Removing the Sump- fixing oil pickup pipe filter

I hadn't meant to drop the sump because I believed that the lower end of this motor is fine. Sadly that belief was seriously challenged ads I started to clean and decarbonise the head and piston crowns. Diesel EGR spray cleaner is an excellent way of loosening carbon and if you can arrange for the component to sit in it for a while so much the better. The first problem came as I cleaned the head, There was a mark in cylinder no 3- its in a non-critical area and shouldn't affect gasket seating but I wondered how this had been caused.I cleaned the pistons in all cylinders and got a shock. Piston 3 shows markings of exhaust valve contact and piston 4 has inlet valve marks as well.

Piston No 4 Exhaust side down-most

Piston No 3 Exhaust side down-most

Pistons 1 and 2 were unmarked. I was told that this motor was in good condition, yet these marks could indicate a timing belt failure at some point in the past. However I also know that the motor was rebuilt so maybe this was why. If so then any damage should have been fixed and perhaps the pistons were simply reused. Although marked, they are obviously quite serviceable. However this obviously raises the spectre of potential damage to the bottom end, bent conrods or damaged big and little end bearings not to mention possible main bearing damage. I was clearly going to have to investigate this and one tip I had got from the forum was to check the oil pick up pipe filter for debris. Since this is in the sump there was now no choice, I would need to drop it, check the filter (and possibly bearings) and clean out the sump.

Removing the sump was very simple and I forgot to take any pictures. However, as I had already removed the front and rear seal carriers it was simply necessary to undo all the bolts around the sump and tap it with a mallet to loosen it. The trick (if it be a trick) to removing it is to tilt it towards the exhaust side to make sure the baffle clears the oil pick up pipe filter rose.

Sump detached with baffle in place-pretty mucky

I detached the baffle and degreased it as well as the  sump, cleaning them with paraffin and then POR15 degreaser before spraying it clean. Much of the old Wellseal came off at this stage.


A word of warning though as the baffle gets very slippery in POR15 and it has very sharp edges- as I now know to my cost!

A quick look at the oil pickup filter showed me what I was fearing- there was a lot of debris trapped there. In order to remove the pick up pipe you need to first remove the hex retaining plug in the Auxillary housing. There is a special tool for this but in my case the plug was very loose and a suitably sized bolt also works well. (Pictured after removal). I can also say that  a motorcycle wheel spindle key will also fit and is easier to turn with a spanner- I will use that when refitting and I need to compress a new olive!

Bolt head fits the hex profile on the pipe retaining plug and unscrewed easily

 The pipe is then held on by a bearing cap bolt midway along and  the olive compressed below the hex plug. I removed the bearing bolt using a breaker bar and slipped the pipe bracket off the stud before  immediately retightening the cap bolt. The pipe was then drifted down through the nylon olive and detached. The old olive was fished out with a wire probe. Now I could look at the filter properly...

Crud in the oil pickup filter

 The filter was gummed with quite a lot of debris- (its looking less and less like this motor has been rebuilt). I tried to flush this out with paraffin and a brush but its quite tangled into the mesh and the only thing that happened was that the oil filter disintegrated. Shockingly its only glued together and after 40 years or so the glue is clearly no long doing its job.

Filter cap has detached from rose.

I cleaned the filter thoroughly using paraffin and carb cleaner spray, clearing each of the gauze recesses with a toothpick and flushing with lots of paraffin.

At least filter rose is clean

Mag probe passed though cleaning liquid.

The filter did eventually come clean. I tested the debris with a magnet and found that its a mixture of magnetic and non magnetic metal material including some very fine wire fibres almost like hair.  There was clearly some bearing metal in there and possibly also copper from the thrust washers- but how much is too much?...  and given how hard it was to clean, has this stuff simply been carried over from a previous problem? There was also quite a bit of wellseal so there's a lesson there for reassembly.

I am clearly going to need a new filter rose, but as new ones are quite expensive (£30) and need to be brazed onto the pick up pipe I thought I'd try a repair first. In order to do this I used joining screws of the type used to connect kitchen cabinets.

Joining screws as supplied (above) and as cut (below). Splines at top of female screw will help to anchor it in the plate.

 These are too long as obtained for kitchen use, so its necessary to cut the shaft of the female screw to 1.7 cm and the screw itself to app 0.8 cm. This has been done in the pic above. The next step is to make some clear room between the folds of gauze app 180 degrees apart round the rose by gently folding two adjacent pleats apart. I then drilled a 5.5 mm hole in the lower plate of the filter (the one that had detached) and a 4 mm hole through the top opposite the first- supporting  them on a wooden block. The joining screws then simply pushed though these holes the splines retaining the female screw and tightening then allowed the filter to be set at the right distance apart to give a good seal around the mesh. Once sorted I removed the screws and applied thread lock to the female screws before joining the two sections together.  I used only two screws which gave a good solid seal but 3 or 4 might be better.

Oil pick up filter repair

Oil pickup filter screen repair