316 - 1977 - petroscf - Greece

[petroscf]

hahahahah sort of, yes!!

[gerrit323]

WOW .. really nice job .. happy for you that the car is finally running as it should .. you struggled for some years but finally a nice driving and good sounding e21.

Enjoy

[petroscf]

Thank you !

[BertjeConti]

Aha thanks, nice to read it turned out all well. Have fun with it

[petroscf]

[Jeroen]

Great! It took some effort and money as well I guess but sorted now!

[petroscf]

Well, hopefully yes.
I will keep my fingers crossed for some time though, until I feel absolutely safe.
Here is one concern, if I should have moved this to the Technical Section, please Jeroen move it in there and we could continue this there:
I have read the faq section about cooling issues. I guess what is written there fully covers all 4 cylinder and 6 cylinder models with factory specs and gives some extra tips about electric auxiliary fans etc
I wonder whether the above are or should be adequate for non factory specs engines such as higher c/r, hotter cam etc., engines that touch higher rpm range, (like my engine) not to mention probably central/north European climate mainly?

I don’t have these overheating issues I used to have in the recent past with the other engine and I do hope these totally belong to the past.

However I do still have some temperature issues : especially on hot Athenian summer days and if I decide to step on it I sometimes see temp rising over the middle and approaching 3/4.
Also on a hot afternoon while I was about 100km away from Athens on a motorway I drove a bit illegaly for some time “playing” with another car (oops I did not say that), temp almost reached 3/4
Of course I now do bother less than before as I have connected both the factory fan (which we had removed in the previous engine) and the auxiliary electric fan which apart from the automatic switch (iirc turns on at 92deg C) is connected with another switch, on demand (I can turn it on whenever I want).
On the other hand, due to 71deg C thermostat, in cool driving conditions (evening, low rpm, no traffic at all etc) gauge indication may show about 1/4 or just a bit over that.
Now this is my question: is this so big fluctuation normal? Why modern cars never have this big differences in temp gauge indication?
I was thinking whether a larger/more powerful radiator would help minimize this fluctuation from 1/4 up to almost 3/4 and ensure a more steady indication on the temp gauge?
Or this might be just my idea? Your opinions are more than welcome.
Also, welcome will be opinions/ideas on solutions (for example, if bigger rad what and from where to order?)

[gerrit323]

Modern cars also have those fluctuations but the temp gauges have electronic settings build in .. for exampe everything between 85° and 95° shows the gauge in the middle .

In the e21 these electronic settings are not build in so the gauges fluctuates more.

Difference between middle and 3/4 was 4° so not to worry if the temp gauge does not go further than 3/4.

In my hartge spec 323i I also had and extra electric fan on demande with a switch .. never had cooling issues

[petroscf]

Good, what you say is very relieving!
Still wouldn’t you care for a fresher, of possibly newer specs, higher cooling capability etc (if all these are available or can be custom made) rad?
Also, I wonder what each line on the temp gauge stands for (well, approximately)
Would be good to know what does it mean near 1/4 or near 3/4 or even near 4/4 (which on my car’s gauge is a bit before the red end)

[yatisr]

My car is a Malaysian based 323i. The daily temperature here is at least 32 C, which I presume is similar to what you experience in summer in Athens. I use a three-core radiator together with the standard clutch fan, thermostat and air-conditioning auxiliary fan. My daily commute to and from work in Kuala Lumpur requires driving through rush hour traffic on most days. On really bad days, I can be sitting in traffic with the air-conditioning on for more than half an hour. The temperature in my car's engine will stay at the half way mark on the gauge. At most, it will creep just above the half way mark. When running at speed (130kmh), the gauge will be just above the quarter mark. The 3-core radiator is the key to keeping the engine cool in the Malaysian climate. I understand that with the standard BMW radiator E21s in Malaysia run hot. The 3-core radiator in my car is locally fabricated from copper. The unfortunate thing is that it is not very durable and springs leaks after about a year and a half. I am sure that this is a fabrication and materials issue: aluminum would probably be less problematic, but it is difficult to get someone in Malaysia to make a bespoke 3 core radiator out of aluminum in Malaysia. But notwithstanding the leaks, the radiator in my car keeps the engine cool. My car goes in next week to cure a leak in the radiator (sigh). But she is still keeping her cool despite this leak. Yatis

[Jeroen]

Perhaps the additional electric fan could be a help, but the 3/4 mark is not a problem imo. Above that I'd start feeling uncomfortable.

[petroscf]

The additional fan is surely a help, and, as the engine now, as I said, runs much cooler than before (where it was in erratic situation), I don't see the point of having it connected automatically (at 92 deg C I guess), as 1) I haven't yet seen this temp and, 2)when I see the gauge climbing to more than the middle I turn on the electric fan with the "on demand" switch
However, a triple core red might be a nice add-on, if I could find one of good manufacturing quality.
My rad core was replaced at some point more than 20 years now, I don't now what it was from factory. Now it is double core. However, I don't remember ever having any leaks. Of course no water ever gets in there, only coolant.

[petroscf]

So another question coming here is: If between middle and 3/4 is about 4 deg C, (if we assume middle being about 80 deg C, where the factory thermostat opens, letting coolant flow) then 3/4 is about 84-85 deg C? Then the automatic aux fan switch which iirc is at 92 deg C should automatically open only if temp climbs higher than 3/4?
Maybe it would be better then to find and fit an automatic switch a bit lower than 92 degrees, at some point between 80-85 perhaps

[BertjeConti]

Consider that the temp sensor for the temp gauge is situated in the thermostat housing, and thermo switch(es) for the fan(s) are situated in the bottom of the radiator, so your temp gauge shows hot coolant before entering the radiator, and the thermoswitch reacts on the cooler coolant leaving the radiator.

When the gauge is in the middle, the coolant temp in the thermostat housing is approx 88-90 degrees. So when the gauge is at 3/4, the temp is approx 94 degree, this is equal to your engine temp, but much higher as the temp in the bottom of the radiator.

Hope this explanation helps

[petroscf]

Yes, indeed this is much helpful
But also this means that the aux fan switch should not be at 92 deg C, as then the coolant temp in the engine would be much higher. I should look for a switch that would let the fan open earlier