Coolant leaking near radiator cap

[Bertimus]

Just bought a 2005 LeSabre with 50k original miles. It's been sitting for almost 4 days (been checking every day for any type of leak) and just today I noticed a few drops under it. It's coolant and I traced the leak to be coming from the radiator cap or somewhere near it. The engine starts/ sounds/smells great. The oil is fine (no milkiness). No smoke from the tailpipe. No check engine light. When I first opened the radiator cap it was almost overflowing. The coolant reservoir levels are on point. Could it be a bad cap?

 

[MelsRegal]

Rent a pressure tester or just replace the cap.

 

[2007LucerneCXL]

Besides the cap the overflow tank and hose should be looked at but lack of details it's guessing about the source.

 

[sightcrr]

I borrowed a pressure tester from Auto Zone with $245 deposit and none of the 25 or so caps would make a good seal. Bought a new 15psi cap from gm for about 10 bucks to make sure I had the right pressure and good seal. My leak was from a broken antifz fill kit.

 

[sightcrr]

The first thing I would have done or do is replace coolant elbows and if you want the easy way the idler pulley and bracket.

 

[BuickGirlFromMars]

is your radiator cap part of the radiator, the body of the end tank and the snout you put the cap on, made of plastic?



THIS MAy be relevant if its an older lesabre radiator or its refurb

Bulletin No.: 00-06-02-001
File In Section: 06 Engine/Propulsion System
Date: January, 2000
Subject:
Engine Running Hot, Overheating and/or Loss of Coolant (Polish Radiator Filler Neck and Replace Radiator Cap)
Models:
1999-2000 Passenger Cars and Trucks with Composite Radiator End Tank
Condition
Some customers may comment on one or more of the following conditions:
^ Engine running hot or
^ Engine overheating, and/or
^ Loss of coolant/low coolant message
Cause
The radiator filler neck may have an imperfection in the sealing surface.
Correction
Important: DO NOT REPLACE THE RADIATOR.
Using a piece of 400 grit wet/dry sandpaper backed with a flat piece of wood, polish the filler neck sealing surface using a circular motion.
Replace the radiator pressure cap

 

[Bertimus]

Replaced entire radiator. Fixed 🙏🏽

 

[BuickGirlFromMars]

 

[Mad_Coachman]

Give it a rest BGFM. The OP solved the issue in the best way possible. Radiators don't cost that much these days. 😀

 

[BuickGirlFromMars]

Give it a rest BGFM. The OP solved the issue in the best way possible. Radiators don't cost that much these days. 😀

All I’m saying is sandpaper is usually free or cheap if you don’t have to go make a trip for just that.
If it works don’t broke it

wait

if it’s good buy it

Wait
If it’s broke don’t fix it

…
If it get got, got it will get

 

[Mad_Coachman]

The OP solved his problem in the best way possible for him. Whether or not he could have solved it by other means is totally moot at this point as he chose to start fresh. Considering that we're talking about a 16-17 year old radiator he probably made the right choice.