# Coolant Leak location



## Double02 (Mar 10, 2008)

2001 Pathfinder 3.5 V6 LE

Difficulty finding the source of my leak, slow dripping. Spent a couple hours yesterday in the rain trying to locate the source of my coolant leak. I have determined that its coming from the rear of the motor but due to lack of space cannot locate exact locations. It doesn't appear to be the heater core as there are no signs of coolant inside the cab nor smell. The coolant leaking is as bright as it it new( if that helps). The other day when the motor over heated I did notice a slight hissing sound again coming from the rear of the motor. I checked the hoses in back best I could, damm space again, but nothing. Could it be leaking from the water control value? Any ideas would be greatly appreciated.

thanks in advance 
Tom


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## 2005 4x4 Pathfinder (Nov 2, 2009)

Tom you you or anyone that you know have a set of ramps you can pull the Pathy up on to raise it?

If you can raise it, you (or a skrawny kid) can use a light and find the drip path back up to localize the source.

There are no moving parts back there so you might be able to use a coat hanger and some clothes to plunge between the firewall and the engine etc.


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## ntech (Apr 13, 2010)

willing to bet its the gaskets for the rear coolant crossover pipe. There is a pipe that goes from head to head and its on the back where you will have a hard time seeing it. I have done a few of these and they are no fun.


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## SPEEDO (Jun 9, 2003)

get your hands on one of those little dental mirrors... Harbor freight maybe


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## 2005 4x4 Pathfinder (Nov 2, 2009)

I dropped my ground bolt to the engine and it fell d o w n in to the nether regions, under a suspension grommet. I had to remove the skid plate shield and lay beneath with a mirror until I could see it and fish it out.

One of these extendible mirrors and an extendible magnet with an LED light and a 3pronged grabber are really handy when you need them.


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## Double02 (Mar 10, 2008)

Thanks for all the responses. I'll pick up one of those mirrors this weekend and update you all on my findings.

Cheers!
TD


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## bbswift53 (Dec 21, 2009)

Did you ever solve this leak?

ntech -- how long does it take to replace the crossover tube gasket? Can it be done by just taking off everthing down to and including the intake manifold, as the shop manual says for the water control valve?

Gotta get mine fixed, or do it myself.

Thanks.


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## Double02 (Mar 10, 2008)

I wasn't able to locate the leak and didnt want to start dismantling things so I ended up taking it in to CDN TIRE and they crushed up one of those stop leak pellets ( small hockey pucks) in the rad and ran it for twenty minutes to let it set. I have not had any issues with it since.


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## bbswift53 (Dec 21, 2009)

I got an inspection camera in there, and it is a freeze plug leaking. Just to the right of where the crossover tube bolts onto the right cylinder head. I don't see any way of replacing it without pulling the head off. Even if you could get the old freeze plug out, I don't see how you would seat the new one.

How many hours labor (professional, not me) to pull off and put back one head to do this?

I'd hate for it or another one to fail in big way due to corrosion at some inconvenient time, but I'm considering trying to delay/avoid the expense by putting Bars Leak Liquid Aluminum in there.

BTW, the camera was only $20, and worked pretty well. The most useful range is about 2" to 6" from the object. I taped the head to a coat hanger, and snaked it in from below. Prior to, it had looked to be coming from the crossover pipe gasket, but it appears to just be the freeze plug, which is leaking on the gasket.
http://www.amazon.com/gp/product/B007UZ6RVO/ref=oh_details_o02_s00_i00?ie=UTF8&psc=1


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## smj999smj (Jan 1, 2006)

The labor guide calls for 0.5 hours to replace one freeze out plug and 0.4 hours for each additional, not including time to access.

19.6 hours is listed to remove and install the engine
25.0 hours is listed to remove and install one cylinder head, or 28.8 hours for both.

It would be a lot easier to remove the engine to access it than it would be to remove the cylinder head. Also, if you R&R the engine, you also don't have the cost of the intake and head gaskets. You will have the cost of the anti-freeze and, of course, the freeze out plugs.


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## bbswift53 (Dec 21, 2009)

Thanks for the book numbers. They pretty much correspond to the quote I got, which was $2600 plus any hoses. That was for pulling the engine, removing the heads (there is a trivial amount of oil on one, which he says means the head gasket is leaking) and replacing only the 2 freeze plugs in the back of the heads.

I'm getting a quote from him for just pulling the engine and replacing ALL freeze plugs (depending on how the leaker looks when it comes out), and ignoring the trivial oil leak -- never add any between oil changes, and no drips on the driveway, so it isn't much at this point).


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## bazz (Jun 16, 2015)

I know this is an old thread...any chance you remember the name of those pellets used to stop the leak?


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## Double02 (Mar 10, 2008)

Not sure what they were called but they didn't sell them on the floor. You may have to ask the staff. The mechanic I spoke with showed them to me, they're about the size of 4 nickels stacked together. They crushed them up into smaller pieces and inserted them into the coolant system and let it run for 15 minutes or so. Not sure exactly where in the system they introduced them but from the threads I've seen don't put them in the surge tank, they won't get circulated through the system. I've changed the coolant several times since and haven't had any leak issues in 7 years, knock on wood. 

Saw on Google, talk about BAR's stop leak pellets. 


Good luck


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## smj999smj (Jan 1, 2006)

GM came out with those tablets a long time ago for coolant leaks in some of their engines, like the ol' Caddy Northstar V8. They are made from organic materials which you crush up and dump into the radiator. AC Delco #10-108, GM #12378255 and Bars Leak Radiator Stop Leak tablets are all pretty much the same and sell for about $7.


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## nitroscarruthers (10 mo ago)

Double02 said:


> 2001 Pathfinder 3.5 V6 LE
> 
> Difficulty finding the source of my leak, slow dripping. Spent a couple hours yesterday in the rain trying to locate the source of my coolant leak. I have determined that its coming from the rear of the motor but due to lack of space cannot locate exact locations. It doesn't appear to be the heater core as there are no signs of coolant inside the cab nor smell. The coolant leaking is as bright as it it new( if that helps). The other day when the motor over heated I did notice a slight hissing sound again coming from the rear of the motor. I checked the hoses in back best I could, damm space again, but nothing. Could it be leaking from the water control value? Any ideas would be greatly appreciated.
> 
> ...



I can pretty much guarantee that it's the crossover pipe. It runs coolant between the heads on the back of the engine, and is the most common problem this gen of pathfinder has. It's unfortunately very hard to get to. The book recommends dropping engine and tranny (DO NOT DO THIS!!!). The MUCH cheaper fix, is to take the top off the engine, loosen up the rear mounts, and tilt the engine forward to gain access. It is still quite labour intensive, but parts are cheap. Mine cost me under $10 for the crossover pipe gaskets, but $900 labour. Most shops quote just over $1000 if they use this method. Doing it by the book however, is stupid, and will cost you much more money.


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