2000 Mazda MX-5 NB, 1.8
A sound looking NB whose sills nobody has looked inside, with a borescope booked before the hammer
Overview
Compiled by Kept from the seller's intake answers, the documents supplied and published records for the model. The seller does not write or edit this section, and nobody from Kept has inspected the car.
This 2000 Mazda MX-5 is finished in silver over black and is offered from Milnerton by , its third owner and the keeper of the car for six years. It is the NB with the 1.8 litre BP and the five speed manual, and it shows 152,900km. There is no hardtop and there never has been.
The question on any MX-5 that has lived near the sea is the sills, because they rot from the inside outward and a car can look sound from underneath while the inner section has gone. Surface corrosion at both rear arch lips and along the left sill seam was wire brushed and treated in May 2022 and not cut out, and every one of those areas is photographed from underneath.
Asked at intake whether the sills are sound internally, the seller declined. He has not had a borescope in them, will not guess, and has booked one for the Wednesday before this auction closes with an undertaking to publish the result in the comments whatever it shows. Kept publishes the decline as it stands. If the inspection happens and is posted before the hammer, the room will have priced this lot on the answer rather than on the silence.
The mechanical file since 2019 is complete and covers what this engine needs. A clutch in 2019, a replacement soft top in 2021 with the frame checked and the drain rails cleared, and the cam belt, tensioner and water pump in 2023, at which point the crank pulley was replaced and the keyway inspected and reported unworn. The remaining flaws are a hazed plastic rear window and a delaminated corner on the driver's mirror glass.
Model background
The MX-5 is the best selling two seat sports car ever built and the NB is the generation the market spent twenty years ignoring. Mazda replaced the pop up headlamps in 1998, stiffened the shell, improved the gearbox and kept everything that made the first one work, and enthusiasts spent two decades insisting the NA was the pure one and the NB was the compromise. Values have since made that argument look like sentiment.
The 1.8 litre BP is a robust engine with one documented weakness worth knowing about: the crank nose and the keyway, where a loose pulley bolt can wear the key and eventually round the nose off, which is an engine out repair. The fix is prevention, and evidence that the pulley and keyway have been inspected is worth more than any other line in a service record on these.
In this market they rust, because a great many of them live within sight of the sea, and the sills are the place. A car that has been treated on the outside without anybody looking inside is the standard condition of a coastal NB, and the difference between one worth buying and one that is a shell is a ten minute inspection almost nobody performs.
Essentials
- Lot
- KPT-105
- Year
- 2000
- Model
- MX-5 NB, 1.8
- Mileage
- 152,900 km
- Transmission
- 5-speed manual
- VIN
- JM1NB353510203847
- Location
- Milnerton, Cape Town
- Seller
- milnerton_nb
- Seller is
- Private, third owner, 6 years
- Watchers
- 204
Seller interview
Before the car went live, the seller answered a standard set of questions plus a set our tools generated for this model from its documented failure modes. The full transcript is public, including anything they declined.
9 of 10 answered, 1 declined. A high score means the seller told you more, not that the car is better.
Inferred from the seller's answers and this model's known failure points. Nobody from Kept has inspected this car.
1 question the seller declined
NB sills rot from the inside outward. Are the sills sound internally?
Documented MX-5 sill corrosion path. Externally treated sills tell a buyer nothing about the inner section, and only an internal inspection settles it.
Known flaws
The seller's own list of what this car needs money spent on.
- 01Asked whether the sills are sound internally, the seller declined, saying he has not had a borescope in them and will not guess, and has booked one before the auction closes
- 02Surface corrosion at both rear arch lips and along the left sill seam, treated in 2022, not cut out
- 03Soft top is a replacement fitted in 2021, the rear window is plastic and has hazed at the lower edge
- 04Crank pulley was replaced in 2023 and the keyway was inspected and reported unworn at that point
- 05Driver's door mirror glass has delaminated at one corner
- 06Hardtop is not included and has never been with the car
Service record
Documents & what's included
What physically comes with the car.
- 01NATIS registration certificate, in milnerton_nb's name
- 02Invoices for every service from 2019 to 2025
- 03The 2023 invoice recording the crank pulley replacement and the keyway inspection
- 04Photographs of the treated arch lips, the sill seam and the underbody, published
- 05Two keys
- 06Roadworthy certificate issued within the last six months
Note from the seller
The seller's own words, published as written. The only copy on this page they control.
I bought this in 2019 with 121,400km and it has been a Milnerton weekend car since, which means it has lived four kilometres from the sea for six years. That is a disclosure, not a description of the view.
What I would want to know: there is treated surface rust at both rear arch lips and along the left sill seam that I did not cut out, the roof is a 2021 replacement with a plastic rear window that has hazed at the bottom, and the mirror glass has delaminated at one corner. The belt and crank pulley were done in 2023 and the keyway was inspected then.
On the sills, I was asked whether they are sound inside and the honest answer is that I do not know, because nobody has looked. I have booked a borescope for Wednesday morning at a shop in Montague Gardens and I will post whatever it finds in the comments the same day, good or bad. Until then it stands as a decline and it should.
Comments & offers
6 comments · 2 offers
Two hours to go and the borescope was Wednesday, so either it happened and I have missed it or the room is bidding on a promise. The reserve not being met suggests everybody else has done the same arithmetic.
Publishing the footage rather than the shop's opinion is the right call. Let the thread read the pictures.
Booking is confirmed for 09:00 Wednesday at the shop in Montague Gardens and they have agreed to give me the footage rather than a verdict. I will post the video and the still frames in this thread the same morning whatever it shows.
Crank pulley replaced and keyway inspected and reported unworn is the line that makes this worth watching at all. That is the repair that writes these off and almost nobody records having checked it.
Four kilometres from the sea for six years and treated rather than cut. On an NB that is either nothing or it is the whole car, and there is no way to tell from the photographs published. Wednesday will decide what this is worth.
Booking the borescope and committing to publish the result before the hammer is the most useful thing a seller can do with a question he cannot answer. It turns a decline into a deadline.
Comments & bids
6 comments · 2 offersThe crowd checks the report. Offers post inline, and the seller answers directly. Most recent first.
Two hours to go and the borescope was Wednesday, so either it happened and I have missed it or the room is bidding on a promise. The reserve not being met suggests everybody else has done the same arithmetic.
Publishing the footage rather than the shop's opinion is the right call. Let the thread read the pictures.
Booking is confirmed for 09:00 Wednesday at the shop in Montague Gardens and they have agreed to give me the footage rather than a verdict. I will post the video and the still frames in this thread the same morning whatever it shows.
Crank pulley replaced and keyway inspected and reported unworn is the line that makes this worth watching at all. That is the repair that writes these off and almost nobody records having checked it.
Four kilometres from the sea for six years and treated rather than cut. On an NB that is either nothing or it is the whole car, and there is no way to tell from the photographs published. Wednesday will decide what this is worth.
Booking the borescope and committing to publish the result before the hammer is the most useful thing a seller can do with a question he cannot answer. It turns a decline into a deadline.