Coolant Leak? (Pic)

[Naaman]

Was under the car for an oil change yesterday and found this lovely mess.

Seems to be coolant. It's coming straight out from behind the harmonic balancer (as best I can tell). There has never been a puddle under the car, though... go figure. Coolant in the radiator is all the way at the top (when cold) and the dip stick in the reservoir indicates that the fluid as at the proper operating level (it's in the full range) when cold.

IMG_20161117_111121a.jpg

Got a quote for a worst case scenario (coolant, fluid, thermostat, gaskets plus labor: $562).

I looked at some vids online and it seems like this job would take me all day long (first time). Also, would need to figure out what to do with the outgoing coolant. It looks fairly straight forward, though.

Also, it seems like there isn't much other than OEM/replacement pumps. Is there anything that would be an upgrade, if I have to replace the pump?

If the leak is slow enough that it never puddles, is it safe to just monitor it until I have time/money to take it to the shop? Engine temp has been normal all this time.

[SMWS6TA]

water pumps have a weep hole that when they stop spinning they will weep out the hole to relieve some pressure. Check it 1st, 2nd check the coolant bypass tube on the front. Another know leaking spot. They have o rings that somethings go bad.

[Naaman]

Okay, here's another pic. The leak seems to be coming directly from behind the harmonic balancer. I've looked at where (I think) the gaskets go (I can see the edges of at least one of the gaskets on the driver side) and I cannot tell if they are leaking.

Is there a gasket behind the pulley? If not, does this mean that it is the weep hole (and therefore the pump is bad)?


Attachment 26686

Also, when I first discovered the leak, I noted it's color (pinkish/red) and thought it could be power steering fluid. When I checked the reservoir, I noticed it was quite low. There are no puddles under the car at all.

Any possibility that this could be related (underlying issue)?

[SMWS6TA]

No gasket on the balancer, It has a seal to keep the oil in, if you're leaking coolant from that you got bigger issues.

The water pump is directly over the balancer, that is why I'm zero in on it. I'm betting either you have a gasket leaking or like I said earlier.

It could also be one more thing I just thought of. The bearing on the water pump pulley could be one it's way out and you could have a leak around there as well. It's why I had to replace mine last spring.

[SMWS6TA]

You could get a uv dye and use that to trace where it's coming from. Might be easier to zero in on it. You'll need to get the car to operating temp that opens the t stat then look for where the dye is coming from.

[Naaman]

I can see the leak both from under the car and when just looking under the hood: it is coming out from behind the pulley and dripping straight down along the front of the engine.

do you know if the weep hole (or any other part) makes a noise when it leaks?

So, if I buy a water pump and gaskets, will that come with all the parts that could be failing (bearing, etc)?

Also, how much coolant is in there that I will need to catch if I do this in my garage?

[Naaman]

It looks like 6 bolts to remove the pump, plus 4 hoses. It looks like the thermostat goes on the end of the big radiator hose, and the belt tensioner seems to be bolted onto the water pump.

This thread seems to help with identifying the necessary parts I need to locate/deal with.

Here is the process as I am imagining it:

1) Drain coolant from the radiator (should I also drain the engine?). Reattach drain plugs.

2) Remove throttle body/MAF/air lid for access.

3) Pull hoses (4 total).

4) Remove serpentine belt, and belt tensioner.

5) 6 bolts to remove pump.

6) Swap thermostat and belt tensioner from old to new.

7) Install gaskets (any adhesive needed?)

8) Bolt up the new pump to the engine.

9) Attach hoses.

10) Add coolant (50/50 coolant water mix?) Do I need a special tool or anything, or just funnel it in through the radiator?

Torque specs for the water pump and/or tensioner and thermostat bolts?

[SMWS6TA]

if it makes noise your bearings are out on the pump pulley.

[SMWS6TA]

your process is correct, no adhesive needed

[SMWS6TA]

how you can tell the pulley bearing is out, take the belt off now grab the pulley and rock it side to side, if it moves they are bad. Should have no side to side movement.

[Naaman]

Okay, so the pulley doesn't come pre-installed on the pump?

[Naaman]

Never mind about the PS fluid. I checked it just now and it's full. I think that when I looked at it yesterday there was a shadow cast into the reservoir that made it look low.

I tried rocking the pulley side to side (loosened the tensioner and rocked the pulley). It doesn't move. The belt runs smooth and all the pulleys turn true.

