Few issues with my 87 325e...

[ivopivo]

Few things that started happening last night, but were completely fine for 2 days that I've owned the car...

First is it's running a bit hot, between the 1/2 and 3/4 mark. This started last night, and it got to 3/4 at one point so I went to check under the hood and found the sensor (I think it's the sensor.. circled as #1 in photo below) on the expansion tank loose and leaking a bit of coolant. I tightened that up and called it a night because it was late and I just got home... figured I'd deal with it in the morning. So this morning, I went from my house to my parents (didn't have tools) and drove in fairly bad traffic for about 5 miles... gauge stayed right between 1/2 and 3/4 the whole time. Once at the parents', I bled the system for maybe 4-5 mins, closed the bleed screw off, and went to work, but gauge still stayed at the same spot, between 1/2 and 3/4.

Should I just bleed more, bleed a certain way, or.... I don't know how so much air got in while the little sensor was loose, but then again it might have been loose for a few days and just got bad last night (some coolant did leak out but not a significant amount). The thing that confuses me is that the car ran a bit cold prior to yesterday's heating up incident, and gauge would be closer to 1/2 but between 1/4 and 1/2, again for the 2-3 days that I've owned the car.

Any help is appreciated.

Second issue is that the climate control knob, that goes from 0-4, suddenly stopped working yesterday for no reason at all, on 1-3, but 4 works just fine....

Thanks and sorry for noobish questions.

[SpecM]

well, the part you circled is the coolant level sensor. Air pockets will not form from this being loose, it in the aux tank anyway. Keep it tight and top off the coolant, and try bleeding it some more (from the 8mm screw in the thermostat housing, right?) with the front of the car slightly raised ith a jack, or just pull up onto a curb.

the blower fan issue is most likely your fan resistor pack, not related

[ivopivo]

well, the part you circled is the coolant level sensor. Air pockets will not form from this being loose, it in the aux tank anyway. Keep it tight and top off the coolant, and try bleeding it some more (from the 8mm screw in the thermostat housing, right?) with the front of the car slightly raised ith a jack, or just pull up onto a curb.

the blower fan issue is most likely your fan resistor pack, not related

Yea I figured air wouldn't get into the system from the sensor being loose, which is why I'm confused about it running hot out of nowhere... it might be coincidental that the t-stat went to crap at the same time I noticed the loose sensor, but I don't know... not enough coolant seeped out (when I noticed it, it was maybe 10-15 drops down on the the engine burning off, plus level is less than half a cm under the cold/full mark on the tank) for me to even think it's significant so no clue why temps went up all of a sudden. I guess I'll try bleeding again for a longer time after adding more water in the tank.

As for the fan issue, I honestly have no clue where to look for the resistor pack so any help is appreciated (I didn't search that yet but feel free to post any helpful links anyway)

Thanks

[ivopivo]

I just drove it to lunch and it definitely feels like it wants to go all the way to red... I had to drive with the heater on to pull it back a bit from 3/4 (didn't let it get past that) so I'm thinking either t-stat or maybe bad fan/clutch, but being that it stays at about the same temp whether I'm driving 20mph on small streets or 70 on the hwy, I figured t-stat would be a good place to start.

[NeoMishMoo]

Replace thermostat first it is easy an relatively inexpenisve. If you go to a big chain parts house make sure to buy the "more expensive one" (they will probably only have 2 choices). I bought the cheaper one and had to replace it within a year.

Check that first as they are likely to fail.


Oh and as far as only having high heater fan speed. Your blower fan might be going. Keep turning the switch back and forth and drive it a little bit, it might start working fine in a couple days, at least mine did.

[ivopivo]

Replace thermostat first it is easy an relatively inexpenisve. If you go to a big chain parts house make sure to buy the "more expensive one" (they will probably only have 2 choices). I bought the cheaper one and had to replace it within a year.

Check that first as they are likely to fail.


Oh and as far as only having high heater fan speed. Your blower fan might be going. Keep turning the switch back and forth and drive it a little bit, it might start working fine in a couple days, at least mine did.

Yea I might have an 80 degree t-stat sitting in the garage from a few months ago when I wanted to replace the one on my E36 M3 with a lower temp one... they should be the same size.

I'm looking into cleaning the resistor for the heater fan or getting a replacement before getting into the actual fan/blower. Wish me luck

[dj01540i6sp]

I would suspect it is just low on antifreeze. Open your heater valve also to let the air out of it also. Do this on several runs / days then you will have a good bled system to make a good judgment. GL

[ivopivo]

I would suspect it is just low on antifreeze. Open your heater valve also to let the air out of it also. Do this on several runs / days then you will have a good bled system to make a good judgment. GL

It's definitely not low on antifreeze... I checked this morning before bleeding anything and it's roughly 4-5mm below the line on the expansion tank. I'm going to replace the t-stat and bleed the coolant, then go from there.

Oh and sorry but I'm nut sure what the heater valve is?

[ivopivo]

Good news for both these issues...

I know the fan control is temporary, but it simply started working yesterday when I went to pull the car into the garage to change the t-stat...

As for the t-stat, it has me a bit

I took off the hose going into the housing from the driver side, some coolant spilled out, and I put it aside behind the air filter. Then I took off the housing after cleaning it a bit, and finally the t-stat came out. When the t-stat came out, maybe 10-15 oz. of coolant spilled out... I had rags under the housing to collect the stuff so I said "meh, that's nothing"... I go to get the other t-stat on the bench and I guess vacuum, or whatever it was, pulled a lot more coolant out of the housing and spilled out. When I say a lot I mean the expansion tank went down from full line to almost empty... no clue why.

In any case, no biggie, I plugged the t-stat in quickly so no more would come out, got the gasket on there and then the housing. Then I filled up the driver side hose all the way until it started spilling, and connected that back to the housing. Finally, I took off the hose on the pass side that connects to the upper right side on the radiator, filled probably about half a gallon of destilled water (previous owner recently replaced coolant with 50/50 mix of Prestone so I lost roughly half a gallon through the housing after taking out the t-stat) until the hose was full, then connected that back to the radiator. By now, the expansion tank was back up to full.

Here's the weird part. I ran the engine, bleeding screw off, for a LONG time, and the temp never went past 1/2. When it got close I started bleeding quite a bit of coolant out, and then I did it with the heat on too....

The confusing part to me is how is there no air bleeding out when I obviously introduced a lot when replacing the t-stat and how is the temp staying pretty much perfect needle just about at 1/2 mark at the same time? I guess the t-stat was that bad since before I replaced the t-stat yesterday the car would warm up fairly quickly for the past couple days (after it stopped sitting between 1/4 and 1/2) but I still have no idea how it's not starting to heat up with all that air, unless it wasn't that much after I refilled through the top radiator hose...

In any case, I feel bad hating the fact that my car isn't heating up before being properly bled, but I guess it has been properly bled. Off to work now in this great Chicago traffic, so it should be a good test.

[ivopivo]

Survived 45 mins of 0-40mph (mostly 5-15mph) traffic this morning... gauge sat at this...