Hi All,

It's only been recently but when I start the car, for a split second the car seems to tick over extremely high for that moment, and then it calms down like nothing had happened. This is my first diesel I've owned so is this normal? I know in the past you used to have to let the glow plugs warm up slightly... I'm guessing that there is no need on a 08 plate 1.9 TDI?

The noise happens as soon as the starter motor has finished its part of the job in ticking the engine over... hmm!

Also for a diesel, I understand their extra loud when they first start up but how can you tell between a noise that should and shouldn't be there?! lol

Thanks for your help and info!

Leon

It's normal for the 1.9TDI to have a slightly raised engine tickover after start up on a cold morning. This should only last for a brief time but will last for longer the colder it gets. If you have not allowed the glow plugs to heat up properly this may also lead to increased engine speed at start up which may appear to jolt the car engine slightly making the noise you speak of. The injection system goes to full advance when cold starting to precipitate smooth running and reduced emissions. On the whole, the PD engines experience less higher speed idle than the CR engines in cold weather. The glow plugs on the PD engines should be allowed to heat up for the full amount of time before turning the key. Watch for the glow plug light to go out on the dash before turning the key. This reduces emissions, allows the engine to run smoother and allows easier starting in very cold weather. Enjoy the car, I doubt you have anything to be concerned about.

Edit: yes diesel engines can be quite a bit noisier at cold start up. This is due to the fuel combusting unevenly. This casuses a combustion rattle and can sound like the pistons and rings are slopping about in the cylinder bores with an inch of clearance around them!! It's no such thing of course and is not harmful at all. PD's suffer a bit less from this behaviour than Cr engines due to the better (higher pressure) injection process of the unitary injectors.

Edited 31 January, 201214 yr by Estate Man

It's normal for the 1.9TDI to have a slightly raised engine tickover after start up on a cold morning. This should only last for a brief time but will last for longer the colder it gets. If you have not allowed the glow plugs to heat up properly this may also lead to increased engine speed at start up which may appear to jolt the car engine slightly making the noise you speak of. The injection system goes to full advance when cold starting to precipitate smooth running and reduced emissions. On the whole, the PD engines experience less higher speed idle than the CR engines in cold weather. The glow plugs on the PD engines should be allowed to heat up for the full amount of time before turning the key. Watch for the glow plug light to go out on the dash before turning the key. This reduces emissions, allows the engine to run smoother and allows easier starting in very cold weather. Enjoy the car, I doubt you have anything to be concerned about.

Edit: yes diesel engines can be quite a bit noisier at cold start up. This is due to the fuel combusting unevenly. This casuses a combustion rattle and can sound like the pistons and rings are slopping about in the cylinder bores with an inch of clearance around them!! It's no such thing of course and is not harmful at all. PD's suffer a bit less from this behaviour than Cr engines due to the better (higher pressure) injection process of the unitary injectors.

So you'd recommend waiting a few seconds between key turning from stage 1 on the ignition to start up (stage 2)

It does take a few miles to heat up from cold as well....thank god for heated seats!! does it hurt the engine to drive normally or would you recommend driving below a certain rpm until the temp level reaches the normall warmth?

Thanks again Estate Man

Hi Leon, yes...I'd wait until the glow plug light goes out before turning the key if you are starting from cold. If you find you are still getting the fast start up 'shudder' which I think is what you are concerned about (lasts just a few seconds), then you probably need to take the car for a bit of a blast down the motorway to clean out the engine, and don't spare the horse either! Get it nice and hot for a sustained period. Some Miller injector cleaner wouldn't go amiss either and that should help it. But bear in mind it is a big heavy engine and they do have considerable inertia when they start so it's not going to always be smooth like a petrol engine in cold weather with thick cold oil

The 1.9PD engine does take a little while to warm up compared to it's smaller brother, the 1422cc PD engine, due mainly to the fact the smaller diesel works a bit harder and produces extra heat sooner. The 1.9 unit is hardly working at all when in normal driving, unless you are having to 'rag' it a bit because you are late for work!! (that's just an example, not suggesting you actually are late for work at any time!). It's very very difficult to harm a diesel engine whether hot or cold. Petrol engines get flooded with fuel during cold running and that fuel is a solvent which tries it's best to wash the oil away from all the metal parts it comes into contact with. Hence you get much more metal to metal contact in petrol engines during cold running. So petrol engines wear mostly when they are cold. In a diesel, that doesn't happen as the fuel itself is not a solvent, it's a lubricant and it baths everything it comes into contact with in this 'extra' lube which stops most wear from happening. That's the main reason a diesel engine outlasts a petrol engine by a considerable amount (about 2 to 1 in diesels favour). But it is always a good idea to let it warm up a bit before you start to use the performance too much as the oil flows much better and all the engine parts fit together much better when they are hot. I normally don't go over 2,750rpm when it's cold but the revs are slightly less important than the load on the engine. I don't labour it at low revs or rev it hard until it's fully warmed up. Don't worry though, it's a diesel, they are as tough as they come, you won't hurt it.