topping off coolant

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77
Location
long island ny
Thread starter
[b] I noticed that now that its winter time in my location I need to top off my coolant in my 03 buick 3800 lesabre about once a month with approximately 1/2 qt of coolant , is this common or do I have a small leak and if so can I put those AC Delco Tabs in the radiator or something else ? b] Coffee2[/b]
 
Messages
909
Location
PA
Don't add anything yet. Find out how you're losing coolant. If it's a leak, fix the leak whether it be a hose, radiator, water pump, etc. It's possible your head gasket is blown as well, leading to oil contamination or the coolant being burned and tossed out of the exhaust. Many avenues here but pray it's just a leak.
 
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Messages
555
Location
MN
On a Series 2 3800, I'd think you are having either a leaking lower intake gasket or one of the plastic coolant elbows on the back of the engine near the alternator. Barring normal leaking (e.g. radiator/hose/water pump), this is where 3800s leak.
 
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21,330
Location
Apple Valley, California
Originally Posted by TmanP
On a Series 2 3800, I'd think you are having either a leaking lower intake gasket or one of the plastic coolant elbows on the back of the engine near the alternator. Barring normal leaking (e.g. radiator/hose/water pump), this is where 3800s leak.
I 2nd the plastic elbows. Replace them with the metal ones.
 
Messages
3,065
Location
Columbus, Ohio
Originally Posted by TmanP
On a Series 2 3800, I'd think you are having either a leaking lower intake gasket or one of the plastic coolant elbows on the back of the engine near the alternator. Barring normal leaking (e.g. radiator/hose/water pump), this is where 3800s leak.
Ding! Ding! Ding! From personal experience I can say this is it!
 
Messages
24,118
Location
MA, Mittelfranken.de
It is rare that a head gasket goes on these, iron block with iron heads are pretty stable thermally both expand and contract at the same rate so the head gasket lives an easy life compared to mix metal engines. You can get a cheap kit to verify the HG is ok, it works well. https://www.amazon.com/Block-Tester...aWNrUmVkaXJlY3QmZG9Ob3RMb2dDbGljaz10cnVl Get a bottle of GM dye and use about half a bottle and check it with a black light at night, any external leak will jump right out at you https://www.amazon.com/Genuine-GM-1...oolant+dye&qid=1580319927&sr=8-1 https://www.amazon.com/Flashlight-V...lack+light&qid=1580319963&sr=8-7 In all probability it is the lower intake gaskets, a plastic elbow or a burn through from the chimney in the upper plenum, all are common culprits on these. Using the metal elbows is a good idea but use GM o rings on them not the ones it comes with they are crap, use a little Hylomar M on the o rings to fill any corrosion pitting. Always replace the upper plenum and use the smaller diameter chimney supplied with the kit, the one from ATP is the best one I have used so far. http://atpautomotive.com/featured/engine-intake-manifold Use GM only gaskets for the LIM from the dealer either local or online, there have been quite a few variations and the last one from 08 is the best by far, they are aluminum, never use the plastic frame ones which are still sold on the aftermarket. The Aluminum ones from Fel Pro and Mahle are GM latest made AFAIK and safe to use.
 
Messages
84
Location
Heart of Dixie
just my experience, but I noticed this summer my coolant tank was about an inch or so below the full mark. I started topping it off every week or so. took it to a mechanc, they did all the tests and could not find a leak. I decided to just leave it alone and see how far down it would go. been a couple months and it has not gone below the same spot. I did the block test kit mentioned above, also you can pull the radiator cap off (if it has one,) and run the engine, bubbles in coolant can indicate a head gasket issue. of course you know don't pull cap off hot engine. lots of videos on you tube for checking head gasket leak. good hunting.
 
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