New 300tdi owner- hot expansion tank

[Landi]

G'day, I'm new to 300tdi ownership and just have a couple of questions:

I've noticed that even after short drives the expansion tank is hot to touch, and there is pressure in there if i take the cap off. Is this normal? Can someone give me a quick run down of how the expansion tank should behave? I've already been on a couple of long drives and the temp guage hasnt moved, and the radiator and hoses all appear to be in good condition.

The truck has about 200,000km and runs beautifully apart from a ticking noise that increases with revs. sounds like its coming from gearbox or engine. Any ideas? Valve clearances were done about 2 years ago and the trucks had regular oil changes every 5,000km

[rick130]

Absolutely normal.

The expansion tank on a 300Tdi is not an overflow tank, but part of the cooling system.
Think of the expansion tank cap as the radiator cap, and the expansion tank an extension of a radiator header tank.
It's exposed to full system pressure and temps, unlike a 'conventional' overflow tank that takes excess water that expands past a 'normal' rad cap, and then bleeds that back into the system as it cools.

Check the rocker clearances, it's probably good practice to do them every 10,000km, and treat the lash caps on top of the valve stems as a service item.
Lash caps are one area where it pays to go aftermarket. Use either VW air cooled CrMo items or Chev 8mm CrMo caps, I think I used Manley Chev ones the last time i replaced them.
Cheaper and better quality than what Land Rover now supply.

Other ticking noises can be the lift pump, injection pump, etc.

Oil changes can be a subjective thing, use the best quality oil you can.
While it is a direct injected engine and very efficient, it's a highly stressed engine thanks to the small swept volume with a relatively limited sump capacity and, IMO, not enough oil cooling.
Lots of short city trips, stick with a 5,000km oil change regime.
Lots of long country runs you can do 10,000km OCI's, but don't exceed 10,000km in my experience.

[Landi]

Absolutely normal.

The expansion tank on a 300Tdi is not an overflow tank, but part of the cooling system.
Think of the expansion tank cap as the radiator cap, and the expansion tank an extension of a radiator header tank.
It's exposed to full system pressure and temps, unlike a 'conventional' overflow tank that takes excess water that expands past a 'normal' rad cap, and then bleeds that back into the system as it cools.

Check the rocker clearances, it's probably good practice to do them every 10,000km, and treat the lash caps on top of the valve stems as a service item.
Lash caps are one area where it pays to go aftermarket. Use either VW air cooled CrMo items or Chev 8mm CrMo caps, I think I used Manley Chev ones the last time i replaced them.
Cheaper and better quality than what Land Rover now supply.

Other ticking noises can be the lift pump, injection pump, etc.

Oil changes can be a subjective thing, use the best quality oil you can.
While it is a direct injected engine and very efficient, it's a highly stressed engine thanks to the small swept volume with a relatively limited sump capacity and, IMO, not enough oil cooling.
Lots of short city trips, stick with a 5,000km oil change regime.
Lots of long country runs you can do 10,000km OCI's, but don't exceed 10,000km in my experience.

Thanks mate, appreciate it

[Don 130]

A ticking noise could also be a vacuum pump on the way out. With the engine idling, used a stethoscope or length of bar to listen to the vacuum pump.
Don.

[DiscoMick]

The cooling system is pressurized to force the coolant to the top of the engine, which is higher than the expansion bottle. Just make sure the expansion bottle is filled to the mark when cold.
Re. the ticking noise, is it related to the speed of engine revs or the speed of movement of the vehicle?

[Landi]

The cooling system is pressurized to force the coolant to the top of the engine, which is higher than the expansion bottle. Just make sure the expansion bottle is filled to the mark when cold.
Re. the ticking noise, is it related to the speed of engine revs or the speed of movement of the vehicle?

Speed of engine revs. if i go into neutral at high speed for example it will stop

[rick130]

A ticking noise could also be a vacuum pump on the way out. With the engine idling, used a stethoscope or length of bar to listen to the vacuum pump.
Don.

This.

Been a while since I've played with a Tdi. [bigwhistle]

Learning all about TD5's now.

In 15 years I might know something about Tdci's :Rolling:

[Landi]

Thanks for the advice, i'll report back when i get to the bottom of it. Just working through some other issues as well:

- Horrible rattle/chatter sound possibly coming from the passenger footwell. Seems to only happen in 3rd and 4th gear at lower rpm, both under load and lifting off. I'm hoping its not the gearbox...
- At idle theres a rocking sensation/ vibration. Its not a rough idle but seems to surge. I can feel it through the brake and clutch pedals. Theres also a similar vibration at constant speeds on the freeway, almost like a pulsating. Any ideas?

[BathurstTom]

Check the engine and gear box mounts.

Tom.

[Roverlord off road spares]

Absolutely normal.

The expansion tank on a 300Tdi is not an overflow tank, but part of the cooling system.
Think of the expansion tank cap as the radiator cap, and the expansion tank an extension of a radiator header tank.
It's exposed to full system pressure and temps, unlike a 'conventional' overflow tank that takes excess water that expands past a 'normal' rad cap, and then bleeds that back into the system as it cools.

.

I'd just like to add, unless the expansion tank is old and brittle and usually lets go at the4 seam, but if you have pressure problems due to engine problems, then new expansion tank can also split at the seems after short time.

[Landi]

Cool so the valve clearances were way out, and the ticking noise has gone now after being properly adjusted