Member
Hello Jrcook320 this is Dave,
I am new here so thanks for tellling me about the faq I did check it out this time. Here is a question for you I want to clarify. You said "2 on the coolant neck at the top/front of the motor." What is the coolant neck? I am guessing that is where the top radiator hose connects to the top part of the engine? Please advise so I can be clear what it is thanks.
Does your auxiliary fan ever come on (with the a/c off) when your guage and car is getting hot? It sounds as though the answer is no and its normal what my car is doing. If that is the case let me know as I have spent much time on this matter thanks.
Dave
Member
Dave,Originally Posted by DavidCrevenston
You can call me Josh. Correct, the coolant neck is the aluminum manifold where the 2 rad hoses connect to the top of the motor with 2 sensors threaded into the top.
I installed a lower temp fan switch (it might be the middle temp switch but I'd have to pull it to check the temp setting), and it only closes very near the red line. I am running an aftermarket electric fan off the stock aux fan circuit and I have a switch wired into the circuit (the same portion of the circuit that the factory AC used to turn the fan on). I just flip the switch when I'm sitting in traffic of if it's running warm. In normal driving I don't need a fan (this is all covered in the faq).
I MIGHT be normal. If it gets to the 3/4 mark and stops climbing, you might be ok. Clean the gage and sensor sender contacts and/or verify with a thermometer if you have access to one.
If it continues to climb toward redline then there is probably a legitamate problem that needs addressed.
Member
Hello Josh,
Thanks for answering me back loved your video of your car bad a...... nice.. Okay to answer your ?'s its not the contacts behind the guages I have already inspected them when I took the instrument panel apart to replace bulbs and to fix the milage (plastic odometer gears wore out).
You said "I installed a lower temp fan [COLOR=blue !important][COLOR=blue !important]switch[/COLOR][/COLOR] (it might be the middle temp switch but I'd have to pull it to check the temp setting)" Do you mean that the one you installed is on the upper coolant neck and is one of those 2 sensors? If so do you recommend I replace or check those? I don't think they go bad or I have not heard of them going bad have you?
Thanks Dave
Member
David - I have a few questions for you:
1) You are in cold weather, and the guage goes up to the 3/4 mark?
2) If your car is idling for several minutes in your home parking spot, does the guage go up to 3/4?
3) With ac off, when the guage is at 3/4, does the aux fan turn on, and hold it at 3/4?
I know you have yet to do the "paperclip" test, Just figured you can obtain some easy T-Shooting data, til the snow goes away- before you get a chance to do the paperclip test.
Tbd
Member
I have not read the whole thread so forgive me if I am repeating anyone.I have been driving E21's since 1985. The cooling system has always been a concern and here is why. The E21's were delivered new without a coolant recovery system. There is only a overflow tube running from the left side of the radiator cap neck and down the left side of the radiator. Because of this you must check the coolant level on a regular basis. The best time to check it is before you start the car in the morning when the engine is cold. The coolant level will continue to decrease because of this setup and especially if you are running a 50/50 water glycol mixture. You can lose 50% of your coolant this way because as the level drops the engine runs hotter and boils off the water portion of the coolant! Now you are risking an overheat/blown head gasket/cracked head. It's best to run a straight glycol coolant, forget the water. Also it is a great idea to rig yourself a coolant recovery bottle. That way you won't have to check the coolant anywhere near as often.
The water pump impeller has also been a concern. The impellers were originally made from cast iron which will rust away if they are in water. If the temps don't come down with just keeping the system topped up them this is a very likely cause of running hot.
cheers,
Ed
Member
Hello Epmedia,
Okay to answer ? #1 In cold weather does the guage go to 3/4 mark? Not much it only has gone to 3/4 mark (in cold weather) only once when in traffic and sitting at numerous traffic lights a lot.
#2 No
#3 No the Auxiliary fan has yet to come on AT ALL since I got the car even when the guage is at 3/4. Note SO FAR the guage has not gone over 3/4 (yet good news) & the guage only comes on when the a/c is engaged other then that I have never seen it to go on.
