[Asonchadwick]

I recently modified a thermostat to fit into the housing. I am now seeing engine temps measured about 199 on average with a high so far of 204. The tstat claims 203 degrees temp. Usually I am in the 197 to 198 range.

I believe this is a benefit as I am potholed and the engine just never runs warm even in the factory temp tstat I would be lucky to see 185 brand new.

Thoughts?

[lnxguy]

Only issue I see is the tranny is cooled by the same coolant and now that's running hotter. Will it make much of a difference? I guess you'll find out.

Although 10 degrees over stock really shouldn't.

[Asonchadwick]

Originally Posted by lnxguy

Only issue I see is the tranny is cooled by the same coolant and now that's running hotter. Will it make much of a difference? I guess you'll find out.

Although 10 degrees over stock really shouldn't.

Good question and no it won't affect trans temp. The trans cooler has a built in thermostat if I recall and it is fed from the bottom of the radiator. So ambient air temp and ultimately the temperature of the coolant exiting the radiator will have a bigger impact. So far tans temp has remained in line as before.

[lnxguy]

Thumbs up. Forgot about the thermostat in the transmission. One less thing to worry about.

[E85 Sport]

Asonchadwick, what did you modify? It will be interesting to see the long-term results. Impact to fuel economy, etc.

[Asonchadwick]

Originally Posted by E85 Sport

Asonchadwick, what did you modify? It will be interesting to see the long-term results. Impact to fuel economy, etc.

You mean what part of the thermostat did I modify?

Yes I turned on my ac today and got a nice and even 200 degrees at idle. The smell is definitely better!

[E85 Sport]

Yes. Elaborate on the modification you performed.

[Tomnavigator]

I am interested also. What thermostat did you start with. Part number or make model and year of vehicle thermostat was for. What did you do to mount it. Etc.

[Asonchadwick]

Originally Posted by E85 Sport

Yes. Elaborate on the modification you performed.

I had to trim down the bypass disc to fit down into the pump housing.

[Asonchadwick]

Originally Posted by Tomnavigator

I am interested also. What thermostat did you start with. Part number or make model and year of vehicle thermostat was for. What did you do to mount it. Etc.

It's from a BMW 318 4 cylinder gasser and I trimmed down the bypass disc to fit. It's listed as 203 degree and it is non electric non computer controlled.

[Tomnavigator]

Asonchadwick - I agree with you that the higher temp thermostat should help the car. I found three 318i thermostat housings (pictures attached). It depends on the year of the car. Which one of the three did you start with? It would be easier if you let us know the part number of the thermostat you used?

Also when you said you cut down the bypass disk. Is that the round disk on the outside end of the thermostat that is hanging out in these pictures?

Which picture looks like what you started with? or preferably the part number of the thermostat you used.

[Asonchadwick]

Originally Posted by Tomnavigator

Asonchadwick - I agree with you that the higher temp thermostat should help the car. I found three 318i thermostat housings (pictures attached). It depends on the year of the car. Which one of the three did you start with? It would be easier if you let us know the part number of the thermostat you used?

Also when you said you cut down the bypass disk. Is that the round disk on the outside end of the thermostat that is hanging out in these pictures?

Which picture looks like what you started with? or preferably the part number of the thermostat you used.

If I am not mistaken there is only one that is 203 degrees. So the middle one. Also yes the bypass disc is the one that extends into the housing to block off the circuit when the thermostat opens etc. I trimmed off 2mm all the way around. A helpful tool is a piece of exhaust pipe it got at AutoZone and some diamond files I got at harbor freight. Basically make it 2mm even all the way around and you can use the pipe onto install it. My temps never go below 193 and that's coasting downhill etc. And so far I've maxed out at 203 pushing the car. That's a good window.

[Asonchadwick]

I used the mahle TI2495 thermostat and the original bmw thermostat. Also be warned other thermostat housing brands may not work. only that thermostat and the one for me will work.

[Tomnavigator]

Asonchadwick- All three are 203 degree thermostats. They are listed as 95 degree centigrade which is 203 degrees fahrenheit. I agree that using the one you used incrreases the chance it will work. All three I have shown are within $2 of each other in cost. I want to thank you for posting this. I am going to order the parts and put it on my to do list. I replaced the thermostat in my car last year so it won't be at the top of the list.

[Asonchadwick]

Originally Posted by Tomnavigator

Asonchadwick- All three are 203 degree thermostats. They are listed as 95 degree centigrade which is 203 degrees fahrenheit. I agree that using the one you used incrreases the chance it will work. All three I have shown are within $2 of each other in cost. I want to thank you for posting this. I am going to order the parts and put it on my to do list. I replaced the thermostat in my car last year so it won't be at the top of the list.

My engine runs around 197 avg with a high of 203 under heavy throttle and coasting never drops below 193. So that's good enough for me and a solid 10 ish degrees hotter than factory at all times. I like running right around 200 makes me feel my oil is heated and evaporating moisture.