Bad MLS headgasket?

[Heartless]

Ok, finally got my Talon put back together. I'm running forged internals, Mitsu MLS headgasket, block and head magged and resurfaced, ss valves, bc springs, viton valve stem seals, dks 272's, arp head and main studs. I copper sprayed the headgasket and torqued it to 90ft lbs with moly lube as per arp. fired it up today and ran it at 2000rpm for 20min, smoked a bit but cleared up. I kept waiting to put coolant in but it never seemed to go down so I could, and it seemed to be getting hot but the stock gauge never went over half way and my aftermarket never went over 210'F. The water level dropped down after shutting it off, I tried to ad water but it just steamed away, only coolant would go in without steaming away. I let it cool down and and pulled the thermostat, poured water into the block thinking maybe there was an air pocket or something. Fired it back up and it started smoking white then a dark nasty white smoke. Pulled the plugs and got these numbers from a compression check (starting from cyl 1) 150,90,150,150. I'm assuming #2 hasn't finished seating in or something, and coolant is going into cyl #1, it shoots it out when cranking plus if I pull that spark plug wire it stops smoking. I just don't understand how it has 150psi and water getting into the cylinder. I also retorqued the headgasket just in case. Anyone have a suggestion or come across this before?

 

[Thomas91169]

you need to do a leakdown test to verify where the compression leak is coming from. Did you also have the head decked to ensure flatness?

 

[Heartless]

Yes both the head and block were decked, and I'll run a leak-down test tomorrow. But why do I have good compression and getting water into the cylinder?

 

[brute]

What temperature thermostat do you have in there? Have you verified it works? Did the plug from cylinder 2 look different than the others?

I would call MLS and ask about quality control. It may be quite possible you got a 'bad' one.

 

[Heartless]

I forget the number that was on the thermostat but its a stock one, and yes I verified that it is good and works perfectly. The plug from cyl 2 looked exactly the same ( think the rings just need to seat) but thats not the real problem I'm after, well yet, . If I call MLS what am I supposed to say? " I have a bad headgasket fix it!" I'm not thinking there gonna do much but I guess its worth a shot.

 

[Thomas91169]

if the HG failed to seal, its not going to magically fix it self, especially after coolant has ran through the mating surfaces/HG itself.

youll need to remove the head, clean both mating surfaces, clean off the MLS HG if you want to re-attempt with that HG (MLS HG are re-useable), or buy a new one.

you can try reinstalling it without copper HG spray, or try it again with. this debate is always either or. Some spray, some dont. Ive always sprayed my HG with a nice consistent amount of it.

 

[Heartless]

Yeah thats what I figured, just not really wanting to after spending the past 3 weeks taking my time and making sure everything was right and perfect while putting the car back together. I'm doubting I'll re-use it, but I'll probably spray the new one I get. But what I still don't understand how I can have 150psi and water coming in, that just doesn't make any sense to me.

 

[brute]

Well, if they sold you a faulty product, then yes, they should fix it. Although, I have never heard of a problem quite like this.

If you think the rings just need to seat, why is #2 the only one acting fishy? I would say it's either a MLS problem or a head machining problem (assuming you did the installation exactly as instructed).

It's just weird that the other three cylinders seem fine, yet one is acting up. It's also fairly obvious that you are burning coolant/water through at least one cylinder. It also seems odd to me that the

water just steamed away

If it is getting over 212 degrees F, then you may have some thermostat problems.

 

[Heartless]

I suppose they might, and yeah I've never had a problem like this before nor heard of it. I'll find out whats up with cyl #2, but cyl #1 still confuses me as to how it has such good compression yet has water coming in. I'll pick up a new thermostat tomorrow as well. I'll run the test tomorrow and see what I come up with before tearing it apart. Thanx for the suggestions!

 

[DeNoZZo]

if the HG failed to seal, its not going to magically fix it self, especially after coolant has ran through the mating surfaces/HG itself.

youll need to remove the head, clean both mating surfaces, clean off the MLS HG if you want to re-attempt with that HG (MLS HG are re-useable), or buy a new one.

you can try reinstalling it without copper HG spray, or try it again with. this debate is always either or. Some spray, some dont. Ive always sprayed my HG with a nice consistent amount of it.

I don't know about the mitsu mls headgaskets, but my cometic mls recommended to NOT use any type of gasket sealer. I didn't and mine sealed up perfectly.

 

[IgotBoost91]

pressure test the cooling system.

 

[BogusSVO]

How was the head and blocked milled? do you know what type of equipment was used?

http://www.dsmtuners.com/forums/new...face-4g63t-cylinder-head-mls-head-gasket.html

did the surface finish look like the one in the link?

If you have an odd scratch .. you may be misting a little coolent into the cylinder

 

[Heartless]

Like Thomas91169 said "Some spray, some dont", its all in opinion. I don't remember what the shop used to resurface it but yes it looked like the pic and it was a reputable shop and a friend of mine had his machine work done there and didn't have any problems. I'll see if I can get or borrow a testor for the cooling system, waiting on a friend to show up with his leak down tester right now. So can anyone tell me why I have 150psi and water coming in?

 

[jeffo]

Personally, just my preference of course, I will never use an MLS again, because of the issue with pushing coolant. I've had several customers with the same exact issue on a new MLS install. They either seal or they don't. If you aren't planning on boosting >25psi there are better choices, IMHO.

 

[BIGBLAZE79]

What if there is a crack in the head somewhere on the #1 cylinder intake runner that is leaking coolant onto the back of the valve. Just a thought.

I had coolant leaking into my #1 cylinder after doing the same build as you. It was very small and only caused overheating issues on the freeway. I did not use copper spray. Had the head and block decked, ARP studs. I wish I would have known you are supposed to have the surface of the head and block machined to a mirror finish. You could see the mill lines going across the head when I got it back. Don't get me wrong it looked very good and was done by an expensive muscle car hot rod shop in Phoenix, AZ. I don't think they know too much about MLS head gasket surface finish requirements.

 

[Heartless]

Did a leak down test, had very little leakage, put the oil filter cap on and plugged the dipstick tube and the water by the thermostat started bubbling. Pulled the head and sure enough the headgasket had a bad spot on it. Both the head and the block were surfaced to the correct finish for an MLS headgasket as well as the block magged and the head pressure checked. Is there a better headgasket for high boost applications other than the MLS? I'll be running an HX35 at about 30psi after I break in the engine.