Because of that fact typed above that started my quest for the correct answer of should the auxiliary fan come on when the a/c is off (when car is hot). I have gotten 2 different answers 1 the auxiliary fan should come on (with a/c off) when the car gets hot. Answer #2 the auxiliary fan should not come at all (except if the guage goes to red line when the a/c is off). So hence I am perplexed, confused, and ready to give up until I typed to you guys. Thank god you guys are here.....
DAve
Ed,
Hello ? for you..... When the guage goes to 3/4 and the auxiliary fan does not come on you can turn the heater on to cool down the car. I do this and the guage goes down quickly however this is a pain in the ...... to do if its hot out. So I think I am correct in saying that the fact that the car would cool so quickly with the heater on means that the water pump is okay and working probably would you agree? Sorry I worded that ? so funny thanks for your help.
Dave
Last edited by DavidCrevenston; 02-09-2010 at 07:48 PM. Reason: Automerged Doublepost
Member
Flywulf:
are you suggesting running straight ethylene glycol? If so that is terrible advice from both a cooling and a freeze protection standpoint.
Member
Redline on the guage is "too late", overheat. And yes - the aux fan should come on at a specific temp to protect from overheat, as others have mentioned, and for comparison: mine comes on about 1/2 on the guage (mine is a '78). My temp guage hoovers around 3/8 when driving around (I'm guessing that's the t-stat norm for my car).
Soon as you get the chance, do the "paperclip" test. In the mean-time (with the hood closed), let your engine idle for along time and monitor the temp guage, and let it get to 3/4 to see if the aux fan turns on. Report back with the guage readings and aux fan results.
Last edited by epmedia; 02-09-2010 at 08:26 PM.
Tbd
Member
Hello Epmedia,
Thanks for responding back I told you slightly wrong in the last post let me clarify it for you. Answer #2 from another forum is that the auxiliary fan will come on (at some point before the gauge goes to red line). That is the problem nobody knew when (at the 3/4 mark or past that on the gauge when the aux fan would come on). They said it should come on at 198F I think which is what nobody knew or could clarify that ?.
To respond to your other suggestion which is a good one. I already did what you are describing letting the car idle and try to get to the 3/4 mark. It takes a long time to get to the 3/4 mark idling it will get there quicker after driving a while in traffic at many lights. However either way when it reaches the 3/4 mark at idle in driveway or driving the auxiliary fan has yet to come on. The good news on the flipside is I have never seen the gauge go past the 3/4 mark. I have watched under the hood what happens when it gets to the 3/4 mark. It seems that the thermostat opens up fully at that point as the gauge starts to go down right at around the 3/4 mark and cools the car and gauge back down. But at no point does the auxiliary fan come on nor have I ever seen it come on since I bought the car.
Member
You won't likely be able to SEE any corrosion on the gage contacts as it would only be very light there. There could also be corrosion on the coolant temp sensor connection or a frayed wire causing higher resistance.
I've already explained the difference between all of the coolant related sensors and switches, and their location. Epmedia has even shown you a picture of where the fan switch is located. The fan switch is just a SWITCH and is located at the bottom of the radiator. All this does is turn the fan on at a set temp. There are 3 different switches available, all close at different temps. I was referring to the switch in the middle of the range.
The temperature gage sensor is the smaller sensor located on the coolant neck. Clean the terminal with emry cloth and tighten the female side of the connector. Also check for a frayed or corroded wire on that connector. You gage is working, that means don't replace the temp sensor.
The other sensor on the coolant neck is not related in any way to this issue.
Coolant overflow bottle = good idea
running straight ethylene glycol = terrible idea. NEVER run straight antifreeze. It doesn't transfer heat as well as water (your motor will run hotter), and it will still reach a boiling point if temps are too high or if system pressure is too low. Antifreeze doesn't raise the boiling point of water much, it is better at lowering the freezing point.
If you are losing lots of coolant on a regular basis and it's not leaking and you're not burning it, replace your radiator cap. The cap is what holds pressure on the cooling system. This pressure raises the boiling point of your coolant MORE than the antifreeze does. A worn cap will allow the system to vent at lower pressures and you'll boil coolant off at a lower temp.
Last edited by jrcook320; 02-10-2010 at 01:42 AM.
Member
Thanks very much I will check the contact points and the wire for the temp guage as soon as I can.
