Looking to buy a 2003-08 Z4. Anything I should know?

[RickS]

I'm looking to buy a 2003-08 Z4 roadster. Thinking a 3.0 6 speed manual with somewhere between 50-90k miles. The car will be primarily used as a weekend driver in the spring/summer/fall seasons.

I've driven a 3.0, not 2.5. Is there much difference performance or reliability between the two?

What maintenance should I make sure is done or I'll have to do if not (timing belt, water pump transmission service etc)? Most importantly is there things I should avoid. I read some about power top issues, top end engine noise and a rod bearing issue?

Thanks, Rick

[Sterling Roadster]

I think you have the bulk of it covered. Both engines (M54) are among the most reliable BMW engines on the road. And parts are not as expensive as the later engines. Overall I would say these are highly reliable and affordable cars. I have 250,000 or so kilometers on my 3.0 roadster and as of now it's been a couple of oil leaks here and there. Also keep in mind these cars share many parts with other BMW models so taking care of them isn't too difficult. Only super expensive issue I know of is the soft top motor and the rare cars with SMG. I say go for it and post pics when you find the one!

[Kazansky]

Originally Posted by Sterling Roadster

I think you have the bulk of it covered. Both engines (M54) are among the most reliable BMW engines on the road. And parts are not as expensive as the later engines. Overall I would say these are highly reliable and affordable cars. I have 250,000 or so kilometers on my 3.0 roadster and as of now it's been a couple of oil leaks here and there. Also keep in mind these cars share many parts with other BMW models so taking care of them isn't too difficult. Only super expensive issue I know of is the soft top motor and the rare cars with SMG. I say go for it and post pics when you find the one!

Originally Posted by Sterling Roadster

I think you have the bulk of it covered. Both engines (M54) are among the most reliable BMW engines on the road. And parts are not as expensive as the later engines. Overall I would say these are highly reliable and affordable cars. I have 250,000 or so kilometers on my 3.0 roadster and as of now it's been a couple of oil leaks here and there. Also keep in mind these cars share many parts with other BMW models so taking care of them isn't too difficult. Only super expensive issue I know of is the soft top motor and the rare cars with SMG. I say go for it and post pics when you find the one!

Are there any advantages of buying last year of Z4 M 2008 vs. 2006 first year? Any late year updates/ features or known reliability issues?

[StickMon]

Bolts that hold the splined inserts into the ends of the hollow camshafts were upgraded in early 2007.
There's a 100% failure rate on earlier ones. It's about a $1600 fix if you catch it before the engine grenades.
I know because my car had that failure when I bought it, but I didn't yet have the wisdom of this forum.
Sounds like marbles ratting inside a coffee can.

[Efthreeoh]

You're a bit all over the place on your questions. There are 3 engines used in the U.S. market E85 (chassis designation) of the Z4: The S54, M54, and N52. None of these engines use a timing belt.

The S54 is only in the Z4 M Roadster and is a high performance engine with mechanical valve lifters, which require periodic valve clearance inspection and adjustment. The S54 is known to have the rod bearing issue you mentioned. The rod bearing issue is a well-documented reliability issue that is easily cured. The E46 M3 forum and Z4 Post have good info on the subject matter.

The M54 is the in-line 6 BMW used for 2003 to 2005 production. It can suffer from oil leaks as most BMW in-line 6 engines do. There can be camshaft position sensor issues. My sister's M54 in her X3 always had a rusty oil dipstick for some reason and liked to consume coolant, but it never left her stranded. The cooling system in the M54 is slightly suspect. The water pump is belt driven, so it can eventually need replacement as most belt-driven water pumps do.

The N52 is the replacement generation engine for the M54 used for 2006 to 2008 production. It's 22 pounds lighter and in 3.0si trim makes 261 HP vs. the M54 3.0 @ 228HP. The N52 has an electric water pump wherein the early production versions of the engines can see the pump fail due to overheated control electronics. The N52 suffers from oil filter housing gasket (OFHG) leaks, valve cover gasket leaks and leaks from cracked valve covers, and the oil pan gasket will eventually leak. The early production versions also could suffer from the top end noise you mentioned, but it is rare and due to short-duration driven engines. The noise has no bearing on engine performance nor longevity; it's just mechanical noise. BMW did a slight head/camshaft redesign to cure the problem starting with January 2008 production. For customers who complained about it, BMW replaced the cylinderhead with the updated version. Neither of my N52's have shown that problem and both are pre-Jan. 2008 production engines. The N52 can also suffer from a sagging serpentine belt tensioner that is problematic due to the aluminum attachment bolt used for the N52 magnesium engine block. The belt can eventually slip off the tensioner. Also, if the OFHG leaks bad enough, the serpentine belt and get oil contaminated and slip off. It is possible, but rare, that in these cases the belt can be ingested by the engine through the front crank seal, which requires removal of the oil pan and the belt bits cleaned out from the engine. But again it is a rare occurrence. My 2006 E90 325i N52 has over 300,000 miles on it. My '08 Z4 N52 has 92,000 and I've not heard a peep from it: all I've done for it is oil changes every 10,000 miles. It's due for plugs soon. The N52 a very reliable engine.

