I have just completed this job and bundled in a few other jobs (changed main thermostat and cleaned EGR valve and inlet manifold) at the same time.
Using kwempe's write up and doing LOTS of research about removing injectors and all the other tasks associated with this DIY.
There were a few issues I encountered along the way and some useful resources so I thought I would share these.
Removing the inlet manifold
I found this post really useful for detailed description of how to get to the point where the inlet manifold is off..
clicky
The first problem I encountered was that two of the strut brace bolts were already rounded off. Last people to have this off were a very well know BMW indy and I cant believe for the sake of a couple of quid each they dont just put new ones back in after they have mashed them up. Very sad. I had already ordered a new set after inspecting the condition of the ones in place before starting this job. The one on the suspension mount was the first one I attempted and was pretty easy to drill out and use an extractor on. First time I had used extractors and they are really effective. The second one was at the back, not so easy here because the trim on the wiper housing doesn't allow easy access with a drill. I found some quick release drill bits at B&Q that are longer than normal drill bits and allowed me to drill into the bolt. The other two came out with torx driver on a breaker bar.
Once the inlet manifold was off check you have all the nuts bolts and washers. I was missing one sealing washer and so had to hunt for it to reassure myself that it had not fallen down the port which although least likely of cases, is a possibility. Couldn't see it anywhere, took the aero covers off the underside of the car still couldnt find it, took everything out of garage and swept floor, still couldnt find it. Eventually I had to buy an inspection camera from Maplins for £100 to look into the ports. The one I got had a 10mm head and only just got down there, dont get one bigger or it wont fit if you need to look into the ports. With the inspection camera it took 10 mins to look inside all the ports. It wasn't in there in the end, so could carry on with the job and ordered a replacement seating washer. That little £3 piece cost me the whole day and 100 quid for the camera. Useful little tool though for when you drop stuff in all those nooks and crannies on these cars. After poking around in the inlet ports I used a piece of garden hose gaffer taped to a vacuum cleaner to suck out any goo I may have dislodged while poking around.
Removing the injectors
I took Kwempe's advice and WD40'd my injectors a few times in the week leading up to the work. I used mole grips to gain a purchase on the injectors and they all came out ok, not easy and the first one is quite scary and one seemed more stuck than the rest and for a moment thought it wasn't going to come out. They all twisted easily enough, but they need a quite a pull to get them to come up like there is a vacuum holding them in. I also found it easier to remove the oil breather to give me more room for the back two injectors.
I put each injector into clean freezer bags labelled the bags and put them somewhere safe.
Originally I used masking tape to cover the open connections on the rail. This was a pretty bad mistake as the diesel mixes with the adhesive on the tape to form a goo that had me worried for a bit. In the end found that little squares of bin liner held on with small wire ties was a good clean solution for capping the rail nozzles.
I also studied the TIS pages for removing and reinstalling injectors and the accompanying torque settings. I got myself the special tool described for injector nuts, it was £25, but it did allow me to torque the nuts back on at 9nm for my car (Please check the settings for yours they may not be the same). 9nm is not much at all and as many inexperienced mechanics, I had a tendency to overtighten things and would have overtightened these for sure. £25 to know that they are tightened perfectly and evenly is fair enough I think, for such a key part of the system.
The only mishap I had when removing the injectors was when the pliers slipped on one and it clipped the edge off the plastic top. Luckily this has no real function and a bit of superglue put it back where it was. I used 10 x 10 sheets of household bin liners to plug the injector ports as there are no fibres to float around from polythene and this worked really well.
Phew that was the injectors out!
