Losing coolant

[mmelzer2004]

Hey guys, I have had my SL1 for about 3 months now, and I have been needing to put some coolant in the reservoir every few days since I bought it... I didn't think it was that big of a deal since I never felt anything going wrong, no smoke or anything. My step-dad used to be a mechanic and thought it was just evaporating because it might have been too diluted.

In the past couple weeks I have noticed the reservoir getting low every other day, putting in a bottle of 50/50 coolant every week-week and a half . I have also been noticing a sweet smell while driving. I checked the oil and didn't notice a milky consistency, and it only goes down when at temperature, and not when sitting in the parking lot. I don't see anything under my car in the morning before heading to work, after sitting over 12 hours. Could there be a temporary fix to keep it from leaking until I get paid again to take it to a shop for an oil change and for someone to pressure-test it? Also, its been relatively hot lately, so could that also be a factor as to why its draining quicker than it did when I bought the car?

I also have a periodic Service Engine Soon light that goes on for a week, then off for a week. My step-dad is pretty sure its an exhaust leak, but I don't know for sure.

Thanks.

[Old95SL2]

Have you checked the cap on the coolant reservoir when hot to notice if it is letting coolant boil off? Another possibility is the famous crack in the plastic end of the radiator on the driver's side. Since you mention a sweet smell, I would also check the floor board on the passenger side to be sure the heater core is not leaking. Also worth checking for coolant around the water pump, behind the pulley, although I would think if that were it you would see dripping onto the ground.

[mmelzer2004]

I haven't driven my car today, but I'll write those down and check when I get to work tomorrow morning. BTW, I've recently replaced the Reservoir cap, so I'm sure that's not the problem.

I forgot to mention it earlier, but my temp gauge never goes over the 1/4 line.

[rickystarshine]

Have the code scanned & report back what it is.
What year & model car?
Have you changed the ECTS? Odds are good you need to.
How many miles on the car?
Good Luck!

Rick

[mmelzer2004]

Originally Posted by rickystarshine

Have the code scanned & report back what it is.
What year & model car?
Have you changed the ECTS? Odds are good you need to.
How many miles on the car?
Good Luck!

Rick

Its a '99 SL1, haven't changed the ECTS, but have found an old thread about it and will be doing it when I get paid, possibly along with the Radiator if there is indeed a leak. I'll also purchase a code reader when I get paid, as the SES light is currently off and goes on a 1-2 week cycle.

I have something like 136,3xx miles, a few hundred shy of an oil change.

[rickystarshine]

You can get the code scanned for free @ autozone, or advance auto, if there's one near you & you want to save some $

If you're going to do the ECTS, why not change out the thermostat too?

Just throwing that out there.

Rick

[Melissa_M]

you should be able to get the code read for free at parts stores.

Definitely do the ECTS, too. I paid $20 for the part, but have seen aftermarket ones for much less.

M_M

[eric888]

i'm having the same issue with my g/f's '99 SL1 right now. i just changed the water pump and serpentine belt (richpin is the man) and now the coolant seems to be escaping somewhere. no puddles anywhere though. i'll take the above suggestions and post my findings.

[saturnhouse]

Check the radiator on the driver's side, below the large coolant return hose. Its a little hard to see under there, but when they crack, that's usually the location.

[DonP]

I second checking the driver side radiator end tank for a hairline crack, usually below the upper inlet hose, above the upper transmission cooler line is so equipped, or that location if a standard. This crack is common on OEM radiators that have reached 7-10 years age, and is not obvious because at least in its early stages only leaks coolant when the system is hot under pressure, and whilehot it evaporates fast - you may be able to smell it, but not see it. As the system cools, the pressure goes down and the leak stops. The only likely visible sign is perhaps some dampness on the tank along what may look like a mound mark/seam.

There are some photos of the typical crack in this forum in past posts; e.g.,
http://www.saturnfans.com/forums/sho...d.php?t=87041&

[ORIG_97SL2]

Originally Posted by saturnhouse

Check the radiator on the driver's side, below the large coolant return hose. Its a little hard to see under there, but when they crack, that's usually the location.

