is there anything wrong with just removing a thermostat to diagnose if that is the problem with my car sometimes getting hot? with just paying tuition i'd rather not mess with the water pump, but if i need to replace it i'd rather do it when i already have everything drained and flushed. the only thing that would effect is a slight decrease in efficiency as it takes longer to heat up, correct? or am i thinking about it wrong.

8/11/2010 12:40:37 PM

Only real problem about taking out the tstat is the risk of blowing out the heater core. For just diagnosing you'll be alright.

8/11/2010 12:46:55 PM

so just keep the revs low then i guess

8/11/2010 1:16:50 PM

Thermostats are rarely more than $10. If you're taking it off you'll probably need a new gasket. Might as well just toss a new one in if you're going through the trouble of diagnosing it.

8/11/2010 1:24:45 PM

i mean i've already ordered one, but it wont be here for 5 days and i'm antsy about figuring this out. i was going to just get one from the dealership and knock this out today but they wanted $65 for a thermostat that i can get for $17 online.

8/11/2010 1:30:26 PM

Woah...Never seen one cost that much! All mine were like $4 for the regular or $10 for the nice one.

8/11/2010 2:21:47 PM

$10-$17 is price for the cheap one, the slightly upgraded one from the m3 is about twice that (online prices)

i can also get a gallon of bmw oem coolant delivered to my door for about a dollar less than the dealership.

8/11/2010 2:38:53 PM

wait what was the year,make, model?

8/12/2010 12:47:38 PM

97 328i

(and i didn't think about the housing seal so i'm just waiting till everything gets here)

[Edited on August 12, 2010 at 12:59 PM. Reason : .]

8/12/2010 12:59:15 PM

did you put the thermostat in a pot of hot water and test if it's opening properly?

If you think you have a leak you can rent a cooling system pressure tester at Advance to check

8/12/2010 5:58:22 PM

^do they have the bmw adapter

8/12/2010 5:59:47 PM

definitely no leak

basically i can drive all day with no problems but if i idle for a few minutes it starts to get hot. the cooling fan works and the radiator doesn't look too bad so i'm thinking its the water pump but hoping that a coolant flush and thermostat will take care of it. i think i found a good deal on a water pump though so i may just go ahead and do it, i think its just taking off a couple accessory belts while i have everything drained and the fan off to get to it.

[Edited on August 12, 2010 at 6:06 PM. Reason : .]

8/12/2010 6:03:51 PM

you can't get the cheap thermostat at a regular local parts store?

8/12/2010 6:17:52 PM

i've had bad experience with part store parts, i generally try to stay oem if its something where it breaking can cause problems

8/12/2010 6:31:11 PM

so you got the original equipment BMW part online for $17?

if the thermostat goes out, you'll see the temp go up. not a big deal. i'd just use whatever carquest had.

[Edited on August 12, 2010 at 9:40 PM. Reason : fdas]

[Edited on August 12, 2010 at 9:40 PM. Reason : fads]

[Edited on August 12, 2010 at 9:42 PM. Reason : not worth sitting around w/ no car imo]

8/12/2010 9:39:31 PM

yeah its oem

8/12/2010 9:41:02 PM

throw the cheap carquest one in till you get the other unit shipped in. if there is no problem, welp you got an extra.

8/12/2010 10:24:17 PM

Quote :

"and i didn't think about the housing seal so i'm just waiting till everything gets here"

I've successfully used the "make-a-gasket" stuff from the tube when neither Advance Auto or Autozone had the gasket in stock and it held fine for years. Actually, I've had to use that stuff on an engine that had probably overheated and I couldn't get the housing to seal properly even with the proper gasket and gasket sealer (housing was probably warped).

[Edited on August 13, 2010 at 12:05 AM. Reason : l]

8/13/2010 12:05:22 AM

you can get OEM, next day, through carquest FYI

8/13/2010 8:16:59 AM

cool, i had no idea.

8/13/2010 1:22:23 PM

anyone got a 32mm wrench i could borrow for this fan clutch?

8/14/2010 3:50:27 PM

I'm thinking water pump blades have been worn out/down based on what you've told us. No leaks, overheat on idle but not when driving -> higher rpms get the job done. Also thought i heard in a different thread the water pump blades are plastic.

I'm by no means a pro mechanic but like to figure out if i'm on the right path when diagnosing.

8/14/2010 10:35:26 PM

Doesn't sound like a thermostat issue. From what you've said I'd guess a worn out fan clutch or the forward electrical fan, or both.

8/14/2010 11:18:36 PM

well i can see the fan moving well, i'm really thinking water pump

8/15/2010 5:02:48 AM