|
|
Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
|
|
| |
|
|
jj94auto
User
Jun 21, 2012, 7:20 PM
Post #1 of 19
(4711 views)
|
|
Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Hello everyone...
The vehicle is a 1998 Dodge Caravan with a 3.8 V-6 AWD with 135k miles.
I bought the car about a year ago and noticed a neverending stream of small bubbles in the coolant. I noticed that the rear head was cracked and covered with something that looked like JB Weld. The JB Weld had failed and you could see the coolant oozing around it but not really coming out. After removing the head, I could see that the crack was from the inside to the outside of one of the water jackets.
I replaced the rear cylinder head with a remanufactured one and put a new head gasket in. To my dissapointment, this did not fix the problem.
Other Symptoms:
No overheating, no coolant in the oil, no oil in the coolant, No smell of coolant from the exhaust, no visible leaks.
I have done the following:
- Replaced the radiator with a new one
- Replaced the rear cylinder head with a new one and a new head gasket.
- New Water Pump
- Input 100 psi of compressed air using a leakdown adapter into each cylinder. Moved each cylinder to TDC to test. This yielded no bubbles in the radiator.
- Bypassed the water pump by pulling the serpentine belt. This yielded no bubbles and convinced me to put a new water pump in which didn't fix the problem
- Input compressed air to the radiator overflow hose to the radiator. (Both new radiator caps I purchased leaked like crazy so I had to hold the radiator cap down to listen for leaks...didn't hear any though.
- Ran the vehicle with the heater on and radiator cap off for an hour to see if the bubbles would go away.
- Ran the vehicle for weeks to see if the bubbles would go away.
I have also removed the thermostat to see when the bubbling starts and it starts immediately after turning it on even if the vehicle is cold. The bubbles NEVER stop so I don't believe it is trapped air.
I have 2 mechanics that I have known for a long time telling me that this nothing to worry about.
I am worried about it, my wife drives the vehicle with my kids on it and we plan to take 2000 mile round trip road trips since it is a nice vehicle in every other way.
I don't know what else to do. Please help.
Thank you!
(This post was edited by jj94auto on Jun 21, 2012, 7:35 PM)
|
|
| |
|
|
jj94auto
User
Jun 21, 2012, 7:34 PM
Post #3 of 19
(4697 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
To be honest, the level is not a condition that I have monitored closely so I can't give you an honest answer. I do BELIEVE that if I run it for a few days, the radiator level drops down by about an inch but was wondering whether or not that would taper off. I was going to post that information but didn't want to because I wasn't sure. Sorry about that. I paid alot more attention to the bubbles themselves.
I also own 4 other vehicles and none of them act like this. The bubbles go away on their own after running the vehicle without the radiator cap. I am afraid these little bubbles are hot spots that cracked the head in the first place.
(This post was edited by jj94auto on Jun 21, 2012, 7:42 PM)
|
|
| |
|
|
Discretesignals
Ultimate Carjunky
/ Moderator
Jun 21, 2012, 8:51 PM
Post #4 of 19
(4653 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
You mentioned that the bubbles went away when you took the serpentine belt off and ran the engine. That should tell you that you don't have combustion gases getting into the coolant system.
Have you tried pressure testing the coolant system?
Wondering if your getting air into the suction side of the water pump from somewhere. Seen that happen on a few power steering systems when air gets sucked into the return side of the system from cracks in a return hose or loose clamp on a return hose.
You really don't want air getting into the coolant system, because that will create air pockets and cause hot spots and possible overheating.
Since we volunteer our time and knowledge, we ask for you to please follow up when a problem is resolved.
(This post was edited by Discretesignals on Jun 21, 2012, 8:56 PM)
|
|
| |
|
|
Hammer Time
Ultimate Carjunky
/ Moderator
Jun 22, 2012, 3:07 AM
Post #5 of 19
(4620 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
You don't seem to have any symptom that should cause concern. The bubbles alone don't really mean much unless they are causing other issues which they don't seem to be. You may just have some air trapped in the system that will eventually work out but pressure test it anyway to find out if the system is sealed tight.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
We offer help in answering questions, clarifying things or giving advice but we are not a substitute for an on-site inspection by a professional.
|
|
| |
|
|
jj94auto
User
Jun 22, 2012, 8:07 AM
Post #9 of 19
(4597 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Laughing with me or at me? :) lol
I pressure tested the cooling system by sending 15 psi with compressed air to the radiator overflow hose after disconnecting the hose from the overflow. No, that's not how a pressure test is done. Ive heard of a lot of wild creations, but never that one.
|
|
| |
|
|
Tom Greenleaf
Ultimate Carjunky
/ Moderator
Jun 22, 2012, 9:04 AM
Post #10 of 19
(4591 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Pressure test is done where the pressure cap goes specially made to fit and should test pressure cap also. Don't exceed a cooling system's pressure rating, usually around 15lbs and stated on pressure cap if it's the right one.