Dave
Member
I only know when it comes on for my '78
Josh's recommendation for a middle range aux fan switch; aka "trigger" is good, especially for loose engines. I'm not saying it needs to be replaced, I'm only saying it needs replaced if it does not work (which we have not determined the need yet).
Since your guage likes to hover around the 3/4, or below - I too am starting to think that the guage just reads high (fingers crossed). And I can see that in cold weather - that the aux fan may not even get a chance to turn on, especially since you recently changed the rad, pump, t-stat (and verified coolant level is at the bottom of the rad fill neck).
Josh, and others (as usual) made very good points about having a new rad cap, and installing an overflow if you are loosing coolant. I live in CA, USA, and installed one on my '78 years ago. I check it every week, and have not had to add any coolant to the resevoir for several months - sometimes I think all I'm doing is wearing out the seal on the rad cap!! On that same note - keep the rad coolant to the bottom of the fill neck - it makes a difference (when driving in hot weather).
Anyways - check those wire connections for the guage/sending unit like others have mentioned. It would be nice to know if the guage is reading high just because of dirty wires, or a bad/incorrect guage sending unit. I like a guage to read between 3/8 and 9/16 - that seems normal to me
Last edited by epmedia; 02-10-2010 at 05:37 PM.
Tbd
Member
something isn't allowing the coolant to flow throughout the entire system IMO. I would go ahead and replace the thermostat to begin with, or remove it altogether temporarily and see whether this changes the situation. This should be a very simple procedure, w/out having to remove belts and whatnot.
Member
Hello Dhoang & Epmedia,
To Dhoang I have already done everything you suggested to the car and also installed a new radiator cap as well.
To edmedia,
Remember that when the gauge goes to 3/4 is usually when its hot out rarely will it do it in cold weather. It did it in cold weather when driving in D.C. which I rarely do as (the potholes everywhere). I only did it then as there was heavy traffic and sitting at a lot of lights. Normally (cold out) it does not do it unless I drive it in heavy traffic sitting a while at many lights.
Also Remember the gauge does not go ABOVE 3/4 (OR NOT YET ANYWAY) which is good. At that point 3/4 (whether its hot or cold out) the thermostat fully opens and the car immediately cools down quickly and there is not problem. The problem I have is it goes to 3/4 before all this cooling process begins which is why I am thinking that the auxiliary fan should be coming on to cool the car after the gauge goes past the 12oclock position but again I am guessing here and that is the question that is open now.
After bad weather I will start with paperclip test first, then will check the connections on other sensors....
Dave
Member
Good point, where I live freezing is not a concern. Straight glycol has worked beautifully for me, might not be right for others. Please consult your manual for your own scientific wild _ss guess!
Ed
Member
The Official CORRECT ANSWER IS as follows. The owners manuals says 60/40 mix. 60% Water 40% coolant now you guys know.....
Dave
Member
Dave - I have another questions for you:
You mention that you can determine when the t-stat opens;
1) When the t-stat opens, does the temp guage stay the same, or does the temp guage drop significantly?
2) Before you changed all the cooling parts, how did the temp guage read and respond?
I'm only asking this since the weather is preventing you from doing the "paperclip" test and guage wire checks - So, something else to chat about in the mean-time
I know, we are reaching out with all the possibilities - I'ts only because you are unable to do any t-shooting right now, and we may as well make the best of your time with further input. What's an owners manual btw? lol
Tbd
Member
Hello epmedia,
Now you are talking my kind of language finally someone on here that reminds me of ME who asks great ?'s
Okay #1 the Thermostat has 2 opening points (via temperatures in which it opens don’t remember what they are but there are 2 temp points). So the answer is YES at both points when the t-stat opens you can see the gauge is clearly working properly and you can also see it drop. Example: I let the car sit and sit until the gauge finally got right near the 3/4 mark on temp gauge. At that point Exactly 3/4 mark on temp Gauge the thermostat opens up fully (at 180F to be exact). When that happens you can watch/see the temp gauge drop way down from 3/4 to below the half way 12 o'clock position.
#2 Before the gauge was the same accurate and working properly as well. I think before I changed the thermostat (with the old one on) it would take slightly longer for the car to get so hot (to the 3/4 mark. I believe this was due to the fact that the old T-stat was the original and slightly clogged with slime of coolant. It was not clogged a great deal though as I inspected the rest of the hoses and everything looked great.
