Mazda Ute Range

The EGR system is an important part of any modern turbo-diesel’s emissions control package. So if it’s not working properly, or telling the on-board camera that it has a problem, the computer may presume the problem is serious enough to not start the engine to avoid further damage.

You need to go back through your work, checking and double checking that each wire, sensor and fastener is properly fitted and secure. You may also need to check the EGR valve itself to make sure it hasn’t been damaged in the cleaning process. The on-board computer may need a reset after this procedure, so a visit to a diesel specialist might be the best next step.

For a start, this model Mazda BT-50 did have a recall to check the transmission’s output shaft speed sensor. If this failed, the transmission could suddenly shift back to first gear which, if it did so at highway speeds, would have been potentially disastrous. But it’s also possible that this sensor could fail and not allow the transmission to shift beyond first gear, so that would be worth a check. A transmission specialist is your best bet here.

Beyond that, simply servicing a component won’t generally fix a fundamental problem. It would be the same with a worn out or internally damaged engine; servicing that engine with fresh oil and spark plugs will not fix the underlying condition.

The problem of a clutch pedal hitting the floor without actually disengaging the clutch is usually caused by either a faulty clutch master cylinder, slave cylinder or a loss of clutch fluid from the system.

These are not expensive or complex things to fix and new master cylinders and slave cylinder are readily available from parts stores and online sellers. However, if the problem is a lack of hydraulic fluid, you also need to figure out where the old fluid went. There must be a leak somewhere and until that’s fixed, topping up the fluid will only be a temporary fix.

If you’re really unlucky, you might find the clutch has collapsed internally, at which point a whole new clutch will be needed. This vehicle also used a dual-mass flywheel, so you’ll often need to replace that as well to do the job properly.