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Old 10-23-2017, 02:48 PM
neilsontom3000 neilsontom3000 is offline
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Join Date: Feb 2017
Posts: 13
Default Unplanned Head Job (I made the mistake so you don't have too!) Part 1.

Ok, so I had planned on doing the belts only on my 95 940 D24TIC, I've only owned the car for a short time, so had to get up to speed with the oily beast after coming from a petrol only previous background.

I was never happy with the clattering noise of the engine, I'm aware they're pretty noisy machines across the board, but I was sure I had a further issue, after trying to locate where the worst of the clatter was coming from and checking the Vac pump etc, I eventually bought a cheap mechanics stethoscope and pinned the worst of the noise to injector number 6, albeit a couple of others were also up there clattering/knocking away, so I bit the bullet and bought a new complete set of "GTD" injectors with 297 nozzles from Anders here on the site. This is where the fun began, whilst changing the injector seal washers after injector removal I was using a thin hole punch to pluck out the heat seal washers, all from no.1 to 5 popped out no issues, but the last number 6 (my very noisy one, i saw that the heat seal washer was significantly more carbon'd up over the others, i gave the washer the smallest bit of pressure in the hole and ping, snap!!!!...the bloody hole punch just lets go with the majority of it falling into the pre-chamber or beyond!! I blame it on the cheap chineseum hole punches i'd bought, but in reality it was probably a school boy error sticking it in there in first place, I eventually got it out with a heavy gauge eye hook hanging screw and a heavy zip tie attached to the eye (one with a big enough eye to get blocked in the washers should it fall), I was a double fool here as had almost bought a ten quid tapered bar from fleebay for the exact purpose, I wish i had as it quickly dawned on me that this would probably mean the head needing to come off,

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Yup as you can see by the pic above a variety of magnet tools had failed to make it through the pre-chamber, or glow plug hole to scoop out the rogue piece of metal, so the head had to come off to get at it!

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(Above, the offending article sat on top of the piston in cylinder 6!!!!)...so now at least a head gasket job was on the cards, so thought i might as well take the opportunity to do the valve steam seals and check/re-build the hydraulic tappets etc, this is the first time i've done this so it was a bit of a learning curve...

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Once all the various parts are stripped clear of the head under the bonnet (which is quite a bit, and a little out of scope of this thread, though later I'll post up some good service articles i found which helped for anyone who hasn't got a full green book etc, the rocker/valve cover is removed, and the head bolts removed in sequence, the head was then removed and put on a set of head stands to be worked on, the camshaft can be removed by means of removal of the cam caps (there is a sequence (the 2 center, then the outers as i recall) the cam can be lifted clear to gain access to the lifters/tappets, these can then be lifted out with your fingers, or if needed a magnetic tool of some type, if there kinda vacuumed in with oil. The valve springs can then be compressed to remove the valve collets, springs caps, spring, then finally the valve steam seals, and valve removal via the bottom of the head...

After spending twenty odd quid on a set of Sykes Pickavant valve spring compressors, i found they were a bad fit for the job, so thought id try a cheepo ebay set of universal jobs which worked great and were super cheap, so the Pickavant ones' will probably go back on ebay shortly, sorry for crap photo, but below is a photo of the universal compressor (red box chinese jobs off ebay, i'm sure many know the type i mean, in fairness i've got a few of these red box Chinese tools for an old Merc 190 i have; bush tools, spring compressors etc and they work pretty well on the whole if your just a home-gamer ha!)...

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The Pickavant jobs pulled the spring cap and spring at a bad angle for compression, whereas the cheepo one's allow for the compression to be applied straight down in perfect line with the spring to easily get at the collets with a mag tool, again I'll get a few better pics of the tools and get a bit more into detail, but for the meantime it's getting late here and as I've reached the max photos per post, I'll continue part 2 tomorrow, Additionally I hear the forum users are in decline and there's been photo hosting probs and images being zapped, but in my short time owning the car it's proved very useful info for me, so thought i'd stick this up, as it might prove useful to someone still out there now or in the future, Cheers.
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