Decarb

**Nyyyko** · 17-10-2020, 09:18 AM

I’m decarbing the intake this weekend. I’m not finding a clear way to rotate the cam to ensure closed valves as I progress through the cylinders. Some say turn the alternator but that may throw off the timing. Is this correct? What’s the best method?

**Lucas_R** · 17-10-2020, 06:06 PM

You are overthinking it - there is no way to spray into each cylinder anyway (unless you remove the inlet manifold which i assume you are not doing) so just spray it in there and let it clean what it can...better than nothing.

**Nyyyko** · 17-10-2020, 08:42 PM

Negative. Manifold is removed and 3 of the intakes are cleaned. I’ll rotate and clean the fourth tomorrow as well as service the injectors and replace the water pump.

**sn809** · 18-10-2020, 01:15 PM

Well how did you do it??
I wasn't brave enough to do it, but would like to know for the future.

**Nyyyko** · 19-10-2020, 12:46 PM

Went well. The carbon build up wasn’t as bad as I was expecting for 144k kms but there was still a good bit. The injectors really needed a clean with most of the holes blocked. The water pump replacement was a little trickery but I managed... you can access the crankshaft from above and make this a one person job. Runs better but I’m still having some random misfire issues. I’m going to replace the PCV as the engine is pulling a fair bit of vacuum... much more than my diesel work truck... and hopefully that’s that. Only forgot to reclip the HPFP low pressure fuel feed line which I discovered on the test drive. Doh! The fuel rail pressure sensor was not fun to disconnect but got there in the end. Insert a small flathead to lift the locking mechanism. Reassembly was quite fast. If I had to do it again it would be a much smoother operation but all in all not bad. ...note that a magnetic wand is essential for not dropping the two 10mm nuts and a couple of bolts and use some bluetac in the 10mm driver when reinstalling. Spent a while searching for a dropped nut, HA!

**Lucas_R** · 19-10-2020, 03:12 PM

Originally Posted by Nyyyko

Negative. Manifold is removed and 3 of the intakes are cleaned. I’ll rotate and clean the fourth tomorrow as well as service the injectors and replace the water pump.

The fact that you had the intake manifold removed would have been good info to have revealed in your original post, otherwise everyone (including myself) will assume that you are just doing a spray clean via a port on the inlet manifold prior to an oil change like many others do.

**h100vw** · 20-10-2020, 06:52 PM

I have seen shocking build up from as little as 80k. Dread to think what our 220k Passat is like. But can't bring myself to do it. When it's also my day job. ��

**brad** · 22-10-2020, 07:47 AM

Originally Posted by sn809

Well how did you do it??
I wasn't brave enough to do it, but would like to know for the future.

When I did mine I put it in gear and rotated the road wheel. I didn't give a thought to timing chain tensioners not maintaining timing chain tension but I have a Gen1 EA888 BZB block.

**sn809** · 23-10-2020, 02:28 PM

Originally Posted by brad

When I did mine I put it in gear and rotated the road wheel. I didn't give a thought to timing chain tensioners not maintaining timing chain tension but I have a Gen1 EA888 BZB block.

Manual vs Auto??