Losing Coolant - should I try tabs? Or other prod?

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249
Location
NYC NY USA
I have been losing coolant from my reserve coolant tank, a lot like a quarter tank every week or so. I generally drive this car 3x per week to / from work. It is 8 miles each direction. The engine oil shows ZERO signs of having coolant I want to try a cooling system stop leak in a bottle. Anybody recommend a brand/method they had good experience with. The water pump was replaced on this car about 18 months ago. The car is a 95 Buick LeSabre ( has older 3800 - pre head gasket failure series),
 
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757
Location
Fla.
Are you sure the reserve tank isn't cracked? I'd remove and test it before adding stop leak to the system. Does the car drip coolant on the ground?
 
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25,985
Location
Upstate NY
Originally Posted By: PRND3L
Are you sure the reserve tank isn't cracked? I'd remove and test it before adding stop leak to the system. Does the car drip coolant on the ground?
I would find the problem. If its a hose you want to replace it, not mask the problem. You could send oil for a UOA to be sure. How about adding some UV dye? One of those Stant devices that pressurizes the cooling system?
 
Messages
160
Location
Mass
Originally Posted By: RegDunlop
I have been losing coolant from my reserve coolant tank, a lot like a quarter tank every week or so. I generally drive this car 3x per week to / from work. It is 8 miles each direction. The engine oil shows ZERO signs of having coolant I want to try a cooling system stop leak in a bottle. Anybody recommend a brand/method they had good experience with. The water pump was replaced on this car about 18 months ago. The car is a 95 Buick LeSabre ( has older 3800 - pre head gasket failure series),
It is your head gasket, your car is not from the pre-head gasket failure series. No stop leak will fix it. I changed the upper and lower gasket on my brothers 95 Bonneville with the same engine. Your only real fix is to find out which gasket failed and replace it (my advice is to replace both and know that neither will leak in the future).
 
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22,187
Location
Colorado Springs
I believe the 95 uses the Series II V-6, so the main failure point is the EGR stove pipe cooling jacket in the upper intake manifold, along with the lower intake manifold gasket. What you describe is a fairly serious leak. You could try stop leak, but I doubt it would stop that big of a leak. The latest updated metal frame GM lower intake gaskets along with this upper manifold will be the best thing to do.
 
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RegDunlop

Thread starter
Messages
249
Location
NYC NY USA
Everything i know about tgis engine , people have said it was pre head gasket failure model. Being that pontiac switched to the new engine at lrast a uear before buick. I.e., my buick has a series 1 3800 and everybody says head gasket failures are rare. If it were head gasket wouldnt there be coolant in my oil?
 
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Messages
22,187
Location
Colorado Springs
It's not the head gaskets that usually fail on these GM 3.8L engines; it's the plastic upper intake manifold and the lower intake manifold gaskets. The only sure fire way to tell if coolant is in the oil is by getting a used oil analysis. I've dealt with numerous GMs with leaking intake gaskets, to include a 3.8L, and there was no visible sign of coolant in the oil when there in fact was.
 
Messages
22,187
Location
Colorado Springs
If this is a situation where the car is kind of a beater and it wouldn't be financial feasible to do a proper repair (which would likely be over $1,000), you could try something like this: http://www.barsproducts.com/PLT11.htm I'd start with half the bottle though, and add it when the radiator is empty and then refill the system. I've used bars Leaks successfully on 2 GM intake gasket leakers, and one with a heater core leak, and it worked as advertized.
 
Messages
252
Location
Kansas
I just replaced an intake gasket on my old 93 Chevy pickup. You wouldn't know it had a leak, if you didn't check it every week. It wasn't an external leak - no puddles. It would seep into the engine and burn up. The oil looked fine, too.
 
Messages
160
Location
Mass
Originally Posted By: Drew99GT
It's not the head gaskets that usually fail on these GM 3.8L engines; it's the plastic upper intake manifold and the lower intake manifold gaskets. The only sure fire way to tell if coolant is in the oil is by getting a used oil analysis. I've dealt with numerous GMs with leaking intake gaskets, to include a 3.8L, and there was no visible sign of coolant in the oil when there in fact was.
It could just be burning the coolant and not getting into the oil. On the car I worked on the upper intake was covered in just enough fluid to give it a problem once in a while but the real problem was it sucked through a lot of coolant. I ended up replacing the upper and lower gaskets (along with the upper intake due to it warping). You can try the Bar;s leak product but all it did when I tried it was make the coolant a weird color, I have heard stories about that stuff clogging up the heater core or radiator but I was fortunate. I still flushed the system out. At the end of the day if you want a permanent fix it is to replace the gaskets. Like I mentioned do them both so you don't have to worry about them. Everything else is just trial and error and not a permanent solution. Plus if you do the work yourself and don't have a garage there are only so many good days left before winter.
 
Messages
22,696
Location
Apple Valley, California
That 3.8L will have plastic elbo's behind the Alternator. Those will seep and you can't see them. They will eventully break and cause a sudden coolant loss. Also look at the plastic radiator tanks for a crack. Usually where the hot water enters the radiator.
 
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