Oil pressure drop on 4AGE smallport after oil and filter change

[BoostBoy]

EDIT: Please read page 2 for topic change

Hi there....just doing a minor service on my 4AGTE...but I can't remember the oil I used last time...and plus I just wanted to make sure I'm doing the right thing.

My 4AGE small port was rebuilt with forged pistons, etc., and now it's done about 26,000k's since the rebuild. I think from memory last time I was told to use Penrite 15W-40 from the performance shop, but I'm not entirely sure now as I've read a few things that suggest this is the wrong oil to use???

I want to make sure my motor stays new and lasts...and the best way to do that is to treat it right from the beginning...so I'm a little worried because I ended up buying Castrol GTX3 15W-40 and used that for the service...have I done the wrong thing?

[fixeruperer]

castrol gtx3 is just a good everyday oil that can handle the odd thrashing here and there. If your intending to get up it for long periods (like racing) gtx3 wont cope with the heat and the beating and just fail. or if you go burko on the streets you will have to change your oil more frequently (3000-5000ks).

it will be fine if you dont thrash all the time. ARE-IGHT

[BoostBoy]

Okay, nice one....it just gets the odd thrashing here and there...not intending to race it just yet...and I will make sure I get a full service done when I do.

On a side note I've just noticed on the first drive after the oil change, that the needle on the oil pressure gauge has dropped dramatically...it's gone from half-way, to almost at the bottom...should I be concerned?

[fixeruperer]

yes.
at idle or driving, cold or hot ?
i know on them it can be a bastard but hook up a test oil pressure gauge to see what pressure its at.

[BoostBoy]

When driving at normal operating temperature, the needle sits about a centimeter above the lowest point. I don't have a test oil pressure gauge

It's weird because I did nothing but an oil change...the filter I used is actually a better one and slightly smaller than what I had before...so if anything the pressure should increase??

[fixeruperer]

do you know anyone that has an oil pressure gauge that you could hook up ?, you really need to see what pressure its running at.

the oil you had in there before may have been a thicker oil like 20-50, a thicker oil will run at a higher pressure.

[BoostBoy]

After idling the car for a bit I noticed some oil gathering at the bottom of the turbo...I followed the drips back and it looked like it came from the oil line coming out of the block.

Sure enough after a few hours trying to pull it off and a few cuts on my hand later (mind you it was in a very hard to reach spot), I inspected the hose and it had some deep cracks in it! I'm not sure why there was no oil coming from there before...maybe the oil was thick and gunky enough to not come out of the line??

I did notice when I drained my oil though that I only got a litre out of the block...so maybe it was dripping but very slowly.

I guess this would also explain my dramatic loss of oil pressure!

[Julz01]

you probably would have had a thicker oil in their previously, 15w40 sounds about right but for the next oil change I would recommend going for something a bit better then GTx3 , probably something from penrite or nulon.

I use Gtx in my 4ac which is good but ive been meaning to try the nulon 25w-50 we started selling it at work recently so want to see what its like first hand

[30psi 4agte]

..the filter I used is actually a better one and slightly smaller than what I had before...

Whats the go with this?

You should have a Z386 oil filter on it. That is the correct filter. What did you have before?

If the incorrect filter was fitted before it could have something to do with the different oil pressures you are seeing.

[allencr]

I did notice when I drained my oil though that I only got a litre out of the block...

While it is difficult to get 'the wrong oil' and there is no single 'right oil', it is very possible for you to kill the engine a number of other ways!

[BoostBoy]

The oil filter on there previously was a Z3442...I don't know how that filter got on there...must have been from the mechanics...they probably didn't have the right type of filter so they got one with a similar thread...idiots! I've got the Drift Z386 filter on there now...so I expected the oil pressure to increase being a smaller filter than what was on there...

I spent all day yesterday pulling out the cracked oil hose...I chopped the end off where the cracks where (there is enough length in the hose) and re-fitted it...tighten all the clamps, cleaned up all the oil...

I haven't tested it out yet, because it was too late and dark to see anything...will be firing it up this morning to see if I've solved the problem....fingers crossed.

[Hiro]

The oil filter on there previously was a Z3442...I don't know how that filter got on there...must have been from the mechanics...they probably didn't have the right type of filter so they got one with a similar thread...idiots! I've got the Drift Z386 filter on there now...so I expected the oil pressure to increase being a smaller filter than what was on there...
.

Z442 (I'm assuming thats the one you had previously, Z3442 doesn't exist and both Z342 and Z344 are fuel-filters) is 86mm long, Z386 is 76mm long. Same seal diameter (assuming same outer diameter), same thread, same fitting. No real harm in having it on the engine, bigger filter = more media = better filtering (generally)

[Cuzzo]

i have used a 3sgte one and fit the same thread as the z386 one

Not sure what the number is for the 3sgte one but it was larger in length.

[YLD-16L]

i have used a 3sgte one and fit the same thread as the z386 one

Not sure what the number is for the 3sgte one but it was larger in length.

If you've got the remote mount you can go big. I run a Z89A as it was the largest off the shelf readily available one I could find. Huge comapred to a 4A filter.

[Hiro]

i have used a 3sgte one and fit the same thread as the z386 one

Not sure what the number is for the 3sgte one but it was larger in length.

Ryco list the Z386 for 3SGTE ST185s, same as 4AGEs....

Z386, Z432, Z442 all have the same diameter, seal and thread/fitting, just with different lengths, so they should generally be swappable (unless you hit something like exhausts)