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Trooper Engine Rebuild Questions

5393 Views 95 Replies 12 Participants Last post by  truisuzu
OK, here's a single topic for my engine rebuild questions.

Tearing things down and disconnecting the wire harness stuff. There is one sensor down by the oil filter which does not seem to have a plastic disconnect (see attached image). It has a rubber outer skin. Does this thing have a disconnect under the skin?


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Thanks for the ideas! I can't get to the block at the moment as it is all packed up to go to the machinist. I will have him check it all out and tell me what the status is.

Thanks again.
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I have read many topics about drilling the extra holes in the pistons to solve the oil consumption problems. I will be having my machinist drill the holes when he's doing other work. I could do the drilling (and even have a drill press) but I would rather have him do the drilling since he does it every day and if the pistons are damaged, it's on him.

From my reading so far... I take it that there is no official Isuzu service bulletin describing the process? All I have found is a post with a photo from JLEMOND that shows a piston with magic marker lines on it showing the location to drill the additional 4 holes in each piston.

Is there any other post/info I should know about? I want to provide something to my machinist to tell him where to drill the holes (he seems to view the Internet as a vast conspiracy theory... and he may be right!).

Thanks VERY much for this info! In all the posts I looked at... I didn't find that one. On my 2001 pistons, I didn't remove the rings but handed off to my machinist. I did look at the inside area of the pistons and there were only 2 holes per side so I'm sure they need the new holes.

Thanks again.
I will be replacing the motor mounts and the transmission mount before reinstalling the engine. The prices for Isuzu mounts are very expensive vs aftermarket mounts. Is there any particular brands recommended as replacements or brands to stay away from?

Nevermind. Upon further inspection, both motor mounts look great. The rubber all looks good with no cracking, etc. The transmission mount is the only one I'll replace.

Thanks anyway!
Transmission crossmember broken bolt problem.

The transmission crossmember area gets a lot of winter road salt/mud and the crossmember bolts were a bit hard to remove.

One of the bolts broke off with about 1/8-3/16" sticking out (the zone around this bolt is very rusty corroded). It has been soaked with penetrant for several weeks. I tried vise-grips, etc. to turn it to no avail and have drilled out the bolt all the way through to a 1/4" hole. I put a screw extractor in to a good depth and tapped it in and a wrench with cheater pipe does nothing except threaten to break the extractor. The rusted threads seem to be fused.

I can certainly keep drilling the hole bigger and try the extractor deeper into the bolt... but I'm getting closer to the threads. I don't want to break the extractor.

If I was going to try to heat with a propane torch... should I be heating the bolt, or the hole or both?

Well, after trying several more times with the same and larger extractor... the extractors just spin in the drill hole and shred the hole. So it looks like I will have to continue drilling it out.
I do have a welder... but my overhead welding is not great. The bolt is now hollowed out. I will try some heat and the extractor again.
First, an update on the broken bolt for the transmission support crossmember.

As I mentioned, because of the road salt corrosion, the bolt threads seem fused to the hole threads and the bolt would never move (heat didn't work, penetrant for weeks didn't work, extractors didn't work). The bolt has been drilled out to the point that I can just see the threads when looking into the drilled out hole. If it were possible to pull the remaining bolt threads away from the hole threads... the hole might be usable with a new bolt. But because of the threads fusion... the remaining bolt threads will not come out and there is no longer any external piece of bolt to grab onto as this was destroyed in trying to get the remaining threads to rotate out. The next step is to keep drilling and destroy the current threads and try to re-tap for a larger bolt. (This is complicated by the fact that the 'hole' is actually a nut welded on the inside of the frame hole, and this frame hole complicates the drilling further what with the drill bit and tap wanting to deflect off an edge of this hole).

As an aside, the location of the broken bolt is such that a thru-bolt solution can be used in this area instead. I have drilled all the way through the frame mount next to the broken bolt location and modified the crossmember hole to accept a thru-bolt and this will easily replace the original bolt without problems. There will again be 4 bolts holding the crossmember on each side.

