What causes low oil pressure reading on the gauge? Meaning 25-30 at idle and 30-35 anything over idle...
Engine is an 87 T2 Just rebuilt and has new oil pump and new 100 PSI regulators Front and Rear...

Keith

 

What kind of oil pressure did you see prior to the rebuild? The oil pressure senders can be pretty sketchy. If not the sender, and the pressure really is low, then the front cover o-ring and front e-shaft bolt/pellet come to mind. Did you install an aftermarket pellet or shim the stock thermo pellet?

 

I used a thermo pellet from atkins and I double checked that the o ring and plastice washer was there when I put it together... I even put a little high temp rtv on it when I was putting front cover on to ensure it would stay put.

 

Well I built the engine a month ago and had to tear it apart because it blew to side seals because rotor contacted center iron due to oil starvation. This is why I put the new oil pump in and pressure regulators in. Before it was the same. So I just got it back together today.
Although when I first started it today I was holding it at 2k and the gauge read about 50 psi then when I took it for the first cruise I noticed the low oil pressure again...
What gives??

 

First thing I'd do is confirm that the pressure is actually low by trying a different gauge.

 

I just tried a friends known working sender and same result...Well I think I am going to try an mechanical gauge tomorrow, but what else could it be???

 

Sounds like a classic front cover o-ring failure.

 

Actually that is what I thought when I took it apart after the side seal failure but when I pulled the front cover the o ring and plastic washer was still stuck right where it should be...
I am hoping all it is is the cluster or wiring... Cause I cannot afford to tear this thing apart again....

 

describe your exact setup for the front cover o-ring. On my old 88 front iron I had just the o-ring with no spacer and the front cover was sealed with RTV. There was no room for a white spacer ring. On my current build I switched to S5 irons. Those had a larger o-ring area and I used the white spacer with the o-ring, and an OEM front cover gasket they are selling for the later model 13B.

What year are your irons? They would probably have to be really late model 88's or possibly s5's to need the white spacer ring. If you put the white spacer on there with earlier castings, you could have problems. Most old 87 irons should have just the front cover o-ring with no white spacer, and either RTV or a gasket for earlier castings which I have personally never seen. Have you read this writeup about the front cover? http://www.mazdatrix.com/faq/oring.htm

if your front cover o-ring looks like this:
you fucked up.
If using the white spacer, it should look like this: with a wider area to support the white ring.

 

I am pretty sure the Iron I am using on the front is S5 and that the o ring and washer sat down in there nice.
But if the pressure shows low on a mechanical gauge then that is the first thing I will be checking... Thanks for all the advice.
Keith

 

I've had to deal with both, I personally like the s4 front iron just because no teflon washer.

 

Well tore it apart today and this is what I discovered... I had it in there right with the teflon washer... So what is the Problem now? could the gasket have held it out too much? Allowing oil to leak past?

 

Does anyone think that the gasket could have held the front cover out too much not allowing the o-ring to seal like it should. I started it today and the oil pressure was 50 at 2k and after the engine warmed up it dropped back down to the 30-40 I have been having.

 

Bought my car with a fresh rebuild. The oil pressure was at 0 @ idle and would go to 30-35 @ 3k. Pulled the cover off and the o-ring was pinched because of the gasket being wrong. Anyways, just saying the oil pressure was way lower. I used HondaBond instead of a gasket. Have had no problems since.

I also replaced the check valve right at the pulley (bypass thermal pellet) while I was there. There is another check valve at the oil cooler and also the oil pressure regulator.

 

ok so since this came up wtf is hondabond? i keep hearing about it. needed to reseal my sisters tranny but nobody in town knew what i was talkin about when tryin to find it

 

Simple google search provided this-


*High-temperature silicone liquid gasket. *Unique formula is non-acidic and won't corrode aluminium like other silicone gasket products will. ...
YOU CAN BUY SOME AT THE HONDA DEALERSHIP!

 

Hondabond is gray RTV essentially

I'm not sure what to say, I just put a motor together with your exact front cover setup (gasket, spacer, o-ring) and didn't have any problems. One thing I did though was put a little (don't overdo it) Crisco in the groove to make sure the o-ring and spacer don't shift at all. Also make sure everything is very clean.

Can any other common problem cause low oil pressure?

 

Well I put it all back together and I am 100% sure that o ring is good. No gasket on the cover so it should be smashed down tight. Oil pressure is still around 30 psi...
Now I am down to thinking maybe it is the oil cooler and or lines... since oil flows through there before it gets to the back of the engine to the pressure sender...

Anyone else think this could be correct?

 

You mention NEW parts and a rebuild. Unless you took apart your oilcooler why would it break? It worked before?

EDIT: Reading again I noticed you replaced most checkvalves except the oil cooler. Might as well test it cause something caused your old motor to starve of oil.
Have you tried 20w 50?

 

Weird...Did you forget the gasket on the oil pickup?

Sorry to make you take apart the front cover for no reason.

You could temporarily bypass the oil cooler but the truth is that I doubt that is the issue. The oil cooler has a thermostat that keeps it open when cold so it is essentially bypassed during those times.

 

yeah I would check the oil pickup next

 

Ended up being the lines...
Pegs the gauge at 100psi...
Thanks for the help guys!

 

if it is an s4 motor, you need not to put on that white washer. that is only for the s5 engines. go just use a black o-ring that fits in the indentation of the housing snug. make sure that it does not fall out b/c then you wont have any pressure. i had this same problem before. trust me, you will be reading about 60 psi at idle with that o-ring replaced.

 

oil cooler lines?

 

Oil cooler line off of the front cover was partially collapsed not alowing oil through the cooler very well... therfore low oil pressure...

Hell they are 22 years old with 150k on them...