Thermostat Stuck??

[Mohammed_A]

On my s50 swap the water temp gauge goes to half on idle but drops to quarter when driving, on a winter morning the gauge drops between quarter and the blue block....
i did not renew the thermostat with the swap so im guessing its stuck open, any suggestions on how i would know the thermostat is not faulty or is faulty?
what temperature is the standard s50 euro thermostat?

[Kerrath]

Sounds just like what mine's doing. At first it was opening really really hot, then it worked fine for a while and now it runs very cold. I don't know about euro S50, but I think the stock temp for my M50 is 88 degrees.

[Mohammed_A]

so if the stock thermostat temp is 88deg then what should the fan temp switch be....ideally

[Kerrath]

You ought to download the ETM for the car your engine came from to check. The ones for M20s and M50s seem to be 91 and 99.

[Jason89i]

euro s50b32's use an 80c thermostat. they did not deal with emissions like here in the states.

i had the same issue with my euro swap. it ran VERY cool. below freezing and the temp gauge barely moved. on the track, the needle would be slightly below the half mark and sitting in summer traffic was a hair over the half.

euro s50 = 80c
u.s. m50 = 88c

cheers, jason

[bmw325csi]

so whats the remedy for this?

Ive been searching for 1 hour straight!
My car just got a top-half rebuild, now the temp never makes it above the 1/4 mark, its not really a bad thing except nights are cold and my heater just isn't hot enough!

Whats my problem, thermostat? Air in the system? (bled it like 6 times, after the shop that did the work) Dont ask why I'm not taking it back to the shop, I'm too lazy.

oh yeah, there was a point while I was bleeding that the heater blew very hot, but the car was over the 1/2 mark

[Adrian_Visser]

"Upgrade" to a higher temp thermostat if you want more heat from your heater. That said I have no idea what is available for a euro s50 in terms of different thermostats. Air in the system would cause overheating, an air bubble in your heater core would mean no hot air from the heater but the temp gauge would work. Hell in Canada when it's -40C people put cardboard in front of their radiators so their engines will warm up enough for the heater to work but I don't think you need to go that far.

[Fusion]

I had a similar problem, temp low and no heat from heater. First I changed the thermostat (bought 88, but the bad one was 80), which solved the engine temp (now rests at the halfway mark), but not the heating issue. That in my case is caused by swapped hoses to the inside heater core. To save you time, hose from the back of the head goes to the bottom plug and the spider hose that runs from the front along the head goes to the top plug. In other words, opposite of how original e30's are plugged.
But I will be switching back to 80 or 83 degree t-stat come spring to run cooler in the summer. It's a 10-15$ part worth replacing.
I'm running M50 euro.

Please correct me if I'm wrong but I think all M50/M30/M20 tstats are the same in terms of size, they differ in the opening temp 80/83/88/92. Not sure about the S motors.

Oh and you can also tell that the hoses are swapped by driving in city traffic it heats, but above 50mph it blows cold, but will blow hot if you turn the all heater elements off, turn the knob to cold, wait 15 seconds, turn knob to full heat, push vents open, turn speed knob.

[E30_80Y]

this morning i was driving to work in my s52 swapped e30 and all of a sudden BOOM and white smoke spread inside the cabin. My right ankle got splashed with pretty hot liquid which shot out of the bottom center console. can this be the two hose being swapped(like Fusion mentioned) or could it be something else?

[Fusion]

Yea, 100%, they're right above the gas pedal, just have to remove the center console with the ash tray, lay down there and have a look. It's a real bitch to get to because of the M-S50/52 intakes. If it blew off the radiator connection, you could have someone aim it under the intake, you plug it in inside the car, but if there's a hole or something, may have to take the intake off. Also depends on your setup, I couldn't get my hand between the intake and brake booster.

[Jason89i]

this morning i was driving to work in my s52 swapped e30 and all of a sudden BOOM and white smoke spread inside the cabin. My right ankle got splashed with pretty hot liquid which shot out of the bottom center console. can this be the two hose being swapped(like Fusion mentioned) or could it be something else?

heater core. not too uncommon.

[7pilot]

this morning i was driving to work in my s52 swapped e30 and all of a sudden BOOM and white smoke spread inside the cabin. My right ankle got splashed with pretty hot liquid which shot out of the bottom center console. can this be the two hose being swapped(like Fusion mentioned) or could it be something else?

Did you use a pressure bypass valve? Part of the recall campaign.

m

[E30_80Y]

Did you use a pressure bypass valve? Part of the recall campaign.

m

recall??????????? never heard of it.

[7pilot]

recall??????????? never heard of it.

I may be wrong about the regular E30 chassis, but the E30 M3 had this valve installed as part of a recall campaign to prevent the heater core from bursting under excessive pressure.
VW did a similar campaign in the 85 and younger water cooled cars.
m

[Gnarles]

my 89 325i has the same setup. I used the e30 setup when I did my swap.