Glow Plug borescope picture help

[rpdb2002]

I have 93 F350 7.3 IDI turbo. Just replacing the glow plugs with some cheap ebay, I mean

MotorCraft DZ9s. I got 7 done just fine, old ones were Autolites, The last one I did was #5,

and a 3/16" of the tip broke off.

I took a piece of brass rod and pushed the tip down into the cup. Dammit, I forgot to put

that cylinder at TDC first, going to do that now. Does the prechamber hole align directly

with the injector tip hole, to find TDC with a rod?

I put a borescope (cheap sewer cam) down the injector hole and attached the picture. I have

a drill down the GP hole.
If someone has done this before, Please look at the picture, and tell me if that grey circle

to the left of the drill bit looks like a GP tip?

I have been trying a magnet, then a shop vac with one of my wife's sheer stockings in the

hose, to catch the offending piece, without luck.

Just want a second opinion on this picture, if that might be the tip, from someone that has

done this before.

 

[Big Bart]

The resolution is not great, but it does look like a foriegn object, not the top of a piston.

If that is still in the ignition pre-cup up in the head, then get your piston on that cylinder to TDC. That will help keep it from going down into your cylinder.

From the picture it looks like you might be able to get one of those long retrieving tools to grab it. (See below.)

You also could try blowing compressed air into the glow plug hole and see if it will come up the injector hole.

https://www.napaonline.com/en/p/SER2391?cid=paidsearch_shopping_dcoe_google&campaign=GSC-Paint-Body-Equipment&campaign_id=10947560788&adgroup_id=110533803034&adtype=pla&gclid=CjwKCAjwiLGGBhAqEiwAgq3q_gw2nqOa4g4eVImyfjb-6fdcTc5BKDstAMIF0rilr2kYQUsxm7uO2xoC5y4QAvD_BwE&

 

[rpdb2002]

Thanks Big Bart, hoping for a little prayer circle, you answered.
Hoping I don't have to pull the head. Patience is key here.
I am pulling out all the GP tonight, so I can rotate the engine off of the crank with a 15/16" socket by hand.
Do you know if the pre-ignition cup combustion chamber hole is in direct line with the injector bore?
Can I pass a brass rod through there, touch the top of the piston, and have someone else watch the rod for TDC?

I know the picture is grainy, I just ordered a higher resolution borescope today, should be here on Sunday. Going to take out another injector as well, picture to compare then.

Everything waits, until I get TDC on that cylinder.

Thank you!

 

[Big Bart]

rpdb2002,

I do not know if you can pass a rod through the pre-cup to touch the piston and find TDC. Just be careful not to scratch the cylinder wall or get it stuck if you can. (Bent) Also be careful not push the broken tip through. But lets see what others suggest.

You also can pull the valve cover and watch the valves for that cylinder. That will get you close as well.

 

[TahoeTom]

Align the TDC line on the damper with the "0" on the plate. #1 and 4 will be at TDC. Each 1/4 turn of the damper clockwise brings another pair of pistons to the top. 1/4 turn brings #2 and #5 to top. Another 1/4 brings #7 and #6 to top and finally #3 and #8. Divide the damper into four equal segments. I took a strip of thin cardboard like a cereal box and wrapped around the damper and marked the overlap, then divided the length into four equal parts.

 

[Booyah45828]

At one time, there was an image of a head cut in half down the middle of the pre-cup on here. And IIRC, neither the glow plug or the injector offer a straight shot into the cylinder through the hole in the pre-cup.

One of the old members was the one that cut the head and painted it, maybe russ or mel?

Your image isn't the greatest, but I don't think that center orange spot is the end of your plug. In your pic, I can see the top ring of the cup, and the floor of the cup, and that orange spot looks more like a fuel wash spot then a glow plug tip. If the tip is in there, it should be resting on the floor, not 3/4 the way up the wall where that orange spot is.

