WW7

Ever since I installed my 383 engine I have had a terrible time getting the air out of my cooling system..I have tried everything including getting a Airlift evacuator , jacking up the front , and packing the system...What I'm wondering is, could me removing the stock heater hose that had the tube coming off it, the one that went to the back of the intake manifold be causing all my problems...When I installed the new motor I eliminated the hose with the tube, just put in a straight heater hose and capped off the hole in the intake with a plug..Now that I've thought about it, I'm thinking that tube may have helped bleed the air pockets out of the back of the engine...What do you guys think???.Thanks. WW

Cliff Harris

The system should purge itself after several heat/cool cycles.

My procedure is to fill the radiator and run the engine until it gets hot. Then let it cool, open radiator cap and fill the radiator. Repeat until all the air is gone. Make sure the overflow tank is full so it can get pulled into the cooling system.

I guess if you have a remote surge tank (or whatever it's called) you would do it there.

WW7

When I had a standard flow water pump on the car it was hard enough getting it to purge, since I have installed this Stewart stage 1 high flow pump it just won't purge at all..I have a serious air pocket somewhere in the system and after at least 6 hot/cool cycles it's still not purging..That's why I was wondering if hooking up the stock heater hose with the tube to the back of the manifold would help purge the air...I'm also thinking of maybe just putting a bleed screw back there in the hole if I don't use the stock heater hose, maybe that way I can get the air out by opening the bleeder while the car is running..Thanks Cliff , any help is appreciated.......WW

UPDATE::
Here is a video I just found saying that the heater hose with the tube " is" for purging air from the back of the engine..Seems my question has been answered about what the tube is for...I'm still thinking a bleed screw would work in place of the heater hose for purging air......WW

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WVZR-1

Have you considered perhaps a couple "bleed holes" in the thermostat?

WW7

WVZR-1,
Yes, I have always put holes in the stat when I put them in, usually it helps...It isn't helping this time with this high flow water pump, something isn't letting it purge....I still have the stock heater hose with the tube in the garage, I'm going to put it back on to see if it helps. If the video is correct it should help..... Thanks.....WW
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WVZR-1

I'd think maybe doing what's required to do "NEW" hose, tee etc. so you only have to do it once. If your used hose does work then you need to replace it with "NEW" anyway unless the one you eliminated was very recent?

WW7

Thanks for the suggestion......The hose I have is in very good shape, I believe it was replaced soon before I got the car...I just hope it works to purge the air..I'll let you know......WW

antfarmer2

the bleeder valve sounds good to me

WW7

That would be much easier to install, and maybe just as effective....WW

SJW

You already found your answer about the rear hose. A bleeder screw might accomplish the same thing, but you'd have to try it to find out for sure. You've already added bleed holes to the thermostat -- something I always do.

I use my cooling system pressure tester to push the air out of the bleed screws on LTx engines. This gets nearly all of the air out before I even start the engine for the first time after a cooling system re-fill, preventing hot spots from developing in the heads. It works quite well.

I always re-bleed after the first three to five heat cycles, to purge any remaining air bubbles that may have been lurking in the cooling system in places such as the heater core.

Live well,

SJW

WW7

Looks like I may have to go with a bleeder screw anyway , the hose connector has course thread , and the hole in the Edelbrock intake is fine thread..........WW

crowz

Any chance its the heads? Ive seen this in aluminum gm cars before. Sometimes its actual head damage and sometimes its just porous heads. Usually if your having air problems long enough after going postal on bleeding them its the heads from my experience.

Ive used bars leak pellets that gm uses on the assembly line with good results. Never had had an issue with them plugging anything up. Again Cadillac and gm vortec trucks get the treatment on the assembly line. But eventually those have to be re-dosed after awhile.

May not be your problem but figured Id toss it in there.

crowz

Also normally the results are low coolant over time on a sealed system but I have seen it go the other way around though very rare. Hopefully its just the hose you found.

WW7

I don't think it's head related.Ive been running Dart Pro 1 heads for 4 years without problem..I had my water pump (Chinese junk) start leaking out the weep hole last week, but before that the car was cooling fine...Replacing the water pump is what started it all...I went with a Stewart hi flow pump and it seems to be hard purging the air with that pump, maybe because it moves more water, I'm not sure..
I just loosened the bolt on the back of the manifold to bleed some air with the motor running, then tightened it back up ( I used it like a bleed screw ) then went for a ride , and it may have helped a bit , my temps stayed more stable on the half hour ride...I'll just keep working at running it, then letting it cool..Maybe it will eventually purge itself.....WW

crowz

Does sound like its just being stubborn. Good luck with it.

Tom400CFI

What is the symptom? Why do you feel it has air?

JrRifleCoach

WW has had water problems for a while. Seems to me the hi-flow pump has much to do with the overheating. I've been schooled that the hi-flow pumps will shorten the quench time in the radiator. Thus reducing the radiators ability to remove heat. That being said, WW has other info to the contrary that may or may not be the reasons.

I feel after all he has posted, it appears that he has been burping properly.
But maybe WW will chime in and refresh our memories.

Tom400CFI

It seems like a lot of people have been to that same school that you went to.

Myth; Coolant flowing too fast

ANOTHER

And one more

JrRifleCoach

OK. Then what are the advantages of hi-flow pumps?
Does circulating the water faster mean the system will cool faster?
Or helps to reduce hot spots.....

Or is there more to a hi-flow water pump?

WW7

I apologize for the long post..

Tom and Coach,
Your right, I have had this problem before, and it was with a high flow pump (you have a good memory Coach)..I just had the Chinese pump I bought 2 years ago blow out on me 2 weeks ago..I decided to get a decent pump this time so I went with a (Stewart stage 1) which many on here use..With my old pump the temps stayed steady between 180-183 deg as long a the car was moving at least 35mph...When I came to a light the temp went up slowly and if the light was long enough the fan would come on and the temp would go down...With this pump I can be driving a steady 40 mph and the temp will wonder from 178-186 up and down..When I get to a light the temp goes up way faster then it did before and when I move the temp comes down like normal...Here's the one thing that did change dramatically, when I pulled onto the highway last weekend and was getting up to speed, I look down and my oil temperature which usually never goes over 207- 210 deg shot up to 220 degree in a short time...I know this isn't high for oil temp but it's unusual on my car...
Last time when I had the Edelbrock High flow pump the only way I could get the system to purge was to install a Stewart 180 deg high flow racing thermostat..The problem with this is in cooler weather I couldn't get my coolant temp over 160-165 degrees because there are 3 large holes in the stat..The reason I went with the stewart hi flow pump this time is because there aren't any "Made In American" standard flow pumps that I could find and Im tired of replaceing the Chinese junk every few years..I did loosen the bolt on the manifold rear crossover (where that metal tube goes) with the car running yesterday and some air did purge and it made a slight difference .Thanks Wayne

PS I did use a high flow thermostat this time and drilled a (1/16 hole) and a (1/8 hole) in the top..I usually do this on all my stats..