BTW on the subject of torque wrenches, I initially wasted a bit of money buying cheap. Initially I bought a Silverline for £20, that ended up being £20 wasted because I dont feel I can trust it. I then bought a nifty AC Delco digital torque adapter for £50, that promised 5 - 200 NM, quite a claim. This mashed the bolts on my tailgate glass at 20NM when I was repairing the wiring harness because in fact it is really only accurate between 20% and 100% of its range. Thanks AC Delco!! Once you understand it is really a 40 - 200 NM tool it's OK. It doesn't like the cold weather and I am not sure how long its gonna last really. Then for a while I got carried away looking at used Snap-On digital torque wrenches on ebay but then thought its all about trust with a torque wrench and could I trust a used one without getting it calibrated first. Finally bought a Norbar TT50 and a Norbar TT20. These are lovely tools. Simple trustworthy and nice to use. About £70 each on Amazon.
Removing engine cover
Again TIS provides some of the detail on this task, and specifying a particular order that the various nuts and bolts should be removed in. Once all the nuts and bolts are undone comes the task of peeling the thing off. Took me a while looking at it and poking around and gradually increasing my courage to give it the force needed. What I found worked ok for me. Standing at the drivers side of the engine, left hand at the far left corner gave a decent place to get a purchase on the thing and gradually increased the lifting pressure and it finally broke the seal. Then it was easy enough to work a way around until it was all lifted. Then I was caught by the nasty little male torx bolt, which kwempe mentions which I had not been able to find until now. It is simply holding a cable guide. You will find it at the drivers side back corner of the engine cover, between engine cover and bulkhead. Very awkward to get to even with a 1/4 socket while the cover is in place, easier actually when it is half off.
After removing the engine cover I covered the exposed engine with bin liners and tucked them in under the rail.
Removing the old manifold
Self explanatory task. The only problem I had here was that in two cases the stud came out instead of the nut coming off. I tried various things to then get the nut off the stud, including a nut splitter, but eventually just bought two new ones and screwed them in. They go in hand tight and then put one nut on and then another nut screwed on against this one and that allows you to gently tighten with a socket or spanner.
Fitting new manifold
This was again pretty easy. I got a used cast iron one and so had to do a bit of a clean. I got some
gasket remover from amazon and used a plastic windscreen ice scraper to scrape off. Blasted the inside of the manifold with a jet washer and let it dry. Obviously new gaskets all round. Bit of copper grease on the studs, and TIS recommends replacing the nuts which I did. Tightened to 20NM starting at the centre nuts and working towards the outer nuts. No recommendation in TIS for replacing manifold to turbo bolts but I did this anyway Tightened to 55NM. For the sake of a few quid is feels nicer having new nuts and bolts.
Replacing cylinder head cover
Mine went on and off three times before I felt I got it right. TIS states that you should use a small amount of sealant in the corners by the vacuum thingy (Sorry too knackered to look up what its really called).
Loctite 5910 is very close to the BMW stuff that is actually not available.
CHECK, CHECK, CHECK again that you havent got anything in the way when you replace the cylinder head cover. I will loose all cred when I tell you this but after standing back to admire my handywork after initial replacement of this item I realised I had the bonnet release cable running from one side of it to the other...what a TW*T!! and that does say TWIT. I had the bonnet release cables lying around because I was also doing the main thermostat in case you are wondering.
There is no torque specified for this, but I found by gradually increasing the torque setting on the wrench that 16 NM tightened enough to compress the rubber grommets so they sit comfortably in the seating that is moulded into the cover. I used a torque wrench to get even tightness across all of the bolts which is specified in TIS.
Replacing the injectors
I gave the injector body a spray of carb cleaner and wipe down. I used a dishwashing type sponge and some carb cleaner. Then greased the body with engine oil. TIS suggests you should use new copper crush seals to reinstall the injectors again. I used a tiny flat head electronics screw driver to loosen the old crush seals from the injectors. Then replaced with new ones. These are a pretty tight fit onto the injector. After doing a couple by hand I found that using a deep socket (11 mm or thereabouts) was a good way to push the new seals onThe socket allows you to apply force evenly around the seal as you push. There was small amounts of debris in the injector ports which i hoovered out with a piece of clear plastic screen washer tubing again from halfords. I also replaced the rubber o rings.
