83 320i 1.8 Manual ? about tempature running over the 12 O clock Position?

[DavidCrevenston]

Hello I am new at this so perhaps you could welcome me and give me some tips on how this works. I am happy to find a site like this...... Well I do have a question perhaps someone could take a stab at. I have a 83 320i 5 speed the problem is it runs hot a lot. The temp gauge will go over the half way mark (3/4) to be exact when sitting at a red light or when its hot. Is this normal for the E21's 81-83 for those years? If not please advise me as to what it might be. I have already gone over many things such as coolant flush, new radiator, installed new thermostat cooler Tempature (171F versus the factory 180F thought that would help it did a little). Everything else works great belts, fan, new water pump, wow the car is great no problems other then this one I am naming please advise me thanks.
Dave

[tlapham]

normally i would assume thermostat... but if yours is new, i would assume radiator... but if you already replaced that and flushed your coolant, then the only thing i can think of is that maybe your gauge is reading wrong.

[epmedia]

The aux fan should be kickin in about the 1/2 mark to keep it cool. If the fan does not kick in - need to investigate it. I'm not sure where the sensor wires are on your model, and there is a relay in the fuse box as well. 3/4 mark when sitting is only normal if the aux fan does not kick in, and 3/4 is approaching too hot.

Do you still have the AC radiator installed?

Also, turn your heater on for a few minutes, let the engine cool, and check your coolant level again.

[DavidCrevenston]

I know right this is such b..... I am so flusterated here..... I don't know what else it could be. There is another thing it could be but very unlikely it would go bad in my opinion. There are 3 sensors that help make that gauge accurate on that model car. 1 is on the radiator that one looked good to me so I reinstalled it when I put the new radiator on as there was nothing wrong with that sensor that I could see. There are also 2 other sensors that go right into the block on the top of the engine near where the upper radiator hose goes to the engine block. Again I don't think those sensors would go bad they don't get used or touched much at all. Plus I have never heard of those sensors going bad have you?

Hello epmedia you said.... "and there is a relay in the fuse box as well" Please advise me where and what this relay looks like and where it is. If you don't know then can you advise me how I can obtain this information thanks.
dave

[epmedia]

On my '78 the relay is the 5th one back, from the front. There is also a 25amp fuse next to it. The fuse box cover says "Auxilliary Fan". The relay is about a 1" cube, or taller.

Do you have a legible fuse box cover?
Also - read my previous post again - relating to the heater and coolant level...

[DavidCrevenston]

Thanks ep media. 1 last ? for you though...... Once I locate and get my hands on the auxillary fan relay is there a way I can tell its bad? How does one go about testing a relay to tell if its bad or not? If you don't know the answer to this ? do you know how I can obtain this info thanks for your help.
Dave

[tlapham]

with the engine running, connect the two wires at the temperature switch on the bottom of the radiator. the fan should turn on. if it does not work, it could be either the switch or the relay.
you can pull the relay and jumper it across the leads in the fuse box to bypass the relay and turn on the fan.
you can take the temperature switch out, heat it with a torch or your kitchen stove, while checking for continuity. should close at 92 C or something like that.

the heater helps a lot to keep the engine cool. if you're in a jam and need to stay cool, open your windows and turn the heater on full blast.

However, the engine shouldn't be getting all that hot unless you're regularly in stop and go traffic for 20 minutes at a time. the engine powered fan does all the cooling i need. (when i had it installed)

the gauge sensors are just resistors so they can get corroded and make your gauge change reading.... not likely, i know, but it could happen.

[epmedia]

Thanks ep media. 1 last ? for you though...... Once I locate and get my hands on the auxillary fan relay is there a way I can tell its bad? How does one go about testing a relay to tell if its bad or not? If you don't know the answer to this ? do you know how I can obtain this info thanks for your help.
Dave

I don't know the wiring schematic well enough to advise any relay testing, even though I have a spare sitting right in front of me .
However, I would first check the fuse, and clean/tighten all the fuse contacts, before asuming the relay has gone bad. You can remove the relay and verify the contacts are clean and tight. You can also verify the aux fan spins freely, and not sticky - it should rotate very easily and keep spinning for awhile when "flicked" with a screwdriver.

Hope that helps, Robert

[g323]

You're timing could be way too retarded

[epmedia]

with the engine running, connect the two wires at the temperature switch on the bottom of the radiator. the fan should turn on. if it does not work, it could be either the switch or the relay. ...

Oh crap! Check all the ground wires near the fuse box too! Do they connect to some of the sensors?

