HG oil leak!

[ffgb]

On my 1.6NA, I have noticed that I have an oil stain coming out from the right side front middle oil hump in between the block and head.  I remember when I first rebuilt the motor around 4000 miles ago, I didn't have any leaks, but about 500 miles into the rebuilt motor, I noticed that I had coolant leaking out of the front in between the head and block.  I didn't re-torque the gasket after the first warm up because I was told that I didn't have to with ARP studs.  I ended up re-torquing the studs with the existing HG, that stopped the coolant leak.  Now I notice that I have some oil seepage coming from the front part of the HG right in between the oil port on the block and head.  I wiped off the stain from the head to the bottom of the block.  Drive my car for a while, check, no leaks.  Just checked after about 600-700 miles, now there is an oil stain from the head down to the bottom of the block.  It seems oil is still seeping out from that area.  Does this mean that my HG is crapped out and it needs replacing?  I know both the head and block were square when I rebuilt the motor because the block was checked and slightly decked to make straight, also the head was rebuilt and resurfaced to make straight.  Also, I am burning a little oil because the motor is still breaking in. 

Thanks

[maxfax]

Question bombing time...

IIRC you had an 11mm engine correct?? How intolerable is the leak, and are there any signs of oil in the coolant???  What brand of HG did you use??

Could just be a bum gasket..  I've been debating if gaskets are getting cheap or something like that..  I've had a couple in the past few years that would weep externally much like yours..  Not all, but a few.. Makes me wonder if that's why Parts Place suggests using Hylomar..  The last couple I've done I smeared with Hylomar and so far so good..

[ffgb]

12mm engine.  The leak is tolerable, it just sucks to have a nice painted block, only to have an oil stain from top to bottom.  There are no signs of oil in the coolant and no signs of overheating.  The brand of HG I used was a 3-notch Elring.  I am wondering if I should smear some Hylomar on the new HG, only on the existing gasket bead?

[maxfax]

I know what you mean about having a nice painted engine with leaks..  

I've been smearing Hylomar everywhere but on the compression sealing rings..  In reality it doesn't hurt anything to have it on those, but it doesn't really do anything either..

I typically use Elring HG's myself, and I'd say 1 our of 3 weeped...  I've been debating on trying something else on the next one..  I've used Fel-Pro (Repackaged Goetze) in the past with good results.. I think Victor Reinz still has them available as well, but I've never used one..

[ffgb]

Your 1 out of 3 HG's leaking, was that with Hylomar?  Is there really a difference with HG manufactures?  I know there are differences with Grant rings and Goetze rings, but HG's?  I see that you can purchase Hylomar in an aerosol, would this be better than smearing?

Thanks

[maxfax]

All three jobs were done without Hylomar...  The one that leaked wasn't a terrible intolerable leak, just some weeping at the joint.. Wasn't even really noticeable for a thousand miles or so...

I'm not sure how much difference there is between HG makers..  The Goetze and Elring seem identical..  I'm betting a $10 special form a certain vendor may be a different story, but then again who knows..   Honestly I wonder if it maybe could be an age issue..  I'm guessing they aren't selling thousands of these a day, and they may sit around in warehouses for some time..

I've used he spray stuff or the regular smear it on stuff..  I usually use the smear it on stuff because it's more readily available to me, and cheaper..  With the aerosol you could probably get it on there more evenly with less chances of dirty fingers getting stuff in it.. Just make sure you clear the nozzle really well on the spray stuff.. Once the stuff sets up, it's plugged for good.. 

[ffgb]

Thanks for the advice, I am definitely going to use a very thin layer of hylomar, I do not want to take any chances!  Are you smearing the hylomar on both sides of the HG or only on the head side?

[maxfax]

No prob!

The instructions state to put a thin coating on all sealing surfaces and let it set up for some time before installing..  So, I've been putting it on the block, both sides of the HG, and the head...  Thin coating is the main thing, globbing it on thick is mostly a waste since it's gonna squish outta there anyhow..

[rdezsofi]

My first thought on this: Sounds like one of the many issues I've heard of from using the ARP studs. The problem is not the studs. The issue seems to be an aluminum head on a cast iron block. With the factory stretch bolts, they act like springs. As the aluminum heats/cools, expands/contracts, the stretch bolts adjust the clamping force. (They are actually tighter as the head warms and expands.) With the studs, you have a steady amount of torque. I'm hearing the best success is at 120 lbs. As the head heats and cools, those studs are not going to stretch. Where is the movement taken up? At the head gasket. It gets compressed even more than with the stretch bolts. After who knows how many times being squished out, suddenly you do not have that 100 lbs of torque holding them. Then the leaks start. If you had the stretch bolts that act like spring tension.....they would take up the slop from a compressed head gasket up to a point. (Better than a solid stud can do.) There's many schools of thought on this. From all I've read on the subject, if I go with studs, I will go with what seems to hav ethe best success rate I've seen so far: Using the 1.9 AAZ metal head gasket and 120 lbs of torque. It seems the metal head gasket doesn't suffer the same as the standard ones. It also has a few extra coolant holes in it, that can be left as is or you can drill your engine to match it......and get slightly better temp control around the upper cylinders. On a side note, many are using the metal gasket with stretch bolts as well and reporting excellent results..

