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My 1998 STS is pouring coolant.


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So I've been having overheating issues on and off for a little less then a year now,well today I'm sitting in my car talkin to a friend and he says coolant is leaking,I back up and in 5 or so minutes a pretty big pool of coolant has leaked out from under the passenger side.

I then get it home with it only getting barely hot and it's hissing like something is not air tight.I can't find a busted hose though??Could it be a water pump or cracked radiator?

I'm at a loss here,Ive been dealing with the overheating problem for a while,every time I think I've fixed it,it pops back up.I don't think it's the head gasket because the oil is clean,it don't smoke and it runs very smooth.

Any help is appreciated,Thanks

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Have you checked the crossover pipes at the rear of the engine? sounds like one of them. They start on the driver side, go around the rear of the engine and to the passenger side at the reservoir.

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Have you checked the crossover pipes at the rear of the engine? sounds like one of them. They start on the driver side, go around the rear of the engine and to the passenger side at the reservoir.

No I haven't but on my 1998 the return reservoir is on the driver side.1998 is the 1st year of the late 90's and early 2000's style.
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So I've been having overheating issues on and off for a little less then a year now,well today I'm sitting in my car talkin to a friend and he says coolant is leaking,I back up and in 5 or so minutes a pretty big pool of coolant has leaked out from under the passenger side.

I then get it home with it only getting barely hot and it's hissing like something is not air tight.I can't find a busted hose though??Could it be a water pump or cracked radiator?

I'm at a loss here,Ive been dealing with the overheating problem for a while,every time I think I've fixed it,it pops back up.I don't think it's the head gasket because the oil is clean,it don't smoke and it runs very smooth.

Any help is appreciated,Thanks

It is not the water pump... the only time a water pump should be replaced is if it is making noise or if coolant is leaking out of the weep hole. If the radiator tank is cracked, you would see coolant leaking from the crack. The inlet side is always the side that goes bad and that is on the driver's side.

The coolant is most likely coming out of the surge tank overflow tube. What does the temperature gage indicate when the coolant is leaking?

Have you verified the purge line is flowing? Test the surge tank cap with a pressure tester to make sure it holds the rated pressure.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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So I've been having overheating issues on and off for a little less then a year now,well today I'm sitting in my car talkin to a friend and he says coolant is leaking,I back up and in 5 or so minutes a pretty big pool of coolant has leaked out from under the passenger side.

I then get it home with it only getting barely hot and it's hissing like something is not air tight.I can't find a busted hose though??Could it be a water pump or cracked radiator?

I'm at a loss here,Ive been dealing with the overheating problem for a while,every time I think I've fixed it,it pops back up.I don't think it's the head gasket because the oil is clean,it don't smoke and it runs very smooth.

Any help is appreciated,Thanks

It is not the water pump... the only time a water pump should be replaced is if it is making noise or if coolant is leaking out of the weep hole. If the radiator tank is cracked, you would see coolant leaking from the crack. The inlet side is always the side that goes bad and that is on the driver's side.

The coolant is most likely coming out of the surge tank overflow tube. What does the temperature gage indicate when the coolant is leaking?

Have you verified the purge line is flowing? Test the surge tank cap with a pressure tester to make sure it holds the rated pressure.

The temp was at barley over halfway and.I put a brand new cap on it a few months ago.Also my surge tank is on the driver side though.
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Any chance it's drippings from the AC system?

We get those postings about this time every year.

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If that 98 is like my 99 there are no cross over pipes, to the passenger side. In fact the only thing on the passenger side with coolant is the upper radiator hose snout, the alternator coolant lines and the tank. BUT it can leak on the drivers side and run across the plastic lower cover and drip/run out on the ground on the passenger side. Ask me how I know. lol

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If that 98 is like my 99 there are no cross over pipes, to the passenger side. In fact the only thing on the passenger side with coolant is the upper radiator hose snout, the alternator coolant lines and the tank. BUT it can leak on the drivers side and run across the plastic lower cover and drip/run out on the ground on the passenger side. Ask me how I know. lol

Lol,I wish that was all it is..........I took a good look at it today,looks like a collapsed radiator hose,cracked radiator and failed water pump.So pretty much it's gonna be a whole new cooling system.Im gonna start calling around for prices tomorrow probably gonna run a grand I'm thinking.......Looks like it might out of commission for a while.

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Oh ok I do apologize. They changed the Seville a ton in 98. The deville and eldo stayed the same til 99. If thats the case I dont even know about the rear pipes

GM FAN FOREVER

Nice, clean, luxury= fine automobile

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Oh ok I do apologize. They changed the Seville a ton in 98. The deville and eldo stayed the same til 99. If thats the case I dont even know about the rear pipes

Yeah I believe,the Seville was changed in '98-'02.All I know is I love my STS,it's the nicest car I've ever owned.Maybe besides a '89 Caprice I had that got stolen.
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If that 98 is like my 99 there are no cross over pipes, to the passenger side. In fact the only thing on the passenger side with coolant is the upper radiator hose snout, the alternator coolant lines and the tank. BUT it can leak on the drivers side and run across the plastic lower cover and drip/run out on the ground on the passenger side. Ask me how I know. lol

Lol,I wish that was all it is..........I took a good look at it today,looks like a collapsed radiator hose,cracked radiator and failed water pump.So pretty much it's gonna be a whole new cooling system.Im gonna start calling around for prices tomorrow probably gonna run a grand I'm thinking.......Looks like it might out of commission for a while.

By "cracked radiator" do you mean the tank is cracked? If so, a good radiator shop can replace just the tank for less than $100.00 if you bring them the radiator.

Is the water pump leaking coolant from the weep hole? That is the only failure mode in the water pump.

Kevin
'93 Fleetwood Brougham
'05 Deville
'04 Deville
2013 Silverado Z71

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