glow plug replacement

I've already collected my six Bosch duratherm plugs which I'd ordered so open the bonnet and get started.

Right bank of cylinders - well on my left with the bonnet open - start to unclip and move bits of the engine that block access to pull off the glow plug caps - thanks to s0niX's advice that one. Still needs a really hard tug to get the little bleeders off though.

Now the rearmost plug has the large diameter air intake hose from the MAF in the way. I had previously sorted the MAF with electrical contact cleaner but had not had to undo the turbo-side clip. Problem is, the last Audi mechanic has put the 'Jubilee' clip facing backwards, leaving hardly any room to access the screwhead.

Eventually, I undo the clip but now get stuck with one of the two electrical connectors above the hose.

With that final connector undone, there is space to get to the rear glow plug. Clean round the plug with brush and air but that plug is tight, bloody tight. At 70,000 + miles it doesn't look as if the plugs have ever been out and that should have sent off warning bells in my little brain. The marvelous idea of mixed metal in cylinder heads has set up so much electrolytic corrosion that i estimate I'm using around 100 ft.lbs torque to undo each of the three plugs. At least there is straight access to each of those plugs.

Put copper ease on the thread of the new plug, tighten it up by hand, then 15NM torque to seat it and bang on the connector cap. Move on to do the second then the third glow plug.

Left bank doesn't look so easy. Inlet manifold piping in the way for the front plug so no straigt access. Alarm bells should be on loud at this point. Sort out some universal joints, extension bar and ratchet for a 3/8" ratchet set from the ex-RAF engneer next door. Can't shift it the glow plug. Won't even turn. Squirt some WD40 round the base, leave it and move on to the second plug. Turns, but even harder than right bank plugs. It starts moving with a lot of squeaking, replace with new, do same for the third. Reassemble assorted pipe work etc, that was moved out of the way cos wife, offspring and dog emerge from house demanding I take us all by car to go walkies. Curse inwardly as I take all tools back to house and return neighbour's bits.

Drive to walk, return, aim to finish job, retrieve 3/8" ratchet bits from neighbour, undo bonnet, reckon I can just fit socket onto glow plug with 3/8" universal joint. Immense effort follows and ratchet just spins round. I have just stripped the thread. Try not to cry as neighbour comes out and says he used to do a lot of helicoil inserts when working on the planes and helicopters - aluminium you see.

Car not worth starting. Have to call a garage tomorrow, Bank Holiday Saturday, to see if they can tow the car ready to start work on it whenever they have some free time.

Moral. Electrolytic corrosion needs more than a squirt of WD40 to fix.:zx11:

Gutted.

I know how you feel !!

Update

Next morning - Saturday - open bonnet, pull off engine cover, remove section of inlet manifold that prevented straight access to the front left glow plug - on my right as I'm looking at it - try tightening - just turns uselessly - try loosening - turns uselessly - try tapping glow plug down a bit to see if that will engage a thread - try levering glow plug up while unscrewing it - no, I'm still screwed. Neighbour comes out with a knowledgeable mate of his and they work out what's wrong.

The thread of the glow plug is still stuck in its tapped little hole. I have sheared the nut section so that it just wiggles and turns which ever way you try to turn it with no effect on the threaded part.

To me this is good news as there should be no loss of compression and the engine should easily start on five of six cylinders.

WD40, Pulling, drilling and wrenching follows to see if this might release this recalcitrant plug. All that happens is the tip contact comes off, shortly followed by the hexagon part of the shank that had sheared through.

The remains of the glow plug are firmly stuck and after sawing through one of the old glow plugs, I reassure myself that no material has fallen off inside the engine and none will do so.

On reinstalling the piece of inlet manifold I notice that only the top half of a gasket had been in place for the pipe connecting to the turbo. Clean metal under the gasket covered half but ingrained coked soot on the half where the gasket was missing. This on a car that has supposedly only been handled by Audi technicians.

Clean the surfaces, lightly coat with gasket paste, reassemble, have two mugs of tea.

I start the engine - certainly quicker starting than before thank God - more importantly it runs smoothly and quietly, well for me it sounded less wheezy, which was probably the turbo waste gate leaking.

Test drive - things are OK - phone call from local A and E please collect your wife and daughter. Perfect timing, and not unusual due to wife's untreatable neurological problem.

Pop down to A and E, usual wait for Dr to come back after consulting their senior, impressed as none of the usual ' are you taking your medication deary' and get them all back in the now functioning car!

Garage bloke turns up on time in the evening - and this is a Bank Holiday weekend I believe - doesn't charge for the call out and gives helpful advice. Drill out more the core, run the car until engine hot then use an easy out to try shifting remains of the glow plug. I decide to leave things as they are for the time being.