Interesting cooling system pressure test results
05-12-2009, 03:10 AM
#1
Interesting cooling system pressure test results Typing from my phone so I'm gonna keep it short.
Some of you are aware I have an issue where the car will puke coolant out the overflow bottle when it reaches operating temp.
Well a pressure test was last on my list of things to do and I finally got around to it.
Results: system will hold ZERO pressure without bubbling into the overflow tank. Every time you actuate the little hand pump you can hear it bubbling.
I tried it both cold and at operating temp with the system bled. Any pressure applied at the radiator neck goes STRAIGHT to the overflow res.
I also noticed on initial startup, that the hose that dumps back into the filler neck of the radiator, from the back of the engine was pumping out very aerated white frothy water (cooling system has straight water at the moment) back into the radiator. Something is pressurizing the reservoir and introducing air, and lots of it, into the system.
Why would the system not hold any pressure without directing it immediately to the overflow res?
I did notice also that when I started it up and was letting it reach operating temp, inside the exhaust tips was VERY damp... Like maybe its burning some of the water.
What's left, compression test, leakdown test, or just drop it, pull the heads and remove all doubt?
Its so weird, when I got the car up to temp, after it puked and I topped it back off, I actually took it for about a 15 min joyride and it ran awesome never left the normal temp range and is stout enough to demolish the tires all the way through 3rd. Runs great, just pukes when it reaches operating temp lol...
Thanks for any help,
Greg
Some of you are aware I have an issue where the car will puke coolant out the overflow bottle when it reaches operating temp.
Well a pressure test was last on my list of things to do and I finally got around to it.
Results: system will hold ZERO pressure without bubbling into the overflow tank. Every time you actuate the little hand pump you can hear it bubbling.
I tried it both cold and at operating temp with the system bled. Any pressure applied at the radiator neck goes STRAIGHT to the overflow res.
I also noticed on initial startup, that the hose that dumps back into the filler neck of the radiator, from the back of the engine was pumping out very aerated white frothy water (cooling system has straight water at the moment) back into the radiator. Something is pressurizing the reservoir and introducing air, and lots of it, into the system.
Why would the system not hold any pressure without directing it immediately to the overflow res?
I did notice also that when I started it up and was letting it reach operating temp, inside the exhaust tips was VERY damp... Like maybe its burning some of the water.
What's left, compression test, leakdown test, or just drop it, pull the heads and remove all doubt?
Its so weird, when I got the car up to temp, after it puked and I topped it back off, I actually took it for about a 15 min joyride and it ran awesome never left the normal temp range and is stout enough to demolish the tires all the way through 3rd. Runs great, just pukes when it reaches operating temp lol...
Thanks for any help,
Greg
05-12-2009, 12:25 PM
#3
Launching!
Join Date: Feb 2009
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yeah that above is a good idea. i was watching speed the other day and they had a commercial for that liquid that you put in your cooling system to see if exhaust gasses are introduced. you could have the start of a head gasket leak without the steaming and all usually associated with it.
good excuse to get p/p ai or le heads if you dont have already!
good luck
good excuse to get p/p ai or le heads if you dont have already!
good luck
05-12-2009, 02:32 PM
#4
I did figure it out though! You guys want to know what it was?
When I did the opti my buddy helped for a few minutes when I was puttibg the rad back in. Well he took it upon himself to hook up the two small hoses that go to the top of the radiator.
Well he neglected to stop and think about which one goes where, and had them reversed...
The hose leading to the reservoir was hooked, incorrectly, to the LOWER nipple, and the hose for the steam pipe coming from the back of the engine was hooked to the UPPER nipple, where the coolant res hose should have been hooked.
So, the overflow was getting pressurized because it was BELOW the seal of the radiator cap, on the pressure side of the system...
Reversed the hoses, problem solved! (Hopefully for good)
05-12-2009, 04:05 PM
#5
Yes. That wouldn't be it anyway because this is not an issue where you lose coolant over time and overheat, this a pressurization issue.
I did figure it out though! You guys want to know what it was?
When I did the opti my buddy helped for a few minutes when I was puttibg the rad back in. Well he took it upon himself to hook up the two small hoses that go to the top of the radiator.
Well he neglected to stop and think about which one goes where, and had them reversed...
The hose leading to the reservoir was hooked, incorrectly, to the LOWER nipple, and the hose for the steam pipe coming from the back of the engine was hooked to the UPPER nipple, where the coolant res hose should have been hooked.
So, the overflow was getting pressurized because it was BELOW the seal of the radiator cap, on the pressure side of the system...
Reversed the hoses, problem solved! (Hopefully for good)
I did figure it out though! You guys want to know what it was?
When I did the opti my buddy helped for a few minutes when I was puttibg the rad back in. Well he took it upon himself to hook up the two small hoses that go to the top of the radiator.
Well he neglected to stop and think about which one goes where, and had them reversed...
The hose leading to the reservoir was hooked, incorrectly, to the LOWER nipple, and the hose for the steam pipe coming from the back of the engine was hooked to the UPPER nipple, where the coolant res hose should have been hooked.
So, the overflow was getting pressurized because it was BELOW the seal of the radiator cap, on the pressure side of the system...
Reversed the hoses, problem solved! (Hopefully for good)
