Signs of impending water pump failure?

[RL7]

So apparently it is common for water pumps to fail and grenade the engine? I was not aware of this. My water pump makes some squeaking noises only when cold, but my cooling system works perfectly otherwise. Now that I've read of a few cases of catastrophic water pump failure, I'm concerned. Are there any signs/symptoms that foretell this? How common is this?

[mb3000]

Subscribed.

[stealthee]

Are you sure its the water pump squealing and not just an accessory belt?

[EvanH]

Mine didn't "grenade", but it started leaking from the weep hole.

[IPD]

if you have over 120k on your motor and you've never changed the water pump...it's time (imho).

i'd replace the harmonic dampener at the same time. ;)

[RL7]

Are you sure its the water pump squealing and not just an accessory belt?

Yeah, unfortunately. I removed all the timing covers and the ac/alt belt and ran the engine to pinpoint the squeak. Silent in the crank/tensioner area, ps stuff was quiet, and the squeak was coming from the center of the engine. I put a metal thing to the water pump to listen and that seemed to be the spot. Almost definitely the water pump.

[RL7]

if you have over 120k on your motor and you've never changed the water pump...it's time (imho).

i'd replace the harmonic dampener at the same time. ;)

Well... the water pump was off a jdm engine with "less than 30k" on it. I didn't replace it because I wasn't sure of the part I need (not a normal 3s waterpump). Now I kind of feel like an ass for not sourcing a new one. I probably should install an actual dampener at the same time instead of running the lightweight pulley, except I don't really care if I trash the bottom end of the motor. The heads are another story though- they must not be hurt. I wonder if a solid crank pulley imparts more stress to the water pump?

[Emilie@GZP]

it's a 3.0L engine? you would use a regular 3/S water pump. JDM engines are no different than the US Spec ones.

[IPD]

Well... the water pump was off a jdm engine with "less than 30k" on it. I didn't replace it because I wasn't sure of the part I need (not a normal 3s waterpump). Now I kind of feel like an ass for not sourcing a new one. I probably should install an actual dampener at the same time instead of running the lightweight pulley, except I don't really care if I trash the bottom end of the motor. The heads are another story though- they must not be hurt. I wonder if a solid crank pulley imparts more stress to the water pump?

you must not have read the horror stories from ray p. and others about the solid pulleys.

[RL7]

it's a 3.0L engine? you would use a regular 3/S water pump. JDM engines are no different than the US Spec ones.

It is, but it's a non-crossover block. Here's a pic of the water pump. The one I'm using now is on the left.
http://i432.photobucket.com/albums/qq49/rlyons7/waterpumps.jpg

Apparently its part # MD973025 and isn't too difficult to find.

[RL7]

you must not have read the horror stories from ray p. and others about the solid pulleys.

I have not. Does it include damage to the heads and/or water pump?

[stealthee]

you must not have read the horror stories from ray p. and others about the solid pulleys.

You are making it out like its destiny that an engine fail with a solid pulley. Several people have been running 100k miles with a solid pulley with zero issues. I have probably 50k on my solid.

I'd rather run a solid than a stock one that can come apart and cause signigicant damage.

[IPD]

You are making it out like its destiny that an engine fail with a solid pulley. Several people have been running 100k miles with a solid pulley with zero issues. I have probably 50k on my solid.

I'd rather run a solid than a stock one that can come apart and cause signigicant damage.

you're also n/a. this is a well-documented problem for high-hp 6g7x motors.

and there's no danger of the stock one coming apart until you have well over 100k miles on it, or it's been dry-rotting for over a decade.

[stealthee]

There are PLENTY of TT people running solid pulleys with zero issues.

There have been people with 70k miles that had a pulley come apart. Rubber detoriates over time. A solid pulley will never detoriate.

[IPD]

i never disagreed with that. at stock tt levels (240-280whp) and even slightly more, it's not going to be a problem. there is no way i'd run a solid pulley on a 500+ awhp build.

there is no hard & fast "line of demarcation" below which you can safely run a solid pulley. i don't have bookmarks for each and every thread of significant informative value for our platform; if i did, i could link ray's post to this thread. just suffice it to say that the demigods of the 3/s community do not recommend solid pulleys--and i agree with them.

