Problem after 180 degree stat change

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09-21-2005, 06:23 PM

#21

banned3800

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Quote:

Originally Posted by optmusprimer

Quote:

Originally Posted by jr's3800

The 3800'* in the bonneville do not have a large problem with bleeding the air bubbles out of the system...

Still, its proper procedure and for good reason.

Quote:

Originally Posted by jr's3800

the top of tha radiator physically sits higher than the heads...

Exactly. If there was indeed an air pocket, it would work its way to the fill neck or the radiator and as pressurized, eventually push past the cap, venting to atmosphere through the coolant tank. Then in turn, the coolant in the tank would be drawn back into the system in its place. Thats my understanding of the theory of operation behind the pressure release cap anyhow. Please correct me if I am wrong.

Quote:

Originally Posted by jr's3800

Out of all the 3800'* I have worked on, I have never had a single issue with bleeding the sir bubbles out of the cooling system..

I trust you, but that logic isnt strong enough to state that Bonneville owners don't need to bleed after cooling system service, is it? I dont mean to be overly negative, I just dont like to gamble when it comes to my (or a customer'*) cooling system. Something I was taught early on as a mechanic.

I'll agree with that... But if you were to look at the series 1 engines you'll see that they did not have a bleeder on the thermostat housing...

You should bleed the system per the service manual...

Now here is my thought... If you were to take the C and H bodies, the radiator sits higher than the heads in these cars, so in reality its not a large problem...

But if were were to look at the W bodies, say the Grand Prix, the radiator sits lower than the heads, and any car that has a radiator that sits lower thean the head should go through a good bleed process... we have always made sure to do this to any 3100 or 3400 powered car...

But what still botheres me is the continuing coolant loss... And now that the overflow is being emptied in days as opposed to a month really gives me the impression that there is another leak happening...

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09-21-2005, 11:22 PM

#22

BonnevilleSEman

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i just had a problem with mine it, it was the "L" shaped tube that runs from the tenisoner to the intake..it was distorted bad.....might check to see if that is leaking..i lost all my coolant in a day because of it..

James

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09-23-2005, 03:30 PM

#23

umrdyldo

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Well it'* magic I guess that fixes things. I thought into what everyone said about bleeding and the radiator being above the heads. I did all my work on a hill with the car pointing down hill. I just turned the car around and faced it up hill for a day or two. THen I went under the hood and tighten the crap out of the bolt and poof. No leak as of 2 days.
Thanks everyone for the help.
UMRdyldo

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09-24-2005, 11:51 AM

#24

Logan

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Now I am a bit confused. I thought you never found any coolant outside of the block (a leak). But now after turning the car around, to get all the air out; then over torquing a bolt you now have no leak. I guess I am confused as to why you tightened a bolt since none of the coolant was visably escaping the system. Sounds to me like you had an overabundance of air in the coolant system.

I NEVER bleed my coolant system after my thermostat change. Quite frankly nobody told me to, and I never read it on the boards until 2 months or so after I did the swap. Since I don' t have a L36, I didn't see the purpose behind going to a 180 t-stat, so I stuck with the 195. With the 195, I am getting lower (or as low of) temps as people running 180'*. I should have an air bubble in my system. It probably is no longer in there, but my temperatures have not changed. I only put about a quart of coolant in after the swap.

And maybe my L27 is messed, but I have a bleeder screw on the gooseneck. It can be seen here right next to the hose that goes from the EGR to the intake.

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09-24-2005, 12:52 PM

#25

banned3800

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Logan..

The 3800'* are a strange beast... The system should be burped of air when you open the system...

I also have never done this to any 3800...

If you were to look at the L27 or L36 or L67 in a W body you will see that the radiator actually does sit lower than the heads, in this case it becomes very important to bleed the system of air... This is seriously important on the 3100-3500 60* chevy V6 engines...

I have always made sure the system was topped off, with the car running... I then installed the Radiator cap and let the car reach operating temps so that the T-Stat will open, I then make sure the system is topped off again, and watch it for a day or 2 from that point... I usually fill the overflow to above the Full Hot mark... I have never seen it sink to the Full Cold mark... After putting my car back together 2 months ago, I lost that little bit, and that all I have lost.. Its still full...

If you leave large air pockets in the system you can overheat the engine badly, and in the worst cases crack heads or blow( burn ) the head gaskets... But again I have never had this issue with a 3800... Look at the Older LN3 in the 88-91 Bonnevilles... There is not a bleeder screw in site