Everyone I have a problem I need help solving. I have a 2005 XJ8 L. I just changed out the motor with a lower mile used one. The dismantler cut the coolant hose that comes out from underneath the intake. I had to remove the intake and apply a new hose. Upon removal of the intake I had a small piece of plastic fall into the the #1 cylinder that looked like a part of the lock off of a fuel injector. I tried a number of different ways to vacuum out the cylinder from the spark plug hole and through the open valves on the intake side. With the Motor in the car I don't think I can get the exhaust manifold off to try and get it out as I can't get past the exhaust valves. I am open for suggestions is there a chemical I could pour into the top of the cylinder that would dissolve the plastic and I vacuum it out? I really don't need this to cause any issues as the reason I changed motors as it was due to being extremely overheated. Help me please.

 

I doubt that a chemical could dissolve that piece of plastic without severely damaging the cylinder.
Any strong acid or caustic base may severely harm the metal, and usually those plastics are not soluble in organics, but petrochemists may chime in.
Maybe silly but was it a dense or light plastic? May be floated to bring it up for catching it if you pour a heavy enough liquid inside the cylinder?
Alternatively, would it be possible to gently rotate the crankshaft to raise the top of the piston?

 

I would gently rotate the piston to move it to the surface and extract it. If I can't do that; then I would disassemble the whatever it takes to reach it.

No way to start an engine with something inside the piston

 

Take a metal coat hanger, make it strait and bend the working end over on itself about a 1/4 inch. Dob a blob of heavy grease over the fold, insert through the spark plug hole with the piston half bore or more down until you fish it out. A bore scope would assist greatly. In all honesty, if it is a small piece of plastic, it isn't going to hurt anything, and will melt off first start, if it's metal, don't do that.

 

I can see about floating it to the top of the cylinder but taking it apart not an option as I have to pull the whole head and that requires disassembly of the whole front of the motor. Acetone is one option I have heard of as it is not an oxidizer. I would have to float the plastic out to the spark plug hole as I don't think I could get it to position correctly to go back through the intake valves

 

I feel your pain, Joe.

Sorry if I ramble, but I'm going to think out loud:

I assume you have tried vacuuming with a small diameter rubber hose, with an inside diameter of perhaps 1/4 or 3/8 inch, attached to your larger vacuum hose with duct tape?

Floating the part up the spark plug well seems doable if the plastic will float in a suitable fluid like gasoline, that you could afterward pump out with a fluid transfer pump.

Acetone will dissolve some plastics given sufficient time, but if it will dissolve the piece of plastic that fell into the cylinder, it may also dissolve other plastic parts in your engine bay. It will definitely damage any painted surface, so even if you don't get it on anything important while pouring it into the cylinder using a long-stem funnel, the chances are good that it may splash or spill on something while you're pumping it out of the cylinder after the plastic part dissolves, if in fact it does. Plastics used in the engine bay are typically highly resistant to gasoline, oil, and even brake fluid, so they also tend to be resistant to many solvents.

David is probably correct that the plastic part will quickly melt and cause no damage in the combustion chamber, but I would be somewhat concerned about melted blobs of it fouling on one or both Oxygen sensors as they make their way through the exhaust. If you decide to try running the engine to melt the part, it might be prudent to remove the O2 sensors for the first run and let the exhaust pipes get to full operating temperature for 10 or 15 minutes to burn up any plastic residue.

But it would also be worth considering whether the plastic residue might have any detrimental impact on the catalyst.... David, do you have any thoughts?

David's suggestion of a borescope is a good one. There are some decent ones for under $100, and this might be a good reason to buy one. A borescope used in conjunction with a flexible-shaft retriever tool like this might work, or you might just try the retriever tool "blind":



Here's the product listing at Walmart:

General Lighted Mechanical Pick-Up Tool

Another idea that might be worth trying is to apply pressurized air through the spark plug hole to see if by any chance the part might be swirled back out through the intake port.

We'll all be really anxious to hear what works!

