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Coolant leak behind crankshaft?

A

apok

New member
My '04 Grand Prix (172,000km / 107,000 mi) has already been through two coolant leaks (first was a bad block heater three years ago, and more recently a coolant elbow). It's down to -15C (5F) up here in Ontario, and yesterday when going to the store I noticed a pool of coolant on my driveway, thanks to the help of a heavy snowfall. The leak seems to be predominantly on the right-hand side, and the middle. I took a quick look around the engine compartment with a flashlight (it was dark out) and didn't see any obvious signs of leaking/splatter at the coolant elbows, along the serpentine belt, at the upper/lower rad hoses, or at the hoses coming off the belt tensioner/coolant elbows. I parked the car pointing down the driveway instead of up, and I did see where some coolant is pooling (pic below, sorry it's not the best angle) - it's just past the crankshaft on what looks like some sort of pan / tray directly underneath the engine.

I topped up my coolant last night just to be safe, as I had some errands to run today. My driveway is at a pretty decent incline (I use my parking brake to park), and after adding more snow to my driveway, there's less visible leaking after driving around today. I'm wondering if my 'leaking' is old coolant that could've gotten down there when the elbow burst (i.e. snow/slush on the underside of my car assisted it to run off), but this is probably just wishful thinking on my part.

I searched through the forums and it sounds like this could be coming from the water pump, which may drip down and potentially pool under the engine. I'm thinking about getting a stop leak product (Rislone Pelletized Radiator Stop Leak) just to get me by for a few months until I can properly work on my car. I still need to check under the passenger seat to see if it's the heater core, but I'd be surprised if that was the problem. And when the elbows were leaking, I had absolutely no warning other than my engine started redlining in temperature. My engine has been running normally between the 1/4 and 1/2 markings on my temp gauge. I think my coolant ratio is closer to 70/30 coolant/water than 50/50, and I have seen the P0128 code thrown recently during this Winter, which someone noted was due to a less-than-ideal water mixture.

Are there any other areas to check? Has anyone else had a similar problem? I'm going to try to get over to a friends house where there's a flat driveway/garage to jack my car up in, but until then any comments are appreciated.


p60Fz.jpg
 


Water pump.. Internal seal went bad. Dont use that stop leak stuff, Unless you like the idea of a new Radiator and or Heater core... Thats all ive ever seen that stuff seal up :)

P0128

Ive only seen that from a Stuck/Weak thermostat. Either its stuck open a little bit, Or the spring is weak, The coolant pressure will actually open it.

We have a lot of the newer Mercury Milans throw that code. You can see the T Gauge Vary ever so slightly.
 
Sorry the comment was on another forum, "classic too stong of a mix. most antifreexe straight of of the bottle, pure is between 40 and 50 below. dexcool very rarely comes pre mix, at least in my experience. 2 qts out, 2qts of distilled water in. do you think he needs to get 'oe' distilled water? lol. in a very cold climate or very cold conditions, the proper mix is crucial for the coolant to ramp up to temperature quickly."

It's strange, if I let the car idle for 5 minutes after the P0128 comes on, I do see the temperatures rise, so I'm not sure if it's the thermostat acting up or not... I did 200km driving a few weeks back before getting stuck in stop/go traffic. During the long haul I was roughly 1/4 to 5/16 of the temp gauge, but once I hit stop and go I spiked to slightly over 1/2, which then came down. So strange.

I'm gonna pick up an inspection mirror, and remove my overflow tank to get a better look down the side of the engine tomorrow.
 
Mind you, Thermostats can go bad at any time, Ive seen them go as early as 40-50K miles.

Could be the Lower radiator hose that connects to the pump leaking. Something to check.
 
well....it may not just be the water pump. My coolant elbows went bad and i had coolant in that shield thing right there. Also if i remember right, a member told me that the timing cover could leak coolant if the gasket was bad.
 
Even less coolant visible today on my snowy driveway. All the hoses look fine, and it's not the coolant elbows. I popped the overflow off so I could see the bottom elbow, both elbows and the surrounding area were bone dry. Didn't see any wet spots around the water pump but it was hard to see the underside/back, so I'm not gonna rule it out just yet.
 


pull the belt off and see if the water pump pulley has side to side play in it. if so its the leak.

water pumps like to leak here and there, wont leak all week, then park it one day and it leaks, they are sneaky like that.

should it be the wp, when you re install a new one, be sure to use thread sealant on the long bolts, they go right into the water jacket of the block, when you remove them coolant will come out of the bolt holes.
 
