Sport head problems - the plot thickens :-/

[Davenotouring]

Hi y'all.

Spent today taking the head off the sport with help from Demlot (Andrew) Cheers again mate.

It turns out the head had snapped off one of the head bolts and the head and washer of the bolt were sitting down by the spring in the head. Also, one of the small water channels (one of the small holes - two indentical, next to the piston) was blocked with crap.

Does anyone think this could have caused the overheating. The combination of the blocked waterway (this on in particular) and the head being snapped of the bolt? Possibly causing air to be put into the cooling system?

Any ideas?

I'm going to get the head pressure tested, and refaced, if it is ok. Hopefully will drop it in next week if I'm back. So will find out then.

Also took one side of the kit of to find the the rear arch/back of the sill is the worst of it, the rest is ok. So I'll get that done (Toby? ) and it'll be sweet!

[Jhonno]

does sounds like it would tbh - cheap fix

Keep the Sport

[320Touring]

sounds like goodish news!if the gasket wasnt sealed properly (ie the broken stud) then that could account for the air in the system/overheating...

blocked waterway would also contibute-only way to relly find out is get it refaced and cleaned then refitted

fingers crossed for you dude

[Davenotouring]

Just thinking.......

The head bolts were 17mm normal bolts.....

Are they supposed to be torx bolts? Does this mean they aren't genuine, maybe that's why one of them snapped?

[Demlotcrew]

no those are the correct bolts dude!

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=08

Andrew

[Demlotcrew]

http://www.bmwe30.net/cgi-bin/datacgi/d ... Section=08

Andrew

[Toby_Unna]

i've heard of that happening on a few m20s, as per the link andrew posted.

worth inspecting the head as much as possible while it's all apart though as you say.

good result!

[amit325i]

That old torx v hex bolt myth again, the only reason bmw changed them was down to the machine tool changes in the factory, i mean if this was a problem they would have recalled the cars. These bolts as you know are only meant to be used once, some back street mechanics reuse the bolts, which equals eventual disaster. Three of my head bolts snapped on christmas eve on the M4 about 5 years ago, i tried to find the bottom of it,
there is no difference in material. I remember i talk to some expert engineers who advised me that to prove anything against BMW will cost crap loads of money, and it is unlikely after spending it you will find anything interesting.

[Davenotouring]

Right! Update....

The head went off for testing, and I thought I may as well have it fully stripped so it can be 100% tested and so on. New stem seals and all that.

Called them today, one valve was bent, and the guide was broken. Not suprising it was a bit noisy, suspect this could have been due to the snapped head bolt.

Bought a complete head set + bolts from BMW, picking up the head hopefully this weekend, if not then Monday.

Hopefully will be able to build it back up before the middle of June!

[Karan]

good stuff Dave!...... i feel a sport drift session coming on!!!! i guess u'll be ringing the sport then if all is good.......

[Davenotouring]

Meh....

I'm not sure mate.

Civic is great fun......... and more economical!

We'll see if it's done AND running ok by the 18th of June.

[Demlotcrew]

Yes dave i think its really good news. Now to sort the rest of the issues with getting it all back together, like i said if there is the smallest doubt in your mind over 'our' abilities to get the timing spot on, you should take it to a pro!

Andrew

[Davenotouring]

Yes dave i think its really good news. Now to sort the rest of the issues with getting it all back together, like i said if there is the smallest doubt in your mind over 'our' abilities to get the timing spot on, you should take it to a pro!

Andrew

Agreed mate!

[rich_e30]

Sorry to be cheeky but can you give me some idea of how much your head work is costing. I have mine out at the moment and want to get it tested etc.
I rang a bloke the other day and he said Ԛ£150, this 'bout right?

[Davenotouring]

No problem!

I bought a complete head set (all gaskets etc) and head bolts, which totalled Ԛ£210.

The company who are stripping the head (taking out and regrinding valve, new stem seals etc) is costing about Ԛ£150.

So all in all, should be about Ԛ£400 including new coolant, oil, service kit etc!

[rich_e30]

You having it skimmed?

[Davenotouring]

Refaced, which is a kind of skimming.

I mean refaced as in the skim it at the lowest point, I'm not having it 'skimmed' to get a higher compression.

Just so that the faces mate up properly.

[Adammcf]

Sounds good. Where did you get the head from? I might need one myself as I took mine off last night to get it tested.

[Davenotouring]

The one on the car!

I know of a spare head though, complete with both manifolds. PM me if yours 'fails' the pressure test.

[rich_e30]

Sorry for all the questions mate. First time i have ever done anything like this. Steep learning curve ya know! Do you strip the head and let them have the valves? Or just take the complete head to 'em?

[Davenotouring]

I took the head off complete and gave the whole thing to them mate.