Blue Smoke

Background--Car is an 03 ALH with 58k miles. I purchased it used from a private party at 48k miles. Immediately installed PP764's, clutch upgrade, alligator tune. Went on to purchase a hybrid 17/22 turbo, intake, exhaust, intercooler, lift pump, larger TIP, W/M (50/50), 11mm IP, and switched to R520's.

Symptoms--After my dyno I suspected something was wrong with my fueling. I had fueling maxed out in the tune and with the race nozzles I should have been smoking like a train but it was clear once the turbo spooled up around 2500 rpm. Swapped out the lift pump, fuel filter, went back to different nozzles (PP764), no change. I was assuming it was the IP and was on my way to the regional guru (KROUT) when the problem happened. Running up a hill at about 20psi in 5th, egt's up to about 1200, about 90mph, I saw a faint blue hue behind me. Let off the throttle while I was staring in the mirror to see if that was really blue smoke but it was hard to tell. Gave the go pedal a little blip and sure enough saw a bluish cloud forming behind my car. Coasted down to speed and merged onto the shoulder and maintained speed at around 50mph or so and the car started running rougher and rougher. Decided the car had a serious problem and would need a tow back to the house. Shut it off and towed it 50 miles back home.

Problem-- Had KROUT make the trip across the state (thanks again) for a compression check and a teardown. Cylinders 1 thru 3 A-OK, got to #4 and nothing Pulled the head to find this in #4:









Apparently, the wrist pin gouged the cylinder wall pretty severly. My guess is the wrist pin let go first, and when it gouged the cylinder the added stress caused the clean crack all the way through the center of the piston. The cylinder head appears fine. Car never overheated and valves look clean. Timing belt and everything were ok after the incident. My question to those in the know is two fold: 1) Am I right in guessing the wrist pin let go, causing the crack? and 2) Why would the wrist pin let go?

pull out the piston and tell us if the wrist pin is blue. maybe lack of oil or bad squirter on the oil sprayer below the piston.

sorry, looks bad.
Jeff

Further disassembly will wait until further in the week when I get it to a proper shop. No biggie, just a shortblock right LOL. Assuming it's not a bad squirter, anything else cause that? Im still on the train of thought that the wrist pin caused the crack but could it be caused by something else? Just trying to learn WHY it happened so it can be prevented in the future.

wristpins rarely fail unless they are dry or the c-clip walks out of the grove ;-)

Dude!! sucks bro. will the cylider/block be salvageable or do you think a whole new block will be in order?

are you going to rebuild with forged pistons and rods?

Ohhhhh mann

what does the piston next door look like cleaned up. I see some dark blue rings/circles. do the other pistons have numbers .28 stamped on them too? wondering if your motor was rebuild before? Look like you got the good elring headgasket there (w/o rivets).

can't wait to see the piston assembly in pieces on the bench for post mortum.
Jeff

Sorry to see this is what happened. A fueling issue would have been much easier to deal with. FWIW, I recently found I could source some OE VW short blocks from Europe. If you're interested let me know, although it may not happen fast enough for you.

I hope you get it back together and running right soon.

All the pistons have stamped markings on them. To my knowledge, the only "history" this car had was a turbo/intercooler replacement by the dealer under warranty 2 years ago. Not sure why the original turbo was replaced. I'll get pics of the other piston tops soon. I don't have an inside mic set to check the scoring on the cylinder wall but it's real deep and IMO, out of limits. At this point, I'm just looking for a new shortblock replacement. To add some fuel to the fire, I'm doing a cross country move 33 days from now and really want this car back to good shape before I transfer. When it rains, it pours. Good news is I think the cylinder head is fine.

I too don't think it was the wrist pin that let go.........http://pics.tdiclub.com/showphoto.php?photo=46022&ppuser=14463
You can obviously see in my engines case that the same crack across the piston top was caused by a valve hitting the piston because of a tensioner failer..........but in your case its hard to tell actually what went on though i suspect that the chunk that is missing from the top of piston 4 caused the gouging of the cylinder wall from it braking into smaller pieces which can still be seen.

Is the scoring that deep if so either rebore and hone to 81mm and use some pistons similar to Parahna or some T4 units = one saved block.

Here's the rest of the pistons. One thing I didn't notice when they were still dirty is the pronounced star pattern on them. Normal??? It would be the same on the #4 if I had cleaned it as well before those original pics:

Isn't that the spray pattern of the injector nozzle?

Yes, that is the spray pattern. I just didn't know it would be so pronounced. I've seen diesel pistons on cummins melt in this star pattern before. Just curious is the marking is normal.

foobert said:

Isn't that the spray pattern of the injector nozzle?

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Yes, looks like the spray pattern from a 5 hole nozzle (race 520s in this case).

that might be a good indication that the pistons need a good ceramic (or any other)treatment to minimize the possible damage to heavy fueling to the pistons? maybe?

Wow, that sucks . I hope you get it all sorted out before your move.

