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G'day from Australia everyone. Last year I fitted a 2000 LS1 into my Nissan GQ Patrol. I've noticed what seams to be an external head gasket leak on both heads (853 heads).
I've read that some of the 853s had a notch in the head, is this visible from the exterior? I'm thinking possibly the previous owner of the motor installed the incorrect gaskets and or improperly torqued the head bolts.
Check out the photos and let me know what you think.
If there are head notches on the 853s then the MLS gasket (which you appear to have) will leak. Use the 97-01 GM graphite gaskets and the notches won't leak. Or... weld/fill the notches and deck the heads then you can use MLS gaskets. That's what I did.
Either way, like RB04Av said above, there may be other issues going on.
If you have the notch and MLS gaskets they will leak. I've had to pull heads back off the same day from that before.
The notch is near the center of the heads but offset, so on one side of the engine you'll have a leak a hair ahead of the center of the block on the other side a hair behind the center of the block. It's been several years but it was near either cylinders 3 & 6, or 5 & 4.
Ws6store makes MLS gaskets that work with the notch. I think Felpro does too but I can't remember. However GM MLS gaskets and notches DO NOT mix.
Also agree that's just dry antifreeze, it dries in a crusty trail like that. Wouldn't be surprised if that's water wetter, it's pink
Thanks for all the info everyone. Is it safe to say that it's conclusively a head gasket leak? I'd hate to pull the heads off and find out it's the coolant air bleed pipe gaskets or something similar. If it's definitely the gaskets ill rip the heads off and have a look and order the correct ones.
Thanks for all the info everyone. Is it safe to say that it's conclusively a head gasket leak? I'd hate to pull the heads off and find out it's the coolant air bleed pipe gaskets or something similar. If it's definitely the gaskets ill rip the heads off and have a look and order the correct ones.
Nobody can tell you that without being there to confirm that. You'll have to look at everything else and see where the leak is coming from and pull the intake to inspect the rear crossovers.
But if you put notch heads on GM MLS gaskets there's about a 100% chance they are leaking.
The reason the anti-freeze is there, is because the gasket leeeeeeeked. (duh)
ONE possible reason the gasket leeeeeeeeeeeeeeked, is because somebody put RTV on it. Chain of events being, heads MOVE on the block; just like head bolts MOVE in the threads; but RTV CANNOT deal with that. It tears. When you go back and look later, you find it all pilled up into little *****, and whatever it was supposed to seal, LEEEEEEEEEEEEEKS. Odds are, if you schmeeeer RTV on a MLS gasket, that's EXACTLY what will happen.
Moral of the story: NEVER use RTV on any parts that can move. Or parts that can come into contact with fuel because that softens it. Needless to say, both conditions obtain on a head gasket... making RTV singularly and specifically UNFIT for use on them.
I've taken the manifold off and cant see any evidence of coolant at the rear crossover pipes. I guess it's time to dig deeper? I squeezed my camera in and got some pics of along the sides of the heads. The leak is worse than I thought..
Uploads don't seem to be working so here's a link to some pics.
Poor surface prep is likely the cause of that, (or wrong gasket) could also be improper torquing of the bolts but that normally leads to loosing compression.
I see MLS gaskets, and they are 853 heads which I don't know if all of them have the notch but the ones I have seen did. Using notch heads on MLS gaskets = leak at cylinders 3 & 6 between the head and block.
OP you DO have a leak from the front crossover on the passenger side head. Look at the 2nd and 3rd pics, you have a stain/trail coming from above the headgasket across and down the front of the head. It could be just those leaking or them and the headgaskets.
I tried posting last night, but the post seems to have disappeared.. I've pulled the passenger side head off. Both the block and head are flat which is reassuring. Some of the head bolts were definitely tighter than others.
The header surface was quite dirty though.I'm looking at this kit, it says the heads must be stamped with 1MA at the rear. I can't see any stamps, any ideas? Cheers
I'm not particularly happy with the surface of the driver's side head. It's a bit rough to the touch. Should I take it to the local head shop to have it milled?
02-14-2019, 05:56 AM
External Head Gasket Leak 