[SMWS6TA]

the new pumps they are pre-installed

[Naaman]

I picked one up last night but put the job on hold until I could determine if I wanted a 160 or 180 thermostat. According to what I'm reading on forums (from folks who apparently engineered the LS1 over on the Corvette forums), running a cooler thermostat on these "more modern" cars reduces their longevity by preventing the oil from heating up to the point that it's doing what it was designed to do. Anyway, it's got a 160 in there now and I'm thinking I'm going to install a 180 instead.

[SMWS6TA]

Bull.

It just opens it sooner, believe me the longer you run it the temps get plenty hot enough for the oil.

Been running mine @ 165° since 2010 no issues, I even have the fans turn on @ 175°.

[Whamhammer]

Bull.

It just opens it sooner, believe me the longer you run it the temps get plenty hot enough for the oil.

Been running mine @ 165° since 2010 no issues, I even have the fans turn on @ 175°.

I remember in 2013-2014 winter when it was sub-zero, after 1o minutes warmup and a 30 mile drive, my coolant never got hot enough to heat the inside, and that was with a working factory t-stat, I'd imagine a 160' wouldn't help keep the oil at a good temp at that point. Of course that's not an every day thing.

Wouldn't a 160 need a change in the ecm?

[Naaman]

I remember in 2013-2014 winter when it was sub-zero, after 1o minutes warmup and a 30 mile drive, my coolant never got hot enough to heat the inside, and that was with a working factory t-stat, I'd imagine a 160' wouldn't help keep the oil at a good temp at that point. Of course that's not an every day thing.

Wouldn't a 160 need a change in the ecm?

This is largely what the debate came down to. When the weather is cooler, it compromises the longevity of the engine. As for me, when I first got my car back after the build (it was in the mid winter), I noticed that on the first oil change, there was some shrapnel on the drain bolt (which I considered normal). The next oil change (warmer months), no shrapnel at all. No shavings. Nothing. A perfectly clean drain bolt. According to FBJ's comments on the high zinc oils, I figured that the Z-Rod I was running was responsible for this benefit. Now, the weather is cooling off again, and I changed the oil the other day, and this time, there was actually "blade like" pieces of metal that came out of the oil (only on the magnet, nothing in the oil: I dumped it into a clean bucked after draining it and ran my hands through... there was no metal). So it was "minimal" wear/damage, and within what some consider "normal" wear and tear but I have changed the oil in my car 5 times since I've had it back and each time (other than in the cooler times of year) it has been a clean magnet.

One of the other issues that a 160 Tstat can "supposedly" cause is worse fuel economy (another issue I've noticed since getting my car back). Now, I can't blame the Tstat for this directly because there are so many variables since my build. However, I am leaning toward putting a stock thermostat in. If my fuel economy comes back, then I'll be sticking with stock. Also, I'll be looking at the drain bolt next oil change for the shavings as well. For me, this will be all I can afford to do with regard to testing. Although, if I have to, I may just swap thermostats twice a year if it turns out that running stock is "too hot" for the summer months around here (given my build).

Here are two posts from "Evil-Twin" over at Corvette Forum:

Again and again ben dover, you have no clue about this LS1/6 motor and its development... IT is a tight clearanced aluminum alloy engine. it has a sweet spot. Every tuner knows this... keeping it in the sweet spot is what everyone strived for... the sweet spot is 190/200 coolant and 200/210 oil temp.

