Bubbling into overflow tank
Thread Starter
Drifting
Joined: Jun 2000
Posts: 1,752
Likes: 1
Bubbling into overflow tank
Hi folks, just finished tightening up valvetrain (per Lars instructions) and drove it around for about 20 minutes, making 3 stops. It was driving fairly strong but whenever I would stop, there would be a loud gurgling sound. I'd open the hood and for the next 2 mins the overflow tank would be gurgling. Boiling?? Weird.
Any ideas?
The temp never rose over about 210 but its not very hot this evening so that was odd. Plus they are new aluminum heads so I would expect them to be cooler. Usually it wouldn't break 200 on evenings.
Could my temp sender be bad or something and I'm running dangerously hot?? Hopefully not. I would like to dyno it tomorrow morning but may not if something may be wrong.
Thanks in advance for any help.
-terry
Any ideas?
The temp never rose over about 210 but its not very hot this evening so that was odd. Plus they are new aluminum heads so I would expect them to be cooler. Usually it wouldn't break 200 on evenings.
Could my temp sender be bad or something and I'm running dangerously hot?? Hopefully not. I would like to dyno it tomorrow morning but may not if something may be wrong.
Thanks in advance for any help.
-terry
Safety Car
Joined: Apr 2001
Posts: 3,581
Likes: 28
From: Spring, Texas
Re: Bubbling into overflow tank (terryrudy)
Check and replace as necessary:
- Antifreeze/water mixture (min = 50/50, max = 70/30)
- Thermostat (do not use a temp lower than factory spec)
- Radiator cap
- Temperature sending unit
If an when you flush and fill the system, don't forget the heater core/system and overflow tank.
- Antifreeze/water mixture (min = 50/50, max = 70/30)
- Thermostat (do not use a temp lower than factory spec)
- Radiator cap
- Temperature sending unit
If an when you flush and fill the system, don't forget the heater core/system and overflow tank.
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: Bubbling into overflow tank (terryrudy)
The gurgling is either 1)boiling over or 2) purging large air bubbles out of the system. Either way you need to find out, but be careful if it erupts like Old Faithful. Take off the cap when cool, siphon out coolant so you are about 2-3 " below the top and run the engine till warm. Rev the engine and wathc the coolant circulate (better be) This will help purge the air out of thesystem. Use either a digital temp gun on the T-Stat housing or drop a thermometer into the coolant to see what you are really running at.
Racer
Joined: Dec 1999
Posts: 317
Likes: 0
From: olean ny usa
Re: Bubbling into overflow tank (bigvette1)
I had one do that.. let it cool down, checked the antifreexe level and it was fine. put a new cap on it and started it up.. it bubbled into the overflow tank within a minute and the upper radiator hose was bulging slightly.
turned out I had a cracked head. cracked beneath the exhaust valve and was pressurizing the coolant. hope that's not the case, but it's easy enough to check.. look into the overflow tank and see if it bubbles when it's cold.
turned out I had a cracked head. cracked beneath the exhaust valve and was pressurizing the coolant. hope that's not the case, but it's easy enough to check.. look into the overflow tank and see if it bubbles when it's cold.
Drifting
Joined: Jan 2002
Posts: 1,645
Likes: 11
From: Schaumburg IL
Re: Bubbling into overflow tank (terryrudy)
Let's go back to to the origional configuration and setup. Did this problem occur before you tightened up the valvetrain? Not that this is directly related, but it is the last thing you did.
Take time to verify the temperature you are running at. If you are running around the t-stat and the system is purged of air and full, then go to a good radiator shop. tictocdok's post may have some merit in that you have developed a head or head gasket problem and the bubbles are exhaust. The shop can tell in a minute if exhaust is in the coolant. Hope not and good luck.
Take time to verify the temperature you are running at. If you are running around the t-stat and the system is purged of air and full, then go to a good radiator shop. tictocdok's post may have some merit in that you have developed a head or head gasket problem and the bubbles are exhaust. The shop can tell in a minute if exhaust is in the coolant. Hope not and good luck.
