Why did the bottom of my no.1 piston get buggered?

Sonix · **Posted:** Thu Feb 18, 2010 5:09 am

A while ago, I told you all about a clunking noise my engine made, when idling ....
We took the whole engine out, opened up and the finding was as follows:
Top of the engine ...NOTHING wrong .... from the top, all the pistons also looked fine ... BUT ...the sleeve of cylinder No.1 was scratched.
From the bottom, bearings were all fine, crank was still perfect .... took Piston No.1 out and WHOALLA! ... the sides of the piston, UNDER the rings were scratched to crud ! (plus offcourse the rings were buggered).
The connection and bearing from the conrod to the piston was also fine ...
So NOW for the big question ..... I personally believe that this was caused by the lack of oil .... BUT .... what's the chance that an injector could cause this? ..maybe causing overfueling on cylinder 1, or maybe causing cylinder 1 to run lean??? The engine runs smooooth and also idles smooooth ....so I don't know ....

Any ideas?

Diggerfreek · **Posted:** Thu Feb 18, 2010 5:27 am

Sounds like it was a leaky injector that was over fueling causing excessive pressure thus making the piston side load at idle. Once raised above idle, ever thing was fine because is was using/burning the full shot of fuel....

I don't know if the VM has piston cooling jets, but if it was because of a lack of oil, the piston would have melted.....

Sonix · **Posted:** Thu Feb 18, 2010 5:49 am

Diggerfreek wrote:

Sounds like it was a leaky injector that was over fueling causing excessive pressure thus making the piston side load at idle. ....

But with the new piston now in place, and still using the old injectors, the cluncking sound is gone, and the engine idles smoothly .... if it was the injector, wouldn't it still be making a noise while idling?
There are two channels that "delivers" oil to the bottom of the piston ... plus the engine was VERY low on oil, when the cluncking started, thus the idea that oil wasn't delivered to that piston properly ...
BUT ... when removing the diesel return nozzles from the top of the injectors, the No1 injector squirted out a little bit more diesel than the others ... but that was still with the faulty piston and rings in place ... still have to test the "overflow" again now that the new piston is in place ...

flman · **Posted:** Thu Feb 18, 2010 9:06 am

Sonix wrote:

... plus the engine was VERY low on oil, when the cluncking started, thus the idea that oil wasn't delivered to that piston properly ...

Sounds like you found your problem? Lucky for you it was only 1 piston, instead of one :dead:

engine.

Diggerfreek · **Posted:** Thu Feb 18, 2010 4:09 pm

Yeah, they oil would be a contributing factor. Plus it couls still be injector related. If you are running "hot" on one cylinder, with out the oil flow to cool the piston, it would allow the piston to expand.... thus the issue

MrMopar64 · **Posted:** Thu Feb 18, 2010 5:29 pm

Can you post a picture of the damaged piston skirt? Did it happen on both sides or only one?

warp2diesel · **Posted:** Thu Feb 18, 2010 5:57 pm

Fuel wash down is #1 suspect item. But, did you check the oil cooling jet when you swapped out the sleeve? Since the jet has to be right at the bottom of the sleeve, I am sure you pulled it from the engine block, just hope you took a look. One little chip in the oil gallery could clog up the nozzle and make it not cool the piston bottom. Since they cost money and salesmen can't sell them for more money, VM would not use the oil jet nozzles under the pistons unless they felt they were needed.
Another item to verify is the proper coolant. Back before it was learned about what now is common knowledge about coolants, there were a lot of Turbo Diesel engines getting holes in the wet sleeves that caused problems. There are many good choices now available, just don't pick a looser.

Few months ago there was a very good thread on coolants, do a search.

tjkj2002 · **Posted:** Thu Feb 18, 2010 6:10 pm

Sonix wrote:

Diggerfreek wrote:

Sounds like it was a leaky injector that was over fueling causing excessive pressure thus making the piston side load at idle. ....

But with the new piston now in place, and still using the old injectors, the cluncking sound is gone, and the engine idles smoothly .... if it was the injector, wouldn't it still be making a noise while idling?
There are two channels that "delivers" oil to the bottom of the piston ... plus the engine was VERY low on oil, when the cluncking started, thus the idea that oil wasn't delivered to that piston properly ...
BUT ... when removing the diesel return nozzles from the top of the injectors, the No1 injector squirted out a little bit more diesel than the others ... but that was still with the faulty piston and rings in place ... still have to test the "overflow" again now that the new piston is in place ...

