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Discussion Starter · #1 ·
I have a 98 24V. A couple/few weeks ago I popped the radiator cap off and turned out the engine was still a little warm (rookie mistake, I don’t wanna hear it.) I started hearing the “sloshing sound” a few days later, mostly when engine was still on its way to warming up, but occasionally when the truck is warm. I didn’t think I lost very much coolant… I’ve read a couple of threads that were posted 10+ years ago about the same issue. I was wondering if anyone had any ideas and/or solutions? My thought is I probably have an air bubble in the system, and I’m hoping it’s not the heater core. Thanks.
 

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Welcome. Yes you likely have air in it, a quart to a gallon of air. When cold remove the cap. Fill to top with coolant, Start with cap off and run until fully warmed up and circulating(10-20 minutes at least). Slowly fill radiator again until it stays to top of full.
Replace cap and drive. Fill plastic reservoir to half+ full.
 

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Discussion Starter · #3 ·
Welcome. Yes you likely have air in it, a quart to a gallon of air. When cold remove the cap. Fill to top with coolant, Start with cap off and run until fully warmed up and circulating(10-20 minutes at least). Slowly fill radiator again until it stays to top of full.
Replace cap and drive. Fill plastic reservoir to half+ full.
I feel silly for asking this, but I grew up being told there’s no question that is a dumb question… it is safe to do so, correct? I won’t get splashed in the face or anything like that. Don’t wanna find out the hard way lol
 

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No not unless you open it hot again. It blows out from contained pressure, not the basic heat. You do not dump water in a blown out OVER heated engine, not from warming one up with the cap off because of no pressure.
A small amout can run over the top as it warms up and thermostat opens but will in the overflow or on the floor, The cat drinking it is the only one to worry about. When the thermostat opens air will clear the coolant will drop, hence the refilling until full then.
 

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Discussion Starter · #5 ·
No not unless you open it hot again. It blows out from contained pressure, not the basic heat. You do not dump water in a blown out OVER heated engine, not from warming one up with the cap off because of no pressure.
A small amout can run over the top as it warms up and thermostat opens but will in the overflow or on the floor, The cat drinking it is the only one to worry about. When the thermostat opens air will clear the coolant will drop, hence the refilling until full then.
Good deal. I just wanted to make sure. Never done it before
 

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Let us know it turn out.
 

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Yup not to worry if the cap is off from cold. I’ve had to open caps when pressured, road side problems.. some rags like your shirt over the cap and quick reflex time doesn’t the trick.
 

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Discussion Starter · #8 ·
Yup not to worry if the cap is off from cold. I’ve had to open caps when pressured, road side problems.. some rags like your shirt over the cap and quick reflex time doesn’t the trick.
Luckily my engine wasn’t super hot when I did it to mine. I was really only popping the cap off to check inside the neck but thought I let her cool down enough first lol
 

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Ps, check your water pump and radiator tanks for leaks too. That may be the origination of your issue(air). When real hot sitting an hour is best safest bet.
 

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Discussion Starter · #10 ·
Ps, check your water pump and radiator tanks for leaks too. That may be the origination of your issue(air). When real hot sitting an hour is best safest bet.
I do a little walk-around whenever I go to drive the truck just to look for leaks and such (like I figure any vehicle owner should,) and haven’t noticed anything. I’ll keep an eye out.

I just did everything you said to do earlier, went to drive it and heard the noise for a brief second at first, but it went away almost immediately. Will check again in the morning. Thanks again
 

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Check it agian and fill when cold. Check tanks when hot and runnig and look with mirror the vent in back of the water pump when hot just at shutoff. It sucks air back in when cooling off if leaking, same with tank. No coolant smell in cab, right?
 

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Discussion Starter · #12 ·
Check it agian and fill when cold. Check tanks when hot and runnig and look with mirror the vent in back of the water pump when hot just at shutoff. It sucks air back in when cooling off if leaking, same with tank. No coolant smell in cab, right?
Nope no coolant smell in the cab. I’ll check those weep holes on the water pump after I drive it in the morning.
 

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Discussion Starter · #13 ·
5 days later and issue seems to be no more. Thanks again.
 

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You are welcome.
 

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glad you resolved the issue, my slosh sound was from a leaking heater core in cab. lol
 
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