98 Coolant Smell/Steam
#1
05-12-2010, 03:14 PM
98 Coolant Smell/Steam
I apologize in advance this may be a long read...
This evening when I returned home from a stop and go hour or so long city drive I noticed a smell of coolant and saw a slight amount of steam (not smoke) from under the hood.
So, I popped the hood and made a visual check of things. Coolant level looked to be at proper level. I then immediately noticed that coolant reservoir cap was hissing. A constant hiss. I can also hear the coolant still moving around. At this time I do not see any visible coolant leaks or spots on the garage floor. No fluid leakage around cap.
I then waited for her to cool down to do a little more investigation. Opened the reservoir and coolant level appeared to be at proper level. The coolant looked normal as well. Although there was still a small amount of steam coming out of the reservoir. I am not sure if the coolant has ever been changed. Coming up on 100k and more than a decade of service she's well over due then.
I pulled the oil dipstick and the oil was clean as the day I put it in. Not too many miles on it now. Previous oil was clean as well when changed as in not milky. So knock on wood not a HG issue. She has never over heated and this evening was no different. Coolant temperature was between 180°F and 220°F for the entire drive.
I also think it is safe to rule out the water pump because there is coolant flow and no overheating. No visible leaking or weeping from the water pump or anywhere else for that matter.
So, right now my theory is that the reservoir cap has failed letting the coolant boil at a lower temperature. Which in turn causes the hissing from the cap and release of steam. And the boiling or near boiling would be the coolant movement I heard.
I am planning on purchasing a new cap first. Advance is ab $5 and stealership wants ab $15. Any reasons why I should avoid the aftermarket cap. Both are 16 PSI I believe. Also, changing the coolant ASAP weather and schedule permitting.
I have read a few threads of people using and recommending the 18 PSI cap. However, I have not yet bought into that idea. It is true that the higher the pressure the coolant is kept at the higher the boiling point is for said liquid. About 3 degrees for every 1 PSI. Coolant will get hotter before the cap releases pressure. It would take longer for your coolant to boil over with the higher pressure cap, but the engines internal temperature is going to be higher too. Not sure I am willing to that.
Any other thoughts concerns suggestions about the issue or the cap?
I just wanted to post this and see if you all agree with my diagnosis or have any further ideas suggestions or thoughts. Look forward to hearing them and thanks for reading!
This evening when I returned home from a stop and go hour or so long city drive I noticed a smell of coolant and saw a slight amount of steam (not smoke) from under the hood.
So, I popped the hood and made a visual check of things. Coolant level looked to be at proper level. I then immediately noticed that coolant reservoir cap was hissing. A constant hiss. I can also hear the coolant still moving around. At this time I do not see any visible coolant leaks or spots on the garage floor. No fluid leakage around cap.
I then waited for her to cool down to do a little more investigation. Opened the reservoir and coolant level appeared to be at proper level. The coolant looked normal as well. Although there was still a small amount of steam coming out of the reservoir. I am not sure if the coolant has ever been changed. Coming up on 100k and more than a decade of service she's well over due then.
I pulled the oil dipstick and the oil was clean as the day I put it in. Not too many miles on it now. Previous oil was clean as well when changed as in not milky. So knock on wood not a HG issue. She has never over heated and this evening was no different. Coolant temperature was between 180°F and 220°F for the entire drive.
I also think it is safe to rule out the water pump because there is coolant flow and no overheating. No visible leaking or weeping from the water pump or anywhere else for that matter.
So, right now my theory is that the reservoir cap has failed letting the coolant boil at a lower temperature. Which in turn causes the hissing from the cap and release of steam. And the boiling or near boiling would be the coolant movement I heard.
I am planning on purchasing a new cap first. Advance is ab $5 and stealership wants ab $15. Any reasons why I should avoid the aftermarket cap. Both are 16 PSI I believe. Also, changing the coolant ASAP weather and schedule permitting.
I have read a few threads of people using and recommending the 18 PSI cap. However, I have not yet bought into that idea. It is true that the higher the pressure the coolant is kept at the higher the boiling point is for said liquid. About 3 degrees for every 1 PSI. Coolant will get hotter before the cap releases pressure. It would take longer for your coolant to boil over with the higher pressure cap, but the engines internal temperature is going to be higher too. Not sure I am willing to that.
Any other thoughts concerns suggestions about the issue or the cap?
I just wanted to post this and see if you all agree with my diagnosis or have any further ideas suggestions or thoughts. Look forward to hearing them and thanks for reading!
#2
05-12-2010, 06:36 PM
I would agree with you about the radiator cap. I also would avoid the 18 psi cap. That seems to me to bee too much pressure. I think 16 psi is a lot for a cooling system, but there are smart people designing these cars.
I discovered recently that my Seville was gradually losing some coolant and I also smelled antifreeze occasionally. This was going on for at least a couple years. It turns out that the cap was not holding any pressure. I could tell because when the engine was hot I could squeeze the radiator hose and there was hardly any pressure in it. Now with the new cap, the radiator hoses are under pressure when the engine is hot.
I discovered recently that my Seville was gradually losing some coolant and I also smelled antifreeze occasionally. This was going on for at least a couple years. It turns out that the cap was not holding any pressure. I could tell because when the engine was hot I could squeeze the radiator hose and there was hardly any pressure in it. Now with the new cap, the radiator hoses are under pressure when the engine is hot.
#4
05-13-2010, 08:51 PM
Went for a test drive with the new cap this evening.
She ran about 20 degrees cooler tonight on the same trip as before. Keep in mind she never overheated and ran about 220 F. Tonight the gauge never reached above 200. Sat between 180 and 200 with a 78 degree outside temp about the same as previous post when smell and other symptoms were noted in first post.
When I pulled her in the garage I could no longer smell the antifreeze. No steam coming from under the hood. No hissing from the coolant cap. System was holding pressure.
I am still up in the air about changing coolant since it was clean and tested good with flying colors.
I'll keep this thread updated if something goes awry, but hopefully I won't have to do that! Thanks for the help jonrodman!
She ran about 20 degrees cooler tonight on the same trip as before. Keep in mind she never overheated and ran about 220 F. Tonight the gauge never reached above 200. Sat between 180 and 200 with a 78 degree outside temp about the same as previous post when smell and other symptoms were noted in first post.
When I pulled her in the garage I could no longer smell the antifreeze. No steam coming from under the hood. No hissing from the coolant cap. System was holding pressure.
I am still up in the air about changing coolant since it was clean and tested good with flying colors.
I'll keep this thread updated if something goes awry, but hopefully I won't have to do that! Thanks for the help jonrodman!
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