It could take awhile for the problem to reappear with a new piston and rings.

DarbyWalters · **Posted:** Thu Feb 18, 2010 7:26 pm

Could have been a worn out of spec wrist pin...I would guess that you replaced the wrist pin with the piston.

geordi · **Posted:** Thu Feb 18, 2010 9:22 pm

I have to disagree about "fuel washing" causing this. The logic against it is simple: IF the fuel wasn't being burned in the cylinder at idle, it WOULD be getting burned in the exhaust once the RPMs rose. The result would be massive smoke clouds until the fuel had burned off.

OR

If the fuel was "washing" the cylinder walls during idle and NOT ejecting into the exhaust on the exhaust stroke, the result would be either bending the rod from trying to compress solid fluid (can't) OR pushing past the rings into the oil gallery... And FILLING the oil pan. So it couldn't have possibly read as extremely low on oil.

Now, I am willing to admit that I haven't taken enough engines apart to know what "fuel washing" looks like inside a cylinder, but I also am skeptical that it can exist without either massive smoking and detonation, or the oil pan being obviously fuel contaminated.

Now, as someone who was unfortunate enough to directly experience a #1 cylinder failure, I can point to a very possible cause: Was your turbo leaking? Where did the oil go in the first place? The #1 cylinder's oil gallery is directly connected to the turbo's oil feed, it tees somewhere after the outlet of the filter. If the turbo starts leaking oil from a failure, the pressure WILL DROP in the #1 cylinder.

My engine ran low on oil (4 quarts needed to refill it) when the turbo failed, but it was too late - Running on low oil (less than 1 mile coasting!) as the turbo was bleeding it at full volume into the exhaust caused such damage that when I refilled it and replaced the turbo... 10 miles later on the test drive it ejected the cylinders PIECES through the oil pan. The cylinder broke up, the rod managed to INVERT, punching the pan out, and the cylinder liner is all trashed to pieces.

You got LUCKY that you could pull the cylinder and repair it before it got worse, where I didn't. I would be trying to figure out where the oil went, and looking to install an oil pressure gauge somewhere OTHER than where the stock sender is. The stock sender (for the idiot light) is located right at the outlet of the filter, so it is at the BOTTOM of the engine, getting the full flow of whatever oil the pump has access to.

What that means is... The idiot light won't come on until it is BEYOND too late, as my experience proves. The oil light NEVER BLINKED when my engine was bleeding to death. Since the #1 cylinder is the FIRST place that gets starved when pressure leaks, the top of the engine or on that line that feeds the turbo would be the best place to put a pressure sender.

tjkj2002 · **Posted:** Thu Feb 18, 2010 11:13 pm

geordi wrote:

If the fuel was "washing" the cylinder walls during idle and NOT ejecting into the exhaust on the exhaust stroke, the result would be either bending the rod from trying to compress solid fluid (can't) OR pushing past the rings into the oil gallery... And FILLING the oil pan. So it couldn't have possibly read as extremely low on oil.

Now, I am willing to admit that I haven't taken enough engines apart to know what "fuel washing" looks like inside a cylinder, but I also am skeptical that it can exist without either massive smoking and detonation, or the oil pan being obviously fuel contaminated.

You can have a overfueling issue without running bad.Just a slight over fueling is bad but will not make the engine smoke more or cause high oil level.The most noticeable effects are hard starting and rough idle.

geordi · **Posted:** Thu Feb 18, 2010 11:52 pm

tjkj2002 wrote:

geordi wrote:

If the fuel was "washing" the cylinder walls during idle and NOT ejecting into the exhaust on the exhaust stroke, the result would be either bending the rod from trying to compress solid fluid (can't) OR pushing past the rings into the oil gallery... And FILLING the oil pan. So it couldn't have possibly read as extremely low on oil.

Now, I am willing to admit that I haven't taken enough engines apart to know what "fuel washing" looks like inside a cylinder, but I also am skeptical that it can exist without either massive smoking and detonation, or the oil pan being obviously fuel contaminated.

