I have an intermittant problem where the engine strugles to start but when it does the revs go to 3000 then drop down to norm then shoot back up again to 3000. Was told to change temp guage sender as guage was not working all the time and could have been sending false readings. This done but prolem still there and now the water warning light keeps flashing at me even though the water level is fine! Please help.

 

What year, model, engine ... ? We need more details.
I don't think a bad coolant temp sensor will make the rpm go up to 3k, maybe 1200 rpm instead of normal 750-850rpm, depending on engine/yr. Your MAF sensor is good place to start checking, and look or leaks in vacuum lines.

 

hi i have an a4 2.0 fsi same happend on mine
it was a split in breather pipe witch i taped up and it ran ok
hope this helps
jay

 

Good point, a leak in the intake system or a vacuum leak could cause rpm surge.

 

when hes back on he should give more info like fault codes