A long time ago I posted here (or Porsche Pete's?) about a noise my 2001 base Boxster developed. (IIRC, this was at the rear.) It occurred only at slow speeds, like 5 to 15 mph, and only when going over small amplitude but sharp irregularities, such as lumpy asphalt. Grass lawn parking areas, too. After changing out parts piecemeal the solution was replacing the "tuning fork" control arms, (not the "coffin" ones.) Some time later, the front developed the same noise, and changing only those pieces also resolved the issue.
This is a 996 part, but is close enough for illustration purposes:

Back then I described the noises as sounding like tapping hard with your fingernails on a plastic Frisbee.
My 981 Boxster S has developed a similar noise coming from somewhere up front. The conditions for it to occur are the same as the previous situation, although the sound is deeper, like a big panel is vibrating. With that in mind, I've tried cross-bracing the frunk interior panels with padded, tightly fitting lengths of 2X4s, pressed strips of silicone gasket into the spaces at the headlight/fender gaps, the parking light gaps, and to the rear of the front apron where various plastic underbody panels overlap. I've also tried removing the battery cover. The wheel well panels and the adjacent belly pan pieces make noises similar to the problem when wrapped, but they seem too isolated from shocks to be the problem. I've tried driving with the hood released. I doubt it's the sway bar drop links, as they had been changed on the "01.

...Anyway, to me the prime suspects are those "tuning fork" control arms. The dealer checked the front end out, and even emptied the fuel tank shield of trapped gravel, but found nothing. I believe the wear on the arms' front bushings isn't detectible unless the arms are disconnected. (Theres's at least one video online that points this out.)

So, does anyone have experience with these noises with their 981 Boxster, and resolved the issue? The car has >100k miles, btw.

Laz,
I have a 986 and have experienced the rear "clunk" which was resolved by replacing both rear control arms--no front problem yet. In addition, I have a 981 but have not experienced the "clunk" but when I do, the control arms(front/rear) will be the first suspect.
Jerry

Laz,
It appears you like to perform diagnostic testing. If so, a tool like this may help.

[www.amazon.com].

I just pulled my 2002 Base out of storage and am looking at updating deferred items. When I drive, it has a serious rear end "clunk" noise when going over rough road/bumps. I was wondering if it may be the motor mounts (never replaced and Im at 215K miles, but also will check the rear control arms. Thanks.

There's just one engine mount (front) and two transmission mounts.
The engine mount is really a wear item and should be replaced every 50K miles.
The transmission mounts can go much longer and are generally not replaced unless they leak.
A very worn out front engine mount can certainly create a sound clunk, especially when accelerating or breaking
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 314,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna




Edited 1 time(s). Last edit at 06/23/2025 05:16PM by Pedro (Odessa, FL). (view changes)

Thanks, Pedro. Do you still fabricate replacement mounts?

... from me.
It's been about 10 years since Porsche mandated that any parts removed must be destroyed, so we don't have any more mounts to repair.
If you are replacing the front engine mount, purchase and install the one for the 2008 CaymanS, no matter what older Boxster or Cayman you may have.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 314,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

OK, Thanks Pedro. I was curious about what the difference would be between a Boxster and CaymanS front engine mount and did a google search.

In summary, as you obviously knew, it stated the Cayman S front motor mount is strongest /most durable version. Thanks, Pedro for letting me know about this.

The Porsche Boxster and Cayman models are known for sharing many components, particularly within the same generation. The 2002 Boxster (part of the 986 generation) and the 2008 Cayman S (part of the 987 generation) have some key differences, but also some shared or interchangeable aspects regarding the front motor mount.
Similarities and Differences in Front Motor Mounts:
Interchangeability: While the front motor mount designs have evolved, it's generally understood that the latest, strongest version (part number 987-375-023-04) can fit both Boxsters and Caymans. Some sources specifically suggest that a redesigned mount initially used in the Cayman S, built for higher torque and horsepower, can be fitted to a Boxster.
Design Evolution: Earlier Boxster mounts (up to 1998) were attached using three bolts, while later models use a four-bolt design. If using a later-style mount on an early Boxster engine, you may need to upgrade the oil pump housing for proper four-bolt mounting.
Performance: Some owners report that the Cayman S mount provides better performance due to its design, which is built to handle the higher torque and horsepower of the Cayman S engine. The feel of a standard 986 mount compared to a 987 mount may not be significantly different.
Location of the Front Motor Mount:
General Location: Engine mounts are typically found on the bottom sides of the engine, connecting it to the vehicle's chassis.
Boxster (986): The engine mount is attached to the front of the engine case using four bolts.
Cayman S (987): The engine mount location is similar to the Boxster, but it may involve working around the central coolant hoses.
Important Notes:
Solid/Performance Mounts: While performance mounts are available, they can result in a harsher ride and are generally not recommended for street use.
Professional Installation: While some front motor mount replacements can be a DIY project with sufficient access and tools, professional installation is recommended, especially if you're not comfortable working under a car supported by jack stands.
Part Numbers: Always verify part numbers with a Porsche specialist to ensure compatibility with your specific vehicle.
In conclusion, while the 2002 Boxster and 2008 Cayman S have different engine sizes and overall characteristics, their front motor mount designs have evolved, and later versions are often interchangeable. If you're considering replacing the front motor mount on your 2002 Boxster, the latest-generation mount designed for the Cayman S might offer enhanced durability.



Edited 1 time(s). Last edit at 07/01/2025 04:18PM by BarryL. (view changes)

on the "Design Evolution" paragraph it states:
"Earlier Boxster mounts (up to 1998) were attached using three bolts". It should be up to 1997.
The 1998 and newer all have the 4 bolt pattern and upgraded oil pump housing.
Happy Boxstering,
Pedro

Pedro Bonilla
1998 Boxster 986 - 314,000+ miles: [www.PedrosGarage.com]
PCA National Club Racing Scrutineer - PCA National HPDE Instructor - PCA Technical Committee (Boxster/Cayman)

---

Racecar spelled backwards is Racecar

"Racing is life. Anything before or after is just waiting" ... Steve McQueen as Michael Delaney in "LeMans"

"If you wait, all that happens is that you get older"... Mario Andretti

"Being second is to be the first of the ones who lose" ... Ayrton Senna

Did you only replace the rear control arms, leaving all other suspension parts in tact? How many miles do you have on your Boxster? I am planning to replace the front motor mount to see if that is the problem with my rear end "clunk" noise when going over bumps in the road, but may end up having to replace control arms too. Once you tackle one replacement part, its difficult to know when to stop. I have 215k on my 2002 boxster base tip.

... if not exactly the noise, especially wtih the harder bumps.

[www.youtube.com]

The guy talks quite a bit before driving, which starts at about 1:26, and goes to about 2:00.
The cobblestones definitely emphasize the noises I hear with my car.
Near as I can tell, he unfortunately never posts if he resolved the issue. Some of the replies get close, but there's usually a terminology issue as to what part they're referring to.

If I cannot reproduce the problem from outside the car (e.g. by pushing down on each corner) then I will find a bumpy road that easily reproduces the problem, then one by one spray a suspect with a silicone lubricant and reproduce the problem and listen if the sound has changed (or in some cases, gone away). You repeat that process with each of the suspension joints until you find it.

Also, if you have an assistant handy you can ask them to listen for the sound as you drive by. That helps pinpoint it.

Please let us know what it turns out to be.



Edited 1 time(s). Last edit at 07/08/2025 08:57AM by Boxsterra. (view changes)