It is also a good idea to keep in mind for ALL on here reading this that the connections behind the instrument panel for the temperature gauge itself it OKAY. I changed on interior instrument panel lights and had the entire instrument panel out and inspected all connection and everything looked great. It also worth noting here that the problem with the gauge was doing the same problem (getting hot 3/4 mark) before I ever changed or took apart the instrument panel. So that fact narrows down its not my error that I did not put something back correctly when I reinstalled the instrument panel assembly back in the dash above steering wheel.
Hope that info helps thanks for your help.
Dave
Dave - I have another questions for you:
You mention that you can determine when the t-stat opens;
1) When the t-stat opens, does the temp guage stay the same, or does the temp guage drop significantly?
2) Before you changed all the cooling parts, how did the temp guage read and respond?
I'm only asking this since the weather is preventing you from doing the "paperclip" test and guage wire checks - So, something else to chat about in the mean-time
I know, we are reaching out with all the possibilities - I'ts only because you are unable to do any t-shooting right now, and we may as well make the best of your time with further input. What's an owners manual btw? lol
Member
Dave,
That's very interesting… My car started doing a similar thing last summer where temps will occasionaly creep very high to the 3/4 mark when running on the highway or sitting in traffic, then suddenly drop to the half mark (or just below). It acts as if the thermostat is hanging closed, then suddenly releases. I'll run cooling system cleaner through and flush this spring along with a new thermostat (note: I'm already running a 2 year old 71* thermostat)
If I were you I would not be overly concerned at this point. It's either a gage calibration issue due to corrosion or faulty temp sensor (for the gage), or likely a thermostat problem. The fan should not come on at the 1/2 mark. With the stock switch it won't come on until temp is well over the 3/4 mark. You could install the 81* fan switch which is the lowest available to fit in the stock fitting.
I don't understand why you do all this "guess work" with things that are proven and well documented with paint by numbers instructions. There is no guess work.Good point, where I live freezing is not a concern. Straight glycol has worked beautifully for me, might not be right for others. Please consult your manual for your own scientific wild _ss guess!
Ed
Freezing may not be a concern for you, but I assume cooling still is, right? Ethylene glycol is not as efficient at transferring heat as pure water, so the more you use the less efficient your cooling system will be (meaning it will run hotter). Too high a glycol concentration can damage gaskets. Also, pure glycol freezes at a lower temperature than a glycol/water mix does, so it provides less cold-weather protection.
From Prestone's website:
But hey, what do the manufacturers (both auto and coolant) know? You can run Coors in your radiator if you want to make some more wild_ss guesses for all I care.We recommend that you use between a 50% and 70% concentration of antifreeze. At least 50% is necessary to give the adequate amount of corrosion protection, as well as freeze/boilover protection. However, we do not recommend more than 70% antifreeze. This would cause restriction of the heat transfer capabilities, corrosion protection, and freeze protection. The concentration of freeze/boilover protection of the antifreeze mixture can be checked using a Prestone® Antifreeze Coolant Tester.
Member
Yes, for the t-stat - there is a "start to open" temp, and a "fully open temp", which is designed to keep the coolant at a steady temp to the best of it's ability.
Are you able to verify that the "NEW" t-stat is not upside-down?
I know it sounds weird, but it is possible with different hoses installed..
The only reason I ask is because there is a significant change on your temp guage, and just reaching out to other posibilities again, while you are in bad weather and unable to do much t-shooting
Coors sucks...You can run Coors in your radiator if you want to make some more wild_ss guesses for all I care..
Last edited by epmedia; 02-11-2010 at 06:09 PM. Reason: Automerged Doublepost
Tbd
Member
To epmedia & Josh,
Thanks for answering back with good suggestions again. Okay to answer your ? epmedia the T-stat is okay and installed like your diagram. Its a good ? though and I will confirm (double check) when the snow melts. I have a car cover over it now with 1' of snow on top of it.....lol Well the curve part of the T-stat Housing is supposed to connect to the upper/top part of the engine like in your diagram. I copied how it was (Original) and put back exactly the same. Thanks for your help again....
