1994 MU 3.1 engine rebuild (4JG2)

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Diorama
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1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Sat Jan 27, 2018 8:58 am

Got given an Isuzu MU with an engine Knock. The engine had been rebuilt 10000 ks prior. Stripped it down and found No 3 big end bearing completely gone so the conrod was running direct on the crank. Knock found. I have sourced another crank and am in the process of rebuilding the engine (new bearings etc). The thing I am trying to determine is the reason for the failure after 10000ks. I have heard all sorts of theories from bearing cap not torqued properly (it certainly wasn't loose when I took it apart) to the oil cooler not cleaned out properly. The previous owner said it lost oil pressure which I would certainly think it would if a bearing was gone. Don't know whether it lost pressure before the knock or after. Any ideas on the cause would be appreciated.
Also want to confirm oil pump is good before putting it back. Any way this can be bench tested before installing it.

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby BlakeNZ » Sat Jan 27, 2018 2:59 pm

have you priced a new oil pump?

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Sat Jan 27, 2018 3:37 pm

BlakeNZ wrote:have you priced a new oil pump?

No. I don't even know where to get one. I would also assume it would have been replaced when the engine was rebuilt. Thought if I could at least test it and then be able to rule that out as being the cause of the failure. Don't necessarily want to put a new one in thinking that is a likely cause and then find it is something totally different.

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Thu Feb 01, 2018 8:43 am

Can anyone tell me the best place to get a new oil pump and is it possible to bench test the one I have.

BlakeNZ
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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby BlakeNZ » Thu Feb 01, 2018 2:49 pm

Upon reflection,if only one cylinder or bearing has damage, it is unlikely to be a oil pressure issue IMHO. So how are the other bearing shells etc?

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Cameron » Thu Feb 01, 2018 3:53 pm

assuming they're all the same (give me a rego and I can check) I can sell you a brand new genuine oil pump for $575

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Thu Feb 01, 2018 6:35 pm

BlakeNZ wrote:Upon reflection,if only one cylinder or bearing has damage, it is unlikely to be a oil pressure issue IMHO. So how are the other bearing shells etc?
Only one bearing competely gone. No trace of it at all. All other bearings are fine.

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Thu Feb 01, 2018 6:35 pm

Cameron wrote:assuming they're all the same (give me a rego and I can check) I can sell you a brand new genuine oil pump for $575
Rego YL8560.

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Cameron » Fri Feb 02, 2018 2:00 pm

yeah mate same number

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Diorama » Thu Feb 08, 2018 8:31 am

Cameron wrote:yeah mate same number
What is the part number

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Re: 1994 MU 3.1 engine rebuild (4JG2)

Postby Cameron » Thu Feb 08, 2018 8:49 am

8973859830

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