3B engine issue. Suggestions? (1 Viewer)

[CanCrusher]

My high mileage 3B has finally developed what at first seemed to be a major issue. As background, I was cruising at approx. 105 KPH when the engine seemed to "miss" once. A sort of a falter and no more. About 10 Km further down the road it missed several times consecutively, I stuffed the clutch and coasted to the shoulder (engine stalled). As I approached the shoulder I released the clutch and the engine restarted. I got out with the engine running and gave everything obvious a look. Not seeing anything but not being confident to set out on a 200 km road trip I turned around and headed back home, about 30 Km.

This is where things got serious! I shut the engine down at a shop in town and a friend came out to listen for anything I might have missed. Engine started normally and ran for several minutes at idle. I opened the throttle to about 2000 RPM and a "knock" developed for several seconds and the engine stopped with a metal on metal crunch. Would not turn not through a revolution with a socket on the crank pulley. Back and forth about 1/4 turn with contact on both ends.

Removed valve cover and the valve train is intact and turning without any "delay" from crank rotation. Removed the oil pan and everything seems good. All rods are free with side play, mains turn free, no piston or rod failure. Pulled starter, no interference.

Was working alone so didn't try to rotate engine with clutch disengaged - will try first thing tomorrow.

My question is, what about the timing gears, Injection pump drive or maybe even the oil pump (oil pressure was normal on drive home)? That is all pretty unfamiliar territory to me so any help anyone can provide will be much appreciated.

I should add that there was a VERY small amount of aluminum shaving in the oil pan and one other point is that the EGT seemed to run normal but "spiked" a couple of times on the drive home. Of course I was being quite timid in my driving style and speeds were down from normal cruising.

 

[Koffer]

sounds like you may have dropped a pre combustion chamber cup , sound like you will need to pull the head since everything else looked good from the top and bottom

 

[amaurer]

Aluminum shavings in the pan would be weird... much more likely lead/babbit. A small amount is nothing to worry about though.

A dropped cup is a possibility, but I'd have expected you to be able to get 3/4 of a turn or more before the cup interference became an issue.

I'd peek at the cam from below. If it looks fine, I'd pull the timing cover.

 

[jaymundy]

I dunno about the cause, but for troubleshooting I'd go with both what Amaurer and Koffer said....pull the head and pull the timing cover. Regardless of what caused the issue you'll want to do a pretty complete inspection of the engine to make sure the sudden stoppage when it faltered didn't tweak something else. I might even be inclined to pull the camshaft out and inspect it.

Good luck!

 

[jake2far]

It sounds like a precup, it depends on how big of a piece is trapped between the head an piston and if it is side ways. Start with pulling the head, I doubt the gear train has a problem as the gear train is not known for failure were as the precups are. My 3B dropped a precup and did the same thing.


Jim

 

[amaurer]

It sounds like a precup, it depends on how big of a piece is trapped between the head an piston and if it is side ways. Start with pulling the head, I doubt the gear train has a problem as the gear train is not known for failure were as the precups are. My 3B dropped a precup and did the same thing.


Jim

I'm dying to know how a 1" object like a precup can lock an engine with a 4" stroke to 1/4 rotation...

 

[jake2far]

I'm dying to know how a 1" object like a precup can lock an engine with a 4" stroke to 1/4 rotation...

Wow your precups are 1" in diameter. What engine series is that?


Jim

 

[amaurer]

Wow your precups are 1" in diameter. What engine series is that?

Jim

3B precups are ~1.5" in diameter. Its impossible for them to fall out without cracking into at least one piece, so yeah: 1".

 

[lostmarbles]

Relax folks.

In this guessing game .... I too think it's most likely a precup that cracked apart with piece/pieces dropping into a bore.

So I think Cancrusher should have another look from underneath and doublecheck that all piston are indeed fine/free (as he says they are). ........I should imagine it would be quite difficult to tell without being very methodical.

The crank needs to be moved that little bit (1/4 turn?) while watching each piston skirt in turn for "follow-on movement".

I think a dropped precup has seized a piston in a bore and the resulting conrod little-end damage is probably allowing the significant crank movement.

(Perhaps "1/4 turn" is an exaggeration?)

 

[CanCrusher]

Thanks for the input

I spent the day on the 3B and still don't have a definite answer although I have eliminated some possible causes.

Rechecked crank pistons and rods from below, no sign of damage. Cam looks good from below.

Stop points differ after many cycles back and forth with a socket on the crank pulley. Now close to 1 full rotation (probably about 30 degrees shy). Stoppage comes with cyl # 1 and #4 at or near TDC.

Removed timing cover and all seems well. Disabled valve operation by removing rocker shaft, all valves are fully closed and move freely when tapped (so no bent stems).

Head comes off tomorrow - I have to admit I did not think that the precup suggestions were a possibility but little remains!

I will post results again tomorrow night. Thanks for all of the advice, my thoughts are now going to the best possible fix but will have to wait for a positive diagnosis.

 

[jake2far]

Are you being a dick? 3B precups are ~1.5" in diameter. Its impossible for them to fall out without cracking into at least one piece, so yeah: 1".

