[hubstacker]

I drive a 2006 325i and plan to replace my thermostat next week. I was looking at the tutorial from pelican parts and they say to remove the radiator and fan before touching even touching the thing. I was wondering if anyone who has done this before could tell me if I could just skip this step and pull the thing out?

p.s. Thinking about replacing the water pump too as it's on 120k miles, would taking the thing out make the thermostat easier to get to?

[Three_thirty_I]

I replaced the thermostat on mine years ago, removed the electric fan, but didn't touch the radiator. You will need to get the car off the ground as high as possible - I had the rear wheels on blocks and then the front lifted as high as my jack stands would allow. With the under engine pan removed, I didn't need to lower the anti-roll bar, but I think you might have to if you are planning to do the water pump at the same time. With that said, I think doing both is probably easier since my biggest battle was getting the U-hose off the old thermostat while under the car. I did find that I was able to do a lot of work from above since the other various hoses going to and from the thermostat are more visible and accessible there. One thing that I had to consider and be careful about was that since I was only replacing the thermostat was to ensure that the remaining coolant in the pump stays in the pump while doing this - you do not want that to dry out! Other than that, it's not that bad of a DIY, just take your time, get all the tools you need and prep for the work, and it's a messy job with the coolant that WILL splash onto you when you are underneath!

Good luck!

[ouderkirk]

It all depends if you can get under the car or not. I personally would do it the way Auto from Bav Auto did it:

But I feel more comfortable messing with the sway bar than the radiator.

Always check Youtube page of Bavarian Autosport & FCP Euro. Nathan's BMW Workshop & ShopLifeTV are also very good. ShopLifeTV has some great information.... just not all models.. yet.

[TheMidnightNarwhal]

Originally Posted by hubstacker

I drive a 2006 325i and plan to replace my thermostat next week. I was looking at the tutorial from pelican parts and they say to remove the radiator and fan before touching even touching the thing. I was wondering if anyone who has done this before could tell me if I could just skip this step and pull the thing out?

p.s. Thinking about replacing the water pump too as it's on 120k miles, would taking the thing out make the thermostat easier to get to?

I did the thermostat only as my pump wasn't shot yet at 60k miles. I removed intercooler and fan cowl to provide more angle to approach it as I was doing it on jack stands. Did not touch the radiator.

[Three_thirty_I]

One thing to bear in mind is that the location of the water pump and thermostat is ever so slightly different on the N52 from what I remember compared to the N54/5 engines, and I found contrary to that Bavarian Autosport vid, for the N52, the thermostat comes off first, then the water pump, well, I can't see how removing the water pump is all that easy with the thermostat still in place.

[Efthreeoh]

A few questions

Why are you replacing it? Is the ECU throwing a SES light and what codes does the car have?

Have you looked at the t-stat? Is it brown plastic, or metal (aluminum)? If it is brown plastic, then it has already been replaced.

The t-stat/water pump replacement has been discussed for eons on the forum. Here's the bottom line. There is no reason to preemptively replace either the water pump or t-stat until they fail. The t-stat fails safe, which means it won't leave the car stranded. It's designed to stay open and not overheat the engine. So replacing it before it fails (if it ever does) is stupid. When it fails, because it is part of the emissions system, it throws a SES (check engine light) trouble code.

Not every water pump fails, and despite internet myth, they all don't fail at 100,000 miles. Before the pump completely fails and overheats the engine, it will throw trouble codes. The problem is the trouble codes do not trigger the SES light, because they are manufacturer trouble codes rather than emissions-related OBD 2 codes, so a BMW scan tool is needed to read non-emissions-related trouble codes.


The t-stat and water pump are usually replaced by owners together, and unnecessarily. The t-stat bolts to the water pump, so it can be removed from the car without removing the water pump. So if the t-stat fails, there is no reason to remove and replace a good water pump. If the water pump fails, then it can make sense to replace the t-stat since it is somewhat prone to failure (the metal-bodied ones) and because the t-stat is removed from the water pump to replace the water pump, it does save labor to replace the t-stat when the water pump is being replaced.


