What to do while the head is off?

carabuser

Sergeant
Oct 2, 2019
291
191
0
UK
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Z4 35i & 335i
I'm replacing the head on my 335i as a precaution because the previous owner had some issues with ovalling of the injector ports probably caused by a bad injector install. It runs fine but I some of the injectors move more than they should in the head and cyl 6 seems to be pretty bad. I'm having a trusted N54 specialist do the work as I don't have the tools or confidence to change the head.

I picked up a refurbished head with new valve seals pretty cheap. The seller was intending to use it for a build and spent a load of money getting it cleaned up fully, valves re-seated and had a very slight skim done to clean up the mating surface with the head gasket. He then had issues elsewhere on the build and parted everything out.

I'm going to bring everything over from the old head aside from the valves and springs. Cam trays will come from the old head as they are the teflon sealed version which supposedly work better.

I fully intend to keep this car until it either gets written off or rusts to death so I'm quite keen to make the most of this opportunity to take care of any "while im in there" maintenance. This is the list of parts I have so far that I believe will benefit from replacement:

-Head gasket
-Engine mounts (will get 335is part)
-Injector seals and decouplers
-Cam tray bolts (are these needed?)
-Exhaust manifold studs (current ones look OK but I've seen people struggle with these in DIY turbo change videos

I have already got 6 new index 12 injectors and recently replaced the valve cover gasket and OFHG. I've also done the aux belt, pulleys and tensioner recently.

I have considered using this as an opportunity to fit some bigger turbos but unless the stock ones are in bad shape I'll probably just put them back in. There is someone nearby selling some lightly used GC Lite V2.0 but I'm honestly not sure if I want any more power from the car. If they the stockers have leaks or shaft play I'll certainly have them changed though.

Given that the car is a 2009 with only 80k miles, is there any others parts that should be replacing during the process? Anything in the timing system like guides? Or any bolts that I have forgotten that are 1 time use?
 

carabuser

Sergeant
Oct 2, 2019
291
191
0
UK
Ride
Z4 35i & 335i
@fmorelli

I saw your head porting thread. Any advice on what hardware I should be replacing while I have the head off?

I can see 2 part numbers for the head gasket, one I assume is for skimmed heads. The head I have was skimmed but only very slightly to clean up the mating surface, not to correct warp.
 

NoGuru

Captain
Jan 9, 2018
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Just North of Detroit
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BMW 335is
If you have the time and funds, you will need to do something with the turbos in the future. Not saying now is the best time but it would be better then waiting until they go.
 

carabuser

Sergeant
Oct 2, 2019
291
191
0
UK
Ride
Z4 35i & 335i
Here's my rough parts list so far:
Head gasket 11127557265 £140
Assorted gasket set: 11127572758 (Maybe) £182
Set of cylinder head bolts: 11127574303 £48
Engine mounts 22116760330 £95 / 22116793240 ("is" part) £196 (£291 total)
Injector seals 13537584315
Decouplers 13537564751
Exhaust studs 11127593376 (x16) £10 all
Intake studs 11127521167 (x6) £6.24 all

"is" engine mount is expensive. I'll look for the branded alternative if one is available.
 

carabuser

Sergeant
Oct 2, 2019
291
191
0
UK
Ride
Z4 35i & 335i
If you have the time and funds, you will need to do something with the turbos in the future. Not saying now is the best time but it would be better then waiting until they go.
Time and funds aren't a problem. My intention with the car is just to keep it looking stock and use it as a daily, so anything that helps reliability is the priority but will upgrade things as I go when they break.

My plan was to wait until they take the turbos off to make a call. I'm pretty certain the turbos are in great condition but if they tell me otherwise I wouldn't hesitate to change them. The issue is that in the UK we have no ethanol so I'm limited by octane.
 
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