MLS head gasket failure

[Ecoboobs]

Hey guys

After 25000 kms on my built motor I have coolant leaking into Cyl #3. Will be tearing it down next week and buy a 2.0 Fusion/Mondeo(in Aus) block. Has anyone had a MLS gasket fail? Mine was a Supertech one. It's possible I have a cracked head as it was making some power but I'm leaning towards the gasket. Had ARP head studs and everything. Bummed out a bit but get to build this engine properly now.

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[Scootsmcgreggor]

MLS don't typically fail by themselves. Usually head lift or movement relative to the block wears the sealing material off and they leak that way. These Ecoboost engines are prone to both of these failure modes.

ARP 2000 studs on this engine? Or the custom age ones? If not custom age use those on the new engine. Better clamping than arp2000 studs.

 

[Ecoboobs]

Yep ARP 2000 on mine. I think you are right that the head has possibly lifted. Looks like I'll be buying some custom age studs. Gotta loive the money pit. I'll post some pics when I get it out. Hopefully this weekend.

 

[Coyote Chase]

Yep ARP 2000 on mine. I think you are right that the head has possibly lifted. Looks like I'll be buying some custom age studs. Gotta loive the money pit. I'll post some pics when I get it out. Hopefully this weekend.

Which turbocharger and wastegate were you using on your built motor? And how much boost were you able to push without restricting the thottle plate (ETC)??

 

[Ecoboobs]

Which turbocharger and wastegate were you using on your built motor? And how much boost were you able to push without restricting the thottle plate (ETC)??

Been running around 27 PSI on E30 for around 2 years since this build and driven hard. Stock turbo with a turbosmart wastegate - boost curves are fine. ETC throttle openings and torque control are set by my tuner. Pretty sure the ETC angle is wide open from 4800 RPM.

 

[Coyote Chase]

Been running around 27 PSI on E30 for around 2 years since this build and driven hard. Stock turbo with a turbosmart wastegate - boost curves are fine. ETC throttle openings and torque control are set by my tuner. Pretty sure the ETC angle is wide open from 4800 RPM.

That sounds like a nice setup! Boost is well within the ARP limits, even with some exhaust back pressure from the stock turbocharger. I have heard of cylinder detonation lifting the head. Let us know if you find dimples in your engine head where your studs are located.

 

[Ecoboobs]

That sounds like a nice setup! Boost is well within the ARP limits, even with some exhaust back pressure from the stock turbocharger. I have heard of cylinder detonation lifting the head. Let us know if you find dimples in your engine head where your studs are located.

Cheers. What are the ARP 2000 boost limits for info?

 

[Scootsmcgreggor]

Cheers. What are the ARP 2000 boost limits for info?

It’s not quite that simplistic unfortunately. Head lift can come from raw power but more often comes from detonation or pre-ignition. I don’t know with a perfect tune what power it takes to lift a head with arp2000’s but I’m 99% sure a stock turbo cannot do it.

More often on these motors the tops of the cylinders walking around under the head gasket wears the gasket sealing surface out and you get a slow leak either between 1&2 or 3&4. This is a byproduct of an open deck block and why the big power motors are all built with the 2.0 semi closed deck block.

 

[Coyote Chase]

Cheers. What are the ARP 2000 boost limits for info?

I used them on my last build (inline 6) and had my machine shop install a full set of upsized head (2000 ARP) studs. And he guaranteed them for 30 lbs of boost.
However, at the time, they were the best money could buy. Today, I 'd probably go with the new and improved, at the standard OEM size.

 

[Ecoboobs]

I used them on my last build (inline 6) and had my machine shop install a full set of upsized head (2000 ARP) studs. And he guaranteed them for 30 lbs of boost.
However, at the time, they were the best money could buy. Today, I 'd probably go with the new and improved, at the standard OEM size.

Agreed. I will definetly be upgrading them. Here's the results. What do you guys reckon?

 

[Ecoboobs]

If anyone can recommend which upgraded valve springs and head studs to go to with part numbers it would be much appreciated too. Bores are all good and Manley Extreme pistons are holding up well.

 

[Ecoboobs]

Looks like both number 3 intake side head stubs have wound themselves out. Sticking out more than the others when I put a flat piece of MDF across the top of them. Checked them and they were loose. Only thing I can think of is that there was something blocking the threads when I installed them or my torque wrench was out of cal. Also found a few others loose on 1 and 4 but only one stud on each. I didn't use a thread chaser when I installed them. Lesson learned.

Head stud torque:

Intake side: Bolt #1: 1/4 turn loose, Bolt #2: 4 turns loose, Bolt #3: 4.5 turns loose, Bolt #4: 5 turns loose, Bolt #5: 1 turn loose.

Exhaust side: Bolt #1 1/4 turn loose, Bolt #2: .5 turn loose, Bolt #3: OK, Bolt#4: 1 turn loose, Bolt #5: OK

I'm an aircraft mechanic by trade and torqued all the studs up as per ARP instructions. Not sure why they came loose tbh.

 

[Coyote Chase]

Agreed. I will definetly be upgrading them. Here's the results. What do you guys reckon?

Is there anything we can do to reduce the movement of our cylinder sleeves??

 

[Ecoboobs]

I've ordered the 625+custom age head studs and Supertech valve spring kit.

After some more research the head stud kit I originally put in was ARP part number
151-4301
The instructions say to put the head studs into the block dry and snugged with no loctite. I'm thinking that if they went in with red loctite they wouldn't of unwound. This kit is not ARP2000 spec like I originally though. My rod bolts are 2000 spec hence the confusion.

 

[Coyote Chase]

You still have an awesome build! Right now I'm trying to pull 415 HP out of stock long block. Over the winter (during the off season), I hope to pull my head and change my connecting rods and am currently researching a way to reduce any movement of the cylinder sleeves in the 2.3 block.
Please keep us posted on your progress!!
Thanks!

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