Project Daily Sigma (16V TU)

[darrenjlobb]

As anyone who knows me in person will know, ever since taking the Derv Bus off the road, I've been driving either the Audi, or for the last 12 months, my daily driver, in the form of, yes, you've guessed it, a 306... Ph2 Sigma blue 1.6 8v which looks like this:



The idea being it just works, no issues with it really, just service it / drive it....

However...having now covered 160k, and still being on its original gearbox and engine, it was seriously starting to show its issues, mainly the gearbox, which has recently got the point of having to hold it in gear / the radio simply not being enough to overcome the whine on the motorway, and also engine using oil / failing MOT on emissions etc (head gasket is starting).
Obviously the sensible thing to do here would be find another low mileage 8v motor / box and drop it in, or rebuild the current one / find another box, etcetc...

However the child inside of me (most likely missing the DT) decided this was not going to happen, and that I would replace it with something a bit different, and more complicated. One thing I do love about this car, its got to be said, is the way it handles, clearly down to the lightweight TU up front, the front end of this thing really does handle so well, better than any 306 ive driven id almost go as far as saying...

Anyway I decided i wanted to leave a TU in it, thought about converting it to derv but then thought this would be the biggest mistake in history, given it would result in having 3 turbos and a p pump on it in the first month, and that would be the end of all things "reliable" about my "reliable daily driver"!! So decided to put a TU5J4 16V in it out of a saxo vts / 106 GTI...haven't really seen anyone else on here do it so thought why not, bit more power, responsive little TU, shouldn't loose its back road fun, but have a bit more power etc on the motorway / B road hooning

Anyway, decided to buy a motor while the 8v was still running (the gearbox really is THAT bad!!) and rebuilt it while its out the car ready to drop in, so collected some parts together and stripped the motor down:







Really just a good overhaul with new seals / gaskets / oil / filters / cambelt / waterpump / tensioners / some nice newmans camshafts, etcetc

Started putting the motor together:







Trying to keep things looking fairly OEM, so no painted up block or anything really, its just the daily...

Then things went quiet for a while due to being extremely busy on the farm etc, however prompted by the gearbox getting to the point where holding it in gear with your knee was simply driving me insane, I decided it was time to swap it over, I had pre planned most of the issues I thought I would encounter, although did hit several other "issues" along the way, as with everything!

So started by tearing the allmighty 1.6 8v out....








Proceeded to spend a bit of time cleaning the bay, sorting a few small rust spots, and tidying up a few bits and pieces...

Then started tearing down the 8v for ancilieres for the new motor, Wanted to try and retain the oem setup so that i didnt have to bother switching the E-Pas and loose the aircon.

Tearing the old girl down:



Bolting it up, this was the final setup I came up with, ran into several issues here due to the 16v running a normal width cambelt not a narrow one, causing the crank pulley to stick out to far, and nothing to line up, so had to modify the pulleys / use different belts here, but as you can see got it looking pretty much OEM in the end, and still easy to change belts / work on etc, new idler fitted also for piece of mind.



Then started the task of wiring, this was quite a lengthy process, mainly due to the old 8v being on bosch management and the new one being on magneti marelli.

Started with both stock 306 8v and saxo vts looms:



Proceeded to tear off all the tape / plastic:



Went about it by basically separating the "management" side of the loom and the "car sensors etc" side of the loom, on both looms cutting the management parts out, and splicing them into the stock 306 loom, so the oem bulkhead connector plugs in etc, so really just a case of belling out all the wires that join in "half" of the stock looms, to find out what ecu pins they go to, and then looking at ecu pin outs to figure what they are, and then hook them into the other loom, takes a minute or two, but fairly easy once you get going.

Some "lobb" technical notes :