coolant leak (not up front)

I replaced my rad with a mishimoto a couple thousand miles ago after it started leaking. Now I've got a leak coming from directly below on the backside of my k16 or beside it somewhere. I've downloaded the PDF on our cooling system to try to figure out where its coming from with no luck. Its not coming from the head or block freeze plugs. The bottom of my trans pan is covered with coolant. Like I said, I've followed it really high up on the block with a mirror but I can't seem to pinpoint it. Any ideas??

Black plastic tube on passenger side, heater hose wher it runs along the firewall, or secondary cooling system leak maybe? What side is it running down?

It runs down both banks in the back... Its my primary cooling system BC I can top it off in the morning and by the end of the day its below the low line and not able to see it. But, it never takes much coolant to get it back up to visible again..

cracked jug?

Besides the plastic tube and heater hose, you could possibly have an oil cooler gasket oeaking i guess. You have any way of pressure testing it? You could also check up top with your mirror and see if you can trace it furthet.

Ya I may end up borrowing a pressure tester. I hope like hell its just the heater hose haha. I would think if the oil cooler gasket was leaking that id have oil in my coolant or vice versa

Could it be from your fuel cooler or its lines?

stroker221 said:

Ya I may end up borrowing a pressure tester. I hope like hell its just the heater hose haha. I would think if the oil cooler gasket was leaking that id have oil in my coolant or vice versa

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I would tend to agree with you, but there aint much in the galley that will leak, so iwasjust throwin that out there...

It is more than likely the black plastic coolant line that runs under the intake manifold that is leaking. Doesnt take much for it to start leaking.
No Limit makes a nice replacement for it that does not require removing the intake manifold.

Ok thank Yu very much. Guess Ill pull the turbo and downpipe and fix that and the damn egt sensor at the same time. Thank god for singles or I would dread having to pull stockers again

Looks like oil cooler seal. Theres coolant in the valley beside oil cooler and under turbo pedestal. My question is should I worry about coolant mixing with oil until I get it fixed this weekend..

Typically not. The oil and coolant mx internal in the oil cooler, not external. Just make sure you dont get her too hot.

Ok well who offers just an o ring kit for the 6.4? I see them for the 6.0 but thats all

I think you can get them thru ford. But i would replace the whole cooler for piece of mind. It would seriously suck to replace the o rings and a week, two weeks, whatever get the p012f...

I must of had another leak at the same time. Fixed the oil cooler leak but that was the small leak. I still have coolant coming down both rear banks. I topped off the coolant and pressurized it but it never leaked. I believe it's the cover right below hpfp on the rear of block 3 inches above bell housing. Is there a cover there that coolant could get past?