Holden 308 Oil Pressure Drop

Fulley Rebuild Holden 308 Oil Pressure drop below 5psi after driving 10 min
What can go wrong..?

[@RussellBooth1977]

All I can think of is that the builder didn't check bearing to journal clearance with the new bearing shells fitted prior to fully assembling the engine & sending it out to the customer . My 5.7 litre Chevrolet LS1 V8 engine (I know that I am not talking about the 5 litre Holden V8 engine here) had 30 PSI of oil pressure at idle speed,37 PSI at 2000 RPMs & 60 PSI at 4000 RPMs which is within the manufacturers specifications. That was at about 300,000 kilometres or a bit over as I was trying to diagnose a hydraulic lifter noise which appeared once the engine had warmed up so in my case it was due to bad hydraulic lifters, not a low oil pressure issue. I replaced the lifters 5 years ago & the engine has been going good ever Since & with no lifter tick !

[@autoconversion2410]

I have to agree with you mate.. I dont think engine builder check the clearance properly.. he wont admit his mistake.. Thanks for the reply.

[@ziggassedup]

Holden V8's are not known for great oil pressure at any time...Factory specs say 275-415kpa (40-60psi) @2000rpm is acceptable with 20-W50 mineral oil thru a Z160 oil filter and thermostat at 88-90C...I use 20W60 Penrite in my 304 and keep it about a 1/2 liter overfull to splash the cam...it seems to have 17psi @ idle and it's an old engine...That pressure is outstanding...I wonder if the cam bearings weren't up to scratch and they changed them.?...The cam is where the oil goes before it goes thru the crank and bearings...If they only tightened the bigend and main bearing clearances on a fresh engine then the didn't do the right job from Go...Just my opinion...Cheers mate,

[@jimclarke1108]

100% 👍

[@GMans-World]

Zig knows his stuff that's for sure.... I've been watching his channel for years now !!! Old skool rules !!

[@benmclean2291]

Hope you get on top of your oil concerns but regardless, welcome to the Torana club mate 👍

[@spartanpatriot3163]

One of them things man, ive seen this twice, once in my 97 cobra 4 cam 4.6 and in my Speed 3 MZR 2.3. Both built properly with King bearings. No matter the weight of oil they both would have a hot idle of around 10 psi. Both motors lived a long life though and were beat on pretty hard.

[@triggeredleftyvegan6004]

Hopefully you didn't do any damage to lifters or cam with the low oil pressure. Holden V8's have known oil pressure issues. Ive had that in the past hence on my current 355 build I went to a roller cam set up. But it doesn't excuse unfortunately why a fresh build had low oil pressure your engine builder is to blame 100%.

[@_TheBreaker_]

Holden V8s are notorious for very low oil pressure at idle. Stick with a good oil like Penrite HPR30 and you'll be fine. That all looks and sounds normal if you've got a thinner oil, like a LS1 grade oil in it.

[@RolandElliottFirstG]

I have rebuilt a few 253, and 308's some tend to just run low for no apparent reason, I wouldnt worry too much, check oil pump clearances on lobes in this instance.

[@gilesburrett3844]

I'd say great effort by all that's a success right there

[@jamesplotkin4674]

I had similar trouble with a different engine, but it's oil pressure by-pass was in the side of the filter mount and used a cup type plunger behind a spring. I found it was hanging open, so replaced the cup with a ball bearing and the problem went away.

[@autoconversion2410]

This is not bypass valve....thanks for the comments

[@jimclarke1108]

Worn cam bearings will reduce oil pressure , the oiling system lubricates cam bearings first, lifters, then down to the mains and to big the ends

[@nickcOfficial]

Horrible engines for oil pressure, my engine was the same almost dead at idle my old engine builder slapped it together. It’s been redone now but still very bad at idle on cold starts. You’re idle pressure is actually very good.

[@roflman]

253-308s will run forever on 7-8 psi

[@robloxer0007]

Are you sure it was a lifter ticking and not a bearing that was buggered due to bearing quality

[@steveveness3829]

And then there is the difference between bearing manufacturers. Only mention this as have seen many issues over my 40 plus years in the trade. Can't put ang engine together without careful thorough measuring, I personally have had 3 different brands of standard size crank and conrod bearings with all 3 brands showing different clearances. Non of the bearing brands were even race bearings ( wich can give larger clearances if desired depending on desired outcome). Worth sharing wouldn't you say?🙂

[@autoconversion2410]

Thanks for the info.

[@greggc8088]

I would have figured camshaft bearings being the issue since you had no knocking.

[@nickcOfficial]

That’s what mine had an issue with ages ago.

[@Veightdirectorcarclubvictoria]

Use K&N hp2003 oil filter

[@petercunningham3469]

Oil pick up tube to close to the bottom of the oil pan.

[@autoconversion2410]

I checked already.. it was ok. thanks

[@thearchitect4726]

put some thicker oil in it, the moose piss you have in it now s too thin, try 20w - 50, then up to 25w - 60, mineral based with extra zinc, as the engine heats up, the clearances increase and you need more viscosity to take up the bearing clearances, without stripping it down and measuring it up that's the most likely cause, otherwise remove your pressure relief valve out of the oil pump, make sure it is not sticky. The lifter is getting noisy due to the low oil pressure.

[@autoconversion2410]

I did 20 50 ,20 60 and 25 70 no difference at all.. After he changed the bearings im using 25 60 and pressure holding ok..

[@StarlightWorkshop0z]

​@@autoconversion2410he obviously is deaf and blind. Nice motor mate.

[@_TheBreaker_]

Good advice

[@triggeredleftyvegan6004]

Not his fault engine builder obvisoly had wrong clearances.

[@rcwp8110]

Run a non synthetic oil penrite make a great100% mineral oil

[@autoconversion2410]

I did already 20 50 25 60 etc.. no difference..Thanks