[knapmann]

Hello All,

I recently joined the modern world and bought a daily BMW to match my 1972 ’02 Series. I need a touring for practical reasons and a 335i Manual for enjoyment reasons!

My car is N55 powered and has 136k miles on it so not a small number. I was planning on doing a big service in the next month or two and was hoping I wouldn’t have any issues in the meantime however the apparently inevitable plastic cooling system issues on these new models have come to haunt me sooner that I had hoped, (you dont get these problems with the older all-metal engines I’m used to, everything seems to be made to a price these days) I have found a big coolant leak coming from the hose to the front of the cylinder head which needs sorting out which is forcing my hand on other mission creep jobs whilst I’m in there. My plan is:

1) OFHG
2) Water pump
3) Thermostat
4) Thermostat-water pump hose
5) Ancillary belt and pulleys
6) Thermostat to cylinder head hose
7) Aluminium cylinder head hose fitting

Are there any other things I should be doing whilst I’m in there? Like Vanos Solenoid cleaning – I don’t hear much about this being necessary?

Are there any other coolant hoses I should be replacing whilst I have the system apart? I don’t seem to read about issues with many other inaccessible hoses. Im thinking about hoses to the block and turbo etc etc Its had a new expansion tank already.

I think I will look at the Valve Cover and PCV at a later date for now.

Finally do I have to remove the FMIC in order to get the water pump out, some sources say yes and some no, it might depend on what car they are referring to…

Whats the deal with engine sensors, are there any that are troublesome that should be replaced pre-emptively, that are difficult to access etc I dont know what the life expectancy of crank sensors temp sensors lambda sensors etc are on these.

I should add that I have had plugs and oil and filters all done etc.

Thanks in advance!

[Phil325i]

Personally I wouldn't bother with the water pump or thermostat unless or until they fail. For other things worth considering, Google: 'Mike Miller BWM Old School maintenance' for an interesting read.