As kwempe says,
make sure the collar is the right way up, I spent quite a while wondering why the injectors wouldn't tighten down anywhere near until I realised what I had done. :hihi
Once I realised what was wrong, I flipped it over and followed the TIS instruction of gradually tightening each nut alternately up to the specified torque. Replace the top fuel pipe on the injectors at this point but not the electrical connections, they go on after the inlet manifold. Phew that was the injectors back in. A quick check that I hadn't got the bonnet release cable in one of the collars or something equally stupid and a cup of tea :thumbsup
Replace the injector pipes from the rail to the injector, checking that they had seated before hand tightening the nut. Finally tightening them up to the specified torque (9NM for my car).
Replacing the inlet manifold
During this whole adventure I found that this
pick up tool by Silverline was just so useful for loads of things including over and above its intended use of recovering the bits that you drop. The best 2 quid I have ever spent, I totally love this thing. It was really useful when it came to replacing the nuts on the inlet manifold, and especially that one at the back that Kwempe illustrates in one of his photos. The tool allows you to hold the nut, and easily insert it into those tiny spaces then a few twists of the tool and it is on the thread then just release. Makes this kind of thing effortless. I also used it to grip small bits of sponge and inserted it into the fuel injector ports and pulled it out with a gentle twisting action to clean up the walls of the ports :stirthepot and it worked brilliantly although I am not sure that this is recommended.
Again no torque specified for the inlet manifold nuts, but I used a torque wrench to ensure even tightness.
I cleaned out the manifold and EGR valve before replacing them, however I ended up buying a new EGR valve in the end because I broke mine. After I cleaned it up, I was not sure if the valve should open if you push it. Mine did not open even under strong pressure. I had googled it but could not find any answer. I was on my way down to the very polite parts dept at Coopers in Cobham and thought I would ask one of those guys. The BMW technician there had a poke at it and said give it a knock and it should open up. When I got home I tried giving it a few knocks and it wouldn't budge, eventually it was a bit damaged and still not opening, I was beginning to suspect it shouldn't open. I ordered a new one and when I went to pick it up me and the parts guy opened the new one and sure enough it wouldn't open. They knocked me 10% off as a sweetener. I knew I shouldn't have trusted the tech there at the time should have been patient and asked on the forum so considered it my own fault too. Anyway another £130 quid down but getting close to completion.
Finishing off and restarting
When putting air intakes back together, I used vaseline to line the sealing surfaces as described in TIS. I changed the air filter for a new one. Cleaned all the various bits before putting them back and it was all looking and feeling like a good job.
The words "triple check all connections" from kwempe's post were ringing around my head as I put all the final hoses and connections back. I triple checked everything and had a break and came back and checked again, as I was putting the battery cable back I decided to go back and check again then came back and did the battery. When it came to restarting I had an active steering fault come up as I do every time I disconnect the battery, it goes away after a couple of starts usually. When restarting leave the key at position 2 for 20 - 30 secs to let the fuel come through. A few cranks and she was off hurray!!
Got a round of applause from wifey and our five year old and I was feeling very pleased with myself.
Had a slight panic moment as there was a dodgy little squeaking sound coming from front of the engine in the region of the turbo, but I thought this would be just coolant on the one of the belts from the stat change and after a long drive the noise went away.
I think the job I have done is better than would be done by an indy or stealer. Although at a few points I was beginning to doubt my abilities, in the end I thing I did a really good job. I have to say that for a complete novice like me it took a lot of research, buying a lot of tools and actually a lot of time to do, but now I am not a complete novice, I now have a good set of tools and I understand my car a lot more and have a much cleaner air intake system. Car is feeling good and on top of all that I can now use the heater without getting gassed.
There is probably one thing that I should have done and that is to send the injectors off to get them cleaned. Someone like injector tune do a service by post for 20 odd quid each. Maybe I will pop them out later in the summer and send them off.
Thanks for the original post Kwempe.
