recurring air in coolant - X-post...
10-13-2003, 09:42 AM
#1
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recurring air in coolant - X-post...
hi folks!
recurring problem. cooling system gets bled, is fine, then develops air bubbles again.
have changed the cap (will double-check - may have one that is of lower than adequate pressure) with slight improvement, tho.
car runs at or just above the first white mark at highway speed, but will quickly rise to the 2nd white mark upon exiting/stopping unless engine is revved. when its revved, temp immediately drops - consistent with air in the system - along with that gurgling sound under the dash!
car runs great - feels like full power - AFM dithers/reacts properly. no white smoke (that i can see) and only exhibits a bit of black smoke with WOT/full boost condition...which is fine - just means i'm not going lean...22-25 mpg on extended runs (just did 2 days/1200 miles with 80mph moving avg)
not dropping any coolant while parked and the system seemed to pick up air into the cooling system while recently sitting in storage for 2 months. it does shoot some small black 'dots' of liquid from the exhaust upon startup sometimes, but i think this is due to the test pipe and running a bit rich...
plan to do the following:
check the cap to make sure i have the correct one.
get a pressurizer and pressurize the system to ck for any leaks. (any specific places to check - tips on pressurizing??)
inspect spark plugs - what should i look for to indicate a head gasket failure or is this out of the question given the way its running - or how can rule in/out a head gasket failure???
i'm a bit confused here (obviously) and the only related condition that i can even come close to thinking of is the fact that my A/C drain seems to have a partial obstruction which causes the a/c to gradually lose its efficiency over a very long run. after parking the car (even for 10 mins) i get full cooling back - for a time...the a/c continues to drain for a LONG time when i finally park it. it dribbles out over night. i plan to attack this by removing the center console and going in that way - i've already tried numerous times over the last couple years to clear the drain tube from the bottom - i guess i've only been partially successful!! time to get serious (but i doubt this is related by my coolant/air issues...) i guess the reservoir just gets full due to the partial obstruction and it just can't move as much air....it starts out REALLY cold - i just want to keep it this way! i think that the ONLY way this could be related is thru the heater valve - maybe...doubtful, tho.
thanks tons everyone!!
recurring problem. cooling system gets bled, is fine, then develops air bubbles again.
have changed the cap (will double-check - may have one that is of lower than adequate pressure) with slight improvement, tho.
car runs at or just above the first white mark at highway speed, but will quickly rise to the 2nd white mark upon exiting/stopping unless engine is revved. when its revved, temp immediately drops - consistent with air in the system - along with that gurgling sound under the dash!
car runs great - feels like full power - AFM dithers/reacts properly. no white smoke (that i can see) and only exhibits a bit of black smoke with WOT/full boost condition...which is fine - just means i'm not going lean...22-25 mpg on extended runs (just did 2 days/1200 miles with 80mph moving avg)
not dropping any coolant while parked and the system seemed to pick up air into the cooling system while recently sitting in storage for 2 months. it does shoot some small black 'dots' of liquid from the exhaust upon startup sometimes, but i think this is due to the test pipe and running a bit rich...
plan to do the following:
check the cap to make sure i have the correct one.
get a pressurizer and pressurize the system to ck for any leaks. (any specific places to check - tips on pressurizing??)
inspect spark plugs - what should i look for to indicate a head gasket failure or is this out of the question given the way its running - or how can rule in/out a head gasket failure???
i'm a bit confused here (obviously) and the only related condition that i can even come close to thinking of is the fact that my A/C drain seems to have a partial obstruction which causes the a/c to gradually lose its efficiency over a very long run. after parking the car (even for 10 mins) i get full cooling back - for a time...the a/c continues to drain for a LONG time when i finally park it. it dribbles out over night. i plan to attack this by removing the center console and going in that way - i've already tried numerous times over the last couple years to clear the drain tube from the bottom - i guess i've only been partially successful!! time to get serious (but i doubt this is related by my coolant/air issues...) i guess the reservoir just gets full due to the partial obstruction and it just can't move as much air....it starts out REALLY cold - i just want to keep it this way! i think that the ONLY way this could be related is thru the heater valve - maybe...doubtful, tho.
thanks tons everyone!!
10-13-2003, 10:42 AM
#2
Three Wheelin'
Well, it is a major situation getting these cars bled and it may take several times of bleeding them from what I've heard to get all of the air out.
I had a similar situation though and found a teeny tiny leak in one of the heater hoses at the back of the engine going into the firewall. There are like 3 hoses there (2 that attach to the heater valve itself) and one that just runs between the block and the firewall. I never actually saw mine leak, but I did find some evidence of green down on some parts in the back of the engine after looking in the same spot like 20 times over a couple of weeks. I had those replaced and now I don't hear the air anymore and I have had a steady coolant level for a couple of months.
Who knows....maybe your heater valve is leaking a bit and letting some hot coolant into the heater core or something and letting some out as well. Right there it can drip down and hit the exhaust pretty easy, meaning you may never see a drip after parking the car.
You can get an coolant test that checks for exhaust residue in your coolant that will help you determine if you have a leaky head gasket. Supra Turbo MKIII guys did block tests a lot if they were questioning it. I think they were buying the kits for about $50. If you have no exhaust residue in the coolant, I think that can pretty well rule out a headgasket going into the coolant situation.
As for the black drops coming out the back of the exhaust on startup, that is most likely condensation. That pipe is hot and when you stop the car and the exhaust cools off with that hot air in there, lots of time the moisture can settle on the inside of the pipe and droplets can get blown out through the exhaust when you start up in the morning.
Good luck!!!!
I had a similar situation though and found a teeny tiny leak in one of the heater hoses at the back of the engine going into the firewall. There are like 3 hoses there (2 that attach to the heater valve itself) and one that just runs between the block and the firewall. I never actually saw mine leak, but I did find some evidence of green down on some parts in the back of the engine after looking in the same spot like 20 times over a couple of weeks. I had those replaced and now I don't hear the air anymore and I have had a steady coolant level for a couple of months.
Who knows....maybe your heater valve is leaking a bit and letting some hot coolant into the heater core or something and letting some out as well. Right there it can drip down and hit the exhaust pretty easy, meaning you may never see a drip after parking the car.
You can get an coolant test that checks for exhaust residue in your coolant that will help you determine if you have a leaky head gasket. Supra Turbo MKIII guys did block tests a lot if they were questioning it. I think they were buying the kits for about $50. If you have no exhaust residue in the coolant, I think that can pretty well rule out a headgasket going into the coolant situation.
As for the black drops coming out the back of the exhaust on startup, that is most likely condensation. That pipe is hot and when you stop the car and the exhaust cools off with that hot air in there, lots of time the moisture can settle on the inside of the pipe and droplets can get blown out through the exhaust when you start up in the morning.
Good luck!!!!
10-13-2003, 11:07 AM
#3
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Andrew -
thanks for the tip of the coolant test - i've seen those and thats a good call. i'll go pick one up. i've heard of the problems with the heater valve and associated hoses - thats on the list of suspects.
as for the exhaust - thanks for confirming my thoughts that its nothing to be concerned about - unless you happened to be standing behind me when i start it up in the morning!!
thanks!
thanks for the tip of the coolant test - i've seen those and thats a good call. i'll go pick one up. i've heard of the problems with the heater valve and associated hoses - thats on the list of suspects.
as for the exhaust - thanks for confirming my thoughts that its nothing to be concerned about - unless you happened to be standing behind me when i start it up in the morning!!
thanks!
