Oil light turns on at idle

[mwinkle353]

I installed one of their headgasket kits on one of my "other" 3.0L engines. I will say this, if anything about them. They're just as good as, if not better than Fel-Pro gaskets. I haven't used any of their bearings yet. But if I ever need something for any of my metric motors, you'll be sure I'll be calling them for it.

I'm very happy with what I've used from them. And that's all I'll say for now.

[RoadWarrior222]

I "bandaided" mine for now with that "high mileage" type oil, 10W30. Sealed her up, she smokes less, oil pressure up, runs great, better mileage too I think (over normal 10W30 + gloop, or 20W50) plus they stick all that stuff in that the EPA doesn't let them put in the normal grades, zinc, moly all that anti-wear sorta stuff.

[c2xejk]

As options are considered, maybe the next step is to plasti-guage the bearings... That should show if they are worn and