HG installation question

[Dash01]

My 535i with rebuilt head and new HG and bolts has coolant/oil mixture, so there's a leak somewhere. Damnit.

Should I have used sealant on the new HG, or not?

[whiskychaser]

My 535i with rebuilt head and new HG and bolts has coolant/oil mixture, so there's a leak somewhere. Damnit.

Should I have used sealant on the new HG, or not?

Assume you got the head skimmed and pressure tested before you put it back on? Havent had the problem myself but have heard of cheap gaskets not sealing properly. And I would never used sealant on a head gasket. Hope you can find a way to check it out without dismantling

[Dash01]

Which HG brands are best?

Which to avoid?

[whiskychaser]

Which HG brands are best?

Which to avoid?

I'm in UK so who I recommend may be useless to you. If I want one I go to the machine shop who does the heads. They sell them. If not I would bite the bullet and pay BMW prices. What I dont do is go down the local motorist discount shop. But dont go taking the damn thing apart just yet! :-)

[Dash01]

The new HG I put in the car after head rebuild and resurfacing was a Reinz, from a complete gasket kit sold by BMA for ~$103.

After a few hundred miles the car started losing coolant, and one morning I got a low oil pressure light on startup. I shut off the engine immediately. Lots of mocha foamy stuff in oil filter, dipstick, etc. from oil/cooant mixing. No weird noises or overheat, as the engine only ran a few seconds before shutdown.

Back to the headgasket questions: I'm told that HGs come in stock thickness and also slightly thicker to compensate for shaving the head during rebuild. Since the head was shaved by ~0.004" is it possible that would allow leakage if the new Reinz HG was of stock thickness?

How do Reinz and Elring HGs compare? Is either considered a better fit and/or more (or less) reliable?

[632 Regal]

the gasket thickness wouldnt have anything to do with a leak. Did you clean out the bolt holes good before reassembly? If there was oil in the holes you could have possibly hydrolocked the block causing leaks.

Did you angle torque the bolts down properly/after warmup shutdown?

[Dash01]

the gasket thickness wouldnt have anything to do with a leak. Did you clean out the bolt holes good before reassembly? If there was oil in the holes you could have possibly hydrolocked the block causing leaks.

Did you angle torque the bolts down properly/after warmup shutdown?


Yes, I leaned the bolt holes with solvent and Q-tips, then lightly oiled the threads on the
new bolts.

Yes, angle torqued per per Bentley instructions.

I used new head bolts on the assumption that the originals may have become stretched a bit over the years.

If I were to re-torque the head bolts now, what would be the best way to proceed? In other words, the new HG has now been squished, so if I slacken the bolts to re-torque, would I follow the same Bentley procedure as with a virgin HG?

[632 Regal]

Okay if you retorqued them after the primary heat up you should be good to go, new headbolts are required because they are torque to yeild and will break the second time around if you loosen them and retorque. (I might be wrong again, one engine has to have new bolts and the other 6 can re-use). If you did retorque after the heatup then you could possibly have a cracked head. I cant see any other way of water to enter besides a cracked head or block. The gasket should have sealed...a no brainer. Now to figure out where and why.

[Dash01]

Okay if you retorqued them after the primary heat up you should be good to go, new headbolts are required because they are torque to yeild and will break the second time around if you loosen them and retorque. (I might be wrong again, one engine has to have new bolts and the other 6 can re-use). If you did retorque after the heatup then you could possibly have a cracked head. I cant see any other way of water to enter besides a cracked head or block. The gasket should have sealed...a no brainer. Now to figure out where and why.

Well, it ran fine for weeks, so I'm mystified why if the head or block cracked, it was not out the outset. No signs of external leakage, such as seeps or drips. If the head or block cracked, wouldn't there be some sign externally?

This is why I'm wondering about the thickness of the HG after the head had been shaved a bit during rebuild, and whether after various heat cycles + squishing the HG, the HG is a bit too thin, so leaks.

When I pull the head off, what should I be looking for? What about a compression test before removing the head, to see if there's any leakage in any cylinder?

[bill g]

Head or block can be cracked and show no sign externally.
Like Jeff said, the stock gasket thickness is not your problem.
Maybe you got some dirt or grit caught in the gasket/join. Did you make sure the coolant passages in the block were clear, and block surface smooth and clean, especially around cyl no 6?
Compression test would be a good idea.

Bill G