Mazda MX5 2.0L sport - Rattle from engine gets louder at 3500 revs upward

Honest John Back Room » Technical matters
View Threaded
Wed 21 Mar 2012 18:02
Mazda MX5 2.0L sport - Rattle from engine gets louder at 3500 revs upward - Carl65

Hi, Our mx5 has recently developed a rattling noise which is very quiet on starting the engine but gets load when the engine is under load, 3500 revs upwards.
I too kit to a garage today and they advised me that the crank had gone and that this was a common fault on this engine (although a search of the net for this particular problem has been rather fruitless, so I'm not sure if it is a common fault or not).
They say that a new engine is required and this would be around £2000. They also said another option would be to convert the car and fit a 1.8L engine instead (they said these engines are more reliable).

What is your advice regarding the symptoms, does the advice I've been given sound fair or should I get a second / third opinion? Many thanks for any help you can give, Regards, Carl

Edited by Carl65 on 21/03/2012 at 18:09

Reply | Report as offensive | Link
Wed 21 Mar 2012 20:04
Mazda MX5 2.0L sport - Rattle from engine gets louder at 3500 revs upward - craig-pd130

Hard to tell without hearing it, but a diesel-sounding knock when the engine is pulling and under load is a symptom of a dead crankshaft bearing.

Try this -- in 3rd gear at about 2,500rpm, accelerate hard for a couple of seconds and then lift sharply right off the throttle. Does the rattle / knock get louder as you lift off? If so, it's likely that either a big-end or little-end bearing has failed.

It is possible to have a crankshaft reconditioned BUT it's expensive and it's also possible that metal fragments may have got around the engine. A replacement engine may be the best option.

Reply | Report as offensive | Link

10 warranty myths exposed

Here’s how to sort the fact from the fiction when it comes to car warranties.

Cheap Car Warranties

We give you the low down on how to save on insurance, little-known tricks and tips, what insurance groups mean and how to use insurance aggregators to beat insurers.

Insurance group finder and how to save on insurance