Massive coolant leak :(

[Alistair]

Hi everyone,

My 94 Subie (Legacy LS N/A) daily driver overheated badly yesterday (above the H)... made the mistake of trying to get it home (few miles), but it cut out at a stop light. Waited for it to cool, restarted OK and drove it the rest of the way.

Took a look at it today and it had very little coolant. Filled it up and started it, but as soon as the engine warmed up it started gushing coolant. It seems like it's coming out around the back side of the water pump... not quite sure if it's coming from the timing belt cover or the seal around the thermostat / lower radiator hose or somewhere else nearby. It's leaking down all over the oil pan and hissing/crackling from dripping over something hot.

I've been operating with a piece of (possibly kinked) radiator hose instead of a heater bypass hose for some time, since I changed the timing belt, water pump and t-stat last winter. It's been OK until now though. If this is blocked, could that cause the problem?

Or could it be water pump? I'm hoping it's not head gasket. The oil looks fine (from checking dipstick) and there's no smoke coming out the exhaust, but the coolant in the overflow tank does look a little dirty.

Any help appreciated... not sure how I'm going to get to work on Monday

[fishbone79]

Bit difficult to diagnose from your description, but did you check all the obvious, i.e., the lower hose for a crack? If it only leaks when it gets warm, that suggests that it may be related to the thermostat opening. I've also found that the non-oem hoses do not seal as well and sometimes require two clamps (or one hella tight) - any chance you overtorqued the hose clamp down there and it finally let loose and gave up (although it may look fine)?

Is there fluid coming out of the water pump weep hole?

[ej22tVermont]

+1 on fishbones response. Sounds like the Thermostat has a problem. Although it may be a good time to replace ALL the coolant hoses and clamps. This would be roughly $35 and is an easy job. It wouldn't hurt to change the thermostat (If that is the prob), and flush the system. Get the Gates replacement hoses if you do replace them! good luck.

[Alistair]

Thank you for the good suggestions. I took a closer look at it today (now I got some time and another ride for Monday!) and tightened the clamps, then started her up again... only to discover that it's not a massive coolant leak when it gets warm, but a steady coolant leak soon after startup. Doh... can't believe I missed that first time.

It is leaking out from the back side of the water pump. (Edited) -- looks like it is coming out the weep hole. I thought the gasket was out of place, but actually that's just excess gasket sealant that came out around the sides, not the gasket itself.

That was a new water pump that I put in 6 months ago... guess those non-OEM water pumps aren't too good, or maybe a head gasket problem means there's some oil in there making the pump work too hard. Time for a new water pump + check how the coolant looks at the same time.

Thanks again.

[fishbone79]

Thats not a common occurrence, I think the gasket must have gotten buggered or something else is wrong. Was it an aftermarket water pump with the cheapo cardboard gasket? Those aren't the greatest...

The torque spec on the water pump bolts is not much, something like 10 ft-lbs, and the torque sequence is around the pump housing rather than across... but don't quote me on those, look them up.

I kinda doubt a head gasket would do that without you seeing some other signs first.... your reservoir would have overflowed, radiator issues, etc. etc. I'd check the mating surfaces, scrape off the gradue, get a better gasket and the correct sealant, and put it back on there. Make sure you check the pump shaft for premature failure (side to side and front-back).

[fishbone79]

oh, and check/replace your thermostat... it may have a defect and developed a 'shudder' so that it rapidly flutters open and closed, making the gasket take a beating from rapid pressure changes and turbulence. I forget what that's called, but it has a name and I've seen it happen on a few different systems when a cheap replacement thermostat malfunctions.

[Alistair]

Sorry... I edited my post after you replied... I had it wrong about the gasket Not having a good weekend

I will check the t-stat at the same time. That was new 6 months ago too, but looks like some of these aftermarket parts aren't so hot.

Thank you for all your help!