Didn't re-read whole thread but tiny bubbles noted could be some air still in there, lousy grade of antifreeze that should not bubble like soapy water, air getting in from where coolant mix is being sucked into water pump and more,
T
|
|
| |
|
|
Tom Greenleaf
Ultimate Carjunky
/ Moderator
Jun 22, 2012, 10:26 AM
Post #12 of 19
(4581 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Champagne bubbles? Didn't think is was making shaving creme! Pressure tester may be rent-able for free. Mine older by Stant Co. and has been old reliable for a long time. It checks caps too which should hold at the rating and spit out excess of the rating.
Peak brand is no generic IMO and does make a variety including clear/no color, concentrate and premixed.
Off the wall if everything else is proper and working fine probably just leave it alone or if bugging you they make defoamer but meant for hot tubs which I've had and shockingly one tablespoon of the dang stuff and it stops the annoying foam they can make. Absolutely untested so don't use that unless you can boil just a bit down in water and see what happens. I'm not fast to nor really suggesting that and if a literal thimbleful of it didn't cut this out fast I wouldn't put more in. If there was a problem with the water if you changed it with tap water that might be it.
Most use plain tap water which varies depending on your source so will suggest distilled water to almost anyone who asks. I can find it for 88 cents a gallon still. The water out of tap that I use has never been a problem but for a couple bucks I'll use only distilled now and three to do this year known ready for a routine change.
Smile/frown - I see this "Life Time" label on some with no changes needed. Hmmm - does that mean I'm not going to live for another change or the cars wont?
Can't verify that claim and suggest changing it on suggested schedule,
T
|
|
| |
|
|
Sidom
Veteran
/ Moderator
Jun 22, 2012, 12:02 PM
Post #13 of 19
(4571 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
One thing you can look at would be the timing cover. It's been a while but I had a few 3.8 where the O rings in the cover would leak coolant.
There are a few O rings in there but if I remember correctly the ones that were leaking for me were on the left side of the engine at the bottom & a little tough to see. Really the only reason I remember those is because when I got the cover off the O ring looked as though it was "sucked in" instead of just being round or blown out......
Those were leaking coolant but may have had a small bubble problem prior.....Honestly those bubble sound like they are pretty small & would be easy to miss if you weren't specifically looking for them....
|
|
| |
|
|
Sidom
Veteran
/ Moderator
Jun 22, 2012, 1:16 PM
Post #15 of 19
(4553 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
I would want to 1st verify there was a problem before pulling the cover. The ones I had were leaking on the left side by the a/c compressor. I would want to look at the cover to block area and see some coolant corrosion or something that would indicate a leak before pulling the cover. Since yours isn't leaking coolant it may be harder to nail down but I would think there would be some kind of evidence of leak you could see.
I cheated & used a boroscope but you can see it by eye if you twist right & use a flashlight....
|
|
| |
|
|
jj94auto
User
Jun 22, 2012, 2:29 PM
Post #17 of 19
(4539 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Well, I pulled the intake manifold and followed Felpros instructions for RTV on both side of the gasket just to be sure. That wasn't it lol.
Still waiting for the pressure test to come my way tonight and the mightyvac.
|
|
| |
|
|
jj94auto
User
Jun 22, 2012, 5:53 PM
Post #18 of 19
(4519 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
All, the bubbles seem to have gone away....had to have been either 1 of 2 things:
1) Putting RTV around the intake ports and coolant ports for both the head and the top of the valley gasket. Last time I left it dry.
2) Changed my brand of coolant...fresh coolant/water mix now.
It will probably come back with my luck but wanted to share this with you in case it doesn't. I left the cap off and the thermostat was definitely open. Couldn't observe it that way for long because it would have rose over the radiator filler. No bubbles out of the overflow now though (since I had to close the cap). Not even one...let it idle about 30 minutes and no bubbles.
I hate eating my words so I am not confirming anything.
|
|
| |
|
|
jj94auto
User
Jun 23, 2012, 2:53 PM
Post #19 of 19
(4488 views)
|
|
Re: Tiny Bubbles in my coolant...98 Caravan 3.8 V-6
|
Sign In
|
|
Update:
Ran it again until the thermostat opened again. Some large bubbles came out of the overflow. Noticed that one of my new radiator caps was going bad (wasn't sealing the radiator and coolant was trickling past the neck).
Soon bubbles started coming out every 3-5 minutes. The would last about 5 seconds and then stop. That frequency just seems like trapped air at this point.
I think that I can call this fixed. Another thing I replaced was the water pump bypass hose. It was in shoddy shape and ripped when I put things back together. Could that have been the problem or a contributor?
Thank you
|
|
| |
|
Auto Repair Home
SEARCH
WHO'S 
LOG 
2006 Toyoto Camry XLE Driver Side Electric Window Trouble
Tierod end change caused some kind of leak
Grounding Cable, 2017 Jeep Renegade Trailhawk
equipment
Howdy