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Now on to my next question.

When cleaning up the coolant pipes that reside under the common chamber, I wanted to check my Fel-Pro gasket set to make sure I had the proper o-rings for these pipes. I examined then removed the old o-rings. The gasket set seems to have o-rings of the correct size but the existing o-rings looked quite a bit different from the new ones. The existing o-rings looked wider with a bit of a rectangular shape to the cross section (probably from being squished in the pipes for so long?). The new o-rings look like standard o-rings with a circular CS. These pipes were not leaking in any way. When I went to remove the 22 year old o-rings with a small pick, there was NO elasticity at all to the rings. They were very dried out and tore in two right at the pick location then I pulled them off. It's amazing they weren't leaking.

My question is... are the proper o-rings for these pipes normal o-rings with a circular CS? Or are the OEM o-rings different than normal, circular CS o-rings?

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Thanks, for the info... will do.
Common chamber gasket question.

The old original gasket that was installed between the halves of the common chamber... it is black and shiny looking like plastic (and slightly oily to the touch). Then new gasket is gray paper/fiber.

My question is, did the original gasket look like gray paper to start out and it changed to the black plastic look?

There was no sign of sealant used on the original gasket and I'm guessing I shouldn't use it on the new gray paper gasket?

Here's a pic of the gasket differences.

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Engine block oil passage ball bearing question.

My machinist expressed concern to me (which also had been mentioned to him by two others) about the front main bearing oil passage on the 6VE1 block which is deliberately blocked by a ball bearing. He was concerned that this manufacturing technique caused this passage area to be impossible to clean thoroughly after machining. I don't currently have the block with me to examine this zone.

Is this a known problem area when machining these engines?

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I should also mention that the crankshaft has several of these ball plugs.

In looking for more information on this... it seems that a number of engine/crankshaft designs use the ball plug and that some folks remove the ball plug and replace with a threaded plug to allow better cleaning after machining.

Is this a common procedure when machining Isuzu engines and crankshafts?

My machinist seemed unfamiliar with doing this. Also, the hole in the engine where the ball sits has some little bumps of steel on the walls of the hole which prohibit the ball moving out of the hole (not sure if the crankshaft holes also have these bumps). I don't know if these bumps make the drilling out and removal of the balls more difficult or what.

So on the Common Chamber halves gasket question... should a sealant be used when installing this gasket? (The disassembly showed no sign of sealant... but the old gasket does have a very different appearance than the new).
Thanks for the info Shawn! Understand on the gaskets not being the same, it's just the old one is a shiny plastic look (this could be from the 22 year long compression of the halves... it is oily) vs the new fiber look.

Anyway, I will check the surface with a straight edge. It looks good when the halves go together. Might be worth having a light film of sealant just in case.

Thanks again.
I am at the point of needing to drill the extra holes in the new piston ring lands for the oil consumption problem. I do not want to screw this up.

I have a drill press and am trying to set up a rig to hold the piston (rubber base for the piston to lay on and rubber on top to be clamped down). Because of the piston's shape (cylindrical but not a full cylinder) it may be difficult to hold down. Not sure if it is going to work but if it does, I think it will be a time-consuming process to get the piston into the proper position for each hole (I don't mind spending the time). The slowest speed of the drill press is 540 rpm.

(I do have a variable speed hand-held corded drill which can spin much slower but I'm leery of handheld with the tiny 1/16th size bits and holding the piston is still a problem).

I'm going to use a Dremel with a tiny bit to put a pilot divit in the hole location before drilling.

Any tips for getting this done successfully?

Thanks for the ideas! I think my drill press setup is going to work as I have successfully done one piston so far.

The holes in the original pistons are larger than in the ITM replacement pistons. The original holes take up basically the whole land height whereas the ITM piston holes are smaller (1/16"). I'm sticking with the 1/16" size as it's difficult to keep the drill bit from damaging the sides of the land.

Thanks again.
Got all the pistons drilled. Here is my drill press setup for this.

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