In looking at said five star patten on top of the pistons i would suggest that the start of injection and mainly after the piston is on its way back down the cylinders atdc the injectors have still been spraying i.e a too long injection window has been used in your tune.

What were the opening pressures and secondary pressure set too/at.

Hard to say, I've had all sorts of tunes. Could something wrong with the IP cause any of this? I still question my injection pump...

I wouldn't have thought so but it could be caused by nozzle/injector dribble but only in 1 or 2 cylinders........you have a nice even spread/patten on each piston top and would suggest really bad luck and wouldn't make that kind of patten to be fair..........a good guess would be injecting fuel for too long.

Have you have much bad running scinario's before it give way!

I've also forgot to mention that the damage could also be caused by the piston ring/s.........if part of a ring has broken off it could also have caused the damage you see of the bore plus doing so will allow the oil to be burnt through the gap provided giving you the blue smoke you saw.............that and the hole in the piston top anyway.

Hi. Sorry to see this carnage. I wonder what your piston protrusion is? Is it all within range? Or is #4 lower? It is rare to see this. I have seen many engines with catastrophic failure, but not like this.Wrist pins rarely fail. Pistons rarely crack. I wonder if you had an issue from long ago that when you added power.... presented itself. The marks you see are pretty normal. I wish I could have seen them before they were cleaned up.

I realize you are just replacing the engine, but it would be good if you could remove the pistons\rods and we could see them... and the cylinder bore. This will make the diagnosis easier. One other thing..... some of those pistons have been replaced it seems.....

For those that have said the injection timing is too long, or too late, under what basis are you making this statement from?

Patterns on pistons don't really tell us squat, other than that fuel is combusting around the nozzle orifices -- go figure!!

But seriously, I've never seen a piston top that's been in service for any considerable length service that didn't have some kind of coloration after it was cleaned. Where's the data showing this pattern is anything other than normal for that injector nozzle?

Krout will more than likely post pics of the rotating assembly. Odd parts failing? That's the story of my car LOL. I've had all sorts of things fail brand new out of the box, and I'm always the "only one" it had ever happened to. I'm just happy it wasn't anything from the timing belt job I did (first timer here). Timing was spot on before the belt came off. Pump was ran around 75 and block 4 was 3*BTDC. At first, when it blew, I suspected my timing belt job. Good to know I can follow simple instructions

Still, there are several active members that drive their cars much harder than I do for hundreds of thousands of miles with similar mods and no problems. So, yeah, it could have been a pre-existing condition that I amplified with doubling the power, or, it could have been something else. Hopefully, next weekends pics from the teardown will be revealing I appreciate everyones help thus far!

That looks like the last set of Ford PS pistons that I saw that were destroyed by to early of timing. Several of the pistons were cracked right across the top of the pin. The final guess on that particular engine was that the fuel was being put in long before the bowl area was in range, BTDC area, to put all of the fuel in the bowl area. Instead it was spraying early and got a lot of the fuel on top of the piston, rather that in the bowl. Amazing similarity.

I would think that if the injectors were firing way to long, that behind you would have been a long trail of black smoke.

One of my questions is, will a program (add on program) advance and retard the injection timing? This is my first experience with a electirc P Pump, as I call it.

JonFord

take an oil sample and see if it is heavy laiden with diesel fuel. The rally car could add a quart of fuel to the oil after a heavy rally with big fuel and smoking.

Jeff

One thing thats been bothering me is the pattern. I have seen several like this, but I dont remember them having a different rotation 1,2 to 3,4. I have to do some research...I think I would have remembered a pattern such as this..

jsrmonster said:

take an oil sample and see if it is heavy laiden with diesel fuel. The rally car could add a quart of fuel to the oil after a heavy rally with big fuel and smoking.

Jeff

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I would have assumed lots of fuel in the oil as well from the crack of course. Both us did the ol' finger swipe on the piston and it just smelled like oil, no diesel smell to it.

mrchill said:

One thing thats been bothering me is the pattern. I have seen several like this, but I dont remember them having a different rotation 1,2 to 3,4. I have to do some research...I think I would have remembered a pattern such as this..

Click to expand...

Good point! I'd be interested to see what you find out about that. Thank you.

Farfromovin said:

....as well from the crack of course.

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Your car is stoned. That's why it failed.

No way to determine the root cause until all the parts are removed and studied.

Piston could have had inherent manufacturing flaws - voids and porosity.

Severe fueling or over heating begins at the outside ring lands at thinest areas and doesn't seem to be problem here. timing would give bad engine vibration if it was not in sync with other cylinders and it didn't have any obvious indicators for the past week?

Did you check deck height on piston, should be about .040 above deck.

Is there a ring grove worn just below the deck in the cylinder. This is very typical on gassers. (hence ring groover cutter). If motor is overrevved - top piston ring collides hard with groove and breaks piston propogating outward from rod bore below piston.

Jeff

edit; after looking at the 5x injector hole "star" pattern in your pics its obvious there was heavy heat-affected-zones that probably caused fatigue and crack propagation. what oil and what weight were you using? spray coolers should keep heat affect zones cool enough to not discolor like that.