Low on coolant twice last week, but pressure test OK?
12-02-2009, 09:01 AM
#1
Low on coolant twice last week, but pressure test OK? Last week I had begun noticing a coolant smell in the cabin when I sat at a stop light. It would disappear when the car was moving, but returned at the next light, and different cars were around me. For one thing, I don't understand why I'm still smelling 'coolant' when I'm running water wetter & distilled water.
When I left work, I noticed the low coolant indicator was lit on the dash. I checked the level and could not see the top of the water in the radiator. I drove to a 7-11 about a half mile away while keeping an eye on the water temp. I bought 2 gallons of spring water, and it took about a half gallon to get the level to the bottom of the neck. Checked the level regularly over the next couple of days, and ended up adding the rest of that gallon jug and a little from the second.
Then it just seemed to stop disappearing. Put it on friends lift and couldn't find any signs of coolant leaks. Took it to the dealer and had a compression test performed and they say everything tests fine.
I never saw any puddles under the engine. What would cause the water level to drop if the pressure test says there isn't a leak?
When I left work, I noticed the low coolant indicator was lit on the dash. I checked the level and could not see the top of the water in the radiator. I drove to a 7-11 about a half mile away while keeping an eye on the water temp. I bought 2 gallons of spring water, and it took about a half gallon to get the level to the bottom of the neck. Checked the level regularly over the next couple of days, and ended up adding the rest of that gallon jug and a little from the second.
Then it just seemed to stop disappearing. Put it on friends lift and couldn't find any signs of coolant leaks. Took it to the dealer and had a compression test performed and they say everything tests fine.
I never saw any puddles under the engine. What would cause the water level to drop if the pressure test says there isn't a leak?
12-02-2009, 09:40 AM
#2
12 Second Club
iTrader: (4)
Join Date: Dec 2007
Location: Between Bowling Green/Owensboro
Posts: 1,714
Likes: 0
Received 0 Likes
on
0 Posts
Burning the coolant or its dumping into the heater core. I started smelling coolant and loosing a bit of coolant over a month period, one cool day my windshield fogged up and coolant went frikin everyone on it...
12-02-2009, 11:17 AM
#3
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
check the carpet in the passenger foot well and see if it's wet. If so, then time for a heater core.
Quit wasting your money on expensive and unnecessary water. Also, water wetter is snake oil.
Quit wasting your money on expensive and unnecessary water. Also, water wetter is snake oil.
12-02-2009, 12:35 PM
#5
TECH Resident
iTrader: (2)
Join Date: Jan 2003
Location: MD
Posts: 994
Likes: 0
Received 0 Likes
on
0 Posts
why is distilled water "unnecessary"?
If you don't think there's a difference between distilled water and tap water, just look at a steam iron that has been used with tap water. crusty deposits will make it nearly useless over time. distilled water will keep it like new for years.
water cools better then coolant, but does not have the freeze protection and possibly some of the lubricant additives.
If you don't think there's a difference between distilled water and tap water, just look at a steam iron that has been used with tap water. crusty deposits will make it nearly useless over time. distilled water will keep it like new for years.
water cools better then coolant, but does not have the freeze protection and possibly some of the lubricant additives.
12-02-2009, 01:44 PM
#6
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
why is distilled water "unnecessary"?
If you don't think there's a difference between distilled water and tap water, just look at a steam iron that has been used with tap water. crusty deposits will make it nearly useless over time. distilled water will keep it like new for years.
water cools better then coolant, but does not have the freeze protection and possibly some of the lubricant additives.
If you don't think there's a difference between distilled water and tap water, just look at a steam iron that has been used with tap water. crusty deposits will make it nearly useless over time. distilled water will keep it like new for years.
water cools better then coolant, but does not have the freeze protection and possibly some of the lubricant additives.
1. Most of the so called 'distilled water' you get isn't. It's merely filtered, which works ok to get chunks out of the water, but does nothing for the mineral content.
2. In most parts of the country (there are notable exceptions...like San Diego) the water is clean enough out of the hose.
Your analogy of the steam iron is a bad one, because of the steam. The minerals plate out due to the action of boiling in very short order. A boiling cooling system is a bad thing.
12-02-2009, 01:50 PM
#7
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
OK, I see you did a compression test. Have you done a cooling system pressure test? You can rent the gear from A/Z or O'Reilly.
Trending Topics
12-03-2009, 09:01 AM
#10
They did indicate they checked the heads and found no problem there either. Do I need to drain the oil to check for water, or can I see it on the dipstick? What am I Looking for?
The coolant system is a 'sealed' system, right? If the pressure check was good, then the coolant isn't leaving the 'sealed' system...where would it be burning off? New GM radiator cap only a couple of months ago also.
Edit: Hmm, does that pressure test only look for external leaks? If so, how do I confirm the head gasket isn't leaking into the combustion chamber?
The coolant system is a 'sealed' system, right? If the pressure check was good, then the coolant isn't leaving the 'sealed' system...where would it be burning off? New GM radiator cap only a couple of months ago also.
Edit: Hmm, does that pressure test only look for external leaks? If so, how do I confirm the head gasket isn't leaking into the combustion chamber?
12-03-2009, 09:32 AM
#11
Found this... I wonder if the heads I received from TSP were originally cast by Castech?
http://www.gm-trucks.com/forums/inde...0&#entry477800
http://www.gm-trucks.com/forums/inde...0&#entry477800
12-03-2009, 01:28 PM
#12
TECH Addict
Join Date: Jun 2009
Location: Tulsa, OK
Posts: 2,012
Likes: 0
Received 0 Likes
on
0 Posts
They did indicate they checked the heads and found no problem there either. Do I need to drain the oil to check for water, or can I see it on the dipstick? What am I Looking for?
The coolant system is a 'sealed' system, right? If the pressure check was good, then the coolant isn't leaving the 'sealed' system...where would it be burning off? New GM radiator cap only a couple of months ago also.
Edit: Hmm, does that pressure test only look for external leaks? If so, how do I confirm the head gasket isn't leaking into the combustion chamber?
The coolant system is a 'sealed' system, right? If the pressure check was good, then the coolant isn't leaving the 'sealed' system...where would it be burning off? New GM radiator cap only a couple of months ago also.
Edit: Hmm, does that pressure test only look for external leaks? If so, how do I confirm the head gasket isn't leaking into the combustion chamber?
Head gasket leaking into the combustion chamber is what the cooling system pressure check finds. It would be very unusual to see it leak that way and not the other (gases in the radiator). Cooling system @ 18psi v. cylinder at 1000 or so psi.
At this point, you're stuck with either looking for yourself (the shop probably didn't spend a great deal of time in looking) or just living with it until it gets worse.
