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Cometic MLS Gasket - Small Coolant Leaks


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With my new P90 head from Rebello I had to switch to an MLS gasket to get the necessary operating height. Along with the MLS gasket purchase, I got ARP head studs as well. Installed the cometic gasket dry, and torqued down the bolts in 3 segments of 20 ft/lbs each starting from middle working my way out.

 

Getting everything running/tuning and bringing the engine up to operating temp tonight, I realized I have a couple very small seeping coolant leaks. I never had any kind of leaks before.

 

I am 90% sure the headbolt holes are 'dry' holes, not wet holes correct? If they are wet Im wondering if coolant is seeping up the threads and need to be better sealed?

 

My task for tomorrow is to get the valve cover off, and retorque to make sure everything is 60 ft/lbs. While the head was off to Rebello, I didnt do anything with the block. I cleaned the surface well to get any gunk off from old gasket and that was it. It was not resurfaced. I realize that Cometic states it needs a straight edge on both head and block to work properly. But with no previous leaks, should I suspect something not being straight?

 

Do any of you guys have experience with MLS gaskets and if so can you give me some advice? Am I on the right track with retorquing the head bolts to ensure 60ft/lbs?

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Installed dry as the instructions said to. I went out and bought a craftsman torque wrench instead of the oreilly 30$ torque wrench I had. All headbolts went another 1/4 turn until the click. Cleaned up everything real good, and brought the engine up to operating temp. After letting it sit for about 30 minutes went out to check on it and I have some very very small drips now in two spots. both on the drivers side one in the rear, and one up front.

 

I also read on the mustang forum copper spray helps, so Ill go grab some permatex copper sealant and do the whole spray and pray and see what happens...

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Im just going to pull it all off tomorrow and spray the cometic gasket down with the permatex copper spray. Was told to do 3 light sprays, with drying inbetween, then torque to spec. I was also told that over torquing by 5lbs is also ok. I dont feel comfortable using a radiator stop leak solution.... Should take me a couple hours to pull it all off, and another couple to put it back on. Hopefully by end of day on Sunday Ill have some positive results and can get back to tuning this thing. Im also thinking an oil change will be a good idea as well after this whole mess....

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SO... Got everything off. #6 was pretty wet, and noticed a water jacket was blocked on the MLS gasket near #6. I plan to call Cometic up tomorrow directly and ask what the heck. The punch out for the jacket is there, but its not cut. The water jacket is there on the block and on the head. I doubt Ill be able to do anything with a 'return' now that the MLS gasket has been sprayed with copper. I also put down a very thin layer of rtv red silcon gasket on the block as well for safe measure around all the water jackets. But my thinking is if that jacket is blocked off, then it might be trying to get that pressure out any which way it can...

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Here are the pictures I sent over to Cometic. They are reviewing and will get back to me. On your felpro pic, the waterjacket is open where it is in question on the MLS gasket closed off.

 

I have read on other websites, that the holes may be different sizes to help with metering the flow of oil/coolant through the head/block which isnt a concern of mine. I did read on some BMW forums, they weld up coolant passages to help with better flow/pressure, where as an MLS corrects this right out of the box. So not sure if this is intended as some kind of performance mod or not. Hope to hear back from Cometic by end of day so I can get this buttoned up one way or another (to drill it out or not). Its the only hole is question, everything else is open.

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Edited by AZGhost623
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Thanks.  These head gasket questions come up all the time, it will interesting to see what Cometic comes back with.  If you stick a wire through those holes in the head you might find that they're connected, so blocking one does just change the flow in that area of the head, but not stop it.  But that's where flow is low, the back of the head, from what I've seen on this forum so blocking a passage there seems odd.  Maybe they know something special.

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Well they told me to send in my old felpro gasket and they will add a new line to their catalog for it. In the mean time I can either drill out the hole or wait until they get the template modeled for a gasket to fit 1980 to 1983.

Edited by AZGhost623
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