I was fully involved in the prototype design and subsequent launch and post launch debugging of this car, I have 35 years of automotive engineering under my belt I am an SAE Sr Engineer. This motor is almost bullet proof with the right configuration, that is, the right oil, and the motor running at the right temperatures, both oil and coolant. This allows proper lubrication , suspension of contaminants in the oil, and reduction of thermal breakdown... The sweet spot was established buy thousands of hours of run time while developing this LS1 design... simultaneous test were done to develop the algorithms for the oil life monitor, under all types of loads and driving conditions.. unfortunately WE build cars that run in Minnesota in the winter @ -30F, and the same car has to run in the Arizona desert @ +130F. The hp vs. cu. in of the LS1/6 was developed through tight clearances and a lubrication system that needs the right combination. Running an LS1/6 at 160 F will cause premature carbon build up...increase compression ratio, cause automatic Knock retard sensors to retard the timing, thus causing a loss in performance.. WE ( GM engineering ) have seen this scenario so many time we have developed the famous GM De carbonization process... these cars run anywhere from 190F to 235 F. and that is normal in the general design.. the PCM helps to compensate for this variance with appropriate fan settings.. but the car runs best at one temperature..both coolant and oil.. but it will function and various temperatures.. the sweet spot is insider information..keeping it in that sweet spot is what a well tuned engine wants to see.. and where optimal performance is gained...without loss of internal integrity
This is similar to the tire pressure sticker 30 pounds cold on the door... it is just a generic tire pressure sticker setting.. so customers wont use the max pressure settings on the tires,..,, but that 30 psi sticker is just a general statement.. the tires perform best at 30 psi.. but if you set them cold at 30 psi and get out on a Hot black top on a summer 90+ day road where temps can reach 160F, those tires will increase to 36 psi... that is not where they should run... I never allow my tires to get over 30/31 psi "Hot" that's where they perform,, they do not perform cold...so why set the temperature there. Tire pressure is so critical... Nascar pit crews monitor track temperatures all day long and adjust tire pressure accordingly. Two psi can give you better mileage and more tire life... these are critical in Nascar. A few extra laps on the tires and better fuel economy are all part of a well tuned Nascar. Not as critical to a daily driver, but the concept is the same... I consistently get 33 mpg on the highway with my car.. and I can get 45,000 miles out of a set of tires.. because I know what I am doing.. my car is tuned for me and where I live and how I drive... I have been trying to teach this concept to people here... many have adopted this, and other do not..
Running too hot will also cause pre-ignition, and the knock sensors will cause timing retard, loss of performance, and poor gas mileage...esspecially for those that can only get 91 octane gas.
keeping the car in the sweet spot is a function of a custom cooling system adjustment. I use a 160 stat and adjusted fan settings in my car from late April through September, thi9s keeps my car in the sweet spot through the summer. I use a stock stat and fan seeting through the fall and winter..
It takes five minutes to swap stats, with very little ( less than a pint of coolant loss).
This sweet spot concept is used by all tuners, that why they put a 160 stat and adjust fans settings in cars with mods. Summer driving conditions and a 160 stat will never allow your car to see actual 160 F coolant temps. Ambient air will not transfer heat when its 80 to 90 F.
a 90+ day on a black top road can yeild 140/160 F surface temps. So there is very little cooling from a bottom feeder air flow system. Your cooling system needs alittle help to gain optimum performance... Running Too Hot, is a definite NO NO........
Bottom line here..
Listening to wanna be mechanics and BS artist here on this forum can cause you serious damage and shortened engine life.. ben dover , You have no clue, and should not post about things you obviously know nothing about, especially about an LS1/6 engine.

No one ever talks about the negatives of running your car at 160F. on a cold night where ambient temps are 20F... running an LSX with a 160 stat on a 20F night will insure runing the engine at 160 F and coolant at 180.... drive a long distance , highway miles.. and you will put a few nails in the coffin of that LSX. 160 F coolant and 180 F oil are way outside the operating temperatures of the design... running a 160 stat in cold weather is a killer... tuners never tell you that though.... Like I've said a hundred times on this forum.. " EVERYTHING " is a trade off
If a 160 stat was beneficial 24/7 365... we would have put one in the car....

tuners get paid for giving you more HP.. they do that in part by advancing the timing... that's is done by lowering the operating temperature. we bult the LS1 as the first 200,000 mile bench marked V8 engine in the world. WE did tha by running the engine design hotter, not colder.

Everything is a trade off... want a little more power.. go cold but it will cost you in engine life.

[pajeff02]

Yes, the fan settings should be changed with a cooler 'stat. FWIW, I run a 180 in our car.

[Naaman]

What's the rest of your build consist of?

[SMWS6TA]

What's the rest of your build consist of?

me or Jeff?


Me look at my signature below.


Now I live in the deep south, so south I'm next to the Gulf of Mexico in 30 mins. Our temps rarely get below 30* but also run as high as 100+* for month or so. No where near as bad as TX, NM, AZ...


So running a 160* for us is not as bad as what the guy was saying for northern cars. I see his point but at the same time they have to hit the dead middle of the average use.



If you live in the North I say stick with the 185* stat.


Added my signature.