The other day something sounded a bit off with the engine. I could not pin point it but something was niggling me.

 

When I got home later on in the day I though I would give it a check over on the driveway. This time it sounded OK but for some reason I was not able to get high revs, it kept limiting around 3000rpm and would go no higher.

 

Anyone know if this is some sort of prevention or cold start protection?

It's there to stop idiots revving an unloaded engine above 3000rpm

It's quite common to have a rev limit in neutral, as rwbaldwin notes. When an engine is not under load there's not a lot of fuel going in, hence not a very big bang. As the piston goes up this means there's not much bang pushing back as it approaches TDC, so it gets slowed down mostly by the conrod, putting stress on the conrod bearings, gudgeon pin and crank journals. By limiting the revs, this unloaded stress is restricted.

 When you stop,  the engine might sound a bit funny and the fans are running and you try to rev the engine and it won't rev above 3000 rpm. the engine is in DPF regen mode, so when you turn the engine off the fans are still running, the manifold gets very hot under the bonnet as the system is cooking the DPF.

 

So give it time go and have a cup of tea, and all will be back to normal.

 

I never get out of 4th if I am doing a journey less than 3 miles, this gives the engine time to heat up and not to swamp it with diesel in 5 th or 6th gear. my mpg around town is 36mpg and 48 t0 50 mpg

on long runs.    This way the regen only happens once a month. as I don't do long journeys.      (2012 140 manual EL Yeti.)

These motors are rev limited in neutral all the time - I don't think anything will change that..

Also they will not warm up in 3 miles - more like about 12 or even more.

 

Norry

It's quite common to have a rev limit in neutral, as rwbaldwin notes. When an engine is not under load there's not a lot of fuel going in, hence not a very big bang. As the piston goes up this means there's not much bang pushing back as it approaches TDC, so it gets slowed down mostly by the conrod, putting stress on the conrod bearings, gudgeon pin and crank journals. By limiting the revs, this unloaded stress is restricted.

I do not think this is scientifically correct as this would only occur for 50% of the cycles of a 4-stroke engine.

Also they will not warm up in 3 miles - more like about 12 or even more.

Before buying my Yeti, I was a little concerned as they don't have coolant heaters.

Reason I was concerned, is that I've had 3 PD 130 TDIs before, 1 without a coolant heater (an Ibiza) and 2 with (Passats). The Ibiza used to take several miles before I got any heat at all out of the vents (a right PITA in winter - leaving from work into urban crawl where the engine does little work), yet the Passats had warm(ish) air - enough to start demisting/defrosting ice - even before I'd got out of the works car park.

 

The Yeti does seems to warm up reasonably quickly though, perhaps not as quick as the Passats I had - but mine doesn't take anywhere near 12 miles. 

 

I don't know if the engine just warms up a bit more quickly, or there's some sort of auxiliary heating of the cabin air ?

This "thing" about slow warm-up comes up regularly, and I can only state my experience.

When working I have to go to work at 0430, we don't have a garage, and even when the temperature was -10 I was getting noticeable heat from the central vents after 3 miles, and full heat after 15. 

I certainly don't call that slow!

The 2.0 diesel has a rev limiter in neutral

 

Comes in handy,really.

 

In my country there is an emission test during the MOT.

 

They asked me to rev up after sticking the sensor up the exhaust and just left it as is after realising there is a rev limiter.....

Edited 6 October, 201411 yr by oriki