You're timing could be way too retarded

definate possibilty, but we are trying to establish if the aux fan is working .

[Greenfield]

bit off topic, but are you in Old Town, and is your 320 silver?

[myersport]

Copied and Pasted my post from your other thread:

"Is the car actually overheating, or do you have a gauge/sending unit problem? I fought a situation like yours for awhile only to find I had a bad Temp sender. Find an infra-red thermometer (or similar) to test the temp at the thermostat housing and compare it to the gauge reading."

--dennis

[DavidCrevenston]

To Greenfield:
Hello I am Dave since you are so close to me I was wondering if you can recommend a good mechanic (& reasonable) for my 320i.
Oh to answer your question NO that is not my bmw I have seen that one as well near st. marys of old town.
Mine is in WAY better shape and condition. Mine is the same color though. Wow you must have a good memory and go to old town quite often I thought I was the only one who notice that 320i sitting in front of the Lyceum that looks like it never gets driven. POOR Car I wonder who owns it..... Well lets talk since we are so close to each other if you don't mind.


Hello To Everyone About temperature Gauge going over the 12 o clock position.
Okay I have done some things to narrow down the problem.
1st let me say this with the engine running when you turn on the A/C the auxiliary fan does come on right away and stay on. So that right there should narrow down quite a bit of things…… To me that means its not a fuse which leaves us left with 2 things. Either a bad relay or 1 of the 3 sensors is bad. I did pull the relay its looks BRAND NEW AND FINE. However I could not find a fuse or label for a fuse for the auxiliary fan.
Tlapham You said “with the engine running, connect the two wires at the temperature switch on the bottom of the radiator. the fan should turn on.” Please explain this process and what you mean by this in a different word phrasing please. I don’t understand what you are saying. I think what you mean is run 2 wires positive and negative to the connections on the sensor at the bottom of the radiator while the car is running and connect them to somewhere else? I am not sure please clarify for me thanks Dave.
These are my questions for you if you could please help me out here with some or all answers. Does anyone know if there is a fuse for the auxiliary fan & if there is one where it is located at? Is there any test I can do to see if the auxiliary fan relay is bad or good? How many fuse boxes are there and where are there locations on my 320i 83 1.8 manual? I only saw 1 fuse box under hood I am guessing that there is others please advise me?
Thanks for any/all help as this problem has been bothering me for some time and I am sure it is quite simple to fix. Everything works on my car its like new. THEREFORE there must be others on this forum or other e21 owners that have had similar problems to mine. Perhaps there it is notorious for the relay or switch to go bad to the auxiliary fan? I also checked the connection where the auxiliary fan connects to the switch I guess which is near the front grill and headlights.
Dave
Oh I also looked at all the fuses in the fuse box and they look good none blown that I could tell.

[fullswing]

welcome to the forum.

my sig has a link to the complete US manual.

good luck.

[epmedia]

If the aux fan comes on when the AC is turned on, then the relay is good, and the fuse is good. The actual temp guage sending unit is on the engine. Based on what Tlapham said; The trigger for the aux fan is on the bottom of the radiator - if you pull the wire plug off this trigger unit and use a paperclip to connect the two wires, the fan should turn on, which will verify that the wiring is good up to the relay. Based on other mentions as well; the trigger could be bad, or the guage could be reading incorrectly, so do the paperclip test and report back if you want. Also, verify that the radiator is full, based on what I mentioned earlier...

To simplify your thoughts on the aux fan: the fan is triggered by the ac switch, and the trigger on the radiator - and both use the same fuse, and the same relay.

[DavidCrevenston]

Hello epmedia you said "wire plug off this trigger unit and use a paperclip to connect the two wires, the fan should turn on, which will verify that the wiring is good up to the relay. "
Okay I am confused again so please help me clarify this..... I think you mean the following: 1st let me clarify for you that the sensor on the bottom of the radiator has 2 wires that are connected to the sensor. So you are saying for me to pull off both wires (disconnect them) then take a paper clip and touch the paper clip metal part to both sections where both of the wires connect to the bottom radiator sensor with the car running of course is that correct? That sounds very difficult for me to do without a lift s...... I am tired of getting under the car messing with this problem. Shit does anyone on here want to buy the car perhaps that would be easier.... What a nightmare all this stuff I have done already and need to do more of just for a auxiliary fan to come on..... Wow


Hello Epmedia
So let me get this straight now..... when the paper clip is connected to the 2 points of contact on that bottom sensor you are saying the fan will come on with the paperclip touching both points correct? Okay so I am guessing here but if I does not come on with the paperclip test that means the bottom sensor is bad correct?

