3-Series (E46, E90)Chat relating to the BMW 3-Series from 1999 to Current. Models include: BMW 316i, BMW 318i, BMW 318Ci, BMW 320i, BMW 323i, BMW 325i, BMW 330i, BMW 328 Ci, BMW 328i, BMW 325i/xi, BMW 330Ci, BMW 320d, BMW 330d, BMW 335d.
My SES light was on twice last week for about 2 days at a time, and now it's off again. Indications are that something is up with the thermostat based on an OBDII reading. The dealer says it sounds like I need a new thermostat. However, the light has been off for 2 days now. And the engine temp still looks right down the middle, as it has all along.
Should I just wait until it comes on again to do anything?
Well, you need to ask yourself this question. What am i going to achieve by waiting for it to blink again? The best thing to do is replace the thermostat before any damage preceeds. However, if you are going to replace the thermostat you might want to replace the waterpump and belts. Just think preventive maintenance.
the thermostat is monitored, so if it is sticking it will throw a check engine light, once the thermostat is free moving again the light will likely go off...but the thermostat should be replaced if this is the case. The belts should probably be changed if they haven't (or if there is any visible glazing or cracking). The water pump though should be fine if there is no play in the pulley or if you haven't overheated the engine. Preventative maintenance or not, save yourself some dough where you can. Just a suggestion
I've never replaced a BMW thermostat before, but every other car I've done this on takes less than one hour with hand-tools. Very easy. So far, everything's easier to fix on the Bimmer than most cars I've worked on.
Why would you buy a new housing? Is it cracked? If not, don't bother. Thermostats are cheap---housing's aren't. BMW dealer would have the housing if you need it, though.
__________________ Ari Cohen
2002 BMW 325i
well, lets see since the thermostat is integral to the housing that's how it's sold bud...and even if it's not cracked if the engine has gotten hot (overheated) the plastic gets weak and is more likely to fail, why do the same job more than once? and yeah t-stats are like $20 at checker for other rides, not BMW's....
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