The links below are the t-stat/WP DIY I published in 2011 and the N52 coolant hose replacement DIY I published in 2013 and provided for reference. You only need to remove the cooling fan from the radiator to give more room to pull the t-stat. Removing the radiator is difficult because the upper and lower radiator hoses are usually stuck-in-place on the radiator hose bibs and nearly impossible to remove. Additionally, there is a small coolant line that runs from the top of the upper radiator hose elbow back to the coolant reservoir tank. That hose attaches to a small-diameter hose bib, which is easily broken off the elbow, so it is best just not to mess with the radiator and main hoses.

Now considering your car is at least 13 years old, if the coolant hoses are original, you may want to consider replacing the small return line mentioned above, and replace the plastic hose bib on the cylinderhead that attaches the head-to-thermostat coolant hose. The plastic hose bib on that hose softens over time and fails. The DIY for that is posted below as well.

t-stat/wp:
https://www.e90post.com/forums/showthread.php?t=565770

coolant hoses:
https://www.e90post.com/forums/showthread.php?t=936250

hose bib:
https://www.e90post.com/forums/showthread.php?t=1618232

[Three_thirty_I]

Originally Posted by Efthreeoh

A few questions

Why are you replacing it? Is the ECU throwing a SES light and what codes does the car have?

Have you looked at the t-stat? Is it brown plastic, or metal (aluminum)? If it is brown plastic, then it has already been replaced.

The t-stat/water pump replacement has been discussed for eons on the forum. Here's the bottom line. There is no reason to preemptively replace either the water pump or t-stat until they fail. The t-stat fails safe, which means it won't leave the car stranded. It's designed to stay open and not overheat the engine. So replacing it before it fails (if it ever does) is stupid. When it fails, because it is part of the emissions system, it throws a SES (check engine light) trouble code.

Not every water pump fails, and despite internet myth, they all don't fail at 100,000 miles. Before the pump completely fails and overheats the engine, it will throw trouble codes. The problem is the trouble codes do not trigger the SES light, because they are manufacturer trouble codes rather than emissions-related OBD 2 codes, so a BMW scan tool is needed to read non-emissions-related trouble codes.


The t-stat and water pump are usually replaced by owners together, and unnecessarily. The t-stat bolts to the water pump, so it can be removed from the car without removing the water pump. So if the t-stat fails, there is no reason to remove and replace a good water pump. If the water pump fails, then it can make sense to replace the t-stat since it is somewhat prone to failure (the metal-bodied ones) and because the t-stat is removed from the water pump to replace the water pump, it does save labor to replace the t-stat when the water pump is being replaced.


The links below are the t-stat/WP DIY I published in 2011 and the N52 coolant hose replacement DIY I published in 2013 and provided for reference. You only need to remove the cooling fan from the radiator to give more room to pull the t-stat. Removing the radiator is difficult because the upper and lower radiator hoses are usually stuck-in-place on the radiator hose bibs and nearly impossible to remove. Additionally, there is a small coolant line that runs from the top of the upper radiator hose elbow back to the coolant reservoir tank. That hose attaches to a small-diameter hose bib, which is easily broken off the elbow, so it is best just not to mess with the radiator and main hoses.

Now considering your car is at least 13 years old, if the coolant hoses are original, you may want to consider replacing the small return line mentioned above, and replace the plastic hose bib on the cylinderhead that attaches the head-to-thermostat coolant hose. The plastic hose bib on that hose softens over time and fails. The DIY for that is posted below as well.

t-stat/wp:
https://www.e90post.com/forums/showthread.php?t=565770

coolant hoses:
https://www.e90post.com/forums/showthread.php?t=936250

hose bib:
https://www.e90post.com/forums/showthread.php?t=1618232

+1!

