So recently me and my brother bought a 2003 Infiniti m45. At first the car didn't seem to have a whole lot of problems but after a month or two we encountered 2 sort of major issues.

The first issue was a leak in the engine fan fluid system ( hydrolic system that powers the radiator fan). It had a bad leak and after a little bit of diagnosing we figured out it was the water pump. So we replaced the water pump and it seemed to be fine for a while but recently it started leaking a lot. For some reason there seems to be a claug or just too much pressure in the system and the fluid just rapidly squirts out of a pipe going out from the pump but only while the car is on. I'm new to this kind of stuff so currently I have no ideas on how to fix this
and any ideas would help. Here is a picture of the leak as well as a diagram of the system. The red circle is where the leak is.



The second issue started after about a month. One day we were driving home with the windows rolled down and when we got home we tried to roll the windows up but when I pressed the switch nothing happened. None of the windows would roll down from any switch. About a week later it worked long enough to get the windows back up but since then it has not worked at all. The powerlocks as well as the sunroof and moving the seats also stopped working. My first thought was to check all the relays and fuses but none of them were bad(in the interior fuse box as well as the fuse box in traffic engine bay) so I asked a couple people about it and they had no idea what could be causing it.

For the first issue, sorry if I missed the detail, but did you guys replace that line? From the picture it looks like maybe it has a crack or something? Is there any gasket material there as well? Perhaps make a new gasket or pick one up?

For the second issue, if all of the fuses and relays checked out, to me this sounds like a BCM issue (seems to be a common thing these days on both M sub-forums here). The BCM controls a lot of stuff in our cars (interior lights, switch operation, even key detection on newer M's - I'm not sure if Y34's have a physical key or not as I've never sat in one lol).

Welcome to the forum.
First, I'd like to encourage you to post different threads for different topics. Otherwise, your second issue of the electrical system might be missed by someone who chooses to ignore the topic title (in this group, only the 2003 & 2004 M45 used the hydraulic water pump)

Now on to your issues
For the hydraulic fluid, simply put, the hard line is broken. Nice action shot by the way, it really helps visualize the problem I can't tell very well, but it looks like someone attempted a repair by sleeving & brazing the area.
Do you have a close up picture of it with the engine off/not leaking?

On the issue of the electrical stuff, at first it sounded like a circuit breaker (they temporarily disable your circuits, for example, if you continuously play with a window up & down, that window will be unresponsive for a while)
Does the steering column telescope & tilt still? How about the interior lights (map lights & step lights), do they still come on?
If none of those work, find a 40 Amp fusible link. I believe it will be in the engine bay near the battery (I don't have a Y34 or picture for reference). There are other 40A fusible links in there you could swap to troubleshoot with.

That's the easy part. The other option is to go back to that fuse box by the driver foot. Remove it and check the relay that is mounted on its back side.
But before you delve into that, I'll ask: can you open the trunk all the 3 ways? Do the wipers work?

Ilya wrote: ↑

Mon Jan 07, 2019 7:45 am

For the first issue, sorry if I missed the detail, but did you guys replace that line? From the picture it looks like maybe it has a crack or something? Is there any gasket material there as well? Perhaps make a new gasket or pick one up?

For the second issue, if all of the fuses and relays checked out, to me this sounds like a BCM issue (seems to be a common thing these days on both M sub-forums here). The BCM controls a lot of stuff in our cars (interior lights, switch operation, even key detection on newer M's - I'm not sure if Y34's have a physical key or not as I've never sat in one lol).

Thank you for the response. We did not replace the line we just replaced the pump. There is not a crack but it was previously welded because of a previous leak. It does not have a gasket but the metal tube extends into to the connection and there is an o ring in it so it should be sealed. I'm probably going to make another rubber gasket or something to see if I can seal it a bit better. As for the 2nd issue I will look into the bcm.

EdBwoy wrote: ↑

Mon Jan 07, 2019 9:42 am

Welcome to the forum.
First, I'd like to encourage you to post different threads for different topics. Otherwise, your second issue of the electrical system might be missed by someone who chooses to ignore the topic title (in this group, only the 2003 & 2004 M45 used the hydraulic water pump)

Now on to your issues
For the hydraulic fluid, simply put, the hard line is broken. Nice action shot by the way, it really helps visualize the problem I can't tell very well, but it looks like someone attempted a repair by sleeving & brazing the area.
Do you have a close up picture of it with the engine off/not leaking?

On the issue of the electrical stuff, at first it sounded like a circuit breaker (they temporarily disable your circuits, for example, if you continuously play with a window up & down, that window will be unresponsive for a while)
Does the steering column telescope & tilt still? How about the interior lights (map lights & step lights), do they still come on?
If none of those work, find a 40 Amp fusible link. I believe it will be in the engine bay near the battery (I don't have a Y34 or picture for reference). There are other 40A fusible links in there you could swap to troubleshoot with.

That's the easy part. The other option is to go back to that fuse box by the driver foot. Remove it and check the relay that is mounted on its back side.
But before you delve into that, I'll ask: can you open the trunk all the 3 ways? Do the wipers work?

Thank you for the response as well. I will try and inspect the hard line to see if maybe it's broken but I think something is causing the pressure in the system to build up and it just happens to be releasing the pressure at the spot it's leaking at. I can add a couple more pictures tomorrow so you can have a better idea of what it looks like. As for the electrical problem the steering wheel does not move but all the lights work as well as the AC, LCD screen, and the radio. And yes I can open the trunk with the key phob as well as the button in the driver side door and the windshield wipers also work.

I'd start with all the relays/fuses in the engine bay as Ed said and in the car for the electrical issue...but if all of those check out then you might have issues in the other components I previously mentioned.

Just a quick update on the leak, today I took the whole hydrolic fan system apart cleaned it and put it back to get her to see if anything would change and when I put it back together and the leak didn't seem quite as bad so I think the hard line just has a hole right at the connection and I'm just going to buy a new one or have my dad try and weld it(he is a welder). So thanks for the help on that hopefully welding that part/replacing it will fix it.