Citroën HY engine cleaning

When I started to work on the car it became clear that the engine was in a neglected state. When I removed the cilinder head cover it showed an enourmous amount of sludge. I had never seen an engine in this condition before. The weird thing is that even with the neglect the engine ran quite nicely. The reason for me to take the cilinder head off was because I had a problem with the cooling system. After the engine heated up it the cool water started to foam outoff the radiator. This turned out to be a little leak in the rubber hose to the interior heater. This sucked in air (when the heater switch was closed). Anyway I took the cilinder head off.

I borrowed a valve spring tool to release the valve springs but because the valves are placed in the cilinder head with an angle the regular tool was not able to do the job. Therefor I created this simple tool which did the job (cost around 5 Euro).

All parts of the cilinderhead were removed and put aside and labelled to be cleaned and refitted in the right place and order.

The photo on the left is a closeup of one of the valves. As can be seen not exactly clean. The only clean bit is where it hit the valveseat. I removed all the dirt by putting the valve in the lathe and gently pressing (by hand) a knife tool up to the valve until most of the dirt was off.

This photo show the cleaned head with the valves installed again. The valves were grinded into the valve seats with a valve grind hand tool. Mount all the parts with engine oil. As can be seen the valve rockers and shafts still have to be mounted. The shafts are hollow and were completely filled with sludge which I flushed out with petrol. All the parts (apart from the valves) were cleaned in petrol using wire brushes in different diameters as well as toothbrushes.

This picture shows the cilinder head fixed to the main part of the engine. I used a new cilinder head gasket. Check the HY repair manual for the torque and right order to fix the cilinderhead screws. I did not have the cilinder head flattened as I found no reason for that. The old gasket was not blown and the head or sprak plugs had no signs of overheating.

As could be seen on the first pcture a lot of sludge had apearently build up over the years in the engine. For this reason I took the oil sump off in order to clean the sludge at the bottom and to be able to clean the oil filter. A lot of dirt came outoff the sump and filter.

I cleaned the edge of the oil sump and cilinder block and put new seals in the oil sump to prevent it from leaking around the front and back of the sump (this worked well for some time but started to leak after about half a year already). I fitted the oil sump with liquid gasket. After cleaning the surroundings of the engine from years of oil leaking it looked quite decent again.

As can be seen from this picture also the flange of the exhaust pipe was in a very bad state so a new pipe was fitted.