Mine, albeit still a low mileage car, still has the original water pump, but I did replace the thermostat at the time because everyone was telling me that mine was either stuck open or faulty despite no error codes. The old one was still the original metal bodied part and for all intents and purposes still perfectly fine, the new part is then the new plastic bodied OEM part - made no difference to the coolant temps that I keep seeing in the hidden menu which is what had me go down this road. At least when the day comes that I need to do the water pump, I'll know what to do...

[hubstacker]

Originally Posted by Efthreeoh

A few questions

Why are you replacing it? Is the ECU throwing a SES light and what codes does the car have?

Have you looked at the t-stat? Is it brown plastic, or metal (aluminum)? If it is brown plastic, then it has already been replaced.

The t-stat/water pump replacement has been discussed for eons on the forum. Here's the bottom line. There is no reason to preemptively replace either the water pump or t-stat until they fail. The t-stat fails safe, which means it won't leave the car stranded. It's designed to stay open and not overheat the engine. So replacing it before it fails (if it ever does) is stupid. When it fails, because it is part of the emissions system, it throws a SES (check engine light) trouble code.

Not every water pump fails, and despite internet myth, they all don't fail at 100,000 miles. Before the pump completely fails and overheats the engine, it will throw trouble codes. The problem is the trouble codes do not trigger the SES light, because they are manufacturer trouble codes rather than emissions-related OBD 2 codes, so a BMW scan tool is needed to read non-emissions-related trouble codes.


The t-stat and water pump are usually replaced by owners together, and unnecessarily. The t-stat bolts to the water pump, so it can be removed from the car without removing the water pump. So if the t-stat fails, there is no reason to remove and replace a good water pump. If the water pump fails, then it can make sense to replace the t-stat since it is somewhat prone to failure (the metal-bodied ones) and because the t-stat is removed from the water pump to replace the water pump, it does save labor to replace the t-stat when the water pump is being replaced.


The links below are the t-stat/WP DIY I published in 2011 and the N52 coolant hose replacement DIY I published in 2013 and provided for reference. You only need to remove the cooling fan from the radiator to give more room to pull the t-stat. Removing the radiator is difficult because the upper and lower radiator hoses are usually stuck-in-place on the radiator hose bibs and nearly impossible to remove. Additionally, there is a small coolant line that runs from the top of the upper radiator hose elbow back to the coolant reservoir tank. That hose attaches to a small-diameter hose bib, which is easily broken off the elbow, so it is best just not to mess with the radiator and main hoses.

Now considering your car is at least 13 years old, if the coolant hoses are original, you may want to consider replacing the small return line mentioned above, and replace the plastic hose bib on the cylinderhead that attaches the head-to-thermostat coolant hose. The plastic hose bib on that hose softens over time and fails. The DIY for that is posted below as well.

t-stat/wp:
https://www.e90post.com/forums/showthread.php?t=565770

coolant hoses:
https://www.e90post.com/forums/showthread.php?t=936250

hose bib:
https://www.e90post.com/forums/showthread.php?t=1618232

Thanks for the references! A lot of good stuff here! For a while my car has been giving me the code for heater control circuit open. For the longest time, it would come and go, but now it's pretty permanent, as is can't be clear my non-bmw specific scanner.

EDIT: I believe the specific code is p0597 along with "engine running rich in bank 1"

[Efthreeoh]

Originally Posted by hubstacker

Thanks for the references! A lot of good stuff here! For a while my car has been giving me the code for heater control circuit open. For the longest time, it would come and go, but now it's pretty permanent, as is can't be clear my non-bmw specific scanner.

EDIT: I believe the specific code is p0597 along with "engine running rich in bank 1"

Yup, that's the common t-stat failure. I'd pull the fan, and pull the t-stat, and leave the rest of the cooling system alone. You need to get a BMW scan tool as well to keep an eye on the water pump. If you are DIYing your labor is free. IMO no use in replacing an expensive pump if it is in good working order. The only thing you save is the time removing the t-stst again.

