e30: new plugs but temp. goes up!

[selespeed]

hi all experts out there; i had new iridium plugs changed yesterday. the old ones are pretty worn out after using for 80000km. the water temperature was constant at about 1/4 mark until today when it went up to 1/2 mark and stays there pretty much throughout. it did go down to about 5/8 mark as i drove on. why did this thing behave this way? why do new plugs cause water temperature to go up? thanks.

 

[anaksarawak]

hi all experts out there;

i had new iridium plugs changed yesterday. the old ones are pretty worn out after using for 80000km.

the water temperature was constant at about 1/4 mark until today when it went up to 1/2 mark and stays there pretty much throughout. it did go down to about 5/8 mark as i drove on. why did this thing behave this way?

why do new plugs cause water temperature to go up?

thanks.

You might have use the wrong temp plugs.. Some are 5 some are 6.. so becareful.

Check here please
http://www.ngksparkplugs.com/part_finder/car_truck_suv/step2.asp

 

[selespeed]

You might have use the wrong temp plugs.. Some are 5 some are 6.. so becareful.

Check here please
http://www.ngksparkplugs.com/part_finder/car_truck_suv/step2.asp

the plugs are exactly the same as the old ones.

strange thing is as i drove today home, the temp. went down steadily from 1/2 mark to 1/4 and then to rests there below 1/4 mark. it's now all back to the normal readings i used to have. i think the plugs took some hesitation to remove the heat??? seems to be doing ok! the temp. looks like in these pictures...

BTW, i have had these low readings for many years. but it's still within the range. the old plugs show the combustions is very good -- dry and brown. so, compression ok la i guess!!!

oh, btw, i have bkr6eix-11 (mid range heat range)

 

[anaksarawak]

Huh?? I seen many BMW most of them have their temp 1/2 mark hardly on 1/4 mark on normal operating temp..

Better have your car check soon to avoid further damage.

 

[selespeed]

Huh?? I seen many BMW most of them have their temp 1/2 mark hardly on 1/4 mark on normal operating temp..

Better have your car check soon to avoid further damage.

mine is a singapore 316i. has been like that since i bought it years ago. top overhauled last year and mechanic said all ok. no leaks nothings. maybe it dissipates heat better?

for my alfa 156, it's also on 1/4 mark and a lot of my friends' car also have it on 1/4 mark. i guess this e30 knows i am alfa driver!

 

[meetoo]

I think the temp guage on the 1/4 mark is way too cool. Most of us have it on the 1/2 mark and steady as a rock after a few minute of driving. Your cars are running too cool selespeed, and running a cool engine has bad effects too.

I guess you won't agree , but read the 3rd article here: http://www.northstarbmw.org/index.aspx?ns=TechArticles

Abstract:
Thermostats maintain the correct temperature for both the passengers and the motor. If your thermostat is allowing your engine to run cooler then recommended the engine computer may never allow the fuel injection to work properly, causing poor fuel mileage, high emissions, poor performance and possibly fuel dilution in the motor oil.

This is why short trip driving is so hard on oil. If the engine does not get to run at full operating temperature for a good length of time then moisture will start to build up in the oil, causing sludge to form.

 

[meetoo]

Sometimes when you have a problem like this one: http://www.bmwclubmalaysia.com/forums/showthread.php?t=12297
you won't suspect that it's due to another system fault.

 

[selespeed]

I think the temp guage on the 1/4 mark is way too cool. Most of us have it on the 1/2 mark and steady as a rock after a few minute of driving. Your cars are running too cool selespeed, and running a cool engine has bad effects too.

I guess you won't agree , but read the 3rd article here: http://www.northstarbmw.org/index.aspx?ns=TechArticles

Abstract:
Thermostats maintain the correct temperature for both the passengers and the motor. If your thermostat is allowing your engine to run cooler then recommended the engine computer may never allow the fuel injection to work properly, causing poor fuel mileage, high emissions, poor performance and possibly fuel dilution in the motor oil.

This is why short trip driving is so hard on oil. If the engine does not get to run at full operating temperature for a good length of time then moisture will start to build up in the oil, causing sludge to form.

so you reckon it's the themostat!

i have been tracking y fuel consumption diligently without fail. it averaged about 10-10.5km/liter in city/highway and improves to 11.5km/liter on highway. i changed my oil regularly at 10,000km. used to do it at 5,000km but not anymore and only on fully synthetic oil. the oil thing, in my experience, is the one that improved response and performance a great deal.

i have been running this kind of temperature for more than 3 years since i acquired the car. initially i found it a bit "unusual" but mechanic said nothing's wrong. so, after 120,000km the power is still very good and i guess it is ok la! it's only on one occasion that the temperature went up past 1/2 mark because the water hose broke leaking coolant.

however, i found that the fan is working all the time even when engine is cold in the morning. normally, the fan shouldn't come on when the engine is cold. but my e30 is like that! is this normal? are all e30s like that?

 

[meetoo]

It can be anything in your cooling system, not only the thermostat. But that's the first thing to check and replace. It is designed to fail in open position which will result in always-on state for the cooling system. But your fan is always on, which shouldn't be the case also. If the cooling system is working well, even on a hot day the fan cuts in and out every few minutes. Could be the fan's thermostatic switch or coupling is kaput resulting in always-on state.

So it would seem that your car is over-cooling and that will result in one or more other problems IN THE LONG RUN. As I said in an earlier post, an engine running cool is not good, but a lot of laymen will think it is better to be cooler and our untrain trial and error mechanics will add to that fantasy.

