Thread: Blowby

Originally Posted by EchiDna

Italian tuneup time

mine has blowby, but not measurable in litres!!

What exactly is an italian tune up?
And why does my rear main seal leak when no-one elses does?

Originally Posted by Dougal

What exactly is an italian tune up?
And why does my rear main seal leak when no-one elses does?

Flog da fug outta it maaaaayte

Incorrect fitment

Bad seal?

Leaking compression?

Originally Posted by rovercare

Yea, both my rebuilt AND 290k old 4BD1's breath heavy

Don't forget my chev, that was breathy aswell

Originally Posted by Vern

Don't forget my chev, that was breathy aswell

Mine ain't that heavy

Originally Posted by rovercare

Flog da fug outta it maaaaayte

Incorrect fitment

Bad seal?

Leaking compression?

Trust me, I do.
Did I not mention I was chasing a mercedes over a mountain pass.
20psi boost sustained for about 5 minutes.

This is the third seal that I've fitted, it's a genuine Isuzu (made by NOK) and I even cut 10% out of the spring to give it some more tension. Crankshaft surface is good (speedisleeve).

Bigger breather maybe. I need to put a pressure gauge on the dipstick tube and go for a drive. See if it's pressurising.

Originally Posted by Dougal

Trust me, I do.
Did I not mention I was chasing a mercedes over a mountain pass.
20psi boost sustained for about 5 minutes.

This is the third seal that I've fitted, it's a genuine Isuzu (made by NOK) and I even cut 10% out of the spring to give it some more tension. Crankshaft surface is good (speedisleeve).

Bigger breather maybe. I need to put a pressure gauge on the dipstick tube and go for a drive. See if it's pressurising.

Well you've got a boost gauge

Dodgy up a bit of pipe and go for a spin, will wait for your post in half an hour or so

Mightn't be able to build pressure if your rear main is that bad

I'm on holiday at the moment (going skiing again tomorrow) so give me a week and I'll see what I can find.

The original Isuzu rear mains arn't that crash hot. Seriously, the Aust. army has loads of trouble with them! I've replaced three in a row on one of their 6x6's, belive me it's the seals. There is a new type of rear main seal available now. It has to be pressed into the adapter housing and has a "sleeve" built into the seal that presses onto the crank, this superseeds the need for a speedi sleeve, the seal is a three lipped job. I installed one onto mine upon rebuild and so far so good (29000km)
I'll track down the Pt no. tomorrow if I remember.

Just out of curiosity what type of oil fill caps are people running, mine is a screw in type. It sounds like people have the push in type with a turbo'd engine.