Ownership Verified: The Waft-O-Matic fat man car. Meet Sumo, Loose Units E39 523i

First 150km of the trip this weekend were good - But after a run on the autobahn with the speed between 170 - 220 we suddenly hit traffic and went down to 10kph. After about 10 of the slow speed the engine just died and started up again. Since then, it has been running like shit again. I will run the diagnosis tool this weekend, but it seems the sensor issues might just be pointing towards some kind of electrical issue relating to the engine temp...

It does not blow hot air into the cabin any more either, which is very odd. (Heater core?)

Who knows, but it is starting to get on my nerves.
 
Have you changed both thermostat sensors?

Nope - But I will do the thermostat stuff in the coming weeks I have decided. I will order parts this week and when Luigi is sorted I will put the BMW in the barn and work on it for a few days.
 
So, having to top up the coolant system every single day eventually lead to me forgetting to put the coolant cap on - I drove 33km to work without issue, parked up and of course, this happened:



Luckily the cap was just happily sitting there inside the engine bay where I left it :D - At lunch time I went and bought 10L of water, after work I topped up the system and set off. Within 1500m the temp was rising well above normal, so I pulled over and was forced to google how to bleed the system properly, it's not that hard and after finding something to open the bleeding screws with (My toolkit screwdriver is missing, I am going to sort that as soon as possible) I was able to bleed the system and drive home without issues.

Since then I have been keeping the coolant topped up way above minimum and not driving hard - It has been absolutely fine since I have done this, so I am guessing one of my original theories about the system getting too hot and causing sensor issues is possibly correct. So I ordered a new cam position sensor, a new hose from the bottom of the radiator to the thermostat housing, a new thermostat and thermostat housing.

I ordered the thermostat housing two days after the hose and sensor. Guess which arrived first!





The hose and sensor should arrive tomorrow, hopefully, so I can get stuck in and get at least the hose swapped.

Hopefully that resolves the mechanical reliability issues with it. Once that is done I will hopefully have hot air again - It's kind of important in winter.
 
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haha, went to install it tonight only to realise it's the wrong f-ing one... The part came up as correct for E39 523i from 1995 - 2000 or whatever so I ordered it. But there was a special note saying "only for after 1998/09" at the beginning of the listing - I have now ordered the correct part.
 
Haha, I was just looking at the picture thinking

"Hmm... I thought this was supposed to have the same M52B25 (single vanos) as my E36, but that thermostat housing is different. Strange, this must actually be a TU engine."

And then I read the next post... Sorry I was a little late to warn you.
 
And then I read the next post... Sorry I was a little late to warn you.

:D No problem - It just wasted some time, getting it into the barn is quite a hassle but otherwise, nothing lost.
 
These cooling issues seem all too familiar from last summer :D Hope you'll get those sorted once and for all. I have this feeling about the E39 that I have to get another one someday.
 
So, with winter here it seems to have stopped losing coolant unless I really beat on it and then suddenly stop without a "cool-down period". I have not replaced the parts yet because I need it now as Luigi is in it's winter-sleep, does not have winter-tires and also will fall to bits if I drive it through the salt.

However, it looks like Sumo will be replaced soon so I will be able to fix it or provide the buyer with the parts I already have for it.
 
I figured I would do a cross post with the M140i thread as SUMO is now up for sale and this will be the last time I post in this thread.

Goodbye you loyal thing!




And here are the pictures I am using for the ad:


































 
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