Hi there, l have an M reg diesel 306, and sometimes its been having problems starting, i will turn the key and wait for the light to go out then when l try to start it just makes a single click sound, if l keep turn the key eventually after a while it will start,
would anyone happen to have an idea of what could be wrong?

thanks in advance
with regards to the spark plugs, no diesels dont have spark plugs, they have glow plugs which l have already checked with an ohmmeter and they seem to be ok.
burning brightly, thankyou for your input, l have done a google search for solenoid and starter motor and it looks like you were right and that could be my problem,
i have ordered new parts and hopefully can fit them over the weekend,

thankyou for your help :)

You have solenoid trouble at your starter motor.~~

check the spark plugs. sorry forgot they do not have any

BEFORE YOU spend money on a new starter and solenoid.make sure you have a very tight connection of your black negative ground cable from the battery to the engine block. A starter motor needs a lot of Amperes and a very good connection.

When you hold the key on, and it eventually starts, this says ''bad / loose connection'' to me.
It is the two minute, no cost solution.