coolant gurus, I need some insite

arcticsilverM3 · #1 (**permalink**) 07-28-2009, 11:18 PM

here is the story,

I replaced my radiator with a zionsville full competition radiator about a year ago and every thing has been fine except for one or two high readings on my temp needle. i figured, hell its a 116 out here in arizona, its going to run a little warm. Now, flash forward to about a month ago. The car had been leaning toward the warm side, further than before, but not quite to the 3/4th tick mark and again, its 110+, so i figured its just the heat getting to it. Last week it started to hit the 3/4 mark and it would go down when i turned off the A/C so i figured it was again just running hot. Tonight however, the needle would quickly accelerate just past the 3/4 tick and hover between it and the red and would not go down! Now im thinking something is wrong!

Based on my thinking, im assuming that the T-Stat is going bad.

I guess what im asking is if others agree. I have not replaced the T-stat or water pump in some time, so i was going to do both tomorrow. i run 30% coolant and 1 bottle of water wetter mixing with distilled water.

Thanks for reading the long post, i guess i am just looking to see what others think could be happening.

gelb3 · #2 (**permalink**) 07-29-2009, 12:03 AM

One or the other, but if you're doing both that should take care of it. I was in Dallas a couple of weeks ago. The outside temp was pushing 115 with crazy humidity,my car never once went past the halfway line with the AC on full tilt boogie sitting in traffic. All oem cooling system.

arcticsilverM3 · #3 (**permalink**) 07-29-2009, 12:40 AM

cool....makes me think the thermostat has been going bad for a while.

99MPower · #4 (**permalink**) 07-29-2009, 01:04 AM

with as hot as it gets, I would get the 80C thermo, alum thermo housing, and then get a 80/88 fan switch

you already have the spal fan (i'm assuming since you have the zionsville comp cooling kit, SAME kit that I have) so, just run the lower temp thermo and fan switch and that should help keep things cooler

also, I would look into getting the stewart water pump. Yes, it's more expensive, but well worth the added peace of mind.

I run the Zionsville Competition cooling kit as well with the Spal electric fan. I also run the Stewart WP, 80C thermo, alum housing, 80/88 fan switch, water wetter, distilled water, BMW coolant, spal fan triggered for 80C, and Samco hoses. NUMEROUS auto-x and HPDE events in 100+ degree heat and ZERO issues...

if you need any other help, let me know via PM, and I can get you my cell if u want any more info

rowar64 · #5 (**permalink**) 07-29-2009, 01:45 AM

I'm in Gilbert...OBC showed me 120 for exterior temp yesterday...and I do believe it.

Just did mine a few days ago...still running OE radiator that's less than 2 years old so I left that alone but did water pump, tstat, aluminum tstat housing, coolant flush (water wetter as well) and new belts.

I went OEM on my tstat and water pump and your probably fine with that but Calvin's peace of mind statement means a lot so that's a safe way to go. Definitely change your belts as well. That will help your a/c issue.

99MPower · #6 (**permalink**) 07-29-2009, 04:51 AM

also, belt tensioner is a big thing as well if it's never been replaced to keep good tension on all the accessories that run off that belt...

I spent HUGE money on my cooling system, but with all the horror stories I hear, especially with the e36, and my track time, it was WELL WELL worth it..

IMHO... every cooling system should do the minimum every 60K-70K (i've personally replaced a OEM radiator with 48K on it, *cracked at upper neck*)

radiator (if OEM) otherwise Mishimoto alum or higher, and never worry again
thermo (88C or 80C if you track/hot weather area)
alum housing (only once, just make sure you have it)
hoses (upper/lower)
expansion tank/bleed screw
water pump every 80-100K (stewart water pump if you track/hot weather area, and the stewart has lifetime warranty IIRC)
coolant flush every 2 years or 1 year if you track
new fan (euro diesel preferably, or fan delete with electric even better)

BadGTho · #7 (**permalink**) 07-29-2009, 04:54 AM

i would replace the stat, water pump and do a coolant flush/

at this point, from getting too hot too many times, it's best to just replace.

99MPower · #8 (**permalink**) 07-29-2009, 04:56 AM

Quote:

Originally Posted by BadGTho

i would replace the stat, water pump and do a coolant flush/

at this point, from getting too hot too many times, it's best to just replace.