[hubstacker]

Originally Posted by Efthreeoh

Yup, that's the common t-stat failure. I'd pull the fan, and pull the t-stat, and leave the rest of the cooling system alone. You need to get a BMW scan tool as well to keep an eye on the water pump. If you are DIYing your labor is free. IMO no use in replacing an expensive pump if it is in good working order. The only thing you save is the time removing the t-stst again.

thanks, that saves me a lot of cash.

also, you have any recommendations for a proper scanner? was looking to get this one from Foxwell B/C it's under the $200.

[Efthreeoh]

Originally Posted by hubstacker

thanks, that saves me a lot of cash.

also, you have any recommendations for a proper scanner? was looking to get this one from Foxwell B/C it's under the $200.

So I have the ECS Tuning version which is labeled Schawbain (or something like that). I also have a Foxwell 510 for my GM truck. Foxwell makes a decent scanner that is portable and built for the harsh environment to keep in the car, but their customer service sucks big time. I tried to load additional software on my Foxwell (GM unit) for a friends Honda, and followed the directions to a T, but couldn't get it to download on the unit.

If you want to get the Foxwell 510 (it might be a 520 now) get it from ECS tuning because it comes pre-loaded with the BMW software.

I also run Bavarian Tech software, which I had before the Schawbian unit. I still use Bav tech a lot when working at home. I have the Schawbian as my in-car emergency scan tool. A lot of folks here use software on their phone. I'm far from an expert when it comes to coding and scan tools.

[vilord]

piggybacking on your thread...

I've noticed that when it is cold out and I come to a stop light, the heater inside the car stops blowing heat. Revving up the motor makes it hot again.

I've checked for codes using an ICOM/ISTA+ setup, but nothing shows up. The coolant pump works fine. The car does not overheat.

In a traditional car, I'd suspect the thermostat, but is this thermostat supposed to be electrically controlled or thermostatically? Can they fail without throwing codes? Should I swap the thermostat or is there something else I should be worried about (sensors, etc)?

With 165K miles, should I replace the water pump at the same time, even if it is still running just fine?

I will be replacing the radiator support (it is cracked in a few places from the various collisions over the years), so it seems like this is a good time to go in there, but I also don't want to dump hundreds into replacing perfectly good parts.

[TheMidnightNarwhal]

Originally Posted by vilord

piggybacking on your thread...

I've noticed that when it is cold out and I come to a stop light, the heater inside the car stops blowing heat. Revving up the motor makes it hot again.

I've checked for codes using an ICOM/ISTA+ setup, but nothing shows up. The coolant pump works fine. The car does not overheat.

In a traditional car, I'd suspect the thermostat, but is this thermostat supposed to be electrically controlled or thermostatically? Can they fail without throwing codes? Should I swap the thermostat or is there something else I should be worried about (sensors, etc)?

With 165K miles, should I replace the water pump at the same time, even if it is still running just fine?

I will be replacing the radiator support (it is cracked in a few places from the various collisions over the years), so it seems like this is a good time to go in there, but I also don't want to dump hundreds into replacing perfectly good parts.

In my car my thermostat failed open a good amount of time before it actually threw a code. Maybe because it was still closing partially? Noticed car coolant was only around 50c on the highway during winter times and if I idle'd for 10-15 mins the temp would hit operating at around 90c but soon as I drove off it would lower and lower.

But I never had any heating issues my heating worked perfect. I don't think a fail open thermostat would potentially affect your heating that much? Unless my thermostat wasn't fully stuck open.

I would recommend you log your coolant temps to see how hot it is when you say you have no heat.

As for water pump it's your bet. Of course everyone is most likely going to say to change it if you have money to spare. I personally just hate changing parts without them being actually broken so I did the T stat only.

[vilord]

Simple ways to log coolant temp? entering the various codes into the BCM is a pain, especially for it to just revert on every shutdown...

I might have an elm327 around and can load up torque i suppose.

[vilord]

coolant temps fluctuated from 80c-100c, which seemed a bit wide for 90 but not unreasonable. But, got a thermostat code when i read the code for the SES light today so i guess i'll order one up after all.
ordering a couple of the hoses Efthreeoh recommended too