[stealthee]

Correct that, they do not recommend them on high horsepower builds. There is a significant difference.

[IPD]

here:

So upon inspection of my crank pulley... - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f1/so-upon-inspection-my-crank-pulley-458895/#post5396996)
So upon inspection of my crank pulley... - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f1/so-upon-inspection-my-crank-pulley-458895/#post5397079)
So upon inspection of my crank pulley... - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f1/so-upon-inspection-my-crank-pulley-458895/#post5397478)

i WISH i could find the thread about ray's detailed experience with using one on his high-hp build.

[stealthee]

I wont be clicking on those. 3si will not be getting page views from me.

[IPD]

fine. i'll save you the trouble. here's the words, verbatim, from ray's post, august 26th, 2009

So upon inspection of my crank pulley... - Page 3 - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f1/so-upon-inspection-my-crank-pulley-458895/index3.html#post5563746)



here is MY experience on the lightweight pulley thing. you guys are somewhat ALL correct for different reasons.

i base MY findings on what I see myself. by 2005 i made more HP than anyone did with a 3S and i learned ALOT.

a stock damper is like having a flywheel on the front of the crank as well as the rear. take a minute and think about what a flywheel actually does..even on lets say a lawn mower. each power stroke accelerates the crankshaft while the other 3 stroke decelerate it. the flywheel give this a smooth transition.
now add more cylinders. the crank will rapidly accelerate and decelerate with each power stroke.

now add a flywheel to this multi cylinder engine. the crank speed is now smoothed out from the force of the flywheel or mass momentum.

with no flywheel on the front of the crank, the crank needs the rigidity of itself to keep those acceleration forces in check on the front of the crank. the crank itself begins to flex.. more HP (power stroke force) the more the crank will flex.

now add a damper to this engine. the front of the crank now has a flywheel of its own. now the crank doesnt need to use its own rigidity to keep from flexing since this is now also done at the front.

now here is where my real life experience with a 6G72 comes in. in 2005 when i was making 875awhp

1000hp mitsubishi 3000gt on the dyno - Car Videos on StreetFire

i dont even have my own vids..i have to find them online lol

here is what started to happen. i had an aluminum crank pulley. the front of the crank flexed (accelerated and decelerated) so badly that the timing belt eccentric started cracking loose. this was caused from the cams acting as the flywheel for the front. the t belt would get pulled so tight that the belt itself would crack the eccentric loose.

that same effect was cracking loose the adjustable cam gears! the cams couldnt accelerate and decelerate at the same rate the crank was so it would make the bolts slide back and forth.

all of this bending on the crankshaft...not only did it make the t belt almost fall off a bunch of times and ruin my gears.. it broke the crank itself!

when i figured this out, i went to a stock damper and IT ALL WENT AWAY.

my case may be an extreme case due to the power but everything is relative. a lower power engine will have less flex but it still has flex. flexing leads to cracks and cracks lead to breaking.

every 700 plus whp 3S i know of runs a stock pulley. i remember in about 2006 IPO was having his eccentric come loose and i shared my info i had found. he also runs a stock pulley.

9B cars? 15Gs on pump? those would be ok with an aluminum pulley but 500 and up id recommend a stocker and 700 and up is a must 800 and up it will break everything if you dont.

i hope that helps. sometimes i dont have the time to post shit like this anymore.. but this subject deserves a little time

Ray

[stealthee]

fine. i'll save you the trouble. here's the words, verbatim, from ray's post, august 26th, 2009

So upon inspection of my crank pulley... - Page 3 - 3000GT/Stealth International Message Center (http://www.3si.org/forum/f1/so-upon-inspection-my-crank-pulley-458895/index3.html#post5563746)

I've seen that post. Like I said, the majority of 3s owners will fine with a solid pulley.

[mb3000]

Thanks for the info imperfect, for high hp builds OEM is the optimal choice.

With that said, I bought my vr4 with an UDP and im not in the slightest bit worried about it.

[IPD]

if you bought it that way, or will be n/a till the day you die, then don't worry about it.

i, for one, do not buy replacement parts on what is "minimally acceptable". i hate having to re-invent the wheel when i aim for bigger things later.