Losing coolant over time

[Laeron]

As the title says, I seem to be losing coolant over time, sometimes if I forget to keep on top of it it overheats and I need to let it cool off and put some coolant in. Last time it did this quickly and I found coolant dripping around the rf wheel. Thought it was the water pump, but when I got to looking at it, it seems to be completely fine, no sign of leaking through the weep holes, even looks brand new so it was probably replaced by the previous owner recently.

While I was looking I found this: (images attached)

Whatever it is, it's all the way up the back of the engine, and as you can see the rest of the engine is completely clean. Also the coolant is slightly frothy.

Any ideas on what the deal could be and where to look would be massively appreciated, thank you in advance!

[Signmaster]

The area above the oil filter looks more like oil to me actually.


The only real way to find a leak is to get everything clean and dry, then bring the car up to temp and/or pressure test and keep looking until you find the leak. Sometimes the heat will soften hoses, so running the engine can help at times. If everything is clean and dry before you start, just keep looking until you find moisture. Sometimes stuffing paper towels, tissue paper, etc into areas will expose the initial area and you can keep pinpointing from there.

If your photo is the suspect area it could be the reservoir tank or any of the lines in that area. I recently replaced a tank for a small crack that would only vent steam at full operating temp. It would vent against the fender area, run down through the hollow in the support, and finally expose itself at the bumper to fender connection ahead of the RF wheel.

[toggenburg]

In your second photo, the coolant appears to be orange, not green.
Is your car on DexCool?

How many miles on the car, and do you see any frothy stuff on the engine oil cap threads?

[alordofchaos]

Originally Posted by Laeron

sometimes if I forget to keep on top of it it overheats and I need to let it cool off and put some coolant in.

I would look at the radiator fan operation and ECTS first, and possibly the cap for the tank.

You should see a low coolant light before it gets low enough to cause any problems.

But if you are overheating, that could cause the coolant loss - coolant loss is a symptom rather than the cause.

Clean and dry off the area at the top of the tank, put the cap back on, and wrap a dry paper towel under it (may need tape to keep it in place). Drive normally, and if the engine gets to normal temp but you have not overheated, check for moisture.

If it is wet at all, you have a bad cap - moisture normally escapes from there only if it overheats and goes over 15 psi, I think it is. If the cap is leaking, the coolant boils over more quickly

[TwoFistedJustic]

On the 2001-2002 S*2s the intake manifold can be a source of coolant leaks. And if that's happening you have a serious problem. It's fixable, but plan to spend a weekend.

From the perspective of you standing at the front of the car looking in at the engine bay:

Look all the way to your right hand side of the engine, at the back of the engine. There is a rubber coolant hose running from the intake manifold to the firewall. Where that hose attaches to the intake manifold is a potential leak. It's attached to a plastic nozzle. The coolant eats away the nozzle over time, eventually resulting in a catastrophic coolant leak.

You fix it by sawing off that nozzle and replacing it with a metal piece. It's a pretty involved repair, but doesn't require much in the way of special skills. You can get a part from Dorman, but that is garbage. Better to get the part from carsaturn.com. Both are about the same price.

[Saturn Night]

Originally Posted by Laeron

As the title says, I seem to be losing coolant over time, sometimes if I forget to keep on top of it it overheats and I need to let it cool off and put some coolant in. Last time it did this quickly and I found coolant dripping around the rf wheel. Thought it was the water pump, but when I got to looking at it, it seems to be completely fine, no sign of leaking through the weep holes, even looks brand new so it was probably replaced by the previous owner recently.

While I was looking I found this: (images attached)

Whatever it is, it's all the way up the back of the engine, and as you can see the rest of the engine is completely clean. Also the coolant is slightly frothy.

Any ideas on what the deal could be and where to look would be massively appreciated, thank you in advance!

These cars are famous for coolant loss through a cracked intake manifold on 2000-2002 DOHC. It will be visible as a puddle under the car.

Another area to check would be the water pump area and check the oil to see is the worst-case scenario of a failed head gasket has occurred. There is also a small leak that can occur from a cracked head gasket on the back of the block, that is directly above the starter, and right at the #4 cylinder intake runner. It leaks down the block and burns off, so there will be no trace or puddle.

[GTS350]

The only way to look for a leak that is so small it doesn't give you any clue to it's location is with the cooling system under pressure.
The correct way to do this is with a radiator pressure testor. Because the engine can remain cool and the repairs can be completed without waiting for the engine to cool off and you don't have to deal with scalding coolant.
You can have it done or for less than most shops would charge you to do it, you can buy a testor at Harbor Freight for less then $75 ($90 - $18 (20% off coupon on their website)=$72.00) and do it yourself. You will find any weakness in the system and you will have a tool to be able to check other cars cooling systems.