How long does your M20 take to warm up?

[Sagaris]

I haven't had my 325 for very long but when it was a little warmer outside (50F-80F) I could get up to operating temp in a reasonable amount of time.

Now that it is colder (20F-40F) I will just barely reach operating temp. after my 20 minute commute which consists of 15 min. of city traffic and 5 min of freeway driving. (keeping the revs below 2500 until OP. Temp.)

My other car (Toyota) has an aluminum block + head and will reach operating temp. after 10 minutes, or halfway through my commute which seems normal.

I know my M20 is an iron block and will take longer to warm up due to the properties of iron. I wanted to see what it takes to get your car up to operating temp. when it is cold outside. to see whether it is worth replacing the thermostat or not.

[McGyver]

my cabbie reaches a good temp in 10 minutes of back county road driving, but i also rev it up to 4k. probably not the best way to treat my engine, but if it breaks then i will just have to start the s52 swap.

[transatlantic0207]

87is here and my car is pretty consistent in its warm up time, it takes about 6-10m of casual driving from morning start. I always keep it below 3k before it's warmed up.

[etxxz]

florida right now winter time.. ~5min. ^^ good idea on the swap. the sooner you do it, the more time you'll enjoy it ; /

[allwheeldrive]

Mine is similar, takes longer here in winter, but just seems to be the way it goes. You could try a new t-stat to see if it helps. 20 minutes seems excessive.

[StereoInstaller1]

20 minutes is excessive, and will kill your fuel economy.

A new thermostat would be a good idea.

[jlevie]

About 5 minutes in 40F ambients. It sounds like your thermostat may be stuck partially open and/or the fan clutch has seized. Replace the thermostat with an 80C unit and check the fan clutch.

[dashboardmonkey]

about 5 minutes, then the heat actually starts blowing hot air

[MikeDE]

^this...

[PeaveyBassist]

^this...

^this^

[StereoInstaller1]

^^^that^^^

[D.Martijn]

Reviving this old thread.

Lately I've been having problems reaching operating temperature on my M20.
My commute isn't that long but yesterday evening, I went out for a drive, roughly 30min.

This is where the temp needles sits, won't go any higher..




According to my OBC it was 7°C outside. The thermostat got replaced 3-4 months ago with a Gates 80°C one.

Any ideas what could be causing this? I do have a new Behr stat but haven't swapped it out since I first wanted to get your suggestions. What esle could be causing this.

[PshlosE30]

I have the same exact problem with my car too (although its an M50 swapped with an electric fan).... It takes forever to reach optimal temperature.I also tried to change the Tstat with a Behr 80c and installed a new water pump because the old one was leaking. Radiator is from E36 M42... hope someone can help us!

[D.Martijn]

I have the same exact problem with my car too (although its an M50 swapped with an electric fan).... It takes forever to reach optimal temperature.I also tried to change the Tstat with a Behr 80c and installed a new water pump because the old one was leaking. Radiator is from E36 M42... hope someone can help us!

Yeah, it's weird. My uncle also has an iX Touring. When it's summer mine willl reach just the halfway mark between 1/4 and 1/2. While his sits happily on the 1/2 mark. This was when I did the timing belt and T-stat on both cars. Identical parts etc.

[dnguyen1963]

A lot of users on this forum live in warmer climate. In the winter region when the temp is around freezing, it is normal for the temp needle to go up to only 1/4 of the gauge. Yes, mpg goes down as compared to summer driving (24 vs. 27 mpg average for me).