Heater Core leak repair in 2002 Saturn L200


If you find antifreeze soaking the carpet on the passenger side, it is likely your heater core leaking.  Antifreeze has a slippery feel, a color, and smells and tastes sweet (note, it is highly toxic).  If it is just water and you have been running the air conditioner lately, you may only have a blocked A/C drain.

Many times when it is antifreeze, it is NOT that your heater core is in need of replacement, but only the rubber O rings that connect the heater core to the rest of the plumbing.    It is not a hard repair, but it is messy, and the steps are the same whether you need to replace the entire heater core or just the rubber O rings.  

disclaimer: I am not a mechanic but I play one on the internet.  Do this at your own risk.  You want real instructions, buy a manual at the auto parts store.  

First you should probably drain the radiator as much as it will drain.  The valve is on the corner of the radiator, bottom (surprise!) passenger side corner.  Don't leave a puddle for a pet to drink or your pet will die an unpleasant death, seriously.  And it tastes good to them, so hose away any puddles.  






The drain is the red plastic screw in the following picture.  Turn with flat blade screwdriver or pliers.  I raised my car up, you don't have to.  You'll need a shallow flat pan, but you'll need that pan when we get to the inside steps in a minute anyway.  A funnel and a spare jug is handy too.  



Inside the car, pull out this kick panel, and undo the one screw at least to give you some room.  



This is the heater core and connections.  I am pointing to the plastic clip you will need to get off both pipes.  Once you have the pipes off, and that white plastic strap removed, you can slide out the heater core.  Pretty easy for a heater core actually.  Some are ridiculously hard to get to on other cars.  



Get ready for the big deluge after you pull the pipes off!

After I posted this repair page, a more experienced person on saturnfans.com posted that it will spill a lot less if you leave the radiator closed up.  That draining the radiator and letting all that air into the system lets it pour out more.  I'll do it his way next time!  But still be ready to catch the stuff one way or the other.  




These little black plastic clips are 12 years old and I don't want to break them.  All I had to do was lift with my fingernail on each side as in the picture below.  No screwdriver or pliers.  Both opened easily.  Also, I only opened them enough to slide down the pipe out of the way.  The hinge is only plastic and could break.  

If you do break it, keep it.  Place the broken pieces back over the connection when you are done and wrap with a barely snug hose clamp, or even wrap in tape.  As long as it can't pop open it will do its job and keep the pipe from pulling out.  

Below: clip not yet opened, just lift on each side with fingernail.  



Just popped open.



Red arrow is where you lift with fingernail tip or similar.  Easy big fella, that is old plastic.  







I was not able to just pull the pipe out by hand and did use a flat blade screwdriver to pry it up.  Again, gentle,  It's soft metal, probably aluminum?




Even after draining the radiator, I was surprised how much antifreeze came gushing out.  Be ready.  









I went ahead and slid out the heater to make sure I found no leaks in the actual heater, it was clean.  



The O ring will seat against the inside of this, so clean and smooth the inside surface.  




I went to Lowe's and got #15 plumbing O rings.  I had read on some other posts on Saturnfans that this size would work.  As you can see, it looks slightly fatter which makes me think it won't leak.  I put some faucet grease on the O ring to help it slide back in, and it did go back together pretty easily.  I used channel locks to pull the pipe back into the heater core outlet, and of course put the plastic clips back on.  




Original old O ring on the pink paper, new #15 on yellow towel.  



Someone on Saturnfans posted that their heater only leaked when cold.  I think that is what was going on with mine.  When I found the wet carpet (shop vac and towels to clean up, rinsed a bit with clean water and shop vac again), I checked for leaks and let the car run until the fan came on the radiator, and there was only the slightest moisture at the heater core connection.  I think it leaked more during the cold weather.  It appears my repair works fine, but I may not know until it gets cold out next winter (it is May 2014 now).  Of course, we all know cold affects rubber O rings, ask the space shuttle engineers.  

If you found this helpful, click on a google ad, it generates a small credit for me.  

Don

PS: let me know how this page worked for you, at
L200fix_kubmq@ObjectMail.com