GTI Cold start

[Adam T7]

Very true, I let mine idle for about 30 seconds from cold and let it warm down at the end of a journey by idling again for 30 seconds.
The noise the OP mentions is normal, mines done it from brand new and it’s a well cared for engine. Its just the oil reaching pressure as others have posted.

[P6GTD]

In the early days of road cars with a novel “turbo thingie” such as the SAAB Turbo, drivers were warned to let the turbo cool down by leaving a hot engine to idle for a brief period to avoid high temperatures from heat sink.

Alternatively to drive gently for final the few minutes.

I know those days are long gone but after a long fast run, I still complete the final couple of miles home more gently to follow the same principles.

It’s probably pointless……but I like doing it anyway. Or maybe it’s my OCD kicking in.

(Likewise keep revs to under 2500 until I’m confident the engine is fully warmed. As I live 1 minute from a busy roundabout with 3 dual carriageways, this can cause some irritation to other road users!!!).

[Adam T7]

In the early days of road cars with a novel “turbo thingie” such as the SAAB Turbo, drivers were warned to let the turbo cool down by leaving a hot engine to idle for a brief period to avoid high temperatures from heat sink.

Alternatively to drive gently for final the few minutes.

I know those days are long gone but after a long fast run, I still complete the final couple of miles home more gently to follow the same principles.

It’s probably pointless……but I like doing it anyway. Or maybe it’s my OCD kicking in.

(Likewise keep revs to under 2500 until I’m confident the engine is fully warmed. As I live 1 minute from a busy roundabout with 3 dual carriageways, this can cause some irritation to other road users!!!).

I suspect we are a similar age…😂

[symonh2000]

It wasn't as much letting the turbo cool down, it was letting the turbo slow down.

If you give the car beans then turn off straight away the turbo can still be spinning at a pretty staggering speed, like 150,000rpm + and if the engine is stopped it will be spinning with no oil pressure or flow in the turbo bearings. That causes the oil there to become carbonised and eventually the turbo will fail.

I think it is still good practice to allow the car to idle for a short while before switching off if you have come straight from a high speed blast.

[SRGTD]

It wasn't as much letting the cool down, it was letting the turbo slow down.

If you give the car beans then turn off straight away the turbo can still be spinning at a pretty staggering speed, like 150,000rpm + and if the engine is stopped it will be spinning with no oil pressure or flow in the turbo bearings. That causes the oil there to become carbonised and eventually the turbo will fail.

I think it is still good practice to allow the car to idle for a short while before switching off if you have come straight from a high speed blast.

I always treat my car with mechanical sympathy so I ensure the oil’s up to 90 degrees before driving it ‘enthusiastically’, although with the general poor state of the UK’s roads, and seemingly ever-increasing traffic congestion, I’m rarely an enthusiastic driver these days. I also garage my car so by default, my car’s engine gets a short idling period while I’m closing my garage door after getting the car out of the garage and when opening the garage door before putting it away after use. Most of my journeys seem to start and end in a speed restricted area, so it’s gentle driving for me at the start and end of a journey.

I think VW (and I’m assuming other manufacturers do too) also fit an electric cooling pump that continues to operate after the engine’s been switched off that helps to cool the turbo down - it’s that ‘mysterious’ humming noise that can be heard after you’ve locked the car after it’s been used which has been discussed over the years on various VW forums.

[Watts]

It wasn't as much letting the cool down, it was letting the turbo slow down.

If you give the car beans then turn off straight away the turbo can still be spinning at a pretty staggering speed, like 150,000rpm + and if the engine is stopped it will be spinning with no oil pressure or flow in the turbo bearings. That causes the oil there to become carbonised and eventually the turbo will fail.

I think it is still good practice to allow the car to idle for a short while before switching off if you have come straight from a high speed blast.

Not sure if that is relevant these days given stop/start systems?

[SRGTD]

It wasn't as much letting the cool down, it was letting the turbo slow down.

If you give the car beans then turn off straight away the turbo can still be spinning at a pretty staggering speed, like 150,000rpm + and if the engine is stopped it will be spinning with no oil pressure or flow in the turbo bearings. That causes the oil there to become carbonised and eventually the turbo will fail.

I think it is still good practice to allow the car to idle for a short while before switching off if you have come straight from a high speed blast.

Not sure if that is relevant these days given stop/start systems?

Probably where the electric cooling pump comes into play - assuming it kicks in when stop start has switched the engine off.

[jh_97]

From page 132 in the manual:

"When starting from cold, the engine may be a little noisy for the first few seconds. This is quite normal, and no cause for concern.".
Not specific as to whether it's referring to just the higher idle RPM or rattling noise, but again sounds like it's normal.

Also from page 132:
"Do not warm up the engine by running it while the vehicle is stationary. Instead, pull off as soon as there is good visibility through the windows. This helps the engine reach operating temp faster and reduces emissions".
Granted it's an eco tip, but seems like VW are happy for the car to be driven right away

[EB2019]

Not sure if that is relevant these days given stop/start systems?

Agreed, The Turbo slows very quickly to an idle speed and doesn't really generate any meaningful boost, and remains spinning all the time the engine is idling anyway. A very short distance after fast driving is all it really needs to slow down/cool down.

regarding low revs and cold cars, I have read on Porsche forums of ongoing problems where some PDK cars pull away in 2nd gear, that driving with low revs on thick cold oil is really bad and anything other than med revs light throttle puts a lot of stress on bearings and cylinder walls. Assume on our cars below boost  would be low revs high torque applications.

Regarding start up noise, it was on our new Mk7 in 2014 and my 7.5 now, sort of an electrical whine/buzz almost like alternator clutch pulley gone bad for a few seconds. Then it sounds like engine valve overlap to help cat and engine warm up.

[Redreels]

Hi chaps, it appears the rattle is the waste gate actuator rod. I started the car and by holding the rod was able to stop the horrible rattle.
I can see there are wastegate clips available online for a couple of quid but here is a link

https://www.akstuning.co.uk/shop/home/1236-genuine-wastegate-actuator-rod-anti-rattle-clip-06j145220a-mk6-gti-ea888-etc.html

They seem to be aimed for the Mk6 golf but I wondered if they would fit the 7.5 model. Any thoughts please?

I found this video to highlight the matter

https://m.youtube.com/shorts/_cGl6V-86L4