Yet Another 3.0 Head Gasket Thread

[andrewwynn]

To get the fan nut started wrap electrical tape around it enough times you can get 3-5 turns. Works like a charm.

[oldskewel]

Originally Posted by andrewwynn

...
If the chain sound goes away after oil pressure builds it's almost certainly weak tensioner.
...

But I don't think that's what is observed in the video. Not like it takes 3x as long to pressurize and then it's good. It's constantly loose. It's not like I really think it's not the tensioner, just that I'd be more careful before buying parts and swapping them in.

Is it certain that this is a new noise that did not exist before everything was taken apart and put back together? If yes, that's an important clue. Does not seem likely that something as simple as a tensioner could be damaged during the process. Clogged with debris that was disturbed in the process maybe ...

Inlet hole smaller than the outlet? I can believe that, and in general would not think to second guess things like that considering the overall awesomeness of these engines. You need pressure in there, but you also need it to be compliant when needed, so the oil needs to escape, possibly faster than it needs to build pressure.

My tensioner and many other things are original and fine in my 2001 at 199k miles. Well, other than anything related to doors or windows.

On the fan nut, the first couple of times I did a trick I read on here about using a piece of string tied around and taped to the nut to restart it. But I've had it off and on so many times since then, that now I do it just by hand and feel, and can get it within a minute every time. Just takes a steady hand, good alignment, and a feel for when it is in and you can just spin the fan.

[andrewwynn]

You can install the fan without the shroud until all the work is done. The shroud is not needed. (and in winter neither is the fan. My fan and shroud were both off from Jan until about may ).

In the video the sound comes back at throttle off. Drop in power and drop in rpm would lead to the loose side of chain getting more loose so it exactly lines up with weak tensioner. (it could be something else of course).

Until I would get more input I definitely see the tensioner as the most likely culprit.

[Russianblue]

put the new tensioner on. didn't seem to make much difference. pretty stumped now. I might take it in and see if they can tell me where it is coming from.

but I think i've got a bigger problem which i'd mentioned a few posts back.

I have slight oil leak at the back of the cylinder head and I think it's coming from the head gasket. the little bracket that hangs down where the oxygen sensors clip on has a drop of oil on it. I thought it was the valve cover leaking from the half moon but I am seriously doubtful of that at this point.

it falls directly onto the exhaust...and there has been maybe one drop every other day. so I figured I'd live with it. there's been zero smoke, nothing. but then today I could see 'more oil than I am comfortable with' and a bit of burnoff from the cats where the drip drops.

I can also see a small 'bend' in the head gasket where it should obviously be flat. I installed the head with that bracket attached. I am hoping it did't catch something and get bent toward the front of the car, pushing on the gasket and mucking up the install while we were fitting the head on the dowels.

I bought one of those Amazon $20 compression test kits and all cylinders show dry compression between 174 and 178 on a cold engine, which I thought was pretty darn decent. of course who knows how accurate that kit is. there's no oil in the coolant or vice versa. thus my theory about a problem with the gasket possibly having been crunched on install or something.

anyway, I am getting a little fatigued at this point to be honest.

on a positive note, the car runs great and I got new FCP Free ball joints on it today. I wiggled the old ones out with one hand, lol!

note that these pics were taken a week or so apart...the last ones before the first and following an oil change.

[andrewwynn]

My suggestion for high temp jb Weld still applies. Clean the crap out of it and JB Weld about 1/2" past all sides. Your compression #s indicate the important seal is good and with no crossover of oil/coolant (can use test kit to confirm), it looks like a minor leak from outer edge oil channel. The wrinkle looks more like an imperfect torque pattern caused a bunching up.

[Russianblue]

unfortunately I am not sure there is any way humanly possible to reach that area with JB Weld or prep it properly.

even getting those photos with the zoom was a borderline illegal feat of human contortion.

But the bigger issue is that I am not even 100% sure the leak is coming from there, exactly where I am seeing. If you can see in the pic, the area above AND below the gasket both look dry. which is why this is confusing.

I am tempted to see if I can remove that bracket and get some better visibility. I suppose I could always do the UV dye thing too.

re: the imperfect torque pattern, I am 100% sure (and have an Xoutpost witness ; ) that we followed the inside-out pattern. given I didn't use a torque angle gauge I suppose it might not be perfect but honestly don't understand how that gasket could be getting bunched like that. Even if it were say 15 degrees off, that last torque-angling doesn't add a ton of additional clamping pressure. it's just the bolt-stretch.

I think I need another set of eyes on it. Some older, experienced BMW guy eyes who might be able to help me come up with some creative suggestions for this and the timing cover noise (if that's where it's coming from). I cranked it once today and there was hardly any clackety noise at all. I had stethoscope on the timing cover but couldn't hear anything of note.

Kind of a standstill right now until I can get some clarity on those two issues.

[Russianblue]

FYI guys...I know it's been a while but I figure some of you will get notices about this post.

I ended up selling this car on CL in 2022 for $2500 with the complete story about the cylinder head and all the trials and tribulations. The guy I sold it to is a BMW aficionado and had the oil leak fixed in a day. He figured out one of hex plugs on the back of the head had been loosened when the head got skimmed at the shop. that's where the leak was from. I never touched it. SMH. so if you throw out the 2 or 3 small mistakes I made on my repair it would have been perfect. This will end up being the most in depth repair I ill ever do on a car in my lifetime.

he fixed that leak and drove her for 2.5 years from 180k mi to 225k mi. I texted him a month ago and he said she was down due to a 'burned valve'. not sure how that happened, but I had been keeping up with him to see how long that thing would last. he was really disappointed bc he loved that car. he's got several old Bimmers and this was one of his faves. I guess they don't go forever but they will go for quite a while!

118k on my 2005 now so I figure I've got at least another 100k in her !

[Effduration]

Thanks for the update...

I have seen a few burnt valves on M54 engines..The theory is that excess oil due to a failed or weak CCV gets into the intake path and cylinders and you get pre-detonation which will usually chip off a piece of the exhaust valve.

It's really not the end of the world. Either pull the head and replace the valve...and fix any other valve that is not sealing, or go get another cylinder head and run it though a machinist who will test it and fix any valves.

A true BMW DIY'er might actually keep a prepped M54 cylinder head on the shelf..I have 3.. It's the Narcan that brings a dead E53, E39, E46, E83, Z3, Z4 back to life!

As you know, the E53 X5 3.0 takes a head gasket pretty well... It stays on its wheels the whole time, and with a cylinder head ready to go, somebody could do it in a weekend...Heck all the fasteners will come off easily...No reason that X5 is done.