atl5p

99 Coupe, M6 stock. 4th owner. 95k miles

A few days ago, I noticed a strange smell after parking the vette in my garage.
The next day, I notced a belt squeeling while driving. Got home and popped the hood, there was a leak on the pulley/belts.

After closer inspection (and a mirror) I could see coolant leaking from under the radiator.

The leak seems to occur only while running, and shortly afterward. It does not continue to leak when cold and sitting.

So I got on the board, got some instruction for replacement, got a new pump, belts, dexcool, odd bits etc ($280 total).

While replaceing, noticed the old pump was GM, and had the new style metal gaskets. I was expecting paper gaskets on the '99.

I also had to move the thermostat housing to the new WP. My new WP came with both O-ring and Gasket for the thermo housing. However the OLD pump only had the Oring..no gasket. Got me thinking.

Then as I was clearing out the 'old' metal gaskets, I noticed one of the little orange rubber liners were sort of easy to seperate from the metal frame.

Now I've got the 'old' WP and the 'new' WP sitting there....and all new gaskets as well. Hmmm...is this a $5.00 gasket job, or a $140 WP job? Figuring it's Sunday afternoon, I need to drive to work this week, and I can return the 'new' WP to Autozone later, I go ahead and install the 'new'.

So that now, I can post to the board and figure out if my WP was actually bad, or if the gaskets/seals were just leaking.

Facts - Questions:

My 1999 had new style metal gaskets, not paper - was this stock in '99 or has this been replaced in my car before?

Thermostat housing had only an O-Ring. The 'new' kit had Oring AND a paper gasket...was this left out of a thermostate replacement before I got the car? The thermostat inside looked really nice, shiney gold (maybe new?)

I noticed the leak from the passenger side of WP, it just seemed to come from everywhere along the seal, dripping under the passenger side's 3 bolts/pulley. The drip was directly onto the A/C tensioner pulley (top small one in middle).

It would leak while running, would stop leaking a few minutes after stopping engine.

I looked and looked on both the old and new WPs, and could not find a 'weep hole'. I am not a 'water pump' expert..I just like to get my hands dirty to save a grand or two every now and then...

So....was that likely a gasket issue, or more likely a bad pump/bearing?

I'll be glad to answer questions, or post pics.

thanks in advance.

dgrant3830

At 95K miles on the original pump, might as well change it out while you are there. They do not last forever. Do the job correctly with the right parts and don't scrimp on insuring the sealing surfaces are clean.

lucky131969

VetteDrmr

with the above. As far as telling where the original leak came from, you should see a stain on the WP somewhere. My guess is that it's most likely the WP, since coolant gaskets rarely if ever fail once they've set. I wouldn't put much stock into the shape of the original gaskets once you've taken things apart.

HTH, and have a good one,
Mike

atl5p

Could someone tell me how to find the 'weep hole' on the LS1's water pump?

Also, I've read a couple things about 'when' the leaking occurs...I've seen that if it's the pump gone bad/bearing failure, then it will leak only while pressurized, and from the 'weep' hole...but I can't find the weep hole.

What happens when it's a gasket or something....when would it leak then?

Is the 1999 expected to have the metal gaskets? I thought I'd read that my car would have paper gaskets.

I'm just wondering if this pump has been replaced before, and maybe something didn't go right. The serpentine belt had lots of cracks, but the AC belt looked pretty good. (Replaced them both).

I've put 10K miles on since mid October with no coolant issues.

Slow Z06

you just about have to pull the pump to see the weep hole. regardless of whether its a pump or gasket, at 95K i would put an 04 z06 pump on there and be done with it.

mitchcole

What's so special about the 04 Z06 pump?

Slow Z06

From what I understand its the ability to use a standard thermo ( oldschool ) versues having to buy one with the housing attached.

atl5p

I'd already replaced it before posting here. AutoZone Duralast LLT ga-run-tee. (Sunday, Chev dealer closed...WP, what's the big deal, right?)


This new pump did not have the thermostat housing, I had to switch it over from the old pump.

Never even thought of a Z06 pump.

So, anyways...Like I said before I already took the old pump off, so where's the weep hole.

runamuk

That is not specific to the Z06, it is specific to all 04 LS-1 and LS-6's

Slow Z06

AH, good info to know. i had only heard it referred to as a Z06 pump.

Last C5

My 04 vert has the new style pump too. As far as I can tell it's an LS2 pump with an LS1 pulley. The new LS2 pumps have a flatter pulley. Still works, just looks a little different.

Chris.Shea

I had gasket failure @ 40k miles. no orange sealant on passenger side and showed same symptoms. brother had pump failure at same mileage in his 99. he had metal/silicon gaskets. gave him my pump and fixed.

swap gaskets and keep the new pump in the garage for when the original one fails. if it aint broke don't fix it but preventive maintnance wouldn't hurt nearing 100,000 miles.

Sick Z06

Usually on the "input shaft" housing area, between the inner and outter bearings, located facing downward.

Should be able to see it.

atl5p

Would I need to remove the backing plate?

My original WP does not have the bolt-on pulley, it has the big dome without removal bolts.

So. walk me through it. It's laying on the ground as it would face me in front of the car. The big dome pully is facing me. The thermostat is to my left. I don't see any bearings.

Should I pick it up, turn it over, remove the pulley, remove the backing plate?

I wouldn't mind getting my $140 back to put into a Ripper Shifter....write it all off to a 'Belt/Coolant' change.

Sick Z06

Unfortunatly then your weep hole will be hidden under the pulley. Located on the part of the water pump facing the ground.

atl5p

So the pump is on the ground
Pully is facing me (up)
Water ports are facing the ground

I'm having trouble envisioning the weep hole 'under' the pulley (which faces up) vs 'the part of the pump facing the ground'.

When I pick up the WP and turn it over, I can see 2 water ports (inlet & outlet), and in-between there is a round plate which is bolted down. While I have the pump's undersides facing me, I do not see any type of pinhole.

Did you mean to say that the weep hole is underneath this dome-like pulley? The weep hole would then be on the 'front' side of the WP yet underneath this dome?

Or is the weep hole on the side of the pump which faces the engine?

The leak seemed to come from the area where the pump meets the block. The leak did not seem to come from the area between the dome and the front of the WP. Along the entire mating surface between the block and WP (along the underside of the WP) was where the leak seemed to come from.

I just hear folks saying that it could've been the gaskets, that's all.

Heck, the guy who sold the car to me said the passenger window didn't work. He said Chevy looked at it for $100 diagnosis and told him he needed a $400 power window motor (plus labor).

After looking on the boards I 'whacked' it while holding the button. Now it works. So it wasn't the motor, it was the control module. The little diode or whatever that needs to be re-soldered back in is most likely the problem. Saved me $400 in window motor... + added frustration of that not solving the problem... ++ and then who knows$$ to replace the module.

Now tell me....(retorically)...just what the fudge did Chevy do to earn his $100? Push the button, window dosn't move, stamp "need a new motor" on his invoice? WTF?!? (near Greenback TN, forget the dealer's name)

I just don't like replacing something when it ain't broke....I've 'overmaintained' cars in the past for a net loss of money...forget that anymore....I could care less if the stock pump goes out in 20,000 miles down the road, if it's good today I'll want it back on the car until it does die...I've got a shifter to buy.

I'll try to post pics tonight....sorry I haven't 'maintained' this thread very well.
Thanks to the replies so far.

runamuk

Yes, that is where the hole is.