Buying Buying 2016 M4 convertible, what to look out for?

[PatrickD1981]

Hello,
I just joined the forum. Forgive me if this has been discussed, but my search did not really yield a good answer.

I am planning on buying a 2016 m4 convertible with DCT and 43k miles. The price seems really good (39k), but its about a 4 hour drive away.
Can anyone advise me on what specific things I should look for when checking out the car? I know some of the more common serious problems like a spun crank hub, but thats not something I can really look for myself. Its 8 years old at this point, so I want to make sure I check out some visible signs of wear or poor maintenance.
Any help is much appreciated. Thank you!

[icebiker]

Before you go there is the seller willing to take more pics for you? If so:
1) check under the sills in front of the rear wheel wells to see if the water drain plugs are installed. They should be removed in accordance with a BMW service bulletin. They tend to clog causing rainwater to build up and fry the amp. Especially important if the car is in a frequently wet climate
2) have the seller show you the inside of the charge cooler reservoir (middle of engine bay, near windscreen) and radiator reservoir (drivers side of engine bay, midway between windscreen and bumper). If they are dry it could meen a leaky intercooler or weeping seams of the radiator reservoir.
3) video of the convertible top in operation. Should make no noise and raise/lower smoothly (no jerks or hesitation)
4) make sure you have the wind deflector (stored behind the fold-down back seat)
5) check to make sure the pass-through door exists (for carrying any long items). Some early cars didn’t have one
Good luck!

[M3SQRD]

Unfortunately, without a true PPI, it’ll be difficult to identify the major issues on the f8x.

The TMIC is the easiest one to visually identify. The TMIC is located at the back center of the engine and it has a small coolant reservoir. Check to see the level of the coolant. It should be to the top fill line and anything below that may suggest the TMIC is leaking which is based because the fluid is immediately ingested by the engine combustion chambers.

The PCV fails around ~50k miles. With the car running if you hear a hissing or a squealing sound, try removing the oil filler cap. If you can’t get the cap off or if it comes off and the noise goes away then it has a bad PCV. This isn’t ideal because BMW made it integral to the valve cover so the valve cover needs to be replaced. Buy one from FCP Euro so when it inevitably fails again you won’t have to buy a new one.

The original rear differential bushing on a MY ‘16 are fluid filled and eventually they crack, draining the fluid from the bushing(s). The fix is to have aftermarket bushing pressed into the stock diff mounts. Also, while you’re doing this, it’s the perfect time to install an aftermarket dual diff mount bracket to prevent the diff from twisting.

Those are the three common failures on the f8x. I’d strongly recommend you pay for a PPI because it’s going to document the condition of a lot of wearable items such as brake pads, rotor thickness, diff bushing condition, tires, etc. It’ll either show the car is in good mechanical shape with minor replacement parts needed to it being in poor mechanical condition with major replacement of wearable items needing to be replaced.

I don’t own a f83 so I can’t help you identify potential issues with the top and/or its folding mechanism. However, comparably spec’d f83 compared to a comparably spec’d f80/82, the f83 will be at least $5k lower in price. GLWYS! Better to eliminate cars you don’t want from your potential list.

[ajbM4cab]

Also check the engine noise when on a cold start up.
Very common issue is a tapping noise due to the exhaust cams needing to be re-torqued.
Can be annoying hearing a tapping / knocking noise.
Had mine done on approved used warranty.
As usual check for dried out roof seals. Leaks can be common on the front corners.
A product called Gummi Pfledge is very good for treating and softening all rubber seals.

[PatrickD1981]

Thanks for the answers.
After looking at the carfax for that car, I saw that it had 4 owners, so no wonder it was such a low price. I think I will pass.
Also, it sounds like there are a lot of issues to look out for, things I had never even heard of. If that scares me away, am I better off looking for an B58 powered car, like the M440i?

[ajbM4cab]

Originally Posted by PatrickD1981

Thanks for the answers.
After looking at the carfax for that car, I saw that it had 4 owners, so no wonder it was such a low price. I think I will pass.
Also, it sounds like there are a lot of issues to look out for, things I had never even heard of. If that scares me away, am I better off looking for an B58 powered car, like the M440i?

4 careful owners or 1 bad owner, which is the better? Probably need to dig a little deeper on that one.
4 owners not too bad for a near 8 year old car. 1 owner may have even been a dealer demo or a pre register.

I also think each model car will have its own list of common ‘to look out for’ issues.
That list is relatively short for a car which has been around since 2014ish.
Other than those items, the M4 cab is a great car to own and drive.
To note that the M440i cab also inherits a few of those cab related items too.
M440i is another great car equally as rewarding as the M4. 2 close friends both each own one.
I also have a M240i cab and it is also a superb package albeit different from how the M4 delivers.
Have you also considered one of those. The B58 engine is also excellent and extremely tuneable if required.

[WhiteFox]

Don’t be put off these are all edge cases as most F83 no issues at all. If they have been well maintained it’s as good as any other car. I would just get a non modded car and/or one where owner looked after it well.

These cars will have a few owners being 6-7 yrs old but again if serviced and looked after they are fine.

I’ve had mine for a few years and touch wood no issues.