Took off the belt today, the wp pulley didn't have any side to side play. I did see a small amount of coolant pooled under the upper coolant elbow, but everything below looked dry so I'm confident it's not leaking from here. There was a bit of coolant to the right of the lower elbow, which was l ocated pretty close to one of the water pump bolts.

I was just parked on level ground for the last 3 hours, and only saw a few drops underneath my car. Got home, parked in the driveway at an angle, now it's starting to dribble down. Looked around the engine compartment, still couldn't see anything at the elbows or hoses. Gonna try to make it over to a friends garage this week to jack the car up and take a look from the underside.
 
It's stopped leaking, so I'm kinda putting this one on the back burner for now. Baffling though.

I'm going to try to acquire a Mityvac MV4560 Cooling System Pressure Test Kit. PITA because I live in Canada, but I found one warehouse that sells it at a reasonable price. Waiting to hear if they'll ship to me.
 
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I am having a similar problem, I top off the coolant with the green antifreeze (I want nothing to do with that dexmud stuff) the low coolant light shuts off and doesn't turn on the rest of the day. Next day i go to start the car and the Low coolant light is back on, I take off the rad cap and sure enough its low. I have checked everything I can think of, no external leaks that I can see, no smoke from the tail pipes, oil level and color are both fine. Also some days the system will pressurize and other day's it wont. I can also hear what sounds like a supercharger whine but the car is N/A sounds like its coming from the power steering or the water pump. The coolant elbows are brand new and bone dry. I have a feeling the water pump is on its way out and other then that I am completely baffled as to what's causing this. Any help or idea's you have would be appreciated.

Thanks

Also I have replaced the LIM gaskets with the aluminum gaskets if that helps.
 
a crack in the side of the radiator is often very difficult to find as it'll only leak at certain times. Typically not when you think it would. This may explain the loss of pressure. That might also be a bad radiator cap.
 
found out my prob was a pinhole size leak in the lim. You might grab a can of carb cleaner and a good flashlight and see if your lim is leaking. Im betting thats where your leak is.
 
Whereabouts on the LIM was it leaking on you? A small pinhole leak doesn't sound like it would produce alot.
 
Doesn't sound normal either. Normal for a vacuum leak maybe..but coolant? Pics/more info please.

I had a coolant leak this weekend. The crank was soaked, belts were a little wet. I pulled the belts, ran my finger under the water pump and it came back wet. Pump got changed. No more problem. Darn crappy pump only lasted 194,600 miles. WTF, huh?
 


Coolant leak strikes again... this time as I was driving home from Easter. Luckily didn't overheat but the temperature was certainly creeping up. Unfortunately I don't have much time to look at it myself over the next few weeks before going on vacation so I am going to take it into a shop to have them at least do the diagnosis (never ended up finding a reasonably priced pressure test kit). The leak looked like it was coming from just to the right of the lower coolant elbow, but I didn't see anything odd around there.
 
if you never changed the water pump, (they tend to be a off and on again leak) take the belts off and see if the pulley has any play in it, and if the weep hole is wet on the snout of the pump. if the pulleys loose it should be the water pump is shot.

when my pump went bad the drip hit the belts and slung coolant every where. even on the underside of the hood.
 
Just heard back from the shop. It's pissing coolant out of one of the bolts and down the side, and they want to replace the intake gasket. Was quoted 5hrs labour (400) and parts (240), plus pressure test/tax.

Does the intake gasket make sense if it's leaking from a bolt? There's no oil into the engine so it's not leaking internally, oil looked good and no milkiness around the cap. Now that I think about it, there was a bolt just to the right of the lower coolant elbow that looked very wet...
 
LIM bolts do go into the coolant and oil jackets. Coolant is pressurized and oil isn't at that location. If a bolt was excessively loose, yes it could literally pee coolant. Those bolts when you do a LIM job should be cleaned and a sealant should be applied to them.
 
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