acid and let rund for 1 hour and 30 mins then released the pressure and added the washing soda.

let that run for 10 mins after tstat opened and then drained flushed filled flushed and boy oh boy some gross water came out very rusty looking.

looked at tstat housing after very clean no rust deposit's.

just filled back up with purified water and anti freeze ill take it out to night and then reply letting you guys know what happen.

fingers crossed

 

I can't wait to know.

 

Well im super mad it didint work. The car dose run better tho in highway it used to run right around 190 (with 180 tstat) now its at 182. Might try to acid flush agen, if that wont work then ill pull the heads.

Sigh......

 

Are you saying that the car runs at 182° on the highway in the summer with a 180° thermostat installed?

- Eric

 

Yeah

 

So what's the problem?


Sounds like you fixed it.

- Eric

 

it still dose the thing where it will over heat fast if I dont have.the heater on. The new radator fixed the over heating on the high way but, if the heater is off once the tstat opens it will jump to 250 fast and will then come back down. As if the left side is not flowing watter in till the tstat opens ( making a hot pockit of water ) .

 

So, if you're driving the car, it warms up normally to 180°, then the thermostat opens at 180°, and the temperature suddenly goes up to 250°, and then, in about a minute, comes down again to 182° and stays there for the rest of the drive?
And, if you have the heater on, it just goes to 182° and stays there?

This is very strange, and makes me wonder whether you don't have air trapped in the system somewhere.

Why do you say that the problem is on the left side? Have you measured the temperature on both sides? The thermostat doesn't have a preference for one side or the other - it sits right in the middle and is connected to both.
If one side of the engine is confirmed hotter than the other, then the most likely place for a problem would be at the water pump outlets. I believe you said you had replaced the water pump - is there any chance that a piece of gasket or something could be blocking one of the outputs?

- Eric

 

You got it on the dot. I think its on the left side because the heater valve is on that side. the gaskit is to small to be closing the hole of watter. But I dont think its the gaskit also because if that side was traped it woudint stay even once the tstat opens.

 

But once you open that valve it will let water flow from the back of the block left side back up to the watter pump

 

Here's a dumb question: Is your water pump bypass hose connected?

It's the very short J-shaped hose (on 1970's, that is -- on later models the hose is straight and the thermostat housing has a curved hose fitting) that goes from the top of the water pump to the thermostat housing about four inches above it.

If it is connected, are those passages completely clear? Did anyone fill the thermostat housing end with silicone sealant or anything? Or do you have a water pump with only one hose outlet fitting on top (not counting the large radiator inlet at the bottom) instead of two fittings, with the heater hose connected to the only one fitting, and the thermostat fitting capped?



I'm trying here...

- Eric

 

Oh man good point that is connected. But may be cloged will check. Idk you think that if tgat was cloged that it would still jump. I will double check that

 

this is what mine looks like its not blocked but its a little funny

how do you think i could bend that more

 

Start the engine with the radiator cap off and wait until the thermostat opens. Take a garden hose and stuff it into the neck of the radiator with water running at a slow trickle. This should force the air pocket out. Run water until it overflows. Remove the hose let it settle and repeat.

By the way distilled water is on the acidic side and will corrode your system!

 

checked the water pump bypass its in working order did the air bubble thing and it will still do it.

its looking more and more likely that i will have to pull the heads

 

I found my blown head gaske when I went to change the valve guide seals. Got thru airing up 3 cylinders and then whoosh blew a bunch of water out the radiator through a cylinder.

Its not that bad of a job!!

 

I don't remember seeing any response to this comment. But it is very important for the lower radiator hose to have this spring. Your lower hose can collapse onto itself without it. Very difficult to 'see'.

Do you have a spring in the lower radiator hose?

 

yes i have replaced the lower hose with one that has a spring.

 

I’m starting to question if there is a blocked part, if there was(a block) that pocket of hot water would never flow through right? im thinking maybe the water pump is pushing a little more presser on the right bank which is preventing the left bank from circulating its water threw the bypass, And then once the tstat opens it frees up more space for the left bank to flow the water. I got an inferred temp gun going to start the car and turn off right before tstat opens with the heater valve closed and see if I can find a spot that’s hotter than the rest and also maybe try a new water pump.

Are all pumps created equal?

 

PS: Distilled water is only slightly on the acidic side and will corrode your system much slower than calcium will build up from regular water

 

How hi does the temp go right before the tstat opens?? It does not make sense that when you open your heater valve the temp instantaneously jumps to 250! The only time I ever see this is if your moving an airpocket around, or the tstat is sticking.

 

Are all pumps created equal? [/QUOTE]

No, they are not. The best one I have had luck with on a stock to mild 455 is
one for a 71 Olds 98 455 with A/C, or heavy duty cooling with tow package.
at least that's what I tell the parts store.

The impellers are bigger and some are cast iron instead of stamped tin.

just went threw similar problems with my car. Except I don't have a heater
or heater core in it.
Finally said F it and pulled the heads. No cracks but #3 exhaust seat
recessed and wiped out. # 7 starting to go. And this showed 130# on all cylinders.

