[RSL]

Exactly.

If the fan runs 24/7 now (shouldn't), it's just hot wired and depending what he did/where/what gauge wire, could be a fire hazard.

Don't equate the fan moving to it working properly. We knew the fan was on, which means neither the fan nor the relay, wiring, etc. should be a problem. My guess is, if you replace the relay unit and remove the jumper wire he put in, you'll be right back where you were.

[rusty_sojah]

So what do u guys recommend next? A heat sensor? Any info about this part or troubleshooting? I will search later on this part as well, just not familiar with it yet.

[rusty_sojah]

So i have no related error codes, but when i put in the other fan i got a P2EFE error. So this is what made us look at the relay.

Is this the sensor you are referring to?

https://www.pelicanparts.com/BMW/tec..._Replacing.htm

[RSL]

Might need to start checking fuses with that code now. Was it present before everyone started messing with the fan/circuit, only after the fan swap or only after the jumper? Might've tripped something or fan might have an actual problem now.

There are 2 ECT sensors, I think the rad/one on the thermostat housing is used for the fan. That one is not read by MHD, so you'll need INPA/ISTA to verify if it's working.

[rusty_sojah]

Originally Posted by RSL

Might need to start checking fuses with that code now. Was it present before everyone started messing with the fan/circuit, only after the fan swap or only after the jumper? Might've tripped something or fan might have an actual problem now.

There are 2 ECT sensors, I think the rad/one on the thermostat housing is used for the fan. That one is not read by MHD, so you'll need INPA/ISTA to verify if it's working.

No error codes with my fan, which would come on about half the time the AC was turned on. Then swapped for another fan, and it would twitch and act like it was going to start spinning and would move a inches but wouldn't come on, and that fan gave the error code. Then i put my original fan back in and cleared the error and it never came back with my fan.

A few months back i lost all climate control due to a bad wire and a popped fuse, 77 or 88 or something like that.

[RSL]

I'm getting confused. Is the 2EFE old or still active (MHD time stamps them in code history) and is the current fan still working? If the code is current, need to see if the fan still works without the jumper (I'd remove that anyway if you haven't).

If you've had bad wires/grounds or blown fuses in the past, there may still be a lingering issue. The obvious system related components (fan, relay, sensor, etc) may not be part of the problem.

Your call, but at some point have to think it could be cheaper (not to say cheap) and faster to have techs who can diagnose end to end without guessing and replacing part after part on your dime. Either that or get ISTA and try working through any test plans on your own.

[rusty_sojah]

Originally Posted by RSL

I'm getting confused. Is the 2EFE old or still active (MHD time stamps them in code history) and is the current fan still working? If the code is current, need to see if the fan still works without the jumper (I'd remove that anyway if you haven't).

If you've had bad wires/grounds or blown fuses in the past, there may still be a lingering issue. The obvious system related components (fan, relay, sensor, etc) may not be part of the problem.

Your call, but at some point have to think it could be cheaper (not to say cheap) and faster to have techs who can diagnose end to end without guessing and replacing part after part on your dime. Either that or get ISTA and try working through any test plans on your own.

My original fan still works with the little jumper on it from one terminal on the switch relay box to the other terminal. this is still connected as i only drove it home from my buddies house (about a 30 minute drive down the highway in heavy traffic) and parked it. the code only showed up when we put in that other fan he had. after a few minutes of the other fan i put my original fan back in and it had been on the entire ride to his house and that morning when the AC was on but after putting my original fan back in it wouldn't start until we put the jumper on it.

is there a fuse for this fan? i would think the wiring from the switch relay box to the fan is good, or the jumper wouldn't work, right? so for me i think the sensor or the switch relay is bad, but i'm not a good auto tech or auto mechanic

i'm inclined to switch out the relay box first as this is the easiest to access and if that doesn't work then try for the sensors themselves which sound a little messy with having to flush the coolant again in one case and the other inside the oil, which was also recently changed like 300 miles ago...

[rusty_sojah]

it looks like fuse 88 is what folks are saying for the fan, but this fuse controlled my entire climate control system and is actually the one that went out on me a few months back. is there not a separate fuse just for the radiator fan, or is it all on the same circuit?

[rusty_sojah]

Originally Posted by RSL

I'm getting confused. Is the 2EFE old or still active (MHD time stamps them in code history) and is the current fan still working? If the code is current, need to see if the fan still works without the jumper (I'd remove that anyway if you haven't).

If you've had bad wires/grounds or blown fuses in the past, there may still be a lingering issue. The obvious system related components (fan, relay, sensor, etc) may not be part of the problem.

Your call, but at some point have to think it could be cheaper (not to say cheap) and faster to have techs who can diagnose end to end without guessing and replacing part after part on your dime. Either that or get ISTA and try working through any test plans on your own.

is this even the fan relay switch? now that i am searching online for one the parts that keep coming up look different.

i guess this is a plain old relay but it is for the fan as well as possibly other stuff as well. just ordered a new one for 31$ with the ridiculous shipping to Hawaii of like 17$. still not 100% sure this will fix my issue, but as you can see the jumper is hooked up on mine presently and the fan still comes on (seems like a single speed though) with this on and AC on.

[RSL]

Yeah, that's it, but can almost guarantee it's not the problem. I think they had different relays for other fans/years/cars.