I stated I had the same problem, now after Cancrusher has moved the crank around abit he states it turns almost completely which means it is stopping on the bits and pieces of the precup.
My engine dropped a precup, if the pieces are small enough they can and have just gone thru without problems, if they get a little bigger they can act like a stop at TDC and stop the engine, if and this is what I meant they are big enough and hit the piston and head just right it can damage the piston, gall the cylinder wall, and make a crank that moves a little, as Cancrusher played with the crank he got more movement because it worked past the galled part which is what I meant by
"It sounds like a precup, it depends on how big of a piece is trapped between the head an piston and if it is side ways"
this was to say if the piece was big enough it could damage the engine, not that a precup was 3 or 4 inches long or for that matter 1 inch as you stated.
You assumed that I meant the precup parts where large enough to lock the crank to 1/4 turn.

I was just trying to help a fellow mudder with what I think is a very serious problem, what were you trying to do?

Pull the head, you will find the answer.


Jim

 

[amaurer]

Stop points differ after many cycles back and forth with a socket on the crank pulley. Now close to 1 full rotation (probably about 30 degrees shy). Stoppage comes with cyl # 1 and #4 at or near TDC.

Thats very different than just 1/4 turn - this information puts me on the precup bandwagon too. I'd pull the head, good luck.

I was trying to save him the trouble of pulling the head if it wasn't warranted. Yes, precups fall, but every time someone has a knock or a rattle this forum screams "precup ahhhhh!!" and its not always the case. Check the simple stuff first.

 

[VTCDN]

CanCrusher.
Whats Your high mileage 3B got on the OdO ??
I read on here that Overheat has a lot to do with this , plus if the boost from a turbo is always high and 10 psi or more.

Im just wondering on my 200 kms 3B .


VT

 

[CanCrusher]

Kms on 3B

CanCrusher.
Whats Your high mileage 3B got on the OdO ??
I read on here that Overheat has a lot to do with this , plus if the boost from a turbo is always high and 10 psi or more.

Im just wondering on my 200 kms 3B .


VT

The 3b has approx 650K KMs total with turbo over the past 150K Kms. Normal cruising (100 to 110 KPG) boost is around 8 PSI hard pulling on hills etc will build to 14 PSI. EGT normally runs around 900 F pre turbo, seldom touches 1100 F which is where I back out of the throttle.

As an aside the head was new with new precups at the time the turbo was installed.

This engine doesn't owe me a thing, I will do right by a fix!

 

[jake2far]

The 3b has approx 650K KMs total with turbo over the past 150K Kms. Normal cruising (100 to 110 KPG) boost is around 8 PSI hard pulling on hills etc will build to 14 PSI. EGT normally runs around 900 F pre turbo, seldom touches 1100 F which is where I back out of the throttle.

As an aside the head was new with new precups at the time the turbo was installed.

This engine doesn't owe me a thing, I will do right by a fix!

Please post what you find and pictures if possible, it would be great info to share.

Jim

 

[CanCrusher]

Kms on 3B

CanCrusher.
Whats Your high mileage 3B got on the OdO ??
I read on here that Overheat has a lot to do with this , plus if the boost from a turbo is always high and 10 psi or more.

Im just wondering on my 200 kms 3B .


VT

The 3b has approx 650K KMs total with turbo over the past 150K Kms. Normal cruising (100 to 110 KPG) boost is around 8 PSI hard pulling on hills etc will build to 14 PSI. EGT normally runs around 900 F pre turbo, seldom touches 1100 F which is where I back out of the throttle.

As an aside the head was new with new precups at the time the turbo was installed.

This engine doesn't owe me a thing, I will do right by a fix!

 

[Beast II]

I wonder if one of these scope tools would help? Might save alot of work.

Flexible Snake Scope camera shows you the unreachable

 

[cruiser_guy]

When it developed a rattle was it a very pronounced rattle, much more than a normal diesel rattle? I'm betting on the pre-cup as well.

I've lost a pre-cup and it stopped the engine dead. The started did not turn it over at all because of the interference from the precup remains between the piston and the head at TDC. I did not try to turn it back at that time as I knew I had some major issues.

 

[CanCrusher]

Final diagnosis

I spent the afternoon pulling the cylinder head as my last step in diagnosing my engine problem. I wanted to make sure I had covered all possibilities before taking that final step - basically cautious!

I guess I could have/should have taken the plunge right away! Catastrophic failure of the precup in cylinder #1. I was pretty sure that was where this was headed after I disabled the valves and the interference was still there.

Of course the piston is toasted along with the cylinder sleeve in that bore. First look seems to indicate that the block is OK where the sleeve is destroyed.

Time for an overhaul and with as many Kms as I have on this engine I am going to go for broke unless I can find a good used engine. Actually have thought about a 13 BT before transplanting this 3B into a very nice FJ out of Texas. I am so happy with the results of last winter's project that I want to be sure of my reliability factor!

One concern I have is in finding a machine shop to work on the block. Any thoughts from someone with experience with this? A good machine shop should be able to do the work regardless of the engine type or are there special considerations for the Toyota diesel?

Pictures follow for any that are into Cruiserporn. Thanks again for all of the suggestions.

 

[amaurer]

Ooof, ugly. Bummer man.

A question - your pictures look like the precups are recessed into the head??? They should be flush, whats going on there?