Topic: More 3RZ Balance Shaft Talk: Oil pressure.

[alaskanrider]

Hey,
Great forum, the more toyota info I can find the better.

I was wondering if anyone had any oil pressure numbers from a balance shaft delete. It would help me trouble shoot my own.

I was looking at the LC engineering kit an noticed it comes with a squirter. I wonder if it has larger holes in it than the stock one, to alleviate the excess pressure.

Background Info
I recently rebuilt my 3RZ and did a homebrew delete. I'm seeing some pretty high oil pressure now and I am wondering if this is the cause.

For the timing chain lubrication I just left the No. 2 tensioner in place.

Cold, it peaks out at around 125-140 psi at 3k RPM. Warm it comes down to around 90 psi at 3000 RPM. It doesn't really get any higher than those numbers at higher RPMS, but its enough to make the oil filter weep occasionally.

Bearing clearances were plastigauged and came out in spec, possibly on the loose side. The oiling system was primed with the valve cover off to ensure flow to the cam journals. They made a big mess of oil so I assume they are ok.

The motor has got about 300 miles on it now, and oil pressure hasn't come down at all. I recently replaced the front axle, and while I was down there I pulled the oil pan and double checked the relief. No problems there.

Theres alot more info online from the DSM crowd on the subject, and high oil pressure seems to be a common ailment after the mod. Their solution is to port the oil pressure relief, for them its easy because its part of the filter housing. Ours is not so accessible. Any thoughts? Maybe I need a 2rz squirter?

[MRHilux87]

Good Question that I would be interested in knowing the answer too.  Welcome to the forums.  Someone here will know the answer.  Im just completing my 3rz swap and it had a balance shaft delete already on it.  How are you monitoring your oil pressure numbers?  Aftermarket gauge?

[alaskanrider [OP]]

Thanks for the response. Im running a sunpro electrical gauge and sending unit. I double checked them with a compression tester outfitted with a 1/8" adaptor. and the check valve removed. They are within 15-20 psi of eachother, and I've noticed my cheap compression tester runs a bit low compared to my friends tools. I think the electrical unit is pretty close, and these pressures are about double what id like to see anyway. 140 psi freaks me out.

Good luck with your engine. The 3RZ is awesome! I love the way it runs and the powerband. I have no reference to how much the balance shafts affect vibration, as I bought the truck broken, but I'm totally happy with it other than this oil pressure issue. If your used to driving a diesel truck it seems like a super smooth engine even without balance shafts LOL.

Did your truck have some kind of kit? Is it running an aftermarket squirter?

[emsvitil]

Doesn't the oil pump have a pressure release valve on it?

[alaskanrider [OP]]

Doesn't the oil pump have a pressure release valve on it?

It does, and mine is totally healthy as far as i can tell.

[alaskanrider [OP]]

I talked to Wes at LC engineering, he says the balance shafts don't really affect oil pressure on these, and that my relief is probably sticking. Ill post an update when if this does it.

These guys have been great, good company, very helpful.

[Cheesemaker]

I was reading online, that there are are several places you have to block off oil passages, and add a timing chain oiler.  But I never saw anything about excessive oil pressure.

[alaskanrider [OP]]

It's not a difficult mod to do, and I'm not convinced that any new parts are actually necessary to do it. The simplest would have been to just put it all back together without the no. 2 timing chain, but I spun those balance shaft bearings and plugged the second oiler hole because I'm particular.

Im really wishing they had left the relief accessible from the outside on the 3rz like they did on the earlier 4 bangers. This whole process has been really challenging. I'm used to fords and subarus, which literally take me half as long to do all the same things! Hopefully the end result is worth it.

Ill try to doctor the relief this weekend. Its probably gonna take me all day, because of all the things that have to be removed for access. If it works it'll totally be worth it though.

[alaskanrider [OP]]

3rd edit to this in as many days! I finally feel like I can close this thread.

I believe that the stock toyota oil pressure relief is suited to maintain pressure even without the balance shafts.

My problem turned out to be the plug on the face of the block possibly coupled with a sticky relief valve. Its important that it isn't threaded down too far, otherwise it restricts oil flow, possibly to the main bearings. I still haven't been able to locate an oiling flow diagram. My king bearings survived 350 miles without proper oiling so kudos to them I guess.