Coolant seepage from front of engine?

[DIYguy]

There is a slow drip that I found after driving 30+min near the water pump but it doesn’t seem to be from the gasket area of the WP. I’ll check again after fully cool to see if it stops. It was like 1 drip every 60seconds after I turned off the car.

My next step was going to take the serpentine belt off and the water pump wheel to get a better look but it’s so hot out now that I thought I’d seek advice using the pics I could take.

See photos below…

The above is about 5 o clock from the center of the water pump pulley.


In this photo the left bolt in the mirror is just below and to the right of the water pump (5o clock). There also is a second drip higher up (lower in the mirror).

I don’t believe these are the bolts for the water pump. I think they are on the front of the engine. These 2 highlighted below.



Are those highlighted spots a location where coolant could leak from?

Would simply retorquing the bolts potentially resolve it, is the surface below only machined surfaces or is there a gasket between?

Does anyone know the torque for those bolts and should the engine be cool first?

 

[Mooseman]

Are those highlighted spots a location where coolant could leak from?

Yes, as per this pic under the timing cover:

The water pump bolts onto the timing cover.



All that seals it in that area is RTV. You could try tightening them but that one bolt looks like it's been assaulted more than once. And to tackle this, you have to remove the timing cover, which means dropping the oil pan. I've already documented this process and it ain't pretty. The only parts you won't need to do is remove the intake manifold and valve cover, which is not much really compared to the rest:

How to replace I6 timing chain and tensioner

This is the last of several articles during my work to replace the timing chain and tensioner. How to replace the I6 timing chain and tensioner. Difficulty (out of 5): 8 (I'm not kidding) Tools required: Assortment of wrenches, ratchets, extensions, screw drivers. Socket sizes: 7mm, 8mm...

gmtnation.com

First time I've seen a timing cover leak like that but seeing what that bolt looks like, it could have been off before and was botched (hope it was someone else ). There could be some more sin hiding under that cover because the only reason you would remove that cover was to replace the timing chain, the tensioner and/or the guides or the oil pump, which is integral to the cover.

 

[DIYguy]

Thanks very much for the info!

We’ve had the car since new in 2005 until now… 158k miles. And it’s never had the timing cover off as far as I know. I also thought the bolts looked a bit beat up but I think it’s just grime…. The only 3rd party repair in that area was a dealership replaced the oem WP at 58k like 15yrs ago but they shouldn’t have been messing there. (I am on my 4th WP. I replaced myself at 95k and again at 140k.)

In the near future I’ll take the belt off and WP wheel to see if I can simply retorque and get lucky! Hopefully won’t have to do all that and drop the oil pan but I only have a 2WD so it would be a lot easier…

 

[DIYguy]

Car was sitting cold since Saturday… and I rechecked the same spots, zero dripping. So it must have to do with either heating up things, or maybe pressure/psi increase when running/warmed up or just from operating the WP…

I took the belt off and tightened the two bolts circled below but could not access the 3rd with the arrow as it was partially covered by the water pump pulley.

They both loosen easily at ~89inlb, not more, and I re torqued them. To get to the 3rd I have to take the fan clutch out and pulley off the water pump and that was not for this evening…

I did find that the water pump bearing had a little play when the belt was off.
Put all back together and idled it for only 5 min.

Afterwards, there were not leaks at the timing cover but I did have a few drips from behind the WP pulley. I think it must be from the weep hole.


So now I’m going to just replace the water pump and can retorque the timing cover bolts at that time too.

 

[DIYguy]

I’m going to buy either an AC Delco or Gates water pump. Does anybody have any recommendations for either (or another)?

Also, is there a preferred gasket to use or just the one that comes with it?


FYI this will be WP #5… (it’s strange, I’ve had to replace every ~5 yrs)
58k dealership replaced - assume was with OEM ac delco
95k I replaced with Murray from oreillys
135k I replaced again with a warranty Murray
158k Going to replace again

 

[Mooseman]

I've always had good luck with ACDelco. Just use the metal gasket that comes with it or, if it's not included, get one.

 

[DIYguy]

I've always had good luck with ACDelco. Just use the metal gasket that comes with it or, if it's not included, get one.

I don’t think I’ve had a metal gasket before but will do that this time. Maybe that’s been part of the past issues…

 

[Mooseman]

I think your leakage was from the water pump and the coolant was flinged onto those bolts making them appear to be leaking.

Just for reference, I still have my original pump at 201k km (125k miles). I'm probably on borrowed time and I already have a new ACDelco waiting for several years.

 

[c good]

I’m going to buy either an AC Delco or Gates water pump. Does anybody have any recommendations for either (or another)?

Also, is there a preferred gasket to use or just the one that comes with it?


FYI this will be WP #5… (it’s strange, I’ve had to replace every ~5 yrs)
58k dealership replaced - assume was with OEM ac delco
95k I replaced with Murray from oreillys
135k I replaced again with a warranty Murray
158k Going to replace again

How often are you changing the coolant? Miles/Years?

