MLS head gasket issue? or something else.

[AaronGTR]

I've been having a few issues with the engine ever since the rebuild that are really nagging me. I'd prefer not to just drive it "as is" in case it leads to a bigger problem latter on, but I really just have no idea what the problem is, so I could use some input.

I've been getting something that definitely looks and feels like oil leaving streaks down the front of my block. It's dripping off my A/C compressor and starter, and generally making a mess of my cross member and everything else. From all appearances, it seems to be slowly leaking from between the block and cylinder head.







I've looked everywhere else and had the upper manifold off and can't see it anywhere else. It's only on that front edge. Very strange since only coolant goes through the gasket. It's not leaking from the sides or from the rear head either. They are MLS gaskets from Gaskets To Go who did a group buy through the old 60v6.com store back in the day before Cometic would make them for us. They have a viton coating and are supposed to be able to be installed dry, and the shop who did my machine work told me the heads where flat and both surfaces smooth enough to use MLS gaskets.

The only possible thing I can think of is maybe they aren't sealed well along the edge of the heads and oil could be getting between the layers at the edge of the gasket up in the lifter galley at the drain holes in the heads and leaking around? I just can't imagine why it wouldn't be sealed so tight that oil couldn't get in there, and why it would only be leaking from the front edge of the front bank. When I installed the heads I torqued them to 82 ft/lbs. Directions for the head studs say they need to be re-torqued after running, but directions for the gaskets say they don't. I took the valve covers off anyway and checked the torque, and re-torqued them to 90 ft/lbs to see if that would help, but it still leaks.

The other problem that's nagging me is occasional white smoke out the exhaust. It only happens at idle in gear or parked, but not all the time. Doesn't matter if the engine is hot or cold. I can be out driving and sitting at a light and look in my mirror and see wisps of smoke rising behind the car, take off and it goes away, get to another light and see nothing. Get home and get out and look and see nothing coming out the exhaust, but a few times I have. It's never consistent when it happens. The coolant and oil levels aren't going down fast enough (if at all) to tell me what I'm burning. Can't decide if it's another problem with that head gasket, or some problem with the piston rings not sealing well sometimes when the engine isn't loaded? It's really got me worried though. I don't want to have to tear the engine apart again to replace the head gaskets, and I can't afford to pull it again if it's a problem with the rings. I did everything the manufacturer recommend though with the rings so I have no idea what could be wrong.

I guess at this point this engine just has me paranoid. I'd really like to not have an oily mess all over my engine and gunking up my compressor and starter motor though, and I'd also like not to be burning coolant or oil and fouling up my sensors and cat. Any suggestions?

[SappySE107]

Have the heads ever been milled? Over-tightening the studs is not a good idea. If the gasket doesn't seal at 82, then its not going to seal. Stretching the studs will weaken them.

[AaronGTR]

Nope. Heads have never been milled. It's the original surface. Same with the block. Gaskets were new, still in the package, and never had been installed.


I'm going to do a compression test this weekend and see if I find anything. If I do decide to replace the head gaskets, then do I spring for the Cometic gaskets and wait two weeks for them, and worry about possible sealing problems with another set of MLS gaskets? Or do I go with the check OEM gaskets that I know will seal properly but might blow out again? It just kinda ticks me off having to tear apart a fresh engine and replace brand new gaskets that I already paid $180 for and didn't work right, for another set of $185 gaskets. Would the Cometic ones be any better?


I also forgot to mention the oil pressure is still high. I don't think it has anything to do with this leaking issue though. It did come down a little bit from what it was, but it's still higher than I'd like. Cold it's like 75psi while cruising and can get up to almost 90psi at higher throttle. After it warms up to 180 it drops to 30psi at idle and about 50-55psi at cruise, but still gets up to 75-80 under heavier throttle. This is after changing back to synthetic too. Only thing I can think to do is drop the pain and take the pump off so I can take the shims back out of the pressure bypass spring. I don't know how much difference 1/8" will make, but it's the only thing I can think to do.

[SappySE107]

You need to mill the heads, and tear those MLS gaskets apart to copper spray them this time. Or you can blame the gaskets and buy new ones but please mill the heads this time.

