BMW Z4 2006 3.0i Water Pump Failure Advice NEEDED! 5 yrs old, 40k miles driven daily

Hey guys I need some advice. I have a BMW Z4 2006 3.0i and it has 40k miles. I was driving it and the car started to lose power randomly for a split second and then return to normal. The warning lights would flash for a second and then once power came back it would return to normal. This would only happen randomly after about 15 minutes of driving. I took it into the dealership right away and they did an estimate and they said there are multiple faults and things that needed to be replaced.
1. Water pump has failed and needs to be replaced.
2. Cooling fan has faults and might need to be replace but can only be diagnosed after the water pump has been replaced.
3. Oil sensor has failed.
4. Break light switch is failing.

The car has been out of warranty for 11 months.
My question is:

1. Could this be something that just happens and i'm SOL? Or is there an inherent problem with the car that might cost much more money to fix besides just the Water Pump?
2. A day before this occurred, there was a loud ticking noise coming from the engine where the frequency of the ticks would increase along with the RPM but after about 20 minutes of driving it would go away. This would randomly happen as well from a cold start. Is there any possibility that this ticking came from the Water Pump? I ask because I've sent my car in multiple times in the past when it was still under warranty and they could never "reproduce" the ticking noise and everytime i noticed it i didn't have time to take it to the dealer.

Any help is greatly appreciated.

Water pumps were a problem with earlier engines, but with the N52 engines (started in 2006) the water pumps are electric.

The ticking noise is more in line with the valve noise which is endemic with the early N52 engines.

Ticking noise:
You need to identify your engine type. As per Real OEM if your car was built in 2005 you could have either the M54 or the N52 engine. The N52 had a hydraulic lifter issue quasi common to the Z4Si. It made ticking sounds as you describe. It was a lot more reproducible and loud to the point of hearing it while driving. It was more prevalent in the winter months and in some cases BMW replaced the entire head under warranty. If you have the M54 I stumped but to some degree lifters tend to "tick" when the engine is cold, but usually its not very noticable and goes away rapidly. I'm presuming you have taken care of periodic maintenance, oil changes, etc using good quality oil.

If you have the N52 for more info do a search for "Z4Si ticking noise" in this forum as well as zpost, http://www.zpost.com/forums/ and Z4Forum, http://www.z4-forum.com/forum/search.php?fid[]=3

I hope you have the M54 as the water pump is a whole lot cheaper than the N52 electric water pump.

Maybe you want to ask around about the dealers ability to troubleshoot and get some recommendations for a good indie mech. Dealer are somewhat notorious for throwing parts at problems and many seem to use the wonderful BMW GT1 computer as a crutch for lack of ability to find problems.

My own experience with the dealer: http://www.zpost.com/forums/showthread.php?t=475263 Fortunately it was on BMW's dime.

Good luck

Do you have anyway to verify what the Dealer is saying? Would you be willing to buy a code reader, or go to Autozone and have your codes read.

Off the top of my head, I would guess the car is overheating because the lack of a water pump (A very serious issue) That causes the fan sensor to read the car is not cooling down so the fan must not be working.It may also make your oil sensor read funny since the engine is so much hotter than it should be. Could be a cascading effect.

As far as the brake light switch, that sounds like an easy $50 do it yourself fix.

Thanks for the response. I am going to have one of my friends look at the car and fix it. It's just hard to swallow something broken so soon out of warranty. Oh well I hope it's just a bad luck of the draw and there aren't more problems with the car. I'll keep you updated to what my friend says.

I am pretty sure I have the electric pump.