Subaru 2002 Impreza 2.5 TS - Head Gasket

Question

My Subaru started overheating; it had run out of coolant completely.

Once I refilled the coolant, the car ran about a 1.2k mile trip just fine without any overheating.

Recently, the car started doing it again.

I have to periodically open the radiator and dump more coolant in every 300 miles or it will begin to overheat.

Unfortunately, the time has come where I have to drive 1k miles.

I have a new car waiting for me at the end of that 1k drive and all I need to do is make this trip.

Any other alternative will be $1000 atleast; replacing the head gasket at a mechanic is $1700.

No mechanic has actually looked at the engine, so I'm just assuming this is a head gasket based on the symptoms and the fact that is has overheated previously.

What's the best course of action?

Is this something that is urgent and needs to be fixed right away?

Can I use Subaru Coolant System Conditioner to seal the leak?

Note: I don't care if I obliterate the engine by getting there. The car is almost scrap at this point having nearly been totaled with repairs.

Answer 1

What's the best course of action?

Figure out where the coolant is going. Here are some ideas:

• Drain your oil and change it, and the oil filter too. Look for signs of coolant in the old oil. If you see coolant there, good chance it's the head gasket.
• Check your exhaust for white smoke. If the engine is burning coolant, good chance it's the head gasket.
• If there's no white smoke and none in your oil it has to be going somewhere. Go down to your local auto parts store, grab some UV coolant dye and a UV flashlight (you can usually buy leak detection kits with a cheap flashlight and eye protection) and throw it in. Run the engine. Look for signs of coolant leaking. The dye will make it easier to see. If you're losing coolant around the exhaust manifold good chance it's the head gasket. But it could be coming from other places. Be sure to also check inside the passenger compartment, particularly on the floor under the dash. If there's coolant there it could be the heater core.
• When checking for coolant leaks, park over top of something that won't absorb (and therefore hide) puddles, and rev up the engine. I learned this the annoying way (btw, if it gives you hope, that issue ended up costing < 90 USD in parts and about 20 minutes in labor).
• Also check your coolant reserve tank; if it's overfull (like all your coolant is ending up in the tank but not making it back into the radiator) could be an issue with the tank, some hoses, or perhaps the radiator cap.

Is this something that is urgent and needs to be fixed right away?

Depends on where it's leaking from and how costly and inconvenient it is to constantly be dumping coolant into your tank. Also the more you overheat your engine, even if you stop driving right away, the more you risk even more (and expensive) damage. I definitely wouldn't drive it 1000 miles...

More importantly, even if you don't care about the car, you run this risk of being stranded somewhere if the vehicle breaks down.

Can I use Subaru Coolant System Conditioner to seal the leak?

Maybe? I'm not familiar with that product but apparently it is a relabeled version of Holt's RadWeld, which seems to get a decent amount of praise all over the internet.

Without knowing where the leak is it's hard to say. It probably won't hurt but it may not help. I've used similar products (the Prestone stuff) with success for tiny leaks but losing all your coolant every 300 miles doesn't seem tiny.

Your first step is to find the leak.

Answer 2

I agree with the advice given by an earlier correspondent: Seek alternate forms of transport, to get yourself to the new car which awaits you. You risk stranding yourself, and having to deal with junking your old car, in an unfamiliar location, in the middle of a trip. Take a bus, or a train; rent a car, or fly. Your old Subaru is not worth fussing with, since you have a new car anyway. You've got a classic blown head gasket (2.5 engine), and maybe head warpage.