Cracked piston? I think so...

[mcsvt]

Well last night on my way home I heard a slight ticking type noise coming from the engine, only when I would get on the gas. This lasted maybe less than a mile. It wasn't a knock, it's hard to explain, almost like when you hold something against a fan.

I accelerate onto the highway and notice smoke in my rearview mirror. Mainly when in boost. I start thinking maybe my turbo seals started to go. Pull over take a look at things. Car is running like normal, no smoke when I rev the motor. Continue down the road, smoke only gets worse. Pull over again, engine isn't running so good now, no smoke at idle or rev still. Decide not to call AAA, it won't get much worse. Eventually make it home and figure I would check the turbo for play and/or oil, neither is present, but I do find oil all over the engine compartment, oil cap, dipstick, pcv line...

Performed a compression test today, left to right: 0-105-120-120
I put a flashlight down near the plug holes, 1 had an oilly top, the other were dry.

I would say I have a cracked piston, anything I may have missed?
Comments and suggestions welcomed.
Carnage pics bellow:

[shadow88]

Been there a few times.
A leak down test will tell you where the compression is escaping to. Either way, it looks like the head's coming off.

[turbovanman²]

Based on the oil being blown out, you either cracked it or put a big hole in it. Usually, cracked pistons show around 90 psi.

[mcsvt]

Wouldn't be surprised if it was a hole. Guess I will get to find out when I pull the head. Which I have no idea when will happen.

[JohnnyLightning86]

You might have a problem similar to mine. I was told last year I might have a cracked piston, which turned out to be a cracked valve seat in the head. But then recently I also found out the block is cracked. I had tested the compression and it showed 120 in 1,3, & 4, and only 80 - 85 psi in the #2. I don't think the cracked block caused the low compression, but it may have caused a bad oil leak. Only the leak was on the side of the block toward the base.

[mcsvt]

Yeah, I am not completely sure what I will find when I open her up. I will be towing the car this weekend to my familes house and using there garage every weekend I can. It may take a little while, but she'll be back on the road

[mcsvt]

Well I towed the car home yesterday. Pulling a trailer through 2 tight tunnels and across Manhattan during a Sat. rush hour is great fun. But all went well and my old truck pulled and handled amazingly, I need to buy that truck back someday. So anyway...

Pulled the head no issues with getting it off really, besides snapping an extension taking the head bolts out.



I'll let the pictures below speak for what I found.







Any reason for the discoloring here?


How would this headbolt get like this? It was the only one dirty like that.


Comments and suggestions welcome. Looks like I am going to do a complete re-ring and replace the one piston. The cylinder walls all look great.

[turbovanman²]

#1 for sure but hard to see #4-too dark. Other than that, looks good.

[mcsvt]

#4 just didn't get cleaned up like the other three before that pic. It was out of reach from standing on the passengerside, lol. The head dripped all over when we pulled it out.

Thanks for the input

[turbovanman²]

The headbolt is normal, just moisture etc creeping down over time.

[mcsvt]

Cool, new ones will be used when I put it back together.

[moparzrule]

Based on the oil being blown out, you either cracked it or put a big hole in it. Usually, cracked pistons show around 90 psi.

The worst cracked piston compression check I had was 40 PSI (drove on it for a week knowing it was cracked though LOL). The 2 other times it was around 60-70. I think I broke #1 twice and #4 once. Never scored a cylinder, gotta love these high nickel content blocks! Piston got replaced with new rings everytime, compression right back to 130.

[mcsvt]

Well finally got all my parts in and had time to work on the car. With the help of two friends(at different parts of the day) I was able to rebuild the motor on Sat. I took my time and made sure I did everything right the first time.

Sunday morning I disconnected the HEP, primed the motor then repluged the HEP and first crank it started right up Had a fuel leak(hose was to big, i upgraded my hoses and clamps to fuel injection spec), and two small coolant leaks. Got the car warmed up, set the timing to 12 and went for a ride. Only issue on the ride was that my passenger rear parking brake was sticking.

I will post pictures later of the MELTED piston. Also driving a car with an open 3" swingvalve sounds pretty sweet. Only running it at 5psi and I followed the breakin specs that have been posted before.

Next step, make an appointment to have my 3" exhause installed. Thanks to everybody for the help

[DodgeZ]

why did it melt in first place?

[mcsvt]

I think it went lean on me in the #1 cylinder. I was running the timing a bit high as well. My own fault. Couple week prior I was having boost control issues, reaching about 25 at some points. I had just finially got it steady at 17 when this happened. I am only using mahle's. So I think it was a combination of things, all of which should be in check now. Wideband on the way for safety dawes just isn't going to cut it anymore.

[DodgeZ]

being that it is melted and not cracked I'd say it is more of a fuel issue then timing. Number one is side that gets less air and normal fuel issues are on hole 4 (from what I've heard). You think that the injector is good? What are you doing for tuning? What injectors and psi?

[mcsvt]

My initial thinking was injector as well. Still not confirmed that it is ok. Stock regulator, TU Cal set for 22psi, g-valved to 17(normally), +40's, 255walbro pump. Pressure hasn't been checked. It is something I should look at though. When I see the car again next weekend I will check the fuel pressure, I have to make an appointment to get the exhaust hung as well.

On the idea of the injector. When the piston went, I heard a slick ticking. I knew it wasn't right and I slowed down imidiately. It was not a normal valvetrain tick. Over the past year I have learned all the sounds of my car. But the damage was done by the time I pulled over. I was originally going to have my injectors flowed, but was told buying new ones would be cheaper.

[DodgeZ]

I know one guy that had a bad s60 injector. He lost a lot of pistons before he figured it out. If anything you should move it to another hole. I think you can buy them for 30 bucks a piece tho

[mcsvt]

Agreed, moving is a good idea. Possibly replacing it is another. I think my next order from TU will have atleast 1 new injector in it.

Thanks for making me think about it