You can have a overfueling issue without running bad.Just a slight over fueling is bad but will not make the engine smoke more or cause high oil level.The most noticeable effects are hard starting and rough idle.

Ok, I can agree with that, due to the buggered extra map sensor on the CRD, mine has been "overfueling" for a while now and still runs just fine. Unless there is a significant amount of it when the engine isn't running... How would it do anything below the rings? Hard to start makes sense, liquid in the cylinder won't compress. His damage was below the ring level, so clearly was specific to low oil pressure or level.

Sonix · **Posted:** Fri Feb 19, 2010 2:28 am

MrMopar64 .....to answer your question ...the piston got buggered on both sides ...

Thanx for all the info people!

Sir Sam · **Posted:** Fri Feb 19, 2010 2:33 am

Got pics of the buggary?

Sonix · **Posted:** Fri Feb 19, 2010 4:48 am

No pics yet ...sorry ... will see if I can get hold of the broken piston ....

tjkj2002 · **Posted:** Fri Feb 19, 2010 8:01 am

geordi wrote:

How would it do anything below the rings? Hard to start makes sense, liquid in the cylinder won't compress. His damage was below the ring level, so clearly was specific to low oil pressure or level.

"Washing" the cylinder walls with fuel causes low compression,low compression = hard/no starting.

"Washing" the cylinder walls also cleans all the oil off the cylinder walls which = scoring.

geordi · **Posted:** Fri Feb 19, 2010 12:51 pm

Ok, but again... That would have to be BELOW the rings. That is why the rings are there - To keep the seal between the top and the bottom of the piston, or you aer just pressurizing the oil galleries with piston action, and co-mingling the oil and fuel.

I don't believe that happened in this case. IF there was hard starting due to low compression, re-ringing might be the solution, but his failure was low oil level or low oil pressure. That caused the metal on metal, just like mine did.

BVCRD · **Posted:** Fri Feb 19, 2010 1:16 pm

geordi wrote:

Ok, but again... That would have to be BELOW the rings. That is why the rings are there - To keep the seal between the top and the bottom of the piston, or you aer just pressurizing the oil galleries with piston action, and co-mingling the oil and fuel.

I don't believe that happened in this case. IF there was hard starting due to low compression, re-ringing might be the solution, but his failure was low oil level or low oil pressure. That caused the metal on metal, just like mine did.

Geordi, I had a Grand Wagoneer once that had the power valve go out on it. That thing flushed fuel in past the ring to the oil pan. I had to keep the thing floored the keep it running. When I finally pulled over, the oil level in the dip stick was even with thetop of the tube. Now that was some thinned oil!

geordi · **Posted:** Fri Feb 19, 2010 2:17 pm

Wow... It didn't bend a rod while forcing fuel past the rings? :shock:

Then again... I've got a 97 Grand Cherokee that I think the engine compression is probably around 2:1 it runs so poorly. :-)r

But that proves my point: Thinned oil is one thing, your pan was completely stuffed with gasoline. The OP's wasn't, he read low. So I believe that the rings were doing their job... To the detriment (in his case) of the cylinder. Some of that oily diesel fuel might have protected the cylinder, even just slightly. But at least he didn't lose the motor like I did.

BVCRD · **Posted:** Fri Feb 19, 2010 2:32 pm

geordi wrote:

Wow... It didn't bend a rod while forcing fuel past the rings? :shock:

Then again... I've got a 97 Grand Cherokee that I think the engine compression is probably around 2:1 it runs so poorly. :-)r

But that proves my point: Thinned oil is one thing, your pan was completely stuffed with gasoline. The OP's wasn't, he read low. So I believe that the rings were doing their job... To the detriment (in his case) of the cylinder. Some of that oily diesel fuel might have protected the cylinder, even just slightly. But at least he didn't lose the motor like I did.

Mine was in a 1984 Grand Wagoneer. That thing was a tank. Had some sort of vacum assist 4x4 selector from the factory on it. It didn't cook the motor. I limped it into town about 5 miles. I had real clean internals I suspect after that.

Why did the bottom of my no.1 piston get buggered?

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