Cheers,

Don

 

Everyone,

Great Input. Yes I did it the other way actually I have a 3/8 Inch hose that fits in the spark plug hole that is attached to a vacuum via a couple of reducers and duct tape.

I then fed air through the open intake valves with my air compressor and it didn't seem to do much also went backwards the other way and did not seem like enough movement.

Now I am looking into the bore scope and retrieval tool. That is a definite possibility. Now a friend of mine suggested floating it out but instead of H20 use alcohol so you I can keep the water out of the cylinder and it will evaporate.

I am going to experiment with some finger nail polish remover on the same plastic as I had another fuel injector clip break and I managed to keep that one.

 

Here is a photo with perspective of how big this piece of plastic is.

if it doesn't come through let me know as this is my first time adding a photo in the forum.

 

If acetone won't dissolve the plastic, you might try methylene chloride based paint stripper. I know it will eat through latex gloves and some other plastics.

And as small as that piece is, David's suggestion of simply letting it melt and burn in the combustion process might be fine. I think I'd still remove the O2 sensors until you were fairly certain the plastic had burned away and been fully burned in the exhaust system. The reality is that it will probably be ejected through an exhaust valve before it melts much, and it will wind up melting and burning somewhere in the exhaust.

 

Everyone,

I want to Thank you Again for all the input and have a piece of plastic in a bottle of acetone will let you guys know how this goes. I am possibly thinking about starting and letting it mash up and burn in the exhaust my biggest fear is it moves through the exhaust valve and sticks on the closing side and that would be the catastrophe I really don't need right now.

If the acetone doesn't work I will go to the paint stripper next.

Going to be a stressful next few days as I just got a job and really need this running right to get back and forth to work next week Monday.

Thank you everyone for the input will let you know the outcome.

 

A cheap USB camera might be good enough to see in - about $10. They have a LED to provide light at the end.

 

That's a fairly substantial piece of plastic. Larger than what I had envisioned. I would recommend a pickup tool like Don pictured, and spend some time fishing. Most of the plastics used in the engine compartment are impervious to most chemicals due to the environment in which they live, and I would not suggest introducing chemicals. Something that large could in fact get sandwiched between the valve and the seat and cause even more issues than melt off.

 

Well my test with acetone didn't even phase the plastic. Also it doesn't float so floating out is out of the question. So ordering a small USB camera and a tool and see if I can get both through the sparkplug hole and find it.

 

Maybe some glue or sticking paste at the end of a metal wire or of the borescope may work if the plastic piece is light enough?

 

Everyone rolled the Motor over by hand about 15 times heard it crunch up. Kept on rolling over by hand until smooth. Fired it up heard it go through.

Car runs good just have the pesky P0171 code going to have to smoke test to figure that one oit

 

Okay guys tried a crazy idea while waiting for my code reader. I swapped upstream O2 Sensors and cleared the computer drove the car for almost 12 miles at highway speed. Then the P0171 Code came up that ruled out the O2 Sensors.

Next I smoke tested the top end and found the the intake has a slight leak between the Aluminum Runners and the Plastic main housing.

Now the fiasco new intakes are discontinued. I have another one that leaks worse and looking to see what I can do to disassemble and seal it accordingly. As I think buying a used one could be buying another leaky intake unless you can prove it will pass a smoke test.

So at this point will live with the code until I find a reasonable way to fix the leak in the intake itself.

 

Let me suggest you get a set of seals for your plastic intake runners. This is more common an issue than you may think.

New vs. Old

 

Just found a set online for $139 for a set of eight.

The new ones are quite robust vs the old ones.

Thank you for the photo comparison

 

What determined you to look at the coils? Rough Idle, fuel smell at exhaust? I am currently awaiting my OBD2 reader to look at the fuel trims.

 

Currently waiting on the gaskets to completely reseal my intake. Once I receive them I will rebuild it check plugs and coils on that bank as well.
The issue with the last owner he let the car sit for a year and a mouse took up residence under the hood. Not good. I will keep you up to date on what my outcome