Yeah, and this seems to go back quite some time - just by chance watched a video on YouTube by the Car Wizard today on a 2013 BMW with….wait for it…BMW plastic cracking and gaskets failing. Worth a watch and has me now trying to figure out if/when my Thermostat housing will need to be addressed (2016 F56 JCW)…

I already bought the metal oil filter housing from ECS even though mine is not leaking (yet)…checkout the gasket in the video - looks just like the one you show above…I realize these are N series engines…but apparently similar/same parts and problems.

 

If you are running the original plastic one, then I'd recommend swapping it out as a preventative maintenance item - maybe next time you have an oil change or coolant flush? I am willing to bet that my gasket was probably split for a while, but the plastic kept it all together enough that it wasn't an issue, the plastic probably gave away and that's when I started having the coolant pool out.

 

So on the N18 engine, there is a plastic coolant tee that sits (don't ask who designed this) effectively atop the oil filter housing; the cap unscrews upward, and the coolant tee is in the way. While doing an oil change on an engine with ~141K miles on it, that coolant tee tore in two -- I do mean tore, not "shattered" or "cracked" -- tore, it sounded like rice krispies and ripped like paper -- while I was pushing it out of the way with the back of my hand, to work on the oil filter housing cap. Lots of people wind up replacing that plastic tee with a metal plumbing tee, and for obvious reason given my experience.

There is more to say about the N series plastic and rubber, but yeah, same materials are in the F series. I yanked all the plastic and rubber "coolant plumbing" -- so hoses, fittings, plastic crossover pipe -- out of that N18 engine and replaced them (boy is that YouTube a trip down memory lane). Even though the only stuff that came out of my wallet was for parts, it still wasn't cheap. And it was annoying. But it did teach me a LOT that I now apply to my F56S.

I plan on doing the same "swap it all out" with my F56S prior to 140K miles. Water pump has already been replaced with a Meyle HD (metal impeller). Thermostat housing was replaced -- not according to plan but it was more of a saga not to, so just did it -- at the same time. This fitting we're talking about, and every other coolant hose and fitting I can lay hands on, are going to get swapped when I decide to do The Big Operation. May well replace the overflow tank and cap as well. Cooling is one of those things where waiting until it breaks, especially if you know it's going to break sooner or later (coughBMWcoughcoughcough), is a very, very bad idea.

I did put the Bremmen plastic oil filter housing on the F56S (metal one was out of stock when I needed to do the repair). I have been unable to really tell whether the plastic is of better quality and it just hasn't been on the car long enough for "proof." ECS said elsewhere they haven't had bad reports -- which is fine, and I trust it, but my original didn't go kaput until over 72K miles. Since all these various aftermarket solutions are fairly new (last 2 years-ish), it may be a while before we have real field stories about their longevity. Given that context maybe I'll swap it for the metal one when I do The Big Op -- or maybe I'll just let it get a ton of miles on it (kind of may as well, at this point I could remove & replace one of those in my sleep, so not a hassle to me to save it for down the road).

 

In another 10K miles or so I’m planning on a major maintenance - new clutch, put in LSD (WaveTrac), change transmission and upper motor mount (mine are still holding together…for now). I’m going to also do the thermostat housing, water pump, hoses, serpentine belt (already picked up the ECS Kevlar belt on clearance), and various other items at that time. I’ve a lift in the garage so probably next fall will put the car up for a month or so - in meantime I’m collecting parts “on sale” as they come up. Hopefully the LSD gets a discount at some point - and I still need to figure out the clutch - I have the Dinan stage 1 93 octane tune and that is 334hp at crank and 384 ft-lb torque (their measurement - we all know these measurements change/are all over the place - but yes Mohr! Power for sure)…my stock clutch is holding (for now).

Thanks all CJV2, Eddie, jpuliz - have been a great help.

 

@FlyingScot57 glad to assist. Out of curiosity given the discussion of plastic, what do you plan to install for the water pump? Getting something with a metal impeller instead of the factory plastic? Not much of a price variance for a good option or two out there.

 

Definitely metal. I though you had put on a metal pump if I recall another thread and that presented some challenges? Like you I’m slowly on a crusade to get rid of all BMW Plastic

 

I did put a Meyle HD on mine, but the challenges had nothing to do with the Meyle HD proper. Three things:

(1) Water pump change on a 4-banger F series is hard because of the tight clearances at the front of the engine (even getting the belt off is a ridiculous chore that will make you want to kick a dent in the car).

(2) Because of the clearance challenge and because I didn't want to fail to properly seal something and have no recourse, I had an independent shop do the swap.

(3) A bunch of drama emerged when the shop called and said the alternator bracket (which itself is literally a water channel between the water pump, the thermostat, and the engine) needed to be replaced due to sealing concerns -- and BMW only sells that bracket as part of a combined water pump+thermostat+bracket assembly. So I ran out and bought that new combo assembly; we swapped the new water pump that came on it out for the Meyle HD and hey, new plastic thermostat housing so less likely that it will implode anytime soon vs the old thermostat housing.

Now, the kicker is, I still have the original parts and planned to sell the new genuine BMW water pump that came with the bracket (currently listed on eBay, actually), and also sell the old combo assembly (old bracket + old thermostat + old water pump). I took a closer look at the thermostat and I don't think the reason the shop called me up to talk replacing the assembly was sealing concerns. They broke the electrical connector on the old thermostat housing -- and never told me. Bracket is usable, old water pump is usable. Old thermostat is 100% nonviable though.

(side note: it was the plastic of the electrical connector on the thermostat that broke, not metal or conductors. Score one again for BMW plastic.)

My take at present is that it is in fact possible to change out the water pump DIY (though it takes patience and not being impatient or a corner cutter, because any old seal you break will *definitely* need to be replaced/resealed).

Going to a metal impeller pump was not an issue at all; the issue was the general difficulty of changing the pump period (as well as the shop snapping the electrical connector on the thermostat housing and not disclosing their oops).

Don't get me wrong, I'm glad I replaced the whole shebang anyway, unbolt the old stuff and bolt on the new stuff (complete with new seals ready for install) is a good plan for keeping things simple (well, relatively simple anyway). But if you intend to replace *just the water pump*, be ready, and do NOT unbolt either the thermo from the bracket or the bracket from the crankcase unless you are prepared to reseal by hand with Loctite 5970 (that's what the factory seals are, apparently).

 

I had similar plans when the clutch goes, I imagine an entire engine out would greatly simplify something like a water pump. Are you using ITSA for directions on the clutch swap? Also, curious if you are going with a single mass flywheel or the OEM style one?