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4jb1-t oil leaks

Posted: Sun Nov 09, 2014 6:00 pm
by J_Dub
Right so just got back today from picking up the bighorn, knowing it had an oil leak, but after 4 hours driving, the leak has turned into a steady drip or 10.

Oil is evident in a big way from rear of engine right back to the ass end of the gearbox, torsion bars are covered in oil too..

But also when I popped the bonnet to have a nosey fresh oil was all around the turbo. Intake side, quick degrease and turbo clean as again so this has happened on today's trip...

What's going on here?

I know the underbody stuff can be any number of things but just throwing it out there if these models are renowned for blowing a certain seal or gasket..

Does the turbo need a catch can?
I read on another forum that a fellas truck had same symptoms and it was the sump bolts loose that was spraying oil back

Re: 4jb1-t oil leaks

Posted: Sun Nov 09, 2014 6:07 pm
by Ashohman
Mates jeep had that oil sump plug was leaaking just clean around there it would been predi evident if it is.

Re: 4jb1-t oil leaks

Posted: Sun Nov 09, 2014 7:16 pm
by Mattman
It will be rear main seal. You can replace it but it will chew it out quickly and the leak will return.

Re: 4jb1-t oil leaks

Posted: Sun Nov 09, 2014 8:00 pm
by J_Dub
Hhmmm stop leak additive I think.
What about the turbo leak?
I actually think it was over filled of oil and these motors don't like that

Re: 4jb1-t oil leaks

Posted: Sun Nov 09, 2014 8:10 pm
by Mattman
They do prefer to sit below the full level if they have a few kms on them. I am running a catch can.

Re: 4jb1-t oil leaks

Posted: Sun Nov 09, 2014 8:14 pm
by Crash bandicoot
Isuzu's usually only leak oil from two places. rear main seal and power steering.

the rear main is a pig, and if it's breathing heavy oil it'll be in need of some TLC down low but since you have to part the gearbox and engine anyway might as well pull the engine and have a regrind and new bearings and rings installed in the block. (as excessive wear is what causes it).

the other being power steering , some will quote upwards of 800 dollars to rebuild the steering units etc don't bother just use 90w 120 gear oil.

so thick it wont leak and makes a brilliant steering dampener.

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 7:29 am
by J_Dub
Sounds like a good idea that power steer fluid..

So first thing I'm gona do is an oil catch can then steam clean then c where the problem is

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 7:31 am
by Mr Revhead
Mine did a good impression of a sieve when I got it. 2 litres of oil per 100km :shock:
If there's any front seals leaking you will see it dripping off the bottom of the cam cover. If it's leaking there you will need to replace the cam belt as they don't like soaking in oil.
Oil around the turbo, maybe check the oil feed lines. I doubt oil from the rear main would make it to the turbo. The oil cooler is on that side too, but lower down at the back.
When you do the rear main and you notice a groove where it runs it will probably end up like mattman said, but if you are careful you might be able put the seal in fractionally different place so it's not running in the worn groove. I've done 20k since I did that and so far so good.

Really you need to clean the whole engine, drive it, then look to see where it's come from


If you do choose to remove the engine you can do it with G box in place. But you cannot put it back without moving the box backwards.

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 8:57 am
by J_Dub
Cheers revhead, what was the source or ur leaking problem?

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 9:21 am
by Mr Revhead
every seal in the engine :lol:

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 9:22 am
by J_Dub
Haha yea I'm thinking I may have the same issue

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 8:03 pm
by NB42
Sounds obvious but mine just did that and had 3 other mu's at the workshop doing the same. The oil filters do not like to only be hand tight as most cars would be but rather tightened with a tool. I tightened mine right up and its sweet now.

Re: 4jb1-t oil leaks

Posted: Mon Nov 10, 2014 8:28 pm
by J_Dub
Will double check but I'm sure its dry and tight.
I noticed the dipstick tube is sloppy in the sump, and if I'm right in thinking the oil was over filled, then it may have been pushed out the base of the tube

Re: 4jb1-t oil leaks

Posted: Tue Nov 11, 2014 3:49 pm
by Crash bandicoot
in saying that, they are great engines, my rodeo did over 600,000 ks but by that time it really was in need of a full rebuild, the diff oil trick I got from a retired ford tractor mechanic, worked a treat and didn't affect the steering components one bit.