Not this $#!* again! (Coolant leak at rear of engine)

[DaraSue]

I picked up the $99 borescope from Autozone with a $25 off coupon and poked it around in the cylinder where I was worried that I'd lost the washer. Obviously I couldn't get it under the actual valve but from what I could see it didn't look like there was anything down in there. There was just enough of a gap that I'm still a little nervous but I'm hoping it would be just too much of a coincidence that I would happen to lose one down a cylinder and there's another one that got lost down the valley in the same spot.

While I was out I'd left it pressurized to the 9-11 arrow and it looks like it leaked a little more up front but not by the water pump hoses. Arrrghh...

[Rich]

That fat hose seems to be the culprit in the Valley, b/c it was damp under it again this morning (had leaked enough to get a pool in the crevice underneath it even through a paper towel) but I haven't found any leakage from the forked part of the Y-pipe.

And now there are two new leaks, one just forward of the engine bay on the passenger's side and one up front on the driver's side.

I'd had the tester pumped to between the 9-11 and 13-14 arrows overnight (where the red line is in this pic: Attachment 54685) and it didn't really drop noticeably even though it leaked a little.

IDK, before I started messing with it I never saw it leak except for the one by the radiator that I still haven't been able to replicate. I feel like everything I'm doing is just making it worse. Is this normal, to have to redo all the coolant hoses once a year? Should I just put it pack together, let it drip until the snow starts falling and then dump it at the shop for the winter?

Taking these in order:
Get a mirror under the fat hose after you dry it off and the pressure is on. See which end the leak is at or whether the hose itself is failing. Work from there. Since it's a relatively new hose it is probably OK but you need to know where it's leaking while you are in there.

About the new leaks, first be sure they are both coolant, not oil (rear one) or brake/clutch fluid (front one). Then start tracking them both down. The rear one could be from a bad connection at the tee to the coolant bottle or at the heater valve also near front of engine and a bit over toward the passenger side. Again, get a good light on every suspicious fitting after feeling around for wetness. Dry off anything wet, pump up the system and then look for or feel for the leaks. Fix, rinse, repeat til you have a solid system. The off-season is the perfect time for this kind of work if you have the time and the patience. Otherwise any good shop can do it for you, setting aside getting it there now that the VOD is opened up.

About the test pressure, go higher than what you showed us on the gauge. Yellow arrow is past 15psi and that's your standard/target for holding pressure. Any leaks you see at lower pressure need attention to start with but you need to eventually show no leakage at the yellow arrow with system cold. Or at least at 15psi, the cap pressure. The slight over-pressure offset at the arrow from Stant might be set to account for gauge tolerance and/or high-temp effects as mentioned by others.

Finally, no, it's not normal to have to chase leaks annually. Nothing you do on one connection affects other connections, assuming you aren't wrestling the coolant pipes around. Good hoses/clamps/components can go many years without attention on this car. As for how many there are and the VOD setup being so unfriendly, well, it's the price one pays for having a DMC-12 - they come with an old French/Swedish motor far away from the radiator...

[DaraSue]

The new leaks were definitely antifreeze b/c it was bright green where I saw it dripping off the bottom of the car. I'll try poking around with it some more tomorrow.

The weather looks like it's going to be hit and miss for the next couple weeks now so maybe I'm just done for the season and I'll have to mess around with it over the winter. Really wish I'd just left well enough alone and enjoyed the last few warm-ish days before I started taking things apart. I filled the tank last time thinking I was going to have another couple weeks to drive before the snow hit, can I safely siphon out the excess fuel and put it in one of my other cars?

[Rich]

The new leaks were definitely antifreeze b/c it was bright green where I saw it dripping off the bottom of the car. I'll try poking around with it some more tomorrow.

The weather looks like it's going to be hit and miss for the next couple weeks now so maybe I'm just done for the season and I'll have to mess around with it over the winter. Really wish I'd just left well enough alone and enjoyed the last few warm-ish days before I started taking things apart. I filled the tank last time thinking I was going to have another couple weeks to drive before the snow hit, can I safely siphon out the excess fuel and put it in one of my other cars?

Now I see why you were trying so hard to get it back on the road. Sorry you'll miss the last few runs of your season.

Yes, siphoning the gas out is OK, same as in any other car. Your other cars won't care as long as the octane rating works. Along with that plan you may want to see what some in the community say about fuel and winterizing. Maybe you already know how best to do it.

LINK to one winterization thread

[dn010]

At this point I'd say change both left and right hoses and get new clamps. Lowes - get a bag of stainless clamps and use them. Just because the hose looks good doesn't mean the clamp didn't puncture it on the underside. Moving the clamps around or adding a second clamp still leaves a hole to eventually leak. I also cannot find a picture of the brass ring that goes around the air tube but it is the same size as the O-ring and it presses into the hole of the mixture unit in order to seal the o-ring. I'll look around for a part number.

Also, what winter storage are you using, indoor or out?

[dn010]

I believe this is the ring: #102294, of course out of stock!

[DMC5180]

I don’t recall for sure, but I think you need to unbolt the water pump or Y-pipe in order to replace the connector hoses.

[dn010]

If you spray them down with silicone spray you can get them on without disassembling anything. It’s just tedious.


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[DaraSue]

So I might have been a little hasty in blaming the fat hose for all my woes. I pumped it up to the 13-14 mark this afternoon (and it was really resisting even getting that far). I kept seeing moisture on the wall of the valley next to the fat hose, but the pattern and where it was looked like it would have had to have squirted sideways out of that hose, and I couldn't see that happening. So I took a closer look at the hose coming off the bottom left side of the thermostat housing and it turned out there was some coolant running out of that one and dripping down the line between where the cylinder holes are and where the lower "V" of the valley is. Which would explain how it got all the way to the forward end of it.

Inked20171125_141525_LI.jpg

So I tightened the lower clamp and it appeared to stop. We'll see what happens when I get home.

A new wrinkle: drips from the big bolt on the right side of the thermostat housing. Now what?

Inked20171125_142843 (1)_LI.jpg

And this is the hole that (AFAIK) the pipe of agony came out of. Is it supposed to look like this? It looks like there's a scratch or crack inside it.

20171125_131443.jpg

Dan, I'm storing it inside but it's not a climate-controlled garage.

[DMC5180]

Some good news, your brass backup ring/retaining cup and o-ring are in place. The crack you see is just a surface flaw. Nothing to worry about.

The big bolt you mentioned having a drip is actually a threaded plug with a copper or aluminum gasket under the head. You might try tightening it with a torque wrench 18-20 ft lbs should be enough.