BMW manual transmissions are virtually bulletproof. Personally I'd never buy a Z4 roadster with an automatic; it's a sports car after all. If you get a car with over 50,000 miles and can't confirm the oil service interval, just have the trans and diff oils changed so you then know the maintenance schedule of them going forward. I have a Coupe, so I can't speak to the Roadster version directly, but I've been a BMW owner for 30 years and find the Z4 build quality 1st rate. I bought my Z4 4 years ago used with 23,000 miles. I now have 92,000 on it and it's been a tank, with no problems whatsoever. A friend of mine has an '07 Roadster that I've had some contact with, which I've found it to be as robustly built as my Coupe is.

I can't speak to the soft top motor issue, but it's well documented in Z4 Post. Get a Z4, they are great cars.

My 2 cents.

[RickS]

Thanks for the information, I didn't know the difference between a S54, M54, and N52.
I'm used to talking displacement. If you think of anything else let me know this is very useful.

[wdb]

You would do yourself a huge favor by learning the difference.

Then go find yourself a 3.0si

[3GFX]

IMHO....

Save yourself some issues and get a 2005+ 3.0si.

Never a great idea to have the first model year of any car. I have a 2003 3.0i and I will say it has been super solid. But the minute improvements made to the car in engine and other areas are worth the "newer car" premium.

The earlier engines don't have problems if they're kept stock. Incredibly strong and well built actually. One thing that is hard to discover while looking is that earlier models had steering column issues. Generally only replicated on a super hot day. Not a fun fix $ wise.

If you can find one that hasn't seen snow or salt (winter) you will be in good shape. If the top looks to be in good condition you are more likely to have had an owner who has taken car of the top and thus the motor that supports it. This is like any other used car, do your due diligence on the one you look at as every car will have different problems in different areas depending on what you look at.

[Vanne]

Efthreeoh, exellent post mate, if there was a post of the year award, I'd nominate you for that.
Thx for the info and time you put into that.

OP, good luck with finding your car mate.

[Huz-Z]

Cars built before mid-2006 may sometimes exhibit sticky steering. It was apparently due to overly close tolerances in the steering column such that in hot weather, the steering can be sticky. My car is a 2006 that was built before the fix was introduced, and I have never had an issue. But - I live in Canada, so what passes for "hot weather" here is just a regular early summer day in the US (its usually no more than 80F here in the hottest part of the year).

All of the non-M cars came from the factory with run flat tires. They exhibit a very harsh ride and follow tire ruts eagerly, to the point that you will need both hands on the wheel if the car still has them. Most folks quickly replace them with a conventional tire for a huge improvement in ride quality and steering.

Here are a couple of reviews. Why do I like the color of the first one so much?

https://www.auto123.com/en/car-revie...ad-test/47380/

https://www.auto123.com/en/car-revie...ad-test/53868/

[RickS]

You guys have all been a great help. I'm going to focus the search for a 3.0SI 2006-08.I had starting reading post about the sticky steering. Being CT I'd probably see a few of those days.

Again, really appreciate the advise.

[Kazansky]

Thank all very much! I am sticking with Z4 M 2006-2008, hope to "join the club" soon.

[RickS]

Well, purchased a 2006 3.0SI, 6 speed manual, silver, red interior with the M seats. What a blast to drive can't wait until spring arrives to use more regularly. Sept 2006 date on tag so hopefully it doesn't have the sticky steering bug.

Thanks for everyone's input!

[3798j]

Congratulations RickS....you'll come to love it.

[deemo319]

Sounds nice and you chose well.

[Huz-Z]

Congrats!!

Pics please!’

[Efthreeoh]

Congrats brother. We all look forward to hearing how you like the car once better weather allows an extensive drive with the top down.

[deemo319]

[wdb]

Nice get. Need pics.

[RickS]

Here's the 2006 3.0SI I purchased, has 71k miles on it:

[deemo319]

Originally Posted by RickS

Here's the 2006 3.0SI I purchased, has 71k miles on it:

That's a really nice Z.

[RKM]

Originally Posted by StickMon

Bolts that hold the splined inserts into the ends of the hollow camshafts were upgraded in early 2007.
There's a 100% failure rate on earlier ones. It's about a $1600 fix if you catch it before the engine grenades.
I know because my car had that failure when I bought it, but I didn't yet have the wisdom of this forum.
Sounds like marbles ratting inside a coffee can.

To which engine are you referring? I am familiar with common problems from reading this forum. (Top motor, for instance) With a 100% failure rate I would expect this issue to come up frequently.