I put another set on that I had ready to go. No more problems.
I'm not saying you need to pull the heads but you sure have checked
a lot of the other possibilities.

many have posted here about that spring in the lower hose.
I take those out and junk them every time I get one with it for my Olds.
I have more than twice had to pull them out of the water pump inlet
making its way to the impeller. Never had a problem with out it.

 

I have checked a lot of stuff I’m down the last bit. If the water pump thing does not work I’m pulling the heads.
Oldcutllass
The temp jumps right when the tstat opens and as it opens the temps will jump to 240 then after less then a min it will go down the 180.
Red 71
I have pulled the spring out i have put the spring in. have done a lot. I will check out the 71 pump and see how it compares.

 

Well I’m just going to put the heads I’m tired of this. I have removed heads from motorcycles before but never an old big block.
Can I reuse the head bolts? I see at advance auto they have a 10 count of head bolts for 20$,
I know people have trouble making the turkey tray intake gasket seal right should I get a deferent one
Anything else i should know? Or any things that i should do wile I’m in there like harden valve seats. Or will I have any problems with the head being warped and out of specs. I was going to lap the valves to make sure they seat well. And maybe clean up the ports and runners in the intake

 

Has this engine ever been rebuilt? It might be worth to have it gone through at least new bearings and rings. They should be able to get the heads true they just grind it until it's flat on a table like exhaust manifolds. Harden seats would be good maybe swap out the valves and guides. It might be easier to pull the entire motor out though and pull all the freeze plugs and flush that motor really well cause there could be a blockage in the block and not the heads.

 

i have dropped the bottom end checked the bearings and they all looked good when i replaced the oil pump. the engine only have 73,xxx on it.

im 23 and in my last semester at UCF (taking 5 class's) and im working 36 hours. i don't really have the funds just yet to get an engine stand or lift. should i hold out and do a better build once i grad and get a real job.

i have a daily driver.

also i don't want to go nuts with the engine the car needs body work a bit more i think.

 

So your temp goes all the way to 240 before the tstat opens, cause if thats the case, your tstat is no good. That would explain alot!

 

the tstat stays closed till 180 (takes a wile to warm up) once it hits 180 it jumps to 240 (with in 2 sec) and then jumps back down to 180 after 3 sec. so its opeing and then a rush of hot hot water gose by the temp sending unit.

 

Its sticking, it needs to be replaced!! Or you still have a huge air pocket in there!

 

run it without the tstat for a while and see if that stops the big jump in temps.

 

I have never seen an automotive temperature gauge that read that quickly.
Are you saying that your car goes from 180 to 240 and thrn back down over a period of a few seconds once each time you take it for a drive? I wouldn't even be able to tell if that happened. I'd be surprised if anyone could.
Are you using aerospace-surplus parts or something?

Regardless, it sounds to me like the weep hole in the thermostat is bad, or, like I said before, like the bypass is plugged.
There shouldn't be that kind of temperature differential across the thermostat.
Another thought: it's in right side up, right?

- Eric

 

http://youtu.be/B7aBJh3ZEPw


watch that you sorta can see how fast it jumps around. iv also confirmed this with in inferred temp gun.

iv ran the car with the tstat out fixes the problme but never gets hoter then 120 or so i have a 4core rad.

iv checked the bypass plug its clear. today i sat in a parking lot leting it get up to temp it evened out at 180(like it should) once i put it in gear and drove not even all the way out of the parking spot it jumped up to i 250.

opened the heater valeve and it went back down to 190 in under 5 sec(longer then you think when you see that your block is at 250)

im going to try replacing the water pump once more before the heads come off.
will the 71 high flow water pump fit on a 70

i wish i could fly you all over to look at this so you don't think im crazy iv been messing around with this for 5 or 6 months now and have look at all most every part twice.
Thanks guys

 

yes the pumps will interchange. check the over all height , make sure they are the same. this doesn't sound like a head problem. I don't think the
Temps would swing like that. They would just keep climbing.
Maybe have somebody help you look over things. they may see something that you
are over looking. The NAPA TRUE FLOW # 43100 is the one I used. this is new not rebuilt.

Lots of good info on here from these guys. Something sure is strange with that car.

 

Where do you have your gauge hooked in the block? Is it just above the water pump where its supposed to be??

When mine would have that big of a temp swing it was an air pocket!

 

the temp gauge is hooked up right by the t-stat where it should be.

 

Did you get it fixed?? How did it run without the stat???

 

after driving it and having it over heat more i flush the fluid and then try and see if there are air pockets in the system. You can see in the vid that the right bank and left bank of the engine have way deferent temps.
http://www.youtube.com/watch?v=dwOSF5O0YEM
and
http://www.youtube.com/watch?v=yXFJenkVHdk (this one has the heater valve closed)
this is what the block was doing earlier in the day.
http://www.youtube.com/watch?v=0zMcNcbhwzc
if i reved the engine it would make the temps drop but once i slowed down for a red light it would climb back up.
right now it has no tstat in it and it has not got over 180 if i sit at a red light long enough it will start to climb but once i start moving it cools down to 160 or a little lower. i checked the temp of both sides this morning and its even.

man this sucks

 

Have you tried sticking a garden hose in the neck as I explained in an earlier post! let the water run at a moderate flow until all the air is out!! That looks like air pockets to me still.

 

yep tried that :/