[mfuller]

Aaron, when you had the machine work done on the block, did they check the RA (roughness average) of the deck?
Cometic recommends 40RA or better.

[blackbombshell95]

You need to mill the heads, and tear those MLS gaskets apart to copper spray them this time. Or you can blame the gaskets and buy new ones but please mill the heads this time.

I'm glad you milled my heads and my engine builder seperated the MLS wot-tech head gaskets and sprayed them. I've only got 10 miles on the setup but I hope it lasts forever .

[geoffinbc]

I don't see how even a bad head gasket would ever leave oil on the block. The oil drain back is on the inner edge of the head and drains back under no pressure. I do see a stain that looks like oil around the head stud in your second pic. Check your valve covers and make sure there is a dab of silicone where the head and intake meet.

[AaronGTR]

I mentioned in the first post that the machine shop checked the surface of the heads and the block and said both were smooth enough. The cometic gaskets and these ones both said in the directions they needed a 50 RA or smoother, and my shop said it met that. They also checked the heads, as I also already stated, and said they were flat. So why should I need to have them decked? I'm not paying to take them off and have them disassembled again for more machine work that I could have done the first time if it was necessary. And that would screw up my compression ratio too. I don't want to raise it even higher since I'm boosted. If I deck the heads then I would have to either get thicker cometic gaskets, or completely switch the heads and LIM to a 3500 setup. Either way I'd end up spending a bunch more money if I can't make these work. I do NOT want to dump any more money into this thing at this point. If I can't make them work I'm going back to stock gaskets.

Why do I have to take the gaskets apart and spray them with something to make them work, and why wasn't this in the directions if it was necessary? And how the heck would I even separate them? Aren't they bonded together? I know they had some kind of rivets holding the layers together. And where do you get the spray?

Really, at the moment I am kinda pissed off after spending $180 on the first set of gaskets and having them not work. Why do I keep getting products that end up needing modification to work as advertised? If there is a special process needed for installation it should be noted in the directions that came with the part. I'm getting really tired of tearing this engine apart though. I don't have a second car anymore and I'm running out of time/money/patience to fix this thing. I need to get them sealed up properly and be done with it.


I don't see how oil could be coming from the head gaskets either, but like I said, that's the only place it can be seen. I already said there is no oil around the valve cover gaskets. I know to put rtv in the corners. They are bone dry and there is no oil coming from there at all, or anywhere else on the heads that can be seen.

[ForcedFirebird]

As stated in post #5, it is imperative the finish is at least 50ra or better for ANY MLS gasket. The heads from the factory are not straight of fine enough finish for MLS gaskets. The GM gen 3 heads are on the edge of tolerance for graphite gaskets, never-mind MLS.

Ben was suggesting that instead of spending $$ on new Cometic gaskets, you can drill the rivets, spray copper on both sides of every layer and re-assemble. You aren't REQUIRED to do this on first install, but is actually common practice for years. We have a Cometic on the race car and it was topping out 5th gear at 15psi, 56mm turbo at VIR, installed dry.

You are getting really upset for something that was overlooked on your end, not the manufacturer.

[AaronGTR]

As stated in post #5, it is imperative the finish is at least 50ra or better for ANY MLS gasket. The heads from the factory are not straight of fine enough finish for MLS gaskets. The GM gen 3 heads are on the edge of tolerance for graphite gaskets, never-mind MLS.

Ben was suggesting that instead of spending $$ on new Cometic gaskets, you can drill the rivets, spray copper on both sides of every layer and re-assemble. You aren't REQUIRED to do this on first install, but is actually common practice for years. We have a Cometic on the race car and it was topping out 5th gear at 15psi, 56mm turbo at VIR, installed dry.

You are getting really upset for something that was overlooked on your end, not the manufacturer.

No, I'm getting really upset because the machine shop told me everything was good to go. I told them I planned to use MLS gaskets and needed a 50 RA or finer surface finish. They said they were good. And the manufacturer and seller of said gaskets didn't say I needed to do anything special to install them. What else, as the customer, am I supposed to do? I wouldn't say that is my fault.

