lghtngyello03

iTrader: (44)

Alright, a little maintenance history on my car. It's an 03 Evo 8 and the mods are in my sig. Car has 72k on it, and is on stock head bolts and head gasket.

I did the 60k service at 60k with all OEM parts. Fast forward to 72k miles and the OEM water pump starts pouring from the weep hole while running at any time.

So, I change out the water pump and t belt/balance shaft belts again. This time I used a Gates water pump with OEM belts/seals. Drove the car for a couple weeks and started noticing water again at the bottom of my front cover. Clean everything up and drive it like a normal person (no boosting) and notice no water. After that it peaked my curiosity, so I boosted it one evening. Upon getting home, I noticed water at the bottom of my front cover again, and could see it coming from the weep hole. So, I figure crappy Gates pump, and I ordered an OEM pump like I should have from the get go.

Tore the car apart, and put the OEM pump on, install a new OEM radiator cap, and bled the coolant system go for a drive. Under normal driving, it leaks no water at all. As soon as the car sees the slightest amount of boost, it starts leaking from the weep hole. Keep in mind this is a brand new OEM water pump. This couldn't be 2 bad pumps in a row could it?

There is no oil in my coolant, no water in my oil, no skipping, no smoking, not pushing coolant into the overflow bottle, or any other bad signs of a head gasket failing. I do not have a coolant pressure tester, but that is next on my list to buy and check out.

Thinking that it could possibly be my stock, weak head gasket/bolts, causing my head to lift under boost. This was my limiting factor last time I dyno'd, and couldn't turn my boost up anymore for fear of popping the stock head gasket.

I have already planned on pulling the head and installing a new OEM head gasket, ARP studs, OEM thermostat, GSC Beehives, and GSC S2's. Cylinder head will get sent out to be pressure checked, surfaced, and new seals/springs installed while it is off of the car.

Should changing the head gasket and studs fix my issue of pushing water here? Or should I suck it up and have to buy ANOTHER new expensive water pump that will possibly leak again???

Any help is appreciated.
-Scott-

LetsGetThisDone

iTrader: (1)

Test the coolant for hydrocarbons. You could be leaking combustion into the cooling system when cylinder pressure is higher (under boost), but it's sealing under lighter operating conditions. If there are hydrocarbons in the coolant, you'll have your answer.


Is it filling up the overflow bottle also?

lghtngyello03

iTrader: (44)

Not filling up the overflow bottle, forgot to add that to original post.

If there is hydrocarbons in the coolant, that would answer my pressure about my weak stock head gasket and bolts. This would be where my issue would be coming from right?

LetsGetThisDone

iTrader: (1)

Yes. Hydrocarbons = fuel or fuel remnants. If they are present in the coolant it means a combustion camber is leaking into the cooling system.

lghtngyello03

iTrader: (44)

Anyone else had this issue besides myself??

barneyb

I've been reading this forum for years and I don't remember anyone writing that the first sign of a blown head gasket was the water pump leaking. I do remember blown frost plugs.

A little bit of coolant stain at the weep hole is not a bad pump. Coolant has to get onto the seal surface for lubrication. Otherwise here is a link to possible causes.

http://www.flowkoolerwaterpumps.com/..._failures.html

Edit: I can visualize some seal maker in China offering water pump seals at an unbelievable low price and now the rest of the story.

lghtngyello03

iTrader: (44)

It isn't a coolant stain at the weep hole....there is actually enough water that comes out of the weep hole to wet the front cover and drip onto the ground.

No blown freeze plug, I have read about those issues. I have had the front cover off and inspected for this.

I have read a lot of people ran into their water pump going out after a couple of thousand miles due to a possible bad batch of pumps?

This is the 2nd water pump, that doesn't even have 1,000 miles on it and already is leaking out of the weep hole, only under boosted conditions. Which leads me to think the head is lifting causing the pressure to get into the cooling system.

heel2toe

iTrader: (41)

I've had my fair share of water pump and headgasket issues on my car unfortunately. First I blew out the freezeplug on the pump then found the weep hole leaking replaced the pump then blew the headgasket a couple weeks later. Then redid the hg and the pump was fine for a couple years then the friggin weep hole started leaking again. This time around I put in a non Mitsu pump, think it was gates or something like that and it worked well for 50k miles or so until I replaced it with another one when I did my timing belt last year.

So I don't know if Mitsu had a bad string of waterpumps or if that was just a coincidence but I also think a headgasket that is starting to fail could certainly be contributing to your issue.

lghtngyello03

iTrader: (44)

Update on this situation. I got to thinking yesterday at work. So I got home and pulled all 4 spark plugs and hooked pressurized air to each cylinder individually. When air is hooked to cylinder 3, air comes out of cylinder 4. And same if air is hooked to cylinder 4, it comes out of cylinder 3.

So there is a leak in between these two cylinders, which is causing the cooling system to be pressurized and push water from the weep hole of the water pump. More than like has wrecked the seals on this water pump as well.

I will be taking the head off and getting it pressure checked and surfaced and installing new GSC springs/retainers and GSC s2's while it's off, as well as replacing the water pump.

LetsGetThisDone

iTrader: (1)

Well there you go. It must be a very minor leak. Usually when it's bad you'll push a freeze plug out.