Any advice to troubleshoot this coolant leak?

[wrybread]

A couple years ago I blew the head gasket on my 2000 S70 and gave it to a friend, who has been driving it steadily without issue other than having to add coolant really often. That's no biggie where we live since we don't need to use antifreeze here in coastal northern California. But lucky me, that car just came back to me since my friend is moving and not taking the car. And it has a new leak!

Water is steadily flowing out of the rear left (passenger side) of the engine. It's a pretty vigorous dribble. No leaks visible from the line going from the coolant reservoir to the engine.

We havn't jacked it up yet, but does anything spring to mind?

Here's a couple of pics. This is what the coolant reservoir looks like after 2 years of coolant overflows from the blown head gasket:

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And here's under the car after running it for just a few minutes. That's a lot of leakage.

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And here's a video that would make Zapruder proud:



I'm of course worried that the head gasket blowing has gotten worse and it's now leaking coolant out of the engine, but I don't know enough about how all that works to know if that's realistic.

Anyway, any ideas about what our next steps are?

[scot850]

You can see water dripping down the back of the engine. On a 2000 car there is coolant lines at the back of the engine for the oil cooler at the back of the oil pan, the turbo cooling lines and then there is the heater pipes and water pump itself.

I would suggest jacking the car up and supporting it on axle stands and look under with the engine running (careful!!) and see if you can get a better idea of where it is leaking from.

Neil.

[abscate]

. That's no biggie where we live since we don't need to use antifreeze here in coastal northern California. B

Uh oh. You had better research this on the internet.

Coolant doesn’t just lower the freezing point, it raises the boiling point. You need this in all post 1919 cars, everywhere

[454cid]

. That's no biggie where we live since we don't need to use antifreeze here in coastal northern California. B

Uh oh. You had better research this on the internet.

Coolant doesn’t just lower the freezing point, it raises the boiling point. You need this in all post 1919 cars, everywhere

And it's anti-corrosive properties.

Looking at that video, it might be a good idea to pull the upper timing belt cover, and see if it's leaking out the weep hole on the pump.

[abscate]

It’s either the coolant bottle hose going back to the metal water pipe or the water pump leaking back there. About 10:1 odds pipe over pump.

You can see the pipe if you get up over the engine and look behind the right hand side. You can’t see the water pump without taking stuff off

[erikv11]

I put high odds on that the little paper gasket between the coolant pipe and the head is not in place.

[brunocerous]

Did you end up finding the source of the leak?

It looks a bit like the coolant leak I have on the Silver Bullet. I took off the timing cover and saw a tiny bit of liquid at the bottom but none from the weep hole, as far as I could tell. It's certainly not as much as what was on the ground.

My suspicion is the coolant pipe. Is there a tutorial on how to replace it? I haven't found one.

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[scot850]

Water pump typically only leaks in the early days of leaking, when the car is started from cold, or when cooling after driving. With the heat the weep hole may dry off so don't dismiss the water pump based on where the leak is showing.

As suggested a pipe or cracked header tank would be your other choices.

Neil.

[brunocerous]

Water pump typically only leaks in the early days of leaking, when the car is started from cold, or when cooling after driving. With the heat the weep hole may dry off so don't dismiss the water pump based on where the leak is showing.

As suggested a pipe or cracked header tank would be your other choices.

Neil.

Thanks. I hadn’t factored in the engine heat. I’ll have to get it up on ramps and see if I can find the source of the leak.

Where is the header tank?

[scot850]

Coolant header tank is the opaque bottle on the RHS fender by the RHS hood hinge. Where you fill the coolant.

These are known to crack with age. Can be anywhere, but if you lift the coolant tank and the power steering tank (be careful the coolant level sensor is on a short lead under the tanks), and see if the area under the tank is damp or shows signs of coolant residue (white powder).

Also check the coolant tank pressure cap has not started to fail. Again, removing the cap (when cold) look for traces of coolant residue under where the cap sits.

There are a couple of hoses from the coolant tank that can leak. The larger one to the rear of the engine (check both clamps are tight) and the smaller overflow pipe. Depending on the year of the car, some go to the top of the radiator and others to the thermostat case. That pipe also likes to split near the ends with age.

Final place to check is the RHS of the radiator (passenger side) look for leaks at the join between the end caps and the matrix as well as the upper coolant hose.

Neil.