E9X 325i/330i 6MT Cooling Overhaul Package

This cooling overhaul will cover just about everything you could replace on the 325/330's cooling system. We start with the basic water pump and thermostat bundle. These are already vital to the health and durability of the N52 325/330. But to properly maintain these cars for the long term, the rest of the cooling system must be refreshed and preventatively replaced. Here you can add a radiator, expansion tank, cooling hoses, and the BMW antifreeze. This package fits 325/330 with N52 engine and manual transmission.

The sophisticated electronics of the ECU and water pump means catastrophic overheating should be a thing of the past. But the downside is that the electronics can shut down without any warning or symptoms. And troubleshooting is equally frustrating since the water pump electronics are not readable or serviceable. There are several clues to a faulty thermostat or water pump - the fan runs at full speed all the time (even immediately on a cold start), pending (soft) fault code for low coolant flow, or the water pump can be heard running constantly. But when the pump fails it's an immediate shut down of the engine which can be a major inconvenience and lead to additional repairs that might have been avoided with preventative maintance. We recommend a full cooling system overhaul on the E90/E92 every 80-90,000 miles and to check for soft/pending codes at every 5,000 mile service.


Base Cooling Overhaul Package - Water Pump and Thermostat (click to expand) Includes:
+ Genuine BMW electric water pump, p/n 11517586925
+ mounting screws for water pump (set of 3), p/n 11510392553
+ OEM Behr thermostat, p/n 11537549476
+ Original BMW connecting hose from thermostat to water pump, p/n 11537521049
+ OEM-style hose clamps for hose (x 2)

The water pump on the N52 engine has more cooling responsibilities than ever before. The good news is that the pump only works when, and only as much, as it needs to. That means the system can actually stop the pump when it doesn't need to be running. The bad news is that it's now an electrical part, so a failure is usually immediate and with no warning. The preventative replacement is your only insurance from a very inconvenient and costly breakdown in the future. Plus you get the very latest BMW water pump design with any improvements they've made since your original pump was installed.Coolant Hoses (click to expand) With regular driving the hoses should last a very long time. Even the plastic connectors seem to be holding up well. But as a preventative measure new hoses are recommended. We have also seen issues with re-using hoses as the spring connectors get weak over time and may not have the strength to hold the hose in place. They seem to have a tough time holding tension especially when they have been removed and reinstalled. In the interests of a thorough overhaul we recommend replacing these 325/330 water hoses during this job (see diagram):

17127531579, upper radiator hose (A)

17127531581, lower radiator hose (B)

11537552396, water pump to engine �

11537545890, thermostat to cylinder head (includes new o-ring) (D)

There are other hoses too but they are not often replaced during a radiator swap (radiator vent hose and heater core hose) and they don't see much wear. We offer these as well if you want a complete set (see Additional Items at the bottom of the page).Expansion Tank Options (click to expand) The expansion tank on the 325/330 is not prone to failures (unlike previous 3-series cars) so a new one is not strictly required. There aren't many seams or stress points for it to crack and we haven't heard of too many issues. But we wanted to offer it as part of a complete overhaul in case you want to cover everything. Simiarly, the level sensor is not required unless you're getting erroneous 'low coolant' warnings from the dash/iDrive. We do strongly recommend replacing the cap because that is designed to be the weak point in the system. The cap is what regulates the pressure inside the system and it should be replaced every few years anyway.Coolant Temp Sensors (click to expand) There are two coolant temp sensors on the E90 325/330 - in the lower radiator hose and in the cylinder head. Both feed coolant temps to the ECU to regulate the water pump and cooling fan. You should replace the one in the lower radiator hose because it's one of the main sources for coolant leaks, especially when the old sensor is re-used in a new hose. The sensor in the cylinder head is not as prone to leaks and it's easily accessible so you don't have to replace it right away. But we offer it with the package in case you want to have a complete cooling system overahul.
13621433077, coolant temp sensor (in lower radiator hose)
13621433076, coolant temp sensor (in cylinder head, next to oil filter housing)

BUY AS A PACKAGE AND SAVE $$!

This cooling package fits the following BMWs with the N52 engine and a manual transmission:
2006-2006 E90 BMW 325i 325xi 330i 330xi - Sedan
2006-2006 E91 BMW 325xi - Wagon


Click on the options for your kit below and then click "update price" for your kit total.