VW Engines and Timing Belts - an idiot's question

[Pints]

I mentioned to my FiL that I was glad to have got round to replacing the cambelt on my Golf, since I wasn't too keen on my valves meeting my pistons should the belt fail.

He said this doens't happen on Volkswagens, and it's just a case of popping on a new belt once you've got the markings aligned again.

Any truth in this? How/why would VW make an engine allegedly immune to such catastrophe but Vauxhall don't?

[Deerfoot]

Pints said:

He said this doesn't happen on Volkswagens,

He is incorrect.

[Pints]

Was it true for the old 4cyl air-cooled engines?

(Love the idea that the FiL is wrong though)

[Deva Link]

I'm pretty sure all VW engines (for years) are "interference" - ie the pistons will hit the valves if the cambelt breaks.

I would imagine this is particularly so on a diesel, as the compression ratio is higher than a petrol.

Maybe there's a list somewhere of interference and non-interference VW engines?

[Pints]

Deva Link said:

interference and non-interference

Useful. I didn't know these terms.
I've found some good stuff on Google using this in the search.

It seem that the TDI is most certainly an interference engine, and even the FSI and TFSI engines are interference since at least 2003.

Edit: also noted that non-interference engines are also known as "free running"

Edited by Pints on Monday 24th October 20:19

[Tame Technician]

The 1.6 8 valve engine in the A3's is the only one where you could get away with a broken belt not doing any damage.

[Dr G]

Pints said:

Edit: also noted that non-interference engines are also known as "free running"

Isn't free running parkour?

[Nick3point2]

Dr G said:

Pints said:

Edit: also noted that non-interference engines are also known as "free running"

Isn't free running parkour?

[Pints]

Nick3point2 said:

Dr G said:

Pints said:

Edit: also noted that non-interference engines are also known as "free running"

Isn't free running parkour?

I had to google that.

Tit.

[JB!]

technically interference engines, some worse than others, the old 8v lumps which although interference, you have to be really unlucky to actually damage anything when the belt goes.

[Who me ?]

Deva Link said:

I'm pretty sure all VW engines (for years) are "interference" - ie the pistons will hit the valves if the cambelt breaks.

I would imagine this is particularly so on a diesel, as the compression ratio is higher than a petrol.

Maybe there's a list somewhere of interference and non-interference VW engines?

Possibly might be worth mentioning that VW might be better replaced with VAG-Can someone confirm that ?

[NBirkitt]

Pints said:

Was it true for the old 4cyl air-cooled engines?

The old air-cooled VW engines were all overhead valve / pushrod engines, no cambelt required ...

[thebugmon]

To my knowledge, all of the VW water cooled, 8 valve, gasoline, engines, from the 1.5L to the 1.7L are Non Interference. I was a VW mechanic in the 80s, and have owned many VWs and have broken belts and had tensioners fail. I have never seen one bend valves. The Diesel is another story, they are definitely interference. I do not know about the 1.8L, or anything newer.

[Dr G]

A) Welcome to Pistonheads.

B) How on earth did you find a thread that old?