exhaust manifold leak advice

[Mr. Xtremities]

Hello, experts. A bit of a newbie here but learning fast.
2006 Dodge Sprinter 2500, OM647 engine. Only about 150k miles but difficulty with a dead glow plug that I left alone for several years and wrestled with unexplained LHM. Finally learned that those glow plugs are more important than just getting the engine started! (First diesel.)

Glow plugs were stuck (of course), and broke a couple. With a couple leaks I decided to bite the bullet and do the head job. (A local shop wanted $6k to do it...)

Significant oil leak at the back passenger side which I hear is not unusual and a leak at the exhaust manifold was bigger than I expected. For the exhaust leak - at cylinder one/front - I am wondering if the weight of the turbo not being really well supported aside from the exhaust manifold and exhaust pipe put too much stress on that part of the manifold and caused the leak. BTW, the exhaust bolts / nuts were not terribly difficult to remove. Probably because this is still "low mileage" for a diesel.

Shall I just sand the exhaust manifold back to a smooth surface (i.e. to 800 grit as I did with my son's ranger) and use a calibrated edge to ensure all ports are in the same plane? And should I find a way to more securely hold the turbo in place? Pics attached.

(Will be removing & lapping the valves and checking the mating surface w/ a calibrated edge before taking it to a machinist to get the remaining 3 glow plugs out.)

Thanks!



(This after cleaning off the port somewhat.)


(The oil leak after head removed, for reference. Presuming the new gasket and an assured flat and/or re-cut mating surface will eliminate this upon rebuild.)

 

[Midwestdrifter]

The oil leak is probably the valve cover gasket. But could also be the head gasket.

Glow plugs are only necessary for cold starting. If you don't live in a cold climate (below freezing), then they need not function.

The manifold can be surfaced on a decent sized belt sander. Even a handheld one. You want less than 0.060 warp across the whole length. 800 grid isn't necessary. Finish with 250-400grit.

The turbo should have a bracket/brace attached to the bottom with a single bolt.

 

[Midwestdrifter]

Make absolutely certain there is not crack in the head around the glow plug/injector holes. Most of these engines need a valve job at this point.

Check your block deck for ridges from the gasket and corrosion. If needed a light stoning with a granite cutting board and some 180-250grit sandpaper can be called for.

If you have the head faced, make sure to check the valve prominence. If it exceeds the space the valve sets will need recessed to prevent piston contact.

Honestly for the work, I suggest most folks just buy a new AMC head. They come with valves installed, and you just need to transfer your camshafts, lifters and cam girdle/frame.


With the right tool kit, its fairly routine to extract broken off glow plugs without removing the head. The tools aren't terribly expensive.

 

[Mr. Xtremities]

Thanks, Midwestdrifter! I would have not thought to check for cracks; figuring that with a diesel with so few miles on it, all should be well, but I didn't know how to take care of this baby at first.

The block looks good - no ridges or scratches, just some leftover gasket material that I am planning on taking off with a razorblade and scotchbrite pads. I've oiled the block to keep it from rusting while I work the head. But I appreciate the tip on a granite cutting board. If my feelers show me anything out of spec, I'll give that a go.

I've not yet checked the numbers but I've a copy of the sprinter service manual that shows the specs on prominence. Before asking to get this flattened out (if it's not flat enough) I'll make sure the machinist knows how much material is avail. (and of course that it's not cracked to begin with.)

I'd like to get the glow plugs out myself too but I've watched several videos on this and looks like all approaches require some welding to get the tungsten out first. I don't have any welding experience so figure I'm outta luck on that. But, if there are ways ....
I was able to remove two unbroken ones. One was definitely very tight. After the penetrating oil and time, it took about half an hour of tapping a wrench to turn it - half that time after the threads were cleared - before I could get it out. So I know the 3 broken ones are going to need a slide hammer.

 

[Mr. Xtremities]

The oil leak is probably the valve cover gasket. But could also be the head gasket.

Glow plugs are only necessary for cold starting. If you don't live in a cold climate (below freezing), then they need not function.

The manifold can be surfaced on a decent sized belt sander. Even a handheld one. You want less than 0.060 warp across the whole length. 800 grid isn't necessary. Finish with 250-400grit.

The turbo should have a bracket/brace attached to the bottom with a single bolt.

Note --- if someone has a picture of this it would be great. I don't have a bracket or brace on the bottom of my turbo. I see from the service manual pg 11-8 that one should exist.
I recently had it replaced by a local shop who used a Rotomaster rather than a Garrett. (Shoulda done it myself!) So that might have something to do with it. Given the pitting, I'd say the leak was around a lot longer than the ~200 miles I've put on the van since that turbo was installed.

 

[Midwestdrifter]

If you've already got the head out and on the bench it should be fairly easy to use the correct size step drills to remove the body and guts of the plug. From there if the tip is still seized into the head, put the head into an oven at 300°F. Once it warms up you should be able to put on the bench again and drive out the tips with a punch.

 

[Mr. Xtremities]

The biggest challenge as I understand it is that the tungsten rods have to be removed before drilling out the guts of the plug. All solutions I saw for that involved welding a bolt to the tungsten rod and twisting it off. I suppose a solid grip w/ a vice grip might get lucky but doubtful it will have sufficient grip to break it low enough to drill out the screw portion.

 

[Midwestdrifter]

Typically the central rod comes out fairly easily when grabbed from this top and twisted. It's crimped at the bottom, and is fairly brittle.

 

[Mr. Xtremities]

Well, the head is with the machinist. I got two of the tungsten rods out exactly as you said. A third wouldn't cooperate. I decided to let a professional remove stuck steel from the aluminum head anyway. Too much risk for this newbie!