Guys my 2001 pathfinder has developed a coolant leak. It started small, a few dozen drops after I parked it. Nothing was visible from under the hood. From underneath the fluid was coming down the passenger side of the bell housing and dripping off. After a month or so it got worse. It would leak down to a certain level even if it wasn't driven. About 2 or 3 qts. After reading numerous post about the cross over pipe leak. that seemed like the most logical place of the leak. I have since taken
the entire intake manifold off down to the block.I have plugged all the loose coolant lines, clamped off the over flow line to the coolant tank. I pressurized the system thru the purge line at the firewall to 15psi. It will not leak any where now and will
hold that pressure indefinitely. Help what happened to the leak? I don't won't to put it back together like this.
coolant leak
-
nickelghandi
- Posts: 205
- Joined: Mon Jan 28, 2013 3:23 pm
- Car: 1999.5 Nissan Pathfinder LE 4X4 (rusted out: sold)
2004 Nissan Pathfinder LE 4X4
1998 Volvo S70 GLT
2001 Ford F150 XLT - Location: Frankfort, KY, U.S.
- Contact:
Re: coolant leak
So you pressurized the system with the engine torn down to the block? Were all of the hoses still connected or did you remove them during the teardown?
Re: coolant leak
all hose are attached
-
Blindaviator
- Posts: 148
- Joined: Tue Mar 21, 2017 8:49 pm
- Car: 2001 Nissan Pathfinder LE
Re: coolant leak
I would reattach all the coolant lines (you don't need to remove any coolant lines to take the intake apart) and then rent a coolant system pressure tester from an auto parts store... Fill it up with coolant and then pressure it up... If no obvious leaks then start moving coolant lines around and look for leaks... If no leaks then you fixed the problem... ;-P
The IAC has coolant lines attached and you can either reattach them and let the TBI hang there or put in a temporary bypass to test for leaks...
Seriously it is either the transfer pipe on the rear of the head or a coolant line that has a split in it that only leaks when conditions are just right... It is unreal how many coolant lines these engines have so just keep tweaking the hoses until a leak presents it's self... You might also check the 2 temp sensors which are on the transfer pipe right behind the head for leaks / damage... One sensor is for the dash gauge and the other is for the ECU...
Oh and make sure to change the water control valve while you have it apart... It is a bugger to get to and you might as well do it while you have it apart... Make sure to check the hose between the water control valve housing and engine... If it's getting hard then change it out as well... You can get the valve and hose at the dealer for about $25...
The IAC has coolant lines attached and you can either reattach them and let the TBI hang there or put in a temporary bypass to test for leaks...
Seriously it is either the transfer pipe on the rear of the head or a coolant line that has a split in it that only leaks when conditions are just right... It is unreal how many coolant lines these engines have so just keep tweaking the hoses until a leak presents it's self... You might also check the 2 temp sensors which are on the transfer pipe right behind the head for leaks / damage... One sensor is for the dash gauge and the other is for the ECU...
Oh and make sure to change the water control valve while you have it apart... It is a bugger to get to and you might as well do it while you have it apart... Make sure to check the hose between the water control valve housing and engine... If it's getting hard then change it out as well... You can get the valve and hose at the dealer for about $25...
-
nickelghandi
- Posts: 205
- Joined: Mon Jan 28, 2013 3:23 pm
- Car: 1999.5 Nissan Pathfinder LE 4X4 (rusted out: sold)
2004 Nissan Pathfinder LE 4X4
1998 Volvo S70 GLT
2001 Ford F150 XLT - Location: Frankfort, KY, U.S.
- Contact:
Re: coolant leak
Blindaviator, I would say that it is a hose that leaks under certain conditions, but he said it leaks to a certain level even if it is not driven. Assuming that also means not running, then crossover pipe is also likely. I think you are right on the money with your two guesses.
He mentioned that he plugged all lines which made me think hard lines rather than hoses.
lngbrd50
While diagnosing, it might be better (cheaper) to use distilled water instead of coolant. If you have the tools to pressurize the system without running the engine then that is the way to go. If you have to run the engine to build pressure, then you should use coolant because distilled water can boil more easily.
Also, if using coolant instead of water, you could always dye the system with some UV coolant dye and then run the car just up to OT and then presssurize all the way and check for signs with a UV light or blacklight. That is my preferred way to find leaks. Even if it lands on something hot, the dye manages to stay behind.
He mentioned that he plugged all lines which made me think hard lines rather than hoses.
lngbrd50
While diagnosing, it might be better (cheaper) to use distilled water instead of coolant. If you have the tools to pressurize the system without running the engine then that is the way to go. If you have to run the engine to build pressure, then you should use coolant because distilled water can boil more easily.
Also, if using coolant instead of water, you could always dye the system with some UV coolant dye and then run the car just up to OT and then presssurize all the way and check for signs with a UV light or blacklight. That is my preferred way to find leaks. Even if it lands on something hot, the dye manages to stay behind.
Re: coolant leak
Thanks guys I'll keep looking.