[epmedia]

Hello Epmedia
So let me get this straight now..... when the paper clip is connected to the 2 points of contact on that bottom sensor you are saying the fan will come on with the paperclip touching both points correct? Okay so I am guessing here but if I does not come on with the paperclip test that means the bottom sensor is bad correct?

This test is just to verify the "wiring" to the fan/relay, FROM the trigger on the radiator. CAUTION: you may feel a little electric spark on your arm while rubbing against the alternator and wiggling the paperclip. SO, wear a long sleeve shirt .

This test does NOT verify if the trigger on the radiator is bad.

You should not need to get under the car for this test. Remove the plastic intake snorkel. The fan trigger on the radiator is below the battery (on my '78), and there is plenty of room unless you have huge arms and hands.

I just looked at my wires, I'm surprised my aux fan still worked - the wire connections are very green and a little loose. Just reach down there, and unplug the 2 wires, stick a paperclip in the two wire spade connectors. Put the ignition key to "run" position (do not start engine). If the fan does not come on, wiggle the paperclip, or clean the wires with wd40, try it again, wiggle again. (the wiggling is because the paperclip may not be making good connection).

If the paperclip test works, the wiring to the fan/relay, FROM the trigger wires is good. From the looks of my wires from the trigger, you may just need to clean them, tighten the spade connectors with pliers, and spray some wd40, or electrical grease, or both.

Hope this helps...

Here's a pic:

[DavidCrevenston]

Hello Epmedia,
Okay we are getting somewhere now I think I am start to understand you. Thanks for the tip of removing the intake snorkel I forgot I could do that I am so use to going under the car. Okay so let me clarify here I got this correct.......
You are saying to connect the to ends of the paperclip to the 2 wires that I will be disconnecting from the bottom radiator sensor is that correct? I then take the paperclip and rub/wiggle the 2 ends of paperclip to the 2 ends of the 2 wires correct? Okay if this does not work what does it mean then? If it does work and the fan comes on then I am guessing that means the sensor on the bottom of the radiator is bad? Please advise thanks for your help.
Also Please tell me when (at what position is your temperature gauge sitting at) does your auxiliary fan come on half way mark, above half way point or before halfway point?
Also worth noting here corrosion is not possible culprit here as I just changed the radiator and inspected and looked carefully at those 2 wires and their connections they look new. Of course that does bring up another question though. What happens if the 2 wires that connect to the sensor on the bottom of the radiator where switched or not put on correctly? I ask because I wondered if they were not in the correct order as they are not labeled at all. In fact I barely saw color on the wires as it was faded I think 1 wire as green can't remember though. Just a thought that if the wires were connected in the wrong place would that make a difference what do you think? Thanks for your help in this matter as I was close to giving up until I started talking to you guys
Dave

[epmedia]

I just added a pic on my prev comment...
The wires can be reversed.
I have to leave for awhile.... chat later.

[DavidCrevenston]

Hello Ep media wow that helps a ton thanks so much for doing that I understand now.....
Your 78 is a little different then my 83 in the matter of my auxiliary fan trigger (as labeled in your picture) is on the other side near the alternator.
So after test if that fan does not come on I am guessing that means either 1 of 2 problems. 1 the auxiliary fan trigger (bottom radiator sensor) is bad or 2 its on of the sensors mounted on the engine near the upper radiator hose. Would that be correct or could you clarify it for me better as to what it might be after the test. I will do the test as soon as I can right now we have a lot of snow so not good idea now. Thanks for all your help and taking that picture wow what a difference.
Dave


Hello Epmedia,
I also forgot to mention that on my 83 the (auxiliary fan trigger as in your picture) Screws into the bottom of my radiator on the left side (opposite of where yours is on your 78) near the alternator. I just wanted to clarify that so we both know we are talking about the same sensor that screws into the bottom of the radiator.

[epmedia]

Do the test first... (one thing at a time)
My pic is from the top, trigger on the bottom driver side of the radiator.

[GDAus]

Hi .....

according to the specs, the standard temp switch controlling the aux. fan cuts in at 208 F (98 C) ... so, realistically, the fan shouldn't be cutting in at the half way point on the temp gauge ! So maybe you are hunting the wrong problem.

... and like Myersport, I thought mine was running hot. I did a bypass switch for the fan .. When that didn't change anything much I found a thermometer that would fit in the radiator neck and measured the water temp in the radiator directly as the engine warmed up and found the temp was normal - but the gauge said hot. (Of course if you do this ... don't take the radiator cap off a hot engine ... I've seen the sort of burns you can get from that and it's not pretty .. and not worth the risk )

Turned out to be a bad contact on the back of the instrument cluster where the temp gauge was mounted .... but it could also be a bad contact at the temp sensor on the water outlet elbow on the engine. Any bad connection in the circuit adds resistance and will make the gauge read high.