Right on! I was having the same symptom-could smell that sweet Glycol odor, but couldn't see it. The plastic housing there has cracked twice in nearly that same spot. Just a weeping amount, but enough to have the coolant light come on every week or so after refilling the reservoir.

[eric888]

well shoot, i should've checked this thread before replacing the hoses and the ects today. got lots of coolant on me... anyway, i saw one problem immediately. the part that connects to the ects wasn't even connected. just lying there off to the side. we'll see if there are anymore leaks after this. the breather hose wasn't completely secure on the throttle body either. it seems to idle a lot better now.

i've learned a lot about these cars in the past few weeks:

water pump, serpentine belt, reservoir cap, radiator hoses, ects, egr valve, oxygen sensor, spark plugs and wires and air filter have all been replaced. i put a little seafoam in the crank case and gas tank before i got the oil changed too. wasn't brave enough to let it blow some smoke. if this coolant leak deal is fixed, then i'll have to start worrying about the rear wheel cylinders and her reverse slam problem.

[eric888]

Originally Posted by ORIG_97SL2

Right on! I was having the same symptom-could smell that sweet Glycol odor, but couldn't see it. The plastic housing there has cracked twice in nearly that same spot. Just a weeping amount, but enough to have the coolant light come on every week or so after refilling the reservoir.

just checked and that is the culprit. can that be easily repaired or are we better off getting a new and better radiator? thanks saturnhouse, by the way.

[Canyon]

You are looking at a new radiator. I have not heard of them ever being repaired. Pretty easy to replace.

I always change the hoses when I do this job if they haven't been done in a couple of years. If they have been there awhile you may have to cut them to get them off anyway. Check the heater hoses while you are at it as you will have all the coolant out anyway.

[eric888]

is there any particular brand of radiator that you guys recommend? i see the three brands on rockauto.com for a '99 SL1. autozone and advance are significantly higher for one model number i searched for.

i replaced the radiator hoses this weekend before i found the leak.

[BarnOwl]

Just go with the cheapest one. Use this link and enter the code where it asks how you heard about them to get %5 off. Be sure to use a code that hasn't expired.

[eric888]

i used the coupon and ordered a new radiator. $93.07 shipped to my door. thank you guys for the suggestions. i'll try tackling it this weekend.

[saturnhouse]

One follow-up detail on this type of crack. Some folks have had a lot of trouble with them, and a theory has evolved...

The cooling system normally cycles between neutral pressure when cool, and positive pressure when hot.
If you check the coolant level when the engine is hot, you release the positive pressure. Then, if you reseal the system while it is still hot, you have 'reset' the system. From then on, it will cycle between neutral pressure when it is hot, and negative pressure when it is cold.
The theory is that the side tanks are not designed to withstand negative pressure, and they crack.

So, try to only check your coolant when the engine is cold, or wait till it has cooled before you replace the cap on the coolant tank.

[OldNuc]

There should be a vacuum relief valve in the top of the cap. It could be stuck and going negative is not good on the plastic tanks. Might be a good idea to check the cap for proper operation.

If you ever have the system relieve, boil over, it will go negative when it cools and if the vacuum valve is stuck it will then be slightly negative when cold until the cap is removed and replaced.

[mmelzer2004]

I somehow forgot about this thread...

I started noticing some coolant under my car so I popped the hood and looked toward the driver's side of the radiator, and noticed a small crack. It is right above the bracket there, as there is a small puddle of coolant on that bracket. For a temporary fix, I've been informed that gum works to fill it. I'll be going to get a new radiator this weekend and will be replacing it then. Its a big relief that its not the head gasket, I prefer the ~$90 fix, heh.

I'm not exactly car-literate like most people here... what is involved in replacing it? Is it as simple as: Flushing, removing fan, disconnecting coolant hoses, removing radiator, then reversing that? I've been told that I should replace the thermostat and the ECTS at the same time. Where are these located, and I assume I can get them from an automotive store?

Thanks again.