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Engine Specific Info and Questions => IDI Engine => Topic started by: captainpartytime on July 30, 2008, 04:18:33 pm

Title: Piston Diagnosis Help - Photos-
Post by: captainpartytime on July 30, 2008, 04:18:33 pm

I rebuilding a 1.6L Turbo Diesel and am in the process of cleaning the carbon crud off my pistons. This indentation on the piston surface has me worried because its so close to the combustion "dish?". Should this be a cause for alarm or should I just clean them and run them? I tried to give a couple different angles to get a clear picture of the area in question (6 - O'Clock on the piston face)
(http://images.thesamba.com/vw/gallery/pix/464591.jpg)
(http://images.thesamba.com/vw/gallery/pix/464592.jpg)
(http://images.thesamba.com/vw/gallery/pix/464593.jpg)

Title: Piston Diagnosis Help - Photos-
Post by: foxracer1 on July 30, 2008, 04:30:03 pm

Looks like old worn injector leaking fuel in to the combustion chamber. Doesn't look super agressive. You should be able to get by with them.

Title: Piston Diagnosis Help - Photos-
Post by: gigaz2 on July 30, 2008, 04:34:17 pm

http://vwdiesel.net/phpBB/viewtopic.php?t=15349

I worried with the same marks, all the pistons were the same, head cracked like I've never seen and the injectors were discoloured.. :O

my guess was that the previous owner was very happy.. for a short while.


are all your pistons like that? what engine did it came from?

Title: Piston Diagnosis Help - Photos-
Post by: duff on July 30, 2008, 04:50:21 pm

my pistons out of my 1.6 TD looked like that and i went a head and re bored and replaced the pistons. however my mechanic (my friend who helped me tare apart the engine) said it was from the timing being a little early. but the comments about the injectors being bad raised a red flag should i replace my injectors?

Title: Piston Diagnosis Help - Photos-
Post by: captainpartytime on July 30, 2008, 05:05:01 pm

Quote from: "gigaz2"

Are all your pistons like that? what engine did it came from?

These pistons came from a 1.6L ECO turbo diesel (1V) imported from Europe. I was hoping this motor wasn't run hot since the ECO's didn't come with boost enrichment on the IP. This is the worst piston out of the group (#1). #2-3 look fine and #4 has a little less erosion on the same spot.

Title: Piston Diagnosis Help - Photos-
Post by: Vincent Waldon on July 30, 2008, 08:02:47 pm

Quote from: "prothe"

What is the valve indentation doing on top of your piston?

That's just a gentle kiss...*this* is an indentation:

(http://i197.photobucket.com/albums/aa85/vwaldon/piston_with-imprint.jpg)

and it's running just fine.

Like Andrew I'd personally not worry about reusing the pistons... I would however absolutely throw the nozzles in the trash.

Title: Piston Diagnosis Help - Photos-
Post by: captainpartytime on July 30, 2008, 08:11:19 pm

Thanks for the advise guys. As this is my first engine rebuild, I tend to ask a lot of questions (Andrew can attest to that). I will reuse the pistons and look for some new injectors. Can I rebuild them or should I just buy new ones?

Title: Piston Diagnosis Help - Photos-
Post by: Vincent Waldon on July 30, 2008, 08:18:48 pm

Here's what's involved in rebuilding them with new nozzles:

http://vincewaldon.com/index.php?option=com_content&task=view&id=20&Itemid=28

but to do it right you'll need a pop tester to calibrate them... or find a shop that will.

Title: Piston Diagnosis Help - Photos-
Post by: captainpartytime on July 30, 2008, 09:02:09 pm

Thanks Vincent for a very lucid and well illustrated How-to write up. I will also be following your IP timing guide as well. So where do you get your new injectors?

Title: Piston Diagnosis Help - Photos-
Post by: myke_w on July 31, 2008, 12:14:04 am

Hey Kerry - good to see you here! Good luck on the buildup!

Title: Piston Diagnosis Help - Photos-
Post by: captainpartytime on July 31, 2008, 03:27:50 pm

Thanks for the welcome Myke. I'm sure you will be hearing from me a lot more in the near future! :wink:

Title: Piston Diagnosis Help - Photos-
Post by: RabbitJockey on July 31, 2008, 09:05:38 pm

i know they're a little louder when they have valve indents