100% agree.... replace with 80C thermo, stewart water pump, and fresh flush and bleed appropriately and you should be GTG.. enjoy

BadGTho · #9 (**permalink**) 07-29-2009, 05:03 AM

Quote:

Originally Posted by 99MPower

100% agree.... replace with 80C thermo, stewart water pump, and fresh flush and bleed appropriately and you should be GTG.. enjoy

yupp.. and to add.

do so IMMEDIATELY... the gauge in this car does not have a linear correlation to engine temp. when it goes to 3/4 the car is WAYYYY to hot.

that amount of pressure will cause the coolant be under a bunch of pressure, break down and will damage components (copper in stat, waterpump bearings)

rowar64 · #10 (**permalink**) 07-29-2009, 05:36 AM

ben and cal...do you think the ambient temp plays a part in it? I mean it is hot as hell here but the engine gets to a temp that is hotter than our outside temps. After doing mine this past weekend I'm good on temp readings (though you always fear a bad tstat)
Belt changes, although seemingly insignificant...may play a part in this...+1 on the tensioners too...

BadGTho · #11 (**permalink**) 07-29-2009, 06:27 AM

Quote:

Originally Posted by rowar64

ben and cal...do you think the ambient temp plays a part in it? I mean it is hot as hell here but the engine gets to a temp that is hotter than our outside temps. After doing mine this past weekend I'm good on temp readings (though you always fear a bad tstat)
Belt changes, although seemingly insignificant...may play a part in this...+1 on the tensioners too...

i don;t think that the ambient temp has that much to do with it.

coolant temps are in excess of 200 degrees.. the difference between 90 degrees ambient and 100 degrees ambient should not be significant IF (key word if) the cooling system is functioning properly.

gelb3 · #12 (**permalink**) 07-29-2009, 07:01 AM

Ben you prob now a little about this also...back in the day a cooler thermostat didn't always mean cooler temps, The thermostast also regulates the flow of coolant after opening, If the coolant doesnt stay in the radiator long enough for the heat transfer to take place, you are essentially losing any benifits of a cooler thermostat.

No stat in the winter...no get warm inside car....maybe after awhile.
No stat in summer...no stay cool...car get hot things go boom.

No regulated heat transfer in either case.

BadGTho · #13 (**permalink**) 07-29-2009, 08:01 AM

Quote:

Originally Posted by gelb3

Ben you prob now a little about this also...back in the day a cooler thermostat didn't always mean cooler temps, The thermostast also regulates the flow of coolant after opening, If the coolant doesnt stay in the radiator long enough for the heat transfer to take place, you are essentially losing any benifits of a cooler thermostat.

No stat in the winter...no get warm inside car....maybe after awhile.
No stat in summer...no stay cool...car get hot things go boom.

No regulated heat transfer in either case.

you are correct... the stat meters the flow in and out of the rad. it is a vital component.

a cooler stat does mean that the radiator begins to cool the car more quickly.

99MPower · #14 (**permalink**) 07-29-2009, 11:10 AM

Quote:

Originally Posted by BadGTho

a cooler stat does mean that the radiator begins to cool the car more quickly.

why the FDM kit comes with a 80C thermo and most track guys run an aftermarket water temp gauge and keep a very close on eye things. If the car is running TOO cool, I've seen guys change to a WARMER thermo to keep in the operating range..

once the stock temp gauge begins to move from center, IIRC it's already over 220F and you are in trouble. Most temp's even under track conditions and traffic run around 190-205, so once that needle moves to over 1/2 you need to shut the car down IMMEDIATELY and not drive anymore.

Due to you getting to 3/4 on numerous occasion its a required MUST to get a new thermo and new coolant at a MINIMUM. I would suggest a new WP as Ben and I have already stated as well. I'm guessing you hit 250+F in the coolant

jrekucki · #15 (**permalink**) 07-29-2009, 05:42 PM

Thanks for the insite guys. i alread have a new water pump and an 88 degree C themostat for now. i also bought a metal impeller pump, not a stewart. i couldnt afford it today. Plan is to fix her up tonight! new coolant, new pump, new T-stat.

Calvin, do you have a pn for that thermostat? and the fan switch? i looked for a while last night and couldnt come up with it.

i already have the metal T-stat housing, so i purchased a new gasket for that as well.. gotta love workin in a show with same day delivery

i will let you know how it goes