Bubbling coolant

[larrym]

I guess I'm pulling the heads again........ Last year I lifted the head and was blowing bubbles in my coolant. It was over heating and I couldn't drive it all. Well I put a new aluminium rad in this year and shortly after that I noticed it blowing bubbles again. Funny thing is its not over heating, stays right around 175 and runs fine, no white smoke at the tail pipes, no visible traces of water in the oil. I do get some knock showing on the knock gauge if I put my foot into it, even at low boost levels.

I used felpro gaskets when I did them last year and ARP studs to clamp them down. Guess I have to take a real close look at the block if it is in the same spot as last time. It leaked at number 1 front of the head perhaps I have a small crack I can't see...

 

[Phoneguy]

Give it a re torque and add some GM tabs before you pull the heads. It is worth a shot.

Bryan

 

[chriss4655]

Hey Larry If you want a hand give me a call and I will come and help! Might be easier to pull the motor, you could slap your new cam in there while the beast is out!

 

[larrym]

Don't worry Chris I'll be calling! lol I might give her a re torque and see if I can hold off till the snow fly's before I put the cam in

 

[87-WE2]

does it bubble only when it's running?
If it continues to bubble in the reservoir after you shut it off, then you might have a small leak in the cooling system somewhere. If the temp of the coolant is high, and some pressure is relieved (by a leak), then the coolant will boil. I had this happen on my old '78 Regal. I changed water pump, radiator, thermostat, all kinds of stuff. Figured out the heater core was corroded and had a small leak (wet spot on passenger floorboard). I bypassed the heater core and she ran cool as a cucumber.
Just an idea.

If it only bubbles when it's running, you may be right and have bigger problems. $0.02.

 

[chops]

Listen to your buddy and pull the motor that's doing right!!!!!!!

 

[larrym]

Listen to your buddy and pull the motor that's doing right!!!!!!!

That's the way I'm leaning looking to borrow an engine hoist and stand from an other Buick enthusiast!
Just have to take the wife's truck to work 1 day,she drive the F150 4x4 I get the TDI wagon......
I put on 1200 KM a week so the 60 MPG from the VW is good by the way its black and its boosted!

 

[novaderrik]

you can buy test strips that will tell you if there are combustion gasses in the coolant.

 

[bison]

Try putting compressed air in the cylinders and see if you can get some bubbles on each one. It may help finding the bad cyl. Chances are the engine saw some extreme detonation and compromised the seal. Once this happens the fire ring is usually deformed enough to never seal high cyl pressure again. Re-torquing needs to be done before the seal is compromised.

 

[larrym]

Try putting compressed air in the cylinders and see if you can get some bubbles on each one. It may help finding the bad cyl. Chances are the engine saw some extreme detonation and compromised the seal. Once this happens the fire ring is usually deformed enough to never seal high cyl pressure again. Re-torquing needs to be done before the seal is compromised.

I'll do that tonight while I'm testing the coolant for exhaust gas, tester was only $32.00 good tool to have especially if I'm going to drive it like its stolen!



I just glad I didn't hurt something else, like in your avatar. Good having a safety valve of sorts!

 

[bison]

I'll do that tonight while I'm testing the coolant for exhaust gas, tester was only $32.00 good tool to have especially if I'm going to drive it like its stolen!



I just glad I didn't hurt something else, like in your avatar. Good having a safety valve of sorts!

If youre going to drive it like its stolen you are better off data logging egt and cooling system pressure.

 

[larrym]

If youre going to drive it like its stolen you are better off data logging egt and cooling system pressure.

Its street car 0 to 60 most times I race it once a year at our local airport I only "steal it occasionally" this last mishap I think happened when I blew my alky nozzle out of the up pipe! Good thing I let off could have been even more catastrophic had I sprayed alky all over my exhaust.

I have a question though can I test for exhaust gas at the overflow reservoir if its bubbling there or do I have to do it at the rad?

 

[chriss4655]

Hey Larry Happy wednesday!!!!!!! If you need help, an engine stand and a picker call !!!!!!! I can help, saves the rental and having to take the stuff back!

 

[larrym]

so here is my tester.

Fluid in it ready to test.

Testing

And result after 5 min with the motor running warmed up fan came on twice no change....... so no exhaust gases present where is the pressure coming from?

So I guess a compression test or charging the cylinders is my next move, tested it directly at the rad to with the same results.

 

[Red C5]

I'd pressurize the system next. I had a similar problem with my truck.

Peter

 

[larrym]

I'd pressurize the system next. I had a similar problem with my truck.

Peter

Thanks Peter

Thats my next purchase I guess a pressure tester for the coolant system.


Here are the results from my compression test I pretty happy with the results, confused but happy.


1) 160 2) 160
3) 155 4)165
5) 160 6)160

All cylinders appeared to hold the pressure judging by the relief valve on the tester I left them charged for a bit before I released each one.

 

[larrym]

My head is going to explode........ When I got home to check the rad is still bubbling little fizzy bubbles and the odd large one like some sort of chemical reaction is going on in the rad. Its been sitting for 20+ hours no plugs in it no cap on the rad.


So I picked up a pressure tester for the cooling system today and pumped it up to 20 psi held it for about 10 minutes used my stethoscope and listened in each cylinder and nothing. I did find a tiny leak at the heater switch nothing tightening the clamp didn't fix.

 

[Red C5]

You pull the water pump to check it?

 

[larrym]

You pull the water pump to check it?

Not yet could it be the culprit?

Just checked it left it sealed to the pressure gauge and it shows a couple pounds just sitting for half an hour ........

 

[larrym]

Well pressure tester has been on for an hour or so and the pressure keeps climbing, no plugs in it, hasn't been run for over a day so no heat no combustion pressure. Where can this gas be coming from its up to 4 PSI!