I did find later that my temp switch in the radiator had failed and replaced it with a 92 C switch .. but even then, the fan doesn't cut in when my gauge is at ¾ when I'm crawling in traffic in 35 C heat.

Cheers

[mxl556]

Lack of aux fan won't get your engine to overheat unless you're going uphill at the redline in 100+F weather with A/C on...

Simple things first-

- cooling systems is filled with coolant and has not air pockets?
- no coolant leaks?
- radiator/heater is not blocking the circulation?
- thermostat is working?
- headgasket/head is fine?

When does it overheat? While idling or driving?

Max
PS if you don't run A/C you don't really need aux fan. Unless something else is wrong...

[DavidCrevenston]

Do the test first... (one thing at a time)
My pic is from the top, trigger on the bottom driver side of the radiator.

Hello Epmedia,
Well it will be a while before I can do the test as we have a lot of snow here and are getting more tomorrow

In the meanwhile I did some more searching about this problem here are my findings..... From the ONLINE Manual that someone here on the forums gave me it mentioned the following part names and part #'s that could be possible for the problem. Please take a look at them and let me know what you think if these parts are worth looking into and if they could cause the problem. Some of the parts for ex. (temperature transmitter) I have never heard of and don't know where they are on the car? Please advise me if you don't mind thanks again for your help.

Temperature switch for extra fan
Extra fan relay
Temperature transmitter (62 16 050) part #
Look up (320 62 013)
Temperature sensor
320 11 154
　
Dave
　

To GDAus,
Hello so question for you then? When does your auxiliary fan come on at what temperature or what position is the temp gauge at when it comes on? Is the gauge over the 12 o clock (half way position)? So perhaps everything is fine then I don't know confused.... What do you think of these parts do you think any of these could be the cause for the problem and have you heard of any of them going bad on your car?
Temperature switch for extra fan
Extra fan relay
Temperature transmitter (62 16 050) part #
Look up (320 62 013)
Temperature sensor
320 11 154
　
Dave

Lack of aux fan won't get your engine to overheat unless you're going uphill at the redline in 100+F weather with A/C on...

Simple things first-

- cooling systems is filled with coolant and has not air pockets?
- no coolant leaks?
- radiator/heater is not blocking the circulation?
- thermostat is working?
- headgasket/head is fine?

When does it overheat? While idling or driving?

Max
PS if you don't run A/C you don't really need aux fan. Unless something else is wrong...

Everything above is fine checked and verified by myself. The temp Guage only goes to the 3/4 mark only when sitting in traffic or sitting still for a while. It does take a while for it to get there though. However the auxiliary fan never comes on at all unless I turn on the A/C. What do you think the problem could be? When (at what position on the temp guage) is the auxiliary fan supposed to come on?

Thanks for your help Dave

[jrcook320]

As GDaus already stated, the fan is going to come on at whatever temp the fan switch is. The stock fan switch closes at 208* F (probably very near the overheat redline), there is also a 197* switch available, and better yet a 180 deg switch available from bavauto. With the first 2 switches, the point at which the fan comes on is likely going to be over the 3/4 mark.

I don't know exactly what temps the marks on the coolant gage are supposed to correspond to. The stock thermostat is 80*C (176*F), so I would guess that the middle mark on the gage is close to that temp (176). I would also think that the 180 deg fan switch will make the fan come on below or close to the 3/4 mark. Keep in mind, the stock gage is NOT accurate, especially if there is corrosion on a contact, or faulty wiring. I would say that both of those problems are highly probable, so take what the gage is telling you with a grain of salt.

There is only ONE sensor for the temp gage. It is the smaller of the 2 on the coolant neck at the top/front of the motor. The larger sensor there is really the thermo/time switch for the cold start injector, which triggers the cold start injector only during cranking when the motor is cold. The switch on the side radiator is to turn the fan on.

Also, many, many of your questions can be answered by scrolling through the FAQ thread. There is a ton of info there so it can take some time to get familiar. Your questions on fuse/relay locations can be found in the electric trouble shooting manuals (ETM's) which you can find by looking the table of contents. They should also all be marked on your fuse box lid unless they're no longer legible.

And lastly, the BMW owners manual states that it is normal for a 320i to climb to the 3/4 when traveling at elevated speeds for long periods of time.