I also tried PM'ing Ben on here and calling him three times before I decided to use them, to see if they would be ok to use with the bored block and if there would be any possible issues with them, and I never heard back from him. I was kinda disappointed in the level of help I got when I had questions about parts I had bought from him and/or was thinking of buying during my build. I would expect that kind of thing from Milzy, but not from him. I have every right to be upset. I've dumped a shit load of money into this engine and my heads are leaking. Wouldn't you be upset?

[AaronGTR]

And after doing more research...

I know that Cometic says NOT to use copper spray on MLS gaskets. People on some forums agree, some do not. The guys on J-body.org have done both, but it seems those that have, have not had issues with leaking after using the spray. http://www.j-body.org/forums/read.ph...53678&t=453678

Same thing here. http://www.performancetrucks.net/for...askets-422879/ A ford forum I checked out, most guys didn't use spray. A couple links I read though said that if using MLS gaskets the heads and block had to be perfectly flat and smooth almost to the finish point of crank journals, and that most machine shops can't achieve a finish like that. http://www.aa1car.com/library/ic697.htm

I wish we could get some of these to try. http://www.scegaskets.com/page/ICSvsMLS.html Couple of the J-body guys recommended them too, and they seem like they might be good. That company definitely doesn't like MLS gaskets, but it's hard to say who's is better.

I guess if the surface just isn't smooth enough, my best bet might be drilling the rivets and spraying everything, and see if they seal up. Is this the right spray to use? permatex copper gasket spray I'll try that and see if it works, but like I said, this is my only car now so I can't take the heads for more machining. If that doesn't make them seal, I'm done messing with them and going back to stock gaskets.

[unchained01]

Wow sorry to hear that again DAMN And yes the permatex copper gasket spray is the right one

[SappySE107]

You do not have to do anything special to install MLS gaskets other than mill the heads. Thats it. If you want to reuse the gaskets, it seems the popular and proven successful method is to tear them apart, clean them completely, and spray them with copper spray. You ignored what John said, and continued to claim you weren't told something important. It can't be your fault, you were told what you wanted to hear (don't spend the money on milling the heads).

[SappySE107]

I was kinda disappointed in the level of help I got when I had questions about parts I had bought from him and/or was thinking of buying during my build. I would expect that kind of thing from Milzy, but not from him. I have every right to be upset. I've dumped a shit load of money into this engine and my heads are leaking. Wouldn't you be upset?

Had to look cause I didn't remember this. April. The month after we moved, which was when everything got very unorganized and I also had a lot of people wanting parts due to tax returns. Sorry for letting you down. I found a bunch of replies I had sent you in my hunt for what you were talking about. Wish those had some sort of consideration but I don't expect you to remember. Just takes 1 bad experience.

[AaronGTR]

I didn't ignore what Jon said. IMO he ignored what I said... agree to disagree.

I am not a professional engine builder, nor am I an aftermarket parts retailer. The shop I used has an excellent local reputation and is the best one around I could find. You have a good reputation on here. Jon said spraying them is not required... but has been common practice for years. Well, that wasn't mentioned in the included instructions, and I couldn't get a hold of you for clarification or extra information. I tried searching on here for info about using and installing MLS gaskets and didn't find anything relevant or anything that talked about copper spray. If I am not an expert, and I consulted all the "expert" sources I had available, then it is understandable that I'm not happy when they failed. I did everything I could and expected them to work without issues. They didn't, and I have no choice now but to try and fix them, so I'll remove them and try the copper spray and see if it works. I'll let every one know the results. That's about all I can do ATM.


And btw, I totally understand about moving and I don't blame you for being a bit disorganized during that. I was moving myself at that time and my roommate expected me to be out of the house by the first week of may. And in the middle of that I was also trying to fix the engine AND dealing with a settlement process for a work injury, so I had a lot to deal with too. I'm amazed I got it finished on time, but you can see why I didn't have time to wait around for a reply. I had to go with the info I had on hand at the time. I'm really lucky he's still letting me come over and use the garage or I wouldn't be able to fix this and would really be screwed.