M20b25 I thought was head gasket but....

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Avinit4
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Thu Aug 31, 2017 7:35 pm

But after taking head off Head Gasket looks fine so leaves me thinking what was the cause? All ideas welcome people. Thanks
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Gavt
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Thu Aug 31, 2017 9:24 pm

Cracked head. Get it pressure tested whilst its off
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Brianmoooore
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Thu Aug 31, 2017 9:36 pm

M20B25 head gaskets rarely fail, unless corrosion around the crescent shaped water passages in the head undercuts the fire rings of the gasket around the bores.
It's not unusual for a M20B25 heads to crack, though. What were the symptoms that made you remove the head?
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Avinit4
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Fri Sep 01, 2017 11:27 am

Overheated then when put water in cooling system it disappeared bu couldn't see leak. Concluded must be going straight into engine which it was so thought HeadGasket
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Avinit4
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Fri Sep 01, 2017 11:28 am

Am getting head pressure tested
Captain_Birdseye
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Fri Sep 01, 2017 1:07 pm

You've checked obvious, like cooling system, coolant and thermostat all fine? Flushed it all out etc..
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Avinit4
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Fri Sep 01, 2017 2:13 pm

Yes, have just found out Heads Cracked... Kin gutted anyone have a good spare laying around they can let go of for the right money?
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aimlessrock
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Fri Sep 01, 2017 2:17 pm

good used 885 heads are not cheap
E30 320i Convertible (1989)
190 Mercedes (1988)

"there is nothing more expensive than a cheap E30"
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Brianmoooore
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Fri Sep 01, 2017 2:23 pm

Avinit4 wrote:Overheated then when put water in cooling system it disappeared bu couldn't see leak.
Checked your oil level lately?
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Avinit4
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Fri Sep 01, 2017 2:34 pm

Nothings cheap when you need it? Shame as on 197 these specific models entered UK, 325 baur? Ahhh ffs
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Avinit4
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Fri Sep 01, 2017 5:11 pm

Does anyone know if 2.7 eta e30 Head number ending 200 will fit M20b25 block to replace 885 head?
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Avinit4
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Sun Sep 10, 2017 3:57 pm

Well I'm shocked no one could assist with above head question so have found out Heads matches up to block and then needs stuff done to actually work and.even then will lose something from all round performance so defo not the thing to do. on my head he nut & bolt came loose and fell out of rocker on number 5 piston inlet valve. The bolt found its way under the main Camshaft that pushed bolt threw bottom of the Head, will attach pic.. Have now got another 885 Head.. Bla bla bla
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Avinit4
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Sun Sep 10, 2017 4:07 pm

Don't seem able to post picture of it?
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Brianmoooore
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Sun Sep 10, 2017 8:58 pm

Avinit4 wrote:Well I'm shocked no one could assist with above head question
You posted this specific question in another thread, where it was answered in full! I pointed you to the relevant page in the wiki, and reggid, a knowledgeable and respected engine builder, replied as well.
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Avinit4
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Sun Sep 10, 2017 9:08 pm

My quiery in the thread was asking if 2.7 head ending 200 could replace my 885 head. Please give me a link to show me where It's been answer because I missed it?
Have new question tho... The end of my cam shaft has a round protruding bit to line up but my replacement 885 Head has a whole where protruding bit on pully slots into. As far as I can work out I need to either get a new pully with protruding bit or I need to change complete Camshaft? Does anyone know why there's a difference. Both from 325i? Or is my answer contained somewhere else on the internet. Thankyou fellow e30 people x
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Brianmoooore
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Sun Sep 10, 2017 9:18 pm

http://www.e30zone.net/e30zonewiki/index.php/M20 Half way down, under "Head". Same link as I posted in your other thread.

M20 camshaft locates to the cam pulley by a dowel. Do you mean you have a camshaft with the dowel stuck in the end of it, and a cam pulley, also with a dowel stuck in it? If so, remove one of the dowels.
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Avinit4
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Sun Sep 10, 2017 11:07 pm

My appologies Brianmoooore I stand corrected, I have just read about it via your link, Altho I dont know what other thread your referring to tho. I had an issue with e30 Head a few times in my life and cant recall specific content but I ve never had issue I have this time so cant see how i asked same specific question, It may of involved the Head but difference circumstances to now, Anyway thanks for your assistance.

My original Camshaft that on the Fxxxxked head has the Dowel attached to it , and whole in pulley ect that the dowel fits into.

If picture come out this is my one
http://i494.photobucket.com/albums/rr30 ... iwmwcz.jpg

and the is the cam on replacement 885 head
http://i494.photobucket.com/albums/rr30 ... oidgiq.jpg

Hope im making sence now?
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Brianmoooore
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Sun Sep 10, 2017 11:44 pm

This other thread: http://www.e30zone.net/modules.php?name ... c&t=274168 You're the OP!

As I suggested in my last post, you have one cam with a dowel in it and one without. Two identical cams, but only one dowel between them. If you can't get the dowel out of the first cam, either swap the cams or buy a new dowel.
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Avinit4
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Mon Sep 11, 2017 12:03 am

With respect Brianmoooor you said... Do you mean you have a camshaft with the dowel stuck in the end of it, which isnt the same as ...you have one cam with a dowel in it.
The word stuck infers it shouldnt be there, and I do not believe the dowel is stuck I believe its where it should be.. Anyway you have repeated what I said at very start namely I need to change the cam or get new pulley etc with dowel attached.. Thankyou for your help
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Brianmoooore
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Mon Sep 11, 2017 9:48 am

The dowel isn't 'attached' to either part. It's a separate part which is just pushed in, and can remain in either part when the assembly is dismantled.
The pin is a tight fit, and, in my experience, usually stays in the camshaft, but that's down to individual manufacturing tolerances.
Theoretically, you don't need any new parts, but the most you need, for an easy solution, is a new dowel from BMW.
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Avinit4
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Mon Sep 11, 2017 1:20 pm

Thankyou, if I understand correctly you have said I can obtain a new dowel from BMW and put it into new Camshaft then everything will be same as old Camshaft yes?
Regards andy
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Avinit4
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Mon Sep 11, 2017 4:48 pm

The above is exactly what engineering place are doing, yes I could attempt to do it my self but feel I'd only destroy current dowel in process so better a professional touch I think anyway..
lastly, if I'm missing the obvious I apologise but when the dowel is fitted in new Camshaft the, timing belt wheel and pulley etc will all fit back as normal again,yes? Cheers
Andy
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Brianmoooore
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Mon Sep 11, 2017 6:45 pm

It will all have the potential to fit back as normal again, but whether it does or not depends on the skill of the person doing the work.
A second hand head should be professionally crack tested before fitting, should ideally have the deck surface lightly skimmed, and the exhaust valve guides could probably do with replacing, along with the valves and their seats resurfaced.
Check that the face of the cast iron exhaust manifold is flat as well, and have that ground if not.
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Avinit4
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Mon Sep 11, 2017 8:39 pm

Kool much appreciated Il do just that. Thankyou
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Avinit4
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Tue Sep 12, 2017 1:53 pm

Have just seen your link to other thread and can only say I don't remember posting that and I only received notifications for this thread..Maybe should say I only saw notifications of reply for this thread. After clicking on first notification that brought me here I didn't need to look at any other ones because could see on here. Anyway yes the balls up is completely me and I apologise..in Mitigation it Has been nightmare year that began with unexpected death of partner to which I've been making mistakes and forgetting things ever since... So my appoligies for any inconvenience I've caused you or anyone on here. Cheers
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