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The E85/6 Z4 Roadster and Coupe models (2003 through 2008) use the M54 24-valve, double VANOS, 6-cylinder engine. Replacing the water pump on these models is done in the same manner as other BMW models that have the M50, M52, M52TU, M54a nd M56 engines (2.3, 2.5, 2.8, 3.0) , as well as the S50 and S52 M-engines. Below is our DIY Video for replacing the water pump in these engines. However, the E85/86 Z4 models with the M54 engine have a unique problem in removal of the water pump.
The E85/86 Z4 employs the radiator support (front brace) BEHIND the radiator (as opposed to in front, as most vehicles are set-up). The support/brace prevents the water pump from being removed from the engine. BMW’s service procedure is to remove the complete front of the car ….. in order to remove the support/brace and, ultimately, the water pump.
We have found a quick and easy way to remove the pump without the extra work that BMW suggests.
1) Remove any under-engine splash shield(s) in order to access the left (driver) side engine mount and oil pan.
2) Remove the lower securing nut from the left engine mount stud.
3) Place a floor jack under the mount arm or the oil pan (toward the left (driver) side of the pan, with a block of wood large enough to extend past the edges of the lower pan sump, between the pan and the jack pad.
4) Carefully lift the left side of the engine just enough to allow the water pump to be pulled forward through the opening in the structure of the support/brace.
5) Perform the water pump replacement, then lower and reconnect the left engine mount. Install the splash shield(s) and finish the full water pump replacement.
Easy Wheel Cleaning Without the Spray or Splatter!
The new Wheel Woolies is here! A 1/4″ hex speed driver has been inserted through the entire length of the Wheel Woolies handle. This created the ultra strong and incredibly durable Power Woolies cleaning and polishing brush. You can chuck Power Woolies in any power drill. The 1/4″ hex speed driver is sized to fit your standard quick change adapters. The steel hex driver is completely encased in the handle so there’s no chance of scratching your work. Load Power Woolies with your favorite polish or buffing compound. Made of polyproylene, these brushes will not scratch up or splatter like most twisted wire spoke brushes.The soft, dense carpet fibers will hold suds and transfer them to the wheel.
- 1/4″ hex speed driver
- Head is constructed of polypropylene, recyclable fibers
- Chemical resistant
- Steel hex driver is completely encased to eliminate the risk of scratching
I have a 2003 530i. The power brakes don’t seem to work well when I start the engine in the morning or after work. The pedal is harder than normal and I have to press it harder to get the brakes to stop well. I have to drive it a bit and then the power assist seems to come back and all works normal for the most part. Sometimes this also happens in stop and go driving, but once I get moving again the brakes are fine. The shop has replaced the brake pads and the vacuum booster (wow $$$) and bled the brake fluid multiple times, but the issue has not changed. Do you have any suggestions?
The symptoms that you’ve described would fit perfectly into a faulty vacuum check valve or “sucking jet pump” for the vacuum power booster. The power brakes on your E39 5-series (97-03), as well as many other BMW and MINI models, are operated by a vacuum booster that amplifies the pressure that is applied to the brake master cylinder when you press on the brake pedal. A key exception to this is some of the early 6-cylinder and V12 models up through the early ’90s. These models use a hydraulic fluid boost system.
Typical Sucking Jet Pump:
Typical Check Valve:
The vacuum for the vacuum assisted power brake system comes from the engine’s intake manifold. While the engine is running, the intake manifold is normally under a vacuum (internally) and this vacuum is applied to the brake booster. There are engine operating conditions when the vacuum may be low, such as cold-start, acceleration and stop & go driving. When the vacuum is low, the power brakes may not be adequately boosted through the vacuum booster. To help eliminate this issue, there is a one-way check valve in the hose that connects the engine (intake manifold) to the vacuum booster. Additionally, some models also have a device known as a sucking jet pump. This is nothing more than a vacuum divider, but it does incorporate internal check valves for the vacuum to the brake booster. The check valve (and the valves in the sucking jet pump) allows vacuum to be applied to the booster when the engine is producing higher vacuum, but does not allow the vacuum to be dissipated out of the booster when the engine’s vacuum is low. This keeps the power brake assist available through the conditions when there is not enough engine vacuum to properly operate the vacuum booster.
Without having your car here to diagnose in-person, we can’t be certain exactly what the fault is. However, we would not have suggested the repairs that have already been performed. For a “virtual” diagnosis, we would suggest that you replace the vacuum check valve as your described symptoms certainly can be attributed to a faulty check valve. If the check valve does not cure the issue, the sucking jet pump may be at fault. On some models, the check valve is a disc-like plastic unit in-line in the vacuum hose from the engine to the vacuum booster. Your 530i incorporates the check valve into the 90-degree elbow that connects the vacuum hose to the booster. Models that incorporate the sucking jet pump (such as your 530i) have the unit installed in-line in the vacuum hoses between the intake manifold and the vacuum booster.
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