What are these? (2 Viewers)

[wwjdg2tp]

Thanks. Yesterday, I decided to try to start the 3B in the driveway in hopes to use that engine until I can rebuild the 13B. Before doing that, my buddy and I took a peek in the cylinder with a borescope. Unfortunately, we saw a crack on the 3B piston. Please see pic.

Summary:
3B-cracked piston-total rebuild or partial rebuild?
13B -hole in piston with bad main bearings- needs total rebuild

Trying to decide the next step. Since it will take a while to do the work and this was my daily driver, I am leaning towards buying a

100 series (~$8k budget) just for the daily driver in the meantime.

Open to comments or suggestions.
Thanks

 

[bj70bc]

isnt that picture a precup, not a piston?

 

[KiwiDingo]

I hope it's a lesson to those who think Toyota diesels like doing 5500 rpms for long periods.

Absolutely not a lesson for me. If toyota allowed me to rev their engine to a certain RPM and deemed it safe then I'm dam well going to use it.

 

[wwjdg2tp]

Thank you bj70bc for commenting about the pre-cups…after looking into it more since I was unfamiliar with precups, that makes sense and perhaps gives more hope?

What would be your next step if your goal was to get this engine running bare minimum work/cost for an interim daily driver?

 

[bj70bc]

that kind of cracking in a precup is expected and normal..... however undesirable,
pretty sure every precup over 100k km is cracked like that

 

[wwjdg2tp]

In other words, is this crack significant enough to warrant replacing precups and it suggests other failures or is this common for high mileage and ok to run it at this time and monitor.

 

[bj70bc]

its normal in my opinion, weather you replace that after seeing that it is up to you,
looks to be on the minor end of things from what ive seen... but thats only one of 4,
everythings always happier with a re+re head

 

[wwjdg2tp]

Thank you for your opinion…that really helps me.

 

[wwjdg2tp]

Ok-new information on the 3B I was planning to install. I did a compression test today and it didn't come out as I hoped. I don't know if I did it correctly but the numbers are well below the FSM. Is there a way I could have performed it incorrectly to get false low readings?
Here are the numbers:

 

[bj70bc]

either your doing something wrong or its done for

 

[mudgudgeon]

Is there a way I could have performed it incorrectly to get false low readings?

Never underestimate the capacity for idiots to **** things up! (don't ask me how I know )

That said, tell us how you went about it?
If the fitting sealed each time, all you need to do is crank the engine until the pressure on the gauge peaks ( or stops increasing in significant jumps), repeat for each cylinder.

 

[jblueridge]

I once used a gauge that would not hold the pressure... the gauge leaked but not all the way down to zero.
Are you doing this by yourself, i.e. can you watch the gauge while the engine is cranking?
If you are lucky, maybe the gauge and its hose setup are at fault.

 

[AirheadNut]

Your tester may be faulty. I bought a cheap Harbor Freight diesel compression tester and it worked great the first time I used it (got readings of ~420-440psi across the board on a 3L). Since then it has not given me one accurate reading. I’ve gotten results of 300psi on two an excellent running VW TDI’s and it only gave me ~150psi on my Mercedes OM617, which starts and runs excellently.

 

[lacalvette]

In doubt you can fabricate an adapter with an air fitting. Connect it with your air compressor and push air into the combustion chamber.
(Make sure the unit you’re testing is on compression stroke with both valve close) and listen
Rings? Exhaust valve or intake valve leaking..
It could help

 

[wwjdg2tp]

Thank you AirheadNut. After the compression test, I shared the results with my friend who owns the compression kit. He told me then that his 13B showed 250 across the board just after the machine shop rebuilt it and it runs great. Perhaps the gauges are faulty or those numbers are low because he didn't have the engine warm or the engine needs a rebuild.

I did a little more research and read something about if an engine was flooded, it would wash away the oil from the cylinder walls and also give a low compression reading. Weeks ago, I was trying to start it and my primer pump was bad so I was pouring fuel into the intake. It would start but only run for a second or so because it was running out of fuel. So I poured more in until it almost hydrolocked (didn't know this could happen until I asked someone later). So perhaps that could be contribuing to the low readings. It still doesn't explain the one cylinder that was lower than the others.

Researched a little more and read that the engine should be warm. It was not. The engine is out of the truck and I have no water running to it so I can't warm it up right now. I am going to do a wet compression test and post the numbers. My understainding is that if the rings are bad, then the numbers should increase as I add oil to the cylinder. Also, I am probably be just restoring the oil that I washed away by flooding the engine.

Open to thoughts and recommendations. Thanks again.

either your doing something wrong or its done for

Thanks.

 

[wwjdg2tp]

Never underestimate the capacity for idiots to **** things up! (don't ask me how I know )

That said, tell us how you went about it?
If the fitting sealed each time, all you need to do is crank the engine until the pressure on the gauge peaks ( or stops increasing in significant jumps), repeat for each cylinder.

I allowed the engine about 3 cranks until the numbers peaked.

 

[wwjdg2tp]

Just did another dry compression test and compared it to wet (little oil in the injector hole prior to test)

Then later I tried to start it. Only problem is that it wouldn't stay running. When I did the dry compression test yesterday I had the injector lines still removed from the injector pump so I probably pumped the fuel out of it. Spent some time trying to bleed the air out but I don't know the best method. I am now finally getting fuel to the fuel filter bleed screw and to two of the injector lines at the injectors but I think the other two are dry. Batteries need to be recharged so I had to stop. I will try again. I would appreciate any advice on how to bleed the injector lines and if there is some lever or vacuum line or switch that needs to be moved in order for it to stay running.

Here are the compression test results:

 

[lacalvette]

If you unscrew fuel injection to injectors, fuel injection pump to stop and pump the hand priming pump. You should be able to remove air all the way up to injector. There is some soft fuel hose to rigid line connector which may be loose and let air goes in.

If I recall there is a fuel bleed screw on the injection pump.
So you start by filling the filter, than injection pump if there a bleed scew, then injector. (Normally no need to start engine)

Since there is no cooling, I wouldn’t start it.

The difference between the wet and dry compression test could indicate that rings are not sealing properly ;(

 

[wwjdg2tp]

If you unscrew fuel injection to injectors, fuel injection pump to stop and pump the hand priming pump. You should be able to remove air all the way up to injector. There is some soft fuel hose to rigid line connector which may be loose and let air goes in.

If I recall there is a fuel bleed screw on the injection pump.
So you start by filling the filter, than injection pump if there a bleed scew, then injector. (Normally no need to start engine)

Since there is no cooling, I wouldn’t start it.

The difference between the wet and dry compression test could indicate that rings are not sealing properly ;(

Thank you lacalvette. Your reply helped lead me to search further and I found this link with a video confirming the bleed screw you mentioned.

How to bleed fuel system video ( B, 2B, 3B and H Diesels )

Here is a good video showing how to bleed your Diesel fuel system on a B Diesel engine. Should be exactly the same for a 2B, 3B and H diesels. Shows bleeding IP and Injectors. This was from a Dyna truck ( air intake at the side ) Enjoy :) ToyotaDyna ---------- Looking for a LHD, Diesel...

forum.ih8mud.com

 

[relaxedcruiser]

As for your diesel compression tester - have you got a one way valve right at the end of the bit which bolts into the head ?

I build a adapter for my 12ht once and got unsatisfying results - then cut a M6 thread into the end and fitted a schrader valve ( from a tire) The results were way better as the room for the compressed air is smaller.
Plus fully open the manifold butterfly ...