See this site to understand how a thermostat work: http://auto.howstuffworks.com/cooling-system8.htm

That's why I say a thermostat is a renewable item just like the spark plugs. They don't last forever. In fact if you've overheated the car before, some of the wax may have melted out and it will give a wrong result.

 

[meetoo]

BTW, that's probably why your fan fail recently...it was always on!

 

[ersalle]

Selespeed, check ur thermostat. I think ur using a low temperature one. There are 78deg C(if not mistaken),80deg C and 88deg C. For E30 M40 316i/318i you should be using 88deg C. Yhis will make ur normal operating temp almost to 1/2. U can use 80deg C it will sit just above the 1/4 mark. But i think ur thermostat is stuck open. Did u send ur car to TWO-B trading? If u did, hope they didn't meddle with it. They like to set the thermostats stuck open a bit and thats why its reading low. I had some experience with them about this and in the end i replace with a 88deg C thermostat back.

 

[ersalle]

If ur fan is always on, check that its not being bypassed. If no bypass done, then it could be thermal switch faulty(which is very rare)

 

[selespeed]

It can be anything in your cooling system, not only the thermostat. But that's the first thing to check and replace. It is designed to fail in open position which will result in always-on state for the cooling system. But your fan is always on, which shouldn't be the case also. If the cooling system is working well, even on a hot day the fan cuts in and out every few minutes. Could be the fan's thermostatic switch or coupling is kaput resulting in always-on state.

So it would seem that your car is over-cooling and that will result in one or more other problems IN THE LONG RUN. As I said in an earlier post, an engine running cool is not good, but a lot of laymen will think it is better to be cooler and our untrain trial and error mechanics will add to that fantasy.

See this site to understand how a thermostat work: http://auto.howstuffworks.com/cooling-system8.htm

That's why I say a thermostat is a renewable item just like the spark plugs. They don't last forever. In fact if you've overheated the car before, some of the wax may have melted out and it will give a wrong result.

the fan shouldn't be on all the time! and i think the switch isn't working properly.

my temperature reports 1/4 mark but within the range. it is not too cold. what can an overly-cold engine result? in the first place, my engine oil is always properly warmed up before i blast high speed on highways after 15 minutes of slow moving. so, i reckon the oil is hot.

for my alfa, i have never had thermostat replaced. in fact i never heard of themostat being replaced for my buddies in alfa. anyway, thanks for your insights!

i for one, do not believe that such item need to be replaced every 2 years. without going into details, i just feel that a thermostat is supposed to last longer. a car engine is designed to be tolerant to operate within opeating temperature range. if it's lower than the 1/4 mark, then it is sign of concern.

many of my alfa friends have their 156s at 1/4 mark or slightly above 1/4 mark and there are absolutely no problem. perhaps you are a perfectionist.

 

[meetoo]

Good points ersalle! Our great mechanics installing lower temp thermostats, fiddling them or bypassing fan switches. "Engine run cool good wat. Radiator last longer wan. No problem wan, so far no complaint from customer." Sigh! All base on under the cherry tree training.

 

[selespeed]

Selespeed, check ur thermostat. I think ur using a low temperature one. There are 78deg C(if not mistaken),80deg C and 88deg C. For E30 M40 316i/318i you should be using 88deg C. Yhis will make ur normal operating temp almost to 1/2. U can use 80deg C it will sit just above the 1/4 mark. But i think ur thermostat is stuck open. Did u send ur car to TWO-B trading? If u did, hope they didn't meddle with it. They like to set the thermostats stuck open a bit and thats why its reading low. I had some experience with them about this and in the end i replace with a 88deg C thermostat back.

ersalle, what you said struck me as i rememebr many years ago i heard someone saying about this low temp. thingy.

yeah i sent to Two-B. i don't know if they meddled with it. but why are there so many versions of thermostat huh? anyway, how much is a 88 degree themostat?

 

[selespeed]

Good points ersalle! Our great mechanics installing lower temp thermostats, fiddling them or bypassing fan switches. "Engine run cool good wat. Radiator last longer wan. No problem wan, so far no complaint from customer." Sigh! All base on under the cherry tree training.

i am inclined to think they bypassed fan switch. because i am always puzzled why the fan is always on! they did some tricks!

 

[ersalle]

Lower rating thermostat are used on e21's and earlier cars. As for E30s M40 engine using 88deg C. Yes there are many variety of thermostat rating available for BMW engines. U can use any of them, theres even a 91deg C which is used on E36's M40's engine. Thermostat costs around $14 if i'm not mistaken, can get them at ENG SOON. So u did send ur car at TWO-B, i bet they fit in their mod version of thermostat which is stuck open a bit, thats why ur car temp gauge is low.

 

[meetoo]

perhaps you are a perfectionist.

No lah Just that I'm an engineer and things like operating parameters are very important to the proper functioning and maintenance of equipment.

Have you read this?: http://autos.yahoo.com/maintain/repa...ques019_2.html

A thermostat is very cheap, only RM30 to 40.

 

[ersalle]

Pull out the wire they jump(u shape) on the thermal switch.If radiator is in good condition it wont go beyond 1/2

 

[selespeed]

No lah Just that I'm an engineer and things like operating parameters are very important to the proper functioning and maintenance of equipment.

Have you read this?: http://autos.yahoo.com/maintain/repa...ques019_2.html

A thermostat is very cheap, only RM30 to 40.

great engineering mind. i am also technically inclined but don't want to be too technically inclined. just enough to know the basics.

oil change? i experimented with all kinds if oil before. and very frequent oil change. good oils are fundamentally important in protecting engine and improve performance. not exhaust, air filters!