Ok, the working fan is still in. Fuse 88 appears to be the HVAC blower, not the radiator fan. Looks like a small fuse to the fan relay in the fuse box (I think it was 28) and looks like another large fuse possibly in the rear. Your fan does go on when switched or jumped, so I'd expect the fuses should be fine though.

I'd back up a couple steps. You're focusing on the fan because your mechanic said it didn't run, but it obviously works. Time to see what it is or isn't doing when not manually forced on. If you have INPA or ISTA, I'd just start testing or logging what's doing what and when. All the parts seem to work (assuming they weren't wrong about the water pump and thermostat too), so it seems more like a control or intermittent electrical issue, if there there even is a parts problem. You've obviously had electrical issues in the past, perhaps there is still an intermittent one. Checked all the grounds/wires for any more "bad" ones? What caused fuse 88 to blow the first time?

[rusty_sojah]

Originally Posted by RSL

Yeah, that's it, but can almost guarantee it's not the problem. I think they had different relays for other fans/years/cars.

Ok, the working fan is still in. Fuse 88 appears to be the HVAC blower, not the radiator fan. Looks like a small fuse to the fan relay in the fuse box (I think it was 28) and looks like another large fuse possibly in the rear. Your fan does go on when switched or jumped, so I'd expect the fuses should be fine though.

I'd back up a couple steps. You're focusing on the fan because your mechanic said it didn't run, but it obviously works. Time to see what it is or isn't doing when not manually forced on. If you have INPA or ISTA, I'd just start testing or logging what's doing what and when. All the parts seem to work (assuming they weren't wrong about the water pump and thermostat too), so it seems more like a control or intermittent electrical issue, if there there even is a parts problem. You've obviously had electrical issues in the past, perhaps there is still an intermittent one. Checked all the grounds/wires for any more "bad" ones? What caused fuse 88 to blow the first time?

i don't know what caused it to blow but they showed me the wire and it had basically melted. if this switch doesn't solve it i might just bite the bullet and bring to bmw for an hour of their tech troubleshooting and maybe they can find the short or bad wire/connection, especially if i tell them about the previous bad 88 fuse wire hopefully the same tech might remember and know just what/where to check.

i also don't think it would be a sensor if i originally was getting the over temp warnings, and can still read the oil temps just fine. it is definitely drivable in traffic in a warm climate with the fan on with AC/jumper etc...

i was just reading on the z4 n54 side that the fan itself has the controls in it basically to regulate the speed??? if that is true then i might need a new fan after-all but i will deal with that later if necessary..

if you were me would you not drive the car any more with the jumper on it currently?? it seemed fine in bad stop and go traffic friday afternoon after putting that jumper on it. i was going to drive it about every other day this coming work week.

[RSL]

I'd drive it without the jumper and log to see what's actually happening. If ECT gets over 230F and fan still doesn't come on by itself, kick on the A/C to force it on.

I recently logged cooling system params to check some things on the different logics. If you have a laptop and INPA, you can log these as well.

https://datazap.me/u/rsl/cooling-test-70c-target?log=0&data=1-3-5-6-7-8-11

I'm not sure if the Z4 got the 800w fan like 335is and 1M. Somehiw I doubt it, but maybe the Z4is has it. 600w and 800w fans are different animals, so pay attention to which you're looking at when reading.

[rusty_sojah]

Well i replaced the ac/radiator fan relay switch part and i can't tell if im back to square 1 or makung progress or what.

With the AC on the fan blows at a low speed constantly. If i turn pff the AC the fan stops and if at operating temperature it takes about 30 seconds then it springs to life and kicks up to about a medium fan speed for only 30 seconds, then it takes it about 15 seconds to come to a stop and about 15 more seconds of nothing and then the fan kicks back on to a good medium speed for 30 seconds and this just continuously repeats.

I am not sure and am about to bring it to bmw to test voltages and wires and what have you. Honestly not sure if it is the fan or wiring or what.

[RSL]

Hard to say. Still don't have some basic info like coolant temp, oil temp, etc. when things are happening. The fan does change speeds as necessary, but I'd think if it's hot enough to come on from temps, I'd probably expect it to stay on at varying speeds, especially when driving.

Have you driven it since? Still run hot?

[rusty_sojah]

Originally Posted by RSL

Have you driven it since? Still run hot?

i didn't want to stray too far from home since i live in a thick downtown metropolitan type environment and can't just pull over and park if it overheats but i got it up to temp then drove around a 4 square block a few times to test. with the AC on (fan on low) and outside temp at like 78 driving around like a normal person in stop and go it never got past like 235-240. i then turned off the AC and did the same course a few times and once it hit 252 (slowly kept climbing to this 252) i pulled into a shady parking spot and turned the AC on (fan on low) and popped the hood and waited a few mins for the temps to come back to like 235. So yes i feel it is still going to overheat when driving spiritedly and in stop and go traffic like i did all summer long.

i'm going to wait a couple days until the next CC statement cycle and then drop off at BMW for troubleshooting.

[RSL]

Yeah, that's warm, fan should be on by itself without the A/C. Probably a good idea to bring it in. Might wind up being something completely unexpected or multiple things, so finding it/them can be time-consuming or expensive if you're just swapping parts to test. Good luck with it.