OIl cooler on, oil pressure low

Sheck · Postby **Sheck** » Tue Nov 07, 2006 7:33 pm

The knocking sound has completely dissappered so it may of been something else.

I'll prolly go to a thinner oil very soon that should hopefully get the pressure up a little.

As for the thermostat its not nessesary as the oil heats up pretty quick already (time it take for the cold start high oil pressure to stop is only a few hundred meters more than previous). The RX7 cooler looks a similar inlet/outlet size to mine but is much longer and about 3/4 - 1/2 the height of mine (but i'll pop down to my rotary mechanic to see if he has any laying around to compare it too).
I'm thinking i should try and get some fatter lines and fittings. I'm thinking something like 18-20mm internal dia - or maybe an oil cooler with bigger inlet/outlets.

Sigh what a muck around! heheh

Just thinking, i remember seeing a hex screw (for the relif valve i belive) on the outside of the oil pump - does turning this do anything? Perhaps i could boost up the pressure a little using this?

Cheers for your help guys!!!
Dave

Sheck · Postby **Sheck** » Wed Nov 08, 2006 6:42 pm

Bigger lines/fittings will work cause any restriction before the pressure sensor will register as a pressure loss. (the filter is before the sensor)

Yea i'm curious as to whether any one else has had this problem..

Dave

sabretooth · Postby **sabretooth** » Thu Nov 09, 2006 12:06 am

Instead of changing the oil grade, have you also tried just some fresh oil?

Sheck · Postby **Sheck** » Thu Nov 09, 2006 8:15 am

It was fresh oil, the stuff in the engine had probably 100km on it and the other liter i put in was fresh.

CT · Postby CT » Thu Nov 09, 2006 10:19 am

Sheck wrote:Bigger lines/fittings will work cause any restriction before the pressure sensor will register as a pressure loss. (the filter is before the sensor)

Yea i'm curious as to whether any one else has had this problem..

Dave

I use -8 lines for mine and it hasn't even been a big problem. Lines are a little over 1 meter each. What size are yours currently?

Sheck · Postby **Sheck** » Thu Nov 09, 2006 6:55 pm

12mm internal diameter not sure what that means in AN size. I've got 2 90deg bends, so that and/or the oil cooler itsself may be the problem.

Dave

CT · Postby CT » Fri Nov 10, 2006 9:36 am

-8 (8/16ths) is half inch or around 12mm OD. I also ran 90s at each end. I always found my pressure around 5psi lower with mobil 1 compared to castrol too FWIW.

Inf3ct0R · Postby **Inf3ct0R** » Wed Nov 15, 2006 11:00 pm

I am about to install my oil cooler this weekend.

mocal sandwich plate and thermostat, 13 row english made cooler with -8 fittings, el-cheapo aeroquip lines and bling bling speedflow fittings

Will update with results ;)

Sheck · Postby **Sheck** » Thu Nov 16, 2006 3:18 pm

I got the car goin again finnaly and with the new 5-40 oil it runs at a higher pressure when cold (hurraah!!) but when warm i can see it build up nicely as i take off from the lights or something then the relive vale must open cause the gauge flicks back down to around 2bar (from the spike of between 2.5-3bar).

I'll prolly be picking up an RX7 ser4 oil cooler on monday (100 bux woot) but then the only problem i'll have is where to fit such a monsterous oil cooler!! they are soo long!!!! I'm thinking behind the radiator, as thats about the only spot it'll go and thats where they are on an RX7 anyways.
(i'll be extra cut if it doesnt fix things!!!)

Dave

Inf3ct0R · Postby **Inf3ct0R** » Thu Nov 16, 2006 5:45 pm

Sheck wrote:I got the car goin again finnaly and with the new 5-40 oil it runs at a higher pressure when cold (hurraah!!) but when warm i can see it build up nicely as i take off from the lights or something then the relive vale must open cause the gauge flicks back down to around 2bar (from the spike of between 2.5-3bar).

I'll prolly be picking up an RX7 ser4 oil cooler on monday (100 bux woot) but then the only problem i'll have is where to fit such a monsterous oil cooler!! they are soo long!!!! I'm thinking behind the radiator, as thats about the only spot it'll go and thats where they are on an RX7 anyways.
(i'll be extra cut if it doesnt fix things!!!)

Dave

really, is that where they are mounted on the rx7's...

I was thinking of mounting it there away from the stones. the heat from the radiator will still be cooler than the oil anyway. but now I have decided to make a shroud for it behind the radiator

Postby **orx626** » Thu Nov 16, 2006 5:52 pm

Sheck wrote:I'm thinking behind the radiator, as thats about the only spot it'll go and thats where they are on an RX7 anyways.

FYI...on first (excluding 3rd series as it has an oil to water cooler) and second generation RX-7's they are actually mounted below the radiator and therefore receive ambient air, not second-hand warmer air that has gone through the radiator. The standard aussie third gen RX-7 has one mounted off to the left hand side behind the front bar like an RX-8.

Cheers,
Danny

Sheck · Postby **Sheck** » Thu Nov 16, 2006 6:06 pm

Oh really? i never looked at my bro's old rx7 when it was jacked up so it looked like it sat behind the rad, very low but still looked like it was there.

Well i done some more thinking and looking and it may be able to fit behind the bumper just on top of the bumper support (plastic thingy), then i'll cut a hole in the front bar to let air through - this will then got throught the top of the radiator.

I wont figure it out till i get it and see if it physically fits in there. Their the only places i can think of it going as they're so big.
Perhaps if i put it behind the rad then i will make up some custom shrouding and undertray to let fresh air pass over it...

Cheers for that danny!
Dave

Boags · Postby **Boags** » Thu Nov 16, 2006 6:22 pm

Sheck wrote:Well i done some more thinking and looking and it may be able to fit behind the bumper just on top of the bumper support (plastic thingy), then i'll cut a hole in the front bar to let air through - this will then got throught the top of the radiator.

Don't you have an intercooler there?

Sheck · Postby **Sheck** » Thu Nov 16, 2006 8:28 pm

nah this will be on top of the bumper support, the IC sits under and behind it. Its kinda hard to explain but basically right behind the material of the front bar inbetween the front two parkers. Will have to cut a hole there.

Might take a photo of it if it fits. (monday)

Dave

Sean · Postby **Sean** » Sat Nov 18, 2006 9:50 pm

I've considered routing the return line from the turbo through an oil cooler before returning the freshly cooled oil to the sump.

I've been too concerned about teh oil draining down easily back to the sump to actually go ahead with teh plan, but have a similar idea in mind...

When the car comes back from the panel shop and goes in to get some more engine development we're going to try my new idea... If it shows promise I'll let you all know

. Tad expensive, but should work nicely.