[ffgb]

I take it that the metal HG is installed dry?  Also, my engine has one front bulge, does this metal HG have two bulges? I am using the 3-notch fiber gasket right now, is the 3-notch metal gasket the equivalent to the 3-notch fiber in compression thickness?

[maxfax]

From what I understand the MLS is installed dry, someone else hopefully will chime in to verify this..  If you have the 2 bumps on the head and block (hydraulic lifter engine) it's a direct replacement, one bump (mech lifters) requires a little work to the gasket.. I think there's a writeup in the FAQ on that...

Rdezsofi, that explanation would be all well and good but, the same thing has happened with the stock bolts..

  The term "stretch bolt" is actually rather misleading since technically all bolts are elastic and stretch, how else would they stay tight?  The technical term for the stock bolts is  "torque to yield" bolt, as when they are torqued they are pulled to their yield point where some of their elasticity is lost and they remain elongated..  Since they are pulled to their yield point they are not so much acting like a spring..  If the head were expanding enough to stretch the bolts that are already in their yield point, they are not going to spring back..

Now as far as the MLS gaskets as used on the AAZ they are an excellent upgrade for high boost applications.. The most important thing about using a MLS gasket is that both the block and head surfaces have to be darn near perfect... The biggest advantage to the MLS is that they seem to hold the compression in quite well, and don;t seem to decay as fast as the fiber gaskets...

In this situation it doesn;t sound as though there is a compression issue, but rather fluid leaks at the head and block joint...  Come to think of it I haven't heard any reports here of the MLS gasket weeping at the joint..  Maybe someone here who has been running one will chime in..  If it is the case that the MLS gaskets are not weeping that leads me to believe that it's a gasket quality issue..

[rdezsofi]

Installed dry, but forgot to mention it's for the hydraulic head. (With the 2 bumps on the front, oil return passages that is.)

As for all bolts stretching.....yes and no. A torque to yield bolt, aka: 'stretch bolt' is a different alloy and designed to stretch and literally acts like a spring. The ARP's do not stretch like that. Much harder alloy. The expansion of teh head is going probably 95% to the fiber head gasket, crushing it over and over again. Supposedly the 'newer' style ARP studs were designed to alleviate this problem. (That's why the old style are being sold for about half the cost of the new style!) On a mechanical head, I would go with the torque to yield bolts and a Victor head gasket. The Hylomar stuff might be a good idea....not sure. I wouldn't want to try and alter the MLS gasket to make it work on a mechanical head.

Of course, the best fix for this is for someone to start making a cast iron cylinder head for our VW diesels! (Aluminum and iron expand/contract at different rates of course....not a good thing.) I could live with the extra 25 lb's of weight!

[maxfax]

I thought the MLS was dry..  I know some other companies suggest sealant..  TO use the MLS on a mech lifter engine one needs to basically plug up the hole in the gasket for the second oil return..  I think there's a writeup in the FAQ on it.. Most just make a small plug of some sort and use the sealer on that part of it..

The few of these I've had seep like ffgb's car had the fiber gasket with the stock bolts..  Never a bad leak to worry about, but annoying..  There's been mention off and on about similar happenings from others..  Hylomar doesn't set up hard like most sealers and will give with the expansion and contraction.. Haven't had one leak yet since I started using it.. Kinda seems like gasket more than fastener or surface issues...

Go figger, the engine with the cracked block that is welded up with head studs doesn't leak a darned thing externally..


Cast head would be fun... Imagine the boost!!   Might see some nice bottom end carnage with cast heads out there..

[theman53]

The hardness of ARP isn't a problem. The new ARP is the same stuff, just has about 40,000 more PSI tensile strength and because of that the higher cost. The stock stuff in my opinion is not good. Everytime you do the final 1/4 turn and hear that metal popping it just sounds bad. I have twisted the heads off 2 of them at the 1,000 mile torque and stripped one out in the drive. A stud allows you to torque past where the bolts yeild to give a greater clamping force that will give a better seal. Plus, after several million compression cycles that "spring" isn't going to like it anymore and that is why it seems the most I could get with stock bolts was around 150,000 to 200,000...if I am going to change a HG that much I want it to be because I am an idiot running too much boost and blowing the gasket out that way

I am running a MLS on a 1.6 mechanical block. I have 12,000 miles on it. ARP studs torqued to 100ft/lbs, aviation gasket sealer on both sides of HG and block and head, only running 25psi peak boost...I think it works fine with no leaks   I had a special torque procedure that I think helped me out. And to plug the hole I used teflon joint sealant tape that should last better than any rubber I could find.

To the OP. I think your problem is either the studs weren't destressed enough or a little hylomar would have helped a ton. I just checked on mine to see if they had loosened at all after the first warm up and they didn't. How many ft/lbs did you end up with when you torqued? The stock deal of 44, 66, then a few 1/4 turns etc won't do for ARP studs if you did that, that could be it.

[rdezsofi]

The hardness of ARP isn't a problem. The new ARP is the same stuff, just has about 40,000 more PSI tensile strength and because of that the higher cost.

Take a close look at the old vs new ARP studs. They changed the design. Shaped different to allow for movement during contraction/expansion is what I've been told by an ARP rep...to correct the problems reported with teh first design.