Dreaded N62 (4.8i)Coolant Leak - Merry Christmas

[x5745li]

I had a 7 before the x5 and no problems. Did you follow the maintenance of changing coolant every two years? This will prevent the dreaded pipe leak. 7 had 150k on it and never had any problems. It was an 02 the first year and a lot of people had issues. Mine was flawless when I traded it in

[jeremym]

Oh man. Threads like this make me cringe--especially with a 2007 4.8 model. Then again, this is the first thread of this nature that I've seen. Hopefully it's not all that common and I luck out.

[TwinTurboGTR]

All N62 motors are susceptible to the Valley Coolant Pipe leak. Why it was made to be unserviceable is beyond me. As for coolant changes every 2 years doesn't necessarily make you bullet proof against a leak. It's just a matter of odds.

[jeremym]

Originally Posted by TwinTurboGTR

All N62 motors are susceptible to the Valley Coolant Pipe leak. Why it was made to be unserviceable is beyond me. As for coolant changes every 2 years doesn't necessarily make you bullet proof against a leak. It's just a matter of odds.

I agree with your last two statements. The *only* thing coolant changes would do is ensure (but still not 100%) that contaminants are out of the system and flushed with new fluid. However, I still don't think that matters as much as the odds, as you say.

[x5745li]

Originally Posted by jeremym

I agree with your last two statements. The *only* thing coolant changes would do is ensure (but still not 100%) that contaminants are out of the system and flushed with new fluid. However, I still don't think that matters as much as the odds, as you say.

The coolant pipe problem occurs because the end of the pipe has a rubber gasket fused onto an aluminum alloy pipe. When coolant is not serviced the ph of the cooling system becomes more caustic. This causes the pipe decay and thus the leak to happen.

[jeremym]

Originally Posted by x5745li

The coolant pipe problem occurs because the end of the pipe has a rubber gasket fused onto an aluminum alloy pipe. When coolant is not serviced the ph of the cooling system becomes more caustic. This causes the pipe decay and thus the leak to happen.

So you're telling me the amount of heat cycles, coolant movement, weather (humidity, temperatures, corrosion, etc.), ambient temp, and other factors don't have anything to do with the issue and that coolant flushes every two years will almost guarantee you never see this issue? I'm sorry, call me a cynic, but I don't buy it.

[x5745li]

Originally Posted by jeremym

So you're telling me the amount of heat cycles, coolant movement, weather (humidity, temperatures, corrosion, etc.), ambient temp, and other factors don't have anything to do with the issue and that coolant flushes every two years will almost guarantee you never see this issue? I'm sorry, call me a cynic, but I don't buy it.

Have you seen what the pipe looks like when it falls apart?
I fixed two of my friends cars with the dreaded pipe problem and
decay of the metal is what caused the failure. Both of them did
zero maintenance on the cooling systems, which is what most people tend
to do on the system.

[TerminatorX5]

subscribed

[gregg3gs]

Sounds like I will be joining the club soon. Six months into this thing and I had to top off the cooling reservoure three times.

Does any one know what parts need to remove to get to this thing (pipe), and whats the best way to confirm this a 100%?

[x5745li]

Make sure you pressure test system when cold (cold shrinks all seals). Could be hoses under intake manifold, Pressure cape, water pump, ....