SOHC or DOHC?

[amstel78]

According to VW, the 2012 Passat TDI features a DOHC powerplant:

Double overhead camshaft, spur belt driven, four valves per cylinder, maintenance free hydraulic lifters, single valve springs

Whereas, the 2012 Golf TDI is described as having a SOHC powerplant:

Single overhead camshaft, spur belt driven, four valves per cylinder, maintenance free hydraulic lifters, single valve springs

The FAQ here states the Golf's engine as being revised to feature 2 overhead cams. I'm assuming then that VW's website is wrong as I also thought both the Passat and Golf TDI's have the exact same engine. Am I correct in my assumption?

[chittychittybangbang]

Which article are you reading in the FAQ?

All 2009+ 4 cylinder TDI engines sold in the US are DOHC. 100% sure the golf TDI is not SOHC. VW's website has a bunch of errors. I seem to recall some sportwagen specs are still listed as "TBD" even though the car's been out for years.

[amstel78]

Originally Posted by chittychittybangbang

Which article are you reading in the FAQ?

All 2009+ 4 cylinder TDI engines sold in the US are DOHC. 100% sure the golf TDI is not SOHC. VW's website has a bunch of errors. I seem to recall some sportwagen specs are still listed as "TBD" even though the car's been out for years.

I don't recall the exact FAQ, but I do know it was from this website.

As for the errors on the website, that's what I thought. Thanks for the clarification.

[The Pirate]

Why do they use those rubber drive belts now instead of the chains? Didnt the chains work well? and you never had to change one...is it just a scam to get you back into the garage?

[amstel78]

Good question and I too would like to know. I prefer timing chains. I can deal with a bit of stretch over the years instead of having to replace a belt. I've done belt jobs on a few of my other cars I've owned in the past and it's something I'm not exactly thrilled to do as it usually involves losing an entire Saturday or Sunday.

[chittychittybangbang]

Vw's diesels have been using belts for many years and VW doesn't have a good history with chains so you're better off this way. 1 belt change every 120k miles in your case is pretty good considering belts used to only last 60k miles.

Also, most VW-Audi designs require you to remove the transmission and a bunch of stuff to replace the chain, if a car goes 300,000 miles, it's probably a wash in terms of maintenance costs but I think it's a little cheaper to build. For example, cost to replace timing chain on an Audi v8 engine is about $8000 at dealer. Cost to replace TB on a TDI is about $1200 at dealer. It can be done in under 1 day in driveway for sure, chain can't.