Testing Driving

stal023

Member
South Carolina
I've test driven a number of Z4, have researched common issues but these are so low to the ground that the only place you can get under them is the rear, plus most the underside is protected by covers and you can't see anything. Best way to really have a look at these? Tips and suggestions would be fantastic.
 
Well if I am meeting the seller at a gas station, I don't have access to a ramp. Say I do have access to a ramp, most the bottom is covered up. Then what?
 
Why are you meeting at a gas station?

Does the gas station have facilities to put it on a ramp, and is the current owner happy for you to remove some of the underside panels (there aren't a lot, and you can probably see signs of corrosion/damage from what you can see without removing them.

But what you have to expect will also depend on the price you're paying...so a $5,000 car will not be expected to be in as good a condition as a $15,000 car.
 
Understand on price. Most don't want to meet at their house, which I get.

Say the owner is okay with me taking off the panels, what are areas of concern for this generation? I understand rear springs can be an issue. What am I looking for to know if they are decent or not? Also I know control arm bushings tend to go bad, again, what specifically am I looking for to know if they are decent or need replacing? Much appreciated everyone.
 
I wouldn't buy a car from someone who will only show it to me at a gas (petrol) station.
 
Indeed, in the uk at least its perfectly normal, indeed expected, to view a car at someones house. That way you can check that the car is registered to that address and that its not stolen.

Cant help you on inspection, but mostly i go on service history and the bits i can see. Rust isnt really a problem for z4s, thats where id want to do a full chassis inspection. Or check the last mot for advisories.
 
I assume you’re in the States?

Most of the suspension, brake lines etc you can see without removing the covers. Are you able to carry a jack in your trunk to lift up the side of the car? Oil leaks you can generally see under the hood, and oil problems by removing the filler cap. Paint, bodywork, wheels, tyres and interior you can tell just by looking, engine condition by listening, and many other issues by taking it for drive, keeping an eye on the gauges and and any warning lights.

Of course, none of the above is a substitute for getting it properly checked over by a mechanic.
 
I think most of it has been covered already.

But depending where you are in the States it may not be an issue. Anyway in the UK the rear brakes pipes often suffer from corrosion. They run under the floor on the passenger side of the car (not sure which side they will be on a US car) inside a plastic cover, but it ends a foot or so in front of the rear wheel and road debris gets lodged in the end of it holding moisture which causes the corrosion.

If you can't take a jack or get it on a ramp maybe parking a rear wheel on a curb would raise the car enough to allow you to see them.
 
Yes, I am in the states. I guess taking a jack wouldn't hurt. Still not sure how to know if the control arm bushing and rear springs are good or not?

What about the heater control valve? I know post facelift the water pump is a known issue. Is this just once it goes out, it goes out, or any symptoms before it goes? What about the vanos solenoids? PVC?

Thanks again, I am learning as I go!
 
The only one I have experienced is the facelift water pump.

And when it dies it's game over! My first Z4 had the pump die at 60K miles and my E91 325i with the same N52 engine had one die at 135K miles. Both were over-heating within a mile, so no significant warning. You can drive them a bit further but they will go into limp-mode.

Maybe useful as a negotiating factor if you look at one that hasn't had a new pump. In the UK an OE Pierburg pump costs around £250, although BMW charge over £500! :o
 
@stal023 - is there no alternative to viewing the car at a petrol station? For one thing, I always specifically ask the seller in advance, to make sure the engine is cold when I first see the car:

1) I want to see how well it starts!
2) blue smoke on start-up (walk away signal) invariably eases after 10 minutes, disguising if there’s a serious issue in the engine, exhaust or exchanges,
3) I like to see where it’s been stored/kept. If the owner looks after wherever the car’s kept, there’s a good chance they look after the car (anyone can fake a log book stamp)
4) oil on the garage floor or driveway are a dead giveaway

Sounds like you may have no choice on where you go to see the car, but even then, nothing to stop you asking the seller to make sure the engine’s cold. If nothing else, it allows you to poke around without burning your hands 😂.
 
I did some research and found how to tell if these parts are no good, etc.
Control Arm Bushings: https://www.youtube.com/watch?v=ENJQpe50WBg

Rear spring: https://www.youtube.com/watch?v=UNPnt2M7fkQ

Vanos: (start at 1:30) https://www.youtube.com/watch?v=YK_xuwkArJ4
https://bmwtuning.co/diagnosing-a-failing-bmw-vanos-system/

PVC: (skip to 1:00) https://www.youtube.com/watch?v=B9xwZLJKR-A
https://www.completeautomotivesystems.com/how-to-diagnose-pcv-valve-failure-in-a-bmw/

I also found this to be informative for those with a manual:
https://www.breakerlink.com/blog/maintenance/8-signs-that-your-clutch-may-be-on-its-way-out/

I found this in another post and I am wondering what this is all about????
"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."
 
In fairness, your links are helpful, too, and I think we can all empathise with the notation (springs video) ref BMW main dealership charges. Thanks 👌That said, if you’re doing this much research, you’re already smarter than the average bear 8)
 
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