[evolutionmovement]

Aftermarket t-stat? Never use those! That should be in a stcikie if it isn't. You'd be better off with no t-stat than an aftermarket POS. I'd say the same for the water pump (the OEM of which has a metal crush gasket, FYI). Aftermarket engine parts are false economy (unless you're talking quality internal race parts, but that's a different story). The water pump might be a rebuild, which today means China, which means 0 quality control. Then again, brand new often means the same thing. RANT WARNING: I wish to hell I could get away with never having to buy anything built in China, but it's an impossibility today. Thank you, WalMart culture for single-handedly killing the market for quality products as well as domestic manufacturing. I'd laugh at the dumb consumers for having to lie in the bed they made, but I'm forced to sleep in it as well. I'd rather do without than buy Chinese garbage, but that's not always possible. Thankfully, there are still tools that aren't built there. RANT OVER.

You shouldn't get that much coolant from a weep hole. There's no way I can think of for the water pump shaft to shear off and allow that kind of volume of coolant out without lunching the timing belt, so I don't know how you'd get that there unless the t-stat cover let go or something. If it's coming out the weep hole at all anyway, the pump's junk. A head gasket probably had nothing to do with this, but due to the overheating, don't be surprised if they're now bad, too, or soon will be.

[fishbone79]

I wish to hell I could get away with never having to buy anything built in China, but it's an impossibility today. Thank you, WalMart culture for single-handedly killing the market for quality products as well as domestic manufacturing. I'd laugh at the dumb consumers for having to lie in the bed they made, but I'm forced to sleep in it as well. I'd rather do without than buy Chinese garbage, but that's not always possible. Thankfully, there are still tools that aren't built there.

Goddam, Steve.... you and I need to have a beer sometime.

I feel the exact same way. My dad's shop is filled with machines and tools from the 30's-80's before globalization was a word anybody knew. I grew up and learned how to work using that stuff, and the quality of it is so far superior to anything available today it makes me a little sad. Back then you couldn't sell a drill press unless it was precise to at least 0.001", now 'professional' grade machines ship with 1/16" of shaft play in the morse taper and are deemed acceptable... Thanks China.

Anyway, back OT, if I were you Alistair, I'd open it up and see what happened... and regardless, replace the WP + gasket with OEM. I bought an aftermarket WP about 6 years ago to replace the one in my car when I did a T-belt job... and found that the new one had more shaft play than the one with 100k on it in the car!

[Legacy777]

Please see this thread for a continuing discussion on Steve's rant.

http://bbs.legacycentral.org/viewtopic.php?t=40755

Ok....back on topic

[Alistair]

Thought I'd post a follow-up now that I finally completed the repair for anyone who has a similar issue... though the cause turned out to be my own incompetence and not the aftermarket part (though I agree with you guys on them being junk and won't be getting them again...)

You guys were right that it was too much coolant to be the weep hole. I opened up the timing belt cover and put some more water in the radiator to try and figure out where it was coming from... was about to start it and saw it was dripping even without starting the engine. I then realized it was coming from the back side of the water pump.... and the water pump bolts were very loose.

It think a combination of too much gasket sealant around the back of the water pump and putting it all together too quickly when I changed the water pump back in the winter (needed to drive to work!) meant that although I torqued it to spec, once the sealant dried up it was too loose. I guess engine vibration over the following 6 months loosened the bolts more until finally the pump came away from the block and all the coolant came out...

I was more careful this time and so far it seems OK, though I haven't driven too far yet. I am still concerned about head gasket due to the overheating. When I rev over about 3000, I'm getting some white smoke but it's not a huge amount. There's also some liquid dripping out of the tail pipe, but it seems more like water than coolant (no trace of yellow). I'm hoping this is just some sort of condensation due to humidity or the car sitting so long. I'll keep a close eye on it.

Of course, I took so long over the repair that my battery was dead and tires were flat, but those were easily resolved. I've been riding my bicycle 35 miles round-trip to/from work every day while the subie has been out of action. After taking an extra 2h commuting every day, having aches everywhere, getting screamed at, beeped at, cut off by school buses.... let's just say I now really appreciate the comfort and luxury of my beaten up old subie.

[ericem]

lol always use oem parts and most gaskets oem metal water pump gasket ftw.