WARNING!! Aluminum thermostats!!BEWARE!

I thought I was doing a good thing by replacing my failing thermostat with one with an aluminum housing. After replacing it everything was fine for a day then my car just died in the middle of traffic on day 2! I thought the fuel pump went out but after some research (and a new $220 fuel pump) I found out it was the fuel pump fuse!

But why was the fuse blowing? Someone on the forum said replace the thermostat so I unplugged the electrical connection on the thermostat replaced the fuse and voalaa! The car cranked right up! Why the thermostat is blowing the fuel pump fuse is still a mystery to me but I'm just going to leave well enough alone and leave the aluminum thermostat in and keep it unplugged, the car is running fine, all the guages are still functioning fine and I haven't experienced anything abnormal so far.

I guess that the electrical connection on the thermostat is for the OBDII, but I keep an eye on my water temp guage just out of habit anyway.

If anyone knows what the connection does feel free to share. Information is M-POWER!!!! Thanks and safe motoring to you all.

In this same vein, my mechanic said it may not be the thermostat itself but I may have a bad wire on the connector end. Just a thought. Still... beware of the aluminum.

They are junk. Remove it and send it back for a refund. They short out as you have found out. Where did you buy it. Other vendors removed them from their sites a long time ago.

+1 they are crap. We had a discussion on this in the general e46 section. Bad item to buy.

My aluminum, aftermarket, TStat seemed to work fine since I installed it over 1 year ago. However, when I read my codes, recently, I get a code indicating my thermostat is "stuck open." The CEL has *not* illuminated. I read codes only because of another unrelated issue.

The coolant temperature floats around 85-89C when fully warmed up, which seemed a little cool to me ( the OEM unit is labelled as a 97C unit, FWIW).

I now have an OEM, plastic one in-hand.

Other than the too-cool temperature, the unit seems fine. Still, I'm going back to OEM.

Going back to the OEM ASAP! Thanks Guys! Next stop Cold air intake, any suggestions or warnings on a system?

Not worth it either. I had an AFE one and it sounded INCREDIBLE. But it had a lot of heat soak and rattled a lot. Went back to OEM and couldn't be happier.

Originally Posted by Solidjake

Not worth it either. I had an AFE one and it sounded INCREDIBLE. But it had a lot of heat soak and rattled a lot. Went back to OEM and couldn't be happier.

saved me $300 haha

$300 going for cosmetic, She needs that kinda love now lolz

sent from phone to bimmer app

I love my BMW Performance intake.

Originally Posted by Solidjake

Not worth it either. I had an AFE one and it sounded INCREDIBLE. But it had a lot of heat soak and rattled a lot. Went back to OEM and couldn't be happier.

Thanks for ALL the input guy's I'm just going to upgrade My air filter to a quality one like K&N or something, and be done with it.