Dave
Oh its also worth adding here I got the cooler 71F T-stat vs. the 80F originally factory T-stat. I did this with hopes of the Tstat open sooner hence keeping the car cooler and not letting it get to the 3/4 mark. My plan did not work it is almost the same as the original 80F Tstat opening....
Dave
Here in VA we call a owners manual that name. Curious what do you call them in CA? I used to live in Lake forest near Irvine CA. I also visited quite often to palm springs & San Diego.... Miss it now......
Dave - I have another questions for you:
You mention that you can determine when the t-stat opens;
1) When the t-stat opens, does the temp guage stay the same, or does the temp guage drop significantly?
2) Before you changed all the cooling parts, how did the temp guage read and respond?
I'm only asking this since the weather is preventing you from doing the "paperclip" test and guage wire checks - So, something else to chat about in the mean-time
I know, we are reaching out with all the possibilities - I'ts only because you are unable to do any t-shooting right now, and we may as well make the best of your time with further input. What's an owners manual btw? lol
Last edited by DavidCrevenston; 02-11-2010 at 08:06 PM. Reason: Automerged Doublepost
Member
I have an '82 and mine barely passes the 2nd mark on the temperature gauge. I think it is weird, maybe that is why mine uses a good bit of gas?
Member
Hello urotuned320i,
Thanks for responding but you have me confused and perplexed trying to understand what you meant. Lets clarify please what you mean I think you mean your gauge goes to the 3/4 75% mark is that correct? I generally refer to the gauge positions as 1/4 25%, Half way (12 o clock position) or 3/4 (75%) as the different positions. Please clarify for me thanks.
Dave
Member
Hello Epmedia,
Okay finally your instructions were perfect thanks. I did the test and it worked fine the auxiliary fan came on no problem good thing you told me to wiggle the paperclip though. Okay so to me this means 1 of 2 things so correct me here if I am wrong. 1 After verifying this test that means it could be a bad sensor that is attached to the bottom of the radiator (highly unlikely). Or 2 what is more likely here after reading jrcook and everyone else's posts there is nothing wrong with the car its normal for the temperature gauge to reach 3/4 and then to start cooling down due to the thermostat opening up fully. It was clearly stated by jrcook and others that the auxiliary fan only comes on at a extremely high temperature around or just past the 3/4 mark and my car has never gone past the 3/4 mark (not yet at least) because every time it gets to the 3/4 mark the t-stat opens up fully and the temperature gauge begins to drop fast back down to near the 1/2 mark slightly past the half way mark to be exact. However if this is true and the car/auxiliary fan is doing what it is supposed to be doing (coming on when car is extremely hot past 3/4 mark) then I did all this troubleshooting for NOTHGING. Please make me feel better here as I am frustrated now. I wish the info of EXACTLY WHEN the auxiliary fan is supposed to kick in would be posted or in the manual. However I even read the online manual someone posted on here on that car and it does not saySo hence forth the problem is SOLVED FOR ME UNLESS you tell me otherwise please let me know what you think thanks very much for your help.
Dave
Member
Hi Dave. Paper clip test = good, great
This quote from you:
"I let the car sit and sit until the gauge finally got right near the 3/4 mark on temp gauge. At that point Exactly 3/4 mark on temp Gauge the thermostat opens up fully (at 180F to be exact). When that happens you can watch/see the temp gauge drop way down from 3/4 to below the half way 12 o'clock position".
If you are just sitting there idling when that occurs, and all wires are clean to the guage; that suggests to me that the t-stat is NOT moving "smoothely" (like JRCook mentioned). I believe the t-stat should hold the guage within about 1/8 of guage travel - from "start to open", to "full open". And of course the guage will continually creep up if "full open" is not enough, which is when the aux fan will turn on at the temp of the fan switch rating (like GDAus mentioned).
Just so you know, I have the low temp t-stat as well, and it hoovers between 3/8, and 1/2 on the guage. I believe (not verified) I also have the low temp "aux fan switch", whick turns on just over 1/2 on the guage.
Essentially - I believe your guage should hoover between 3/8 and 1/2 with the cooler t-stat, not 3/8 and 3/4. And we still don't know if your aux fan switch on the radiator is good - that would require testing that has not been deemed necessary yet. Or - you could just get a new "mid" switch like JRCook mentioned.
I hope I said that right, somebody correct me if I'm wrong.
Tbd
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