[rbarrios]

You can spot a slow leak by looking for signs of dexcool leaking and drying on the timing chain cover.
Heres an example- note the trail of dry coolant (white residue).

Another thing to look for is the signs of coolant being flung by the spinning water pump pulley.

Another sign to look for is drops of coolant that has not dried.

Another sign of the leak is a little more severe- drops of coolant on the floor. (the other spot was much bigger- about 8 inches wide).
This is only 1 drop

And- if you have a much bigger leak- signs of coolant on the vehicle.

here are shots-- with the wheel turned outward-- you can clearly see coolant

 

[rbarrios]

Most people report no failure until theyre in the shop for something else- and the dealers tells them its leaking.

Others- will leak for a while- and suddenly fail. Some leak- and are pressure tested and pass- only to fail a while later.

In my case- it was pretty quick.
Mileage- 39,400.

From one of the pics above its possible it has leaked for a few days.
But it cant be more than a week old. I checked it (visually) last week- yup- I get down and look at that area often.
I drove the vehicle about 100 miles yesterday- and there was no coolant on the driveway. I also smelled nothing.

Today I visited my sister- and strangely- we HEARD the failure. It sounded like bad bearings. Like an alternator going bad(if anyone is familiar with that sound). It lasted for about 30 seconds- went away- and then came back....
At that point I popped the hood- and looked under the car- to see the 2 round signs of coolant- oily looking spots (at 1st I thought- PS pump?).
The noise then went away. I drove home about 2 miles and took the pics above.
The coolant reservoir was at the FULL mark.

 

[rbarrios]

yup under the knife.
Im wondering if theyre going to update the OLM while its there...
As long as it doesnt also modify the programming-- in a way that It would lower my MPG... and change the shifting....

 

[rbarrios]

I have not seen a bulletin.
But theres a website- that you enter your VIN.
and it shows you the most recent software your vehicle can have...

several things I noted---
it does mention an OLM calibration software update.
a calibration that helps with vehicles that roll back on hills (but it does say-- only apply this one- IF CUSTOMER complaints- and that this calibration WILL lower MPG, WILL make PS pump louder).

Also- a calibration for engine start.....

 

[rbarrios]

Well- they must be driving it to a service bay or something---
I Just received my Onstar email.... so I know the vehicle has been started.

I dropped the car off at the dealer at 530-545 am.

 

[rbarrios]

just got a call. 11:15 am.
Water pump fixed.
I dropped it off at 545 am.

 

[rbarrios]

i plan on taking pics.
Its supposed to rain tomm.
so thats going to wash off the spilled coolant.
once rain is over- I hope to see the dirtyness gone-
that whole area was clean (the muddy water spots) came recently when we went to the snow.
Ill let you know what I find.

 

[rbarrios]

That was fast. When you get it back look if you see reddish see-through gasket like material/film.

I see a white sealant..

 

[rbarrios]

Complaint- Cooling Concern, Customer states vehicle leaking coolant.
Cause- Vehicle leaking coolant, Pressure test cooling system. Found water pump leaking.
Correction- Replace water pump.

The pump that was removed was GM 12566029 As stamped on the pump- visible in pics.
Paperwork shows the replacement pump as part # 12637479.

Heres the failed part--- the weep hole is visible. I spun the pump- felt smooth. So I dont know what the noise I heard was?

I went home and looked over the job-
I figured they had to somehow drain or suck out the coolant so it wouldnt leak when they removed the water pump.
there was no sign of a massive leak from the pump- from it being removed. But there was signs of coolant in the area below the radiator cap. (could be they overfilled? or some was spilled while removing it.... but this isnt of concern. Ive drained out coolant before and also end up with similar results. This will probably wash away with tommorrows rain). This is looking from the top of engine down.. and from the bottom looking up

To get to the radiator cap- they have to remove the big plastic shield. You can see the fasteners were removed.
This one took a little bit of damage. scuffs.

the pump installed. You can see the white sealant on the pump

So I always thought they removed the tire and wheel well liner completely to do the pump...But upon closer inspection of the fasteners...
theyre all dirty-- no signs of them being removed.

But I finally figured out how they did it. towards the bottoms- theres a piece of plastic that is bent... these fasteners showed signs of being removed
So it appears that if the vehicle is on a lift--- the person working from undeneath- can remove these fasteners- and have access to the pump.
(I think if youre at home-- you would have to remove tire and wheel well--- or remove tire and sort of follow their example of loosening the flap).

In this shot- you can see that theres signs of the Lower A-Arm getting 'cleaned'-- proabably by their shirt as they performed the repair. (leading edge).

I then sprayed a little simple green- and wiped down the area- so that I can have a reference- in case more coolant leaks.

the reservoir was past the Full mark by about an inch. I suspect most will get sucked back in as any air in the system is expelled.

I also asked if they performed any work on the OLM. The service adviser said there was no outstanding recalls on my vehicle. So nothing else was done to the vehicle. I had not asked for anything else- so only the pump was done.

As I drove home- vehicle shifted normally and I had no sense of engine operating differently. Ill monitor the OLM to see the rate drop.

They also performed a multipoint vehicle inspection. All was ok. They list the tires at 7/32 on all 4.
Brake linings where checked. they show up as the fronts at 5mm and rears at 6 MM.

When I got home- I loosened the front pass tires lug nuts and torqued them to 140.
Ill have to do the other 3 tommorrow.

 

[rbarrios]

Youre Welcome.