Coolant Leak behind Coil Pack

Hi,

Odd story but my friend lets me borrow his Aveo to use until my new ordered Silverado comes in.. just sold mine and needed a vehicle.

Bad part is, today I just noticed a pretty extensive coolant leak. Parked the car at the store, heard it, smelled it. Let the car cool down for 2 hours, put in 1.1 gallon of water, and drove it home with the heater on just in case. Made the 10 mile drive just fine. Got home and there were drops coming from it still. Steam just right behind and below the coil pack. I let it cool again and added 0.5 gallons. So in 10 miles it lost half a gallon of water. Thats a pretty big leak, but not a straight out hole/cut.

Im a capable mechanic, but know nothing about Aveos, and its very dark here right now. Any experienced Aveo people have a clue at what is actually leaking? Hoping its something common and I can just order a common hose and have it back under way for my drive to work Monday.

So, any educated guesses on what is leaking right under and behind the ignition coil pack on the drivers side of the engine of an 05 Aveo automatic?

Thanks,
Rick

It sounds like the thermostat housing. Super common problem on the first gens, and very easy fix

Quote:

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Originally Posted by Pickles

It sounds like the thermostat housing. Super common problem on the first gens, and very easy fix

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Unless the diagrams Ive seen online are wrong, that is on the other side of the engine.

The coil packs on this car are on the right side. The thermostat is on the left.

My leak is right behind and below the coil packs.

I wont be able to look at the car again till its dark but I suppose with enough light I can just figure it out.

Any other ideas from Aveo owners?

Ok I gotcha, I have a 2nd gen so I don't know where it is on the first gen

Anyone? Bump...

I went out there today, added water, and let it warm up hoping to see the water and trace it.

The water doesnt start to flow until everything gets hot, not a drop. And then once its hot, it flows at a high rate. Drop after drop in a continuous path.

Its coming from what first looked like right under the intake manifold, near the right rear corner of the engine (the side with the brake fluid).

That hose then goes into the firewall, so I assume this is a heater hose line.

Any tips on how to get to this? It looks really hard to get to, way under the intake manifold.

Quote:

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Originally Posted by rickr84

I went out there today, added water, and let it warm up hoping to see the water and trace it.

The water doesnt start to flow until everything gets hot, not a drop. And then once its hot, it flows at a high rate. Drop after drop in a continuous path.

Its coming from what first looked like right under the intake manifold, near the right rear corner of the engine (the side with the brake fluid).

That hose then goes into the firewall, so I assume this is a heater hose line.

Any tips on how to get to this? It looks really hard to get to, way under the intake manifold.

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Yes, the leak that you are describing is coming from a bad heater hose. No tips on how to access it. Half the battle is in making the correct diagnosis, so you are halfway there. ;)

There seems to be a guy on this forum that took apart an entire engine that ruined a head/piston...

For that guy or anyone else that knows:

Does it appear you can do this without removing the intake manifold? Can I reach in there SOMEHOW after removing a few things, or do I need to take apart everything around it including the intake manifold?

Thanks,
Rick

Quote:

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Originally Posted by rickr84

Does it appear you can do this without removing the intake manifold? Can I reach in there SOMEHOW after removing a few things, or do I need to take apart everything around it including the intake manifold?

Thanks,
Rick

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On most cars it's relatively easy if you can locate both ends of the hose and get at them. But on a Chevy... :confused: I've seem some pretty dumb engineering over the years so anything is possible - or maybe almost impossible.

I actually took my own advice from the Stop Leak forum in General Discussions, put $3 worth of Barbs Stop Leak Heavy Duty (the one with the pellets), and by the time I got home from the store where I put it in, the leak had stopped. Let it run for 30 minutes, cycling between heater on and off, and shut it off. Not a drop leaked out.

Told my friend he has to do the timing belt soon anyway, so when hes that deep into it, spend a bit more time and take that intake manifold off and get to that hole for real. Or if its as good as my previous stop leak experiences, itll be fine for years.

Nothin' beats taking you own advice. :thumbup:

"Whatever works" ;) :D ;)

I just ran into this same problem today. I came to the forum for answers but I couldn't find a great one. Nobody really had any "tips." I figured I'd share how I removed and replaced this hose.

My 2004 five speed started leaking from a pinhole in the heater hose (the one stemming from the center of the block). I pressure tested the system to locate the leak, and then began biting my nails, worrying that I'd have to remove the intake manifold and a whole bunch of other things just to replace a stinking hose. But with a little redneck ingenuity I was able to pull it off with only removing one part. Here goes:

Get underneath the car, put it up high on jack stands.
Remove the starter assembly (two long bolts on the starter itself (10mm), and three nuts to the wires (2x12mm, 1x13mm). The starter should basically fall out.
Once you have the starter removed, you should be able to see straight up to where the hose connects to the outlet on the block. In my case, the prongs for the squeeze clamp were facing the wrong direction (upward toward the hood). This was problematic because the intake manifold braces are tunnel-like and C-shaped, and the hose goes right into one of these "tunnels." There is no room to get pliers or a tool on that clamp. This is when I got creative.. I took a length of wire, and doubled it over, and looped it up over BOTH prongs of the squeeze clamp. The wire was long enough to where I could wrap my hands in it (wear gloves) and heave-ho until the clamp rotated enough to where I could fish a pair of water pump pliers up there and back the clamp off of the outlet. The clamp on the firewall is easy to get to and remove.

When putting the new hose back on, I lubed it up and put a screw clamp on it, facing DOWN. I put a socket on the screw and used every extension I had, which made it easy to tighten the clamp using a ratchet from below the car. Note that the new hose was a length of standard heater hose from autozone and it was STRAIGHT, without the unnecessary bends that the stock ones have for some reason. I put a squeeze clamp on the firewall end of the new hose, pressure tested the system, and reinstalled the starter.

Filled it up with coolant, ran the engine and cycled the heater until it reached operating temperature. No runs, no drips, no errors.

Hope this helps you guys in the future!!!

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Originally Posted by Thymeclock

Yes, the leak that you are describing is coming from a bad heater hose. No tips on how to access it. Half the battle is in making the correct diagnosis, so you are halfway there. ;)

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I did this job a few months ago on my 2005 Aveo. Very tight job and even then getting the starter out was not any fun.

Take out the starter; then take the bolts from the diagonal intake support bracket. No need to remove bracket, just move it out of the way. That'll give a whole lot more room.

The parts store did not have the Aveo hose. I brought the old one w/ me and we matched an off the shelf part with the right diameter hose for some other car. I don't have the p/n any more. I used new screw clamps and not the junk that was there.

chuck