 

[DIYguy]

How often are you changing the coolant? Miles/Years?

Well I’ve never had to change coolant on its own except once because I changed it every time the WP dies! (Every 5 years)


2005 new
2008 - 58k dealership replaced - assume was with OEM ac delco
2013- 95k I replaced with Murray from oreillys
2019 -135k I replaced again with a warranty Murray
2025 new radiator and new coolant
2025 - 158k Going to replace again

 

[DIYguy]

I think your leakage was from the water pump and the coolant was flinged onto those bolts making them appear to be leaking.

Just for reference, I still have my original pump at 201k km (125k miles). I'm probably on borrowed time and I already have a new ACDelco waiting for several years.

That makes sense. Since the crankshaft rotates CW, then the water pump is counter clockwise and if it is dripping in the weep hole then dripping fluid would get flung off to the right side of the water pump…

 

[Mike534x]

Wow thats crazy, a new water pump every 5 years???


I'd consider going back to OEM, a new ACD pump can be snagged for $48 on RockAuto. Also, if your plastic fan blade sort of wobble side to side/up/down while the engine is running I would consider replacing it when doing the water pump. That "out of round" warp stresses the pump shaft/bearing and leads to premature wear which could be why you go through em so fast.

 

[DIYguy]

Wow thats crazy, a new water pump every 5 years???


I'd consider going back to OEM, a new ACD pump can be snagged for $48 on RockAuto. Also, if your plastic fan blade sort of wobble side to side/up/down while the engine is running I would consider replacing it when doing the water pump. That "out of round" warp stresses the pump shaft/bearing and leads to premature wear which could be why you go through em so fast.

Every 5 years…I know! But the upside was that I’ve not had to do a coolant replacement

It’s hard to say if the fan is out of round or movement is because of play in the WP bearing at this point but it does not seem to be very significant (if I look at the fan edge while it’s running it seems to be in nearly the same place.)

I agree about need for a better WP and will not put the Murray back but still I seem to have failed the first 2 ACDelco…
I’m hoping the metal gasket also makes a difference though. I know the last 2 with Murray were just fiber.

 

[Mike534x]

I'm not a huge of the fiber gaskets either. I've had good luck with Gates water pumps, if you wanted to try Melling it's about the same price as ACD and that comes with a rubber molded one.

 

[DIYguy]

Now when I was searching I couldn’t believe finding this. I had no idea Home Depot was distributing auto parts now too…. It just blew my mind that they had 10 in stock.

ACDelco Engine Water Pump 252-822 - The Home Depot

Accelerate an elegant and vibrant performance in your vehicles easily with the addition of this extraordinarily designed ACDelco Engine Water Pump.

www.homedepot.com

 

[Mooseman]

It's probably a front for another company using HD's site, like Walmart, which is EXACTLY the same price.

ACDelco Professional 252-822 Water Pump Kit Fits select: 2002-2009 CHEVROLET TRAILBLAZER, 2004-2012 CHEVROLET COLORADO - Walmart.com

Buy ACDelco Professional 252-822 Water Pump Kit Fits select: 2002-2009 CHEVROLET TRAILBLAZER, 2004-2012 CHEVROLET COLORADO at Walmart.com

www.walmart.com

Looks like ACDelco has gone to a fibre gasket. The metal one, which you can tell by the bead all around, is available separately on RA. And if you look at the pumps there, some of the others do have the metal gasket, including the Melling. There's also the GMB and FVP (which is a GMB). The gasket from Victor-Reinz is just $1.07. Personally, I'd give Melling a shot. It's $5 cheaper and has the metal gasket.

More Information for MELLING MWP506

 

[DIYguy]

Replaced the WP last weekend (and with metal gasket). When I installed everything else then there was an awful sound from the fan clutch for a few seconds after starting (like a grinding) so I took everything apart and ran over to autozone and got their Duralast fan clutch.

…well that threw a code and the fan seemed to wobble so I then traded it in and the second one was even worse.
Got my money back and put in a Dorman 622001 from another parts place since I needed to get back up running. The Dorman seems to be working ok (made in South Korea). I can’t believe I had to put the fan clutch back in 4x . But I got really good at it by the end, lol.

Can’t post the video here but here is a photo of the bad fan clutch and you can tell from the blur how much play there was. Looked even worse than in the photo.

 

[Mooseman]

The video you could upload to YT and post the link to it here if you like. I think we get it though.

It's crazy that a parts store would even sell junk like that. The Dorman we've had mixed results here. We usually recommend first the ACDelco/Behr and second the Hayden. You needed it now so you got what you had to.

 

[DIYguy]

The Dorman seems to be running fine. I’ll do the rag test or check the speeds with torque in a few weeks to make sure it’s doing what it’s supposed to.

I would’ve gotten the ACDelco instead if I could’ve have but at this point I’m not inclined to change again as long as it’s working!

 

[Mooseman]

I'm sure it'll work fine for a while but with anything from Dorman that involves electronics, they don't seem to last. Run it till it dies and get a new one from them. It has a lifetime warranty.