 

[rpdb2002]

Got the new borescope today. Unfortunately, no glow plug tip in sight.
Must have fallen into the cylinder already.
Going to pull off the intake, drop the intake valve a little, see if I can find my offending chunk of metal.

Edit: Has anyone been successful at retrieving a glow plug tip through the intake valve? I have an "head on the block" valve spring compressor, for doing valve seals.

 

[rpdb2002]

I found some pictures on this site, that were posted by ToughOldFord back in Februay 2014 https://www.oilburners.net/threads/cracked-injection-cup.67940/
I hope that I do not violate protocol on this forum, by re-posting his photos on this thread. Just using them for reference. I appreciate his photographs.

Just wondering if anyone has been successful to pull out an injector tip through the intake valve, with the intake pulled off? Does anyone have 7.3 IDI heads off the vehicle? What is the hole size in the precup? Could I possibly solder a small pickup magnet to an old speedometer cable, or flexible wire, and fish the cylinder?

 

[TahoeTom]

You could rotate the engine with a breaker bar and see if it comes to a stop when the piston with the broken GP comes to the top. Possible it broke off long ago and has already left an imprint in the piston. Someone said they fished one out by removing the exhaust manifold. I can't vouch for the story.

 

[Big Bart]

RPBD,

I think the question I have is when you pulled the glow plug out
1) Did it get stuck, you pryed it out, and it broke off clean? (You can see it is a clean break on the glow plug end?)
2) Or did it come right out and was missing the end. (In which case what is done is done, the engine would have spit it out by now, if still running good (Good compression in that cylinder.) I would count myself lucky, leave it be, and move on.)

If it came right out and was missing the head, likely it slowly broke down in the pre-cup, then got eaten and spit out the exhaust valve.

So we are trying to help you determine if pulling the head is going to be for not. Now if you are pretty sure it broke off, then you are doing the right thing trying to get it out.

Also test with a old glow plug but not sure the tip is iron, so may not be magnetic.

 

[rpdb2002]

When I pulled the glow plugs, all came out relatively easy, except number 5. It is an Autolite, as were the others. I can tell the the tip is bulged out. I don't see a fresh clean break, but I do see a carbon build up inside the broken injector (see attached photo). There is a little bit of shiny on the outside of where the glow plug rubbed on the glow plug head bore when I extracted that glow plug.

My main concern was, will those small pieces pass through the turbo without catastrophic damage?

Can I get just a valley pan grommet, air chamber square O-ring, put it back together and run it? I think at this point, I will not find anything by looking in the intake valve. I bought a new borescope with a 5mm camera, and do not see anything in the pre-combustion cup.

 

[Big Bart]

I will let others toss out thoughts.

It does not look like a clean break from you. So my feeling is this wore down or fell off prior, likely was smashed around in the pre-cup during compression/ignition, as little pieces came off, was spit out the exhaust.

I would pull the injector, put the piston as close to tdc of the exhaust stroke (Exhaust valve open), and blow air between the glow plug hole, and then the injector hole. See if anything comes out or if you hear anything moving around. If not put it back together and send it.

My gutt says the engine already chewed this up and spit it out based on your pick.

 

[Double-S-Diesel]

seeing the pict of the glow plug I agree with big bart

 

[IDIBRONCO]

I may be wrong, but it looks like that glow tip was burned off to me. Now did the tip swell, break off and then burn more off? Quite possibly, bit I don't think that the tip just broke off like this from being removed from the head. With a leaky injector, I've pulled out glow plugs that looked like this and came out as easily as the others did.

 

[rpdb2002]

Thank all of you for your quick replies!

Measuring against the other glow plugs I removed, the missing piece is approximately 3/16" long.

Hopefully the pieces that went through, were small enough to not damage the turbo. Or, maybe sitting in the y-pipe?

Guess I will put it back together, and run with it.

Having a bear of a time getting this turbo back into place, no clearance to the firewall. Think I will take off the transmission cross member off and drop the tail shaft a couple inches. Maybe remove the passenger side motor mount, drop the engine down to frame to get clearance?