Open heart surgery

[Jshbrwr]

Hey so I decided to attempt to do a head gasket job on my ETA...it had been overheating and honestly had come from a very suspect past. I’d guessed that it had overheated before my ownership (broken thermostat) and went through as much as I could (water pump, coolant flush, thermostat, some other stuff) before realizing I had to “go deep” and pull the head.

So....after getting the head off, I’m greeted with this:



Now I know it looks bad, but I really don’t know exactly what it’s supposed to look like. Seems the head gasket doesn’t have any blown bits, but I’m seeing a bunch of that weird orange crusty stuff and wonder if that caked up crap is constricting the coolant flow? Just want another opinion on whether or not I’m looking at the origin of the overheating problem. Obvious that I’m replacing the gasket and likely getting the head cleaned up and checked for straightness before it goes back in.

Oh and also cylinders 1 and 6 look extra oily. Not sure what that means but if you’ve got ideas, let’s hear em

[e30davie]

did you compression test it before pulling it appart?

Was it blowing smoke? any lip on the bore? apart from over heating did it run alright? plenty of power? nice and strong?

If you have some confidence that the bottom end is in good shape all you can do is clean it all as good as you can, slap a new gasket on, get the head cleaned and checked. and bolt it all back together and hope for the best.

Your only other option is to keep going and do the rings/bearings at the same time. bit of a job though and the added cost etc.

[Jshbrwr]

Open heart surgery

Ran ok except for the overheating issue...no smoke, also did compression test and came up 135-150 range for all cyls with the one nearest the firewall the lowest...wondering if that has something to do with all the oil at the top [emoji848]

I’ll do what I can without pulling the bottom end. Don’t quite have the cash/love this car enough to justify that ha

[Jshbrwr]

So I was lookin at the head and noticed this...looks like my head TDC is exactly 180 of what it should be. I have not budged the cam sprocket since I took off the head...

Two questions/statements:

1. I replaced the timing belt about 100 miles ago but did not mess with the cam sprocket at all then. Does this mean the car has been running with screwed up timing since then (and maybe before I got it)?

2. Also, is this one of the reasons, or THE reason it was running hot? I’m honestly not sure if the cam timing arrow is a thing that can be reversed 180 degrees and still be pretty much ok. Obviously the engine wasn’t running perfect (hot), but I’m a little shocked it ran at all if that little arrow means anything...

I’m thinking if it didn’t matter that much then there would be two arrows on the sprocket, right?

[Julien]

So I was lookin at the head and noticed this...looks like my head TDC is exactly 180 of what it should be. I have not budged the cam sprocket since I took off the head...

Two questions/statements:

1. I replaced the timing belt about 100 miles ago but did not mess with the cam sprocket at all then. Does this mean the car has been running with screwed up timing since then (and maybe before I got it)?

2. Also, is this one of the reasons, or THE reason it was running hot? I’m honestly not sure if the cam timing arrow is a thing that can be reversed 180 degrees and still be pretty much ok. Obviously the engine wasn’t running perfect (hot), but I’m a little shocked it ran at all if that little arrow means anything...

I’m thinking if it didn’t matter that much then there would be two arrows on the sprocket, right?

Rotate the motor another 360 below and that mark would have lined up. 2 turns on the crank equal 1 turn on the cam.

Sounds like you pulled the head a bit prematurely, but it's not a bad thing as it thing disgusting. Get the head cleaned up and checked out by a machine shop, replace that cam gear with a newer gen one as these tend to shatter.. and don't forget new head bolts.

good luck

[Julien]

or find a 323i 731 casting head if you want more #hrsprs

[uturn]

Your "other" stamped pulley should also be replaced with a sintered one.

[Jshbrwr]

Rotate the motor another 360 below and that mark would have lined up. 2 turns on the crank equal 1 turn on the cam.



Sounds like you pulled the head a bit prematurely, but it's not a bad thing as it thing disgusting. Get the head cleaned up and checked out by a machine shop, replace that cam gear with a newer gen one as these tend to shatter.. and don't forget new head bolts.



good luck

Thanks for the info!

[Jshbrwr]

Your "other" stamped pulley should also be replaced with a sintered one.

Not sure what you mean. The crankshaft pulley?

[zaq123]

Not sure what you mean. The crankshaft pulley?

that cam sprocket is garbage, get an updated version that doesn't fail (see pic)
Also upgrade all your other stamped sprockets while you there

[D.Martijn]

To answer you first 2 questions,

The orange stuff is some rust build up on the gasket itself. The coolant ports in the head and engine are a lot bigger than in the gasket, which causes rust to stick to the gasket. This is perfectly normal.

The oil/black caked stuff on top or your pistons suggests it was burning some oil.
This is probably caused by worn/bad valve seals. While you have the head apart, stip it down and replace them.

And like other members already suggested, replace the sprockets to the later version.
The oilpump/intermediate shaft also has a casted sprocket.

[Jshbrwr]

Thanks everybody for the input

[E30hofmeister]

Don’t mean to hijack this thread but to replace the cam sprocket to the newer type, what exactly is needed?
When i did my cam belt i got the newer type sprocket off someone’s part engine, but couldn’t put rotor etc back, so ended up putting my old stamped sprocket back in. I think i must have gotten an m20b20 rather than m20b25 sprocket?

[jeffnhiscars]

Don’t mean to hijack this thread but to replace the cam sprocket to the newer type, what exactly is needed?
When i did my cam belt i got the newer type sprocket off someone’s part engine, but couldn’t put rotor etc back, so ended up putting my old stamped sprocket back in. I think i must have gotten an m20b20 rather than m20b25 sprocket?

with the timing belt on so you dont lose your valve timing, loosen the cam bolt, then slip the belt off and the gear should then be easy to remove. If the replacement gear is properly seated and the rotor wont fit then you ma have the wrong gear. Compare it to your old one to confirm the orientation of everything

[Jshbrwr]

Hey is there anything else you all recommend I do while it’s pretty torn down? The head is getting reworked, I’ll adjust the valves before it goes back in. New seals, gaskets etc are replacing the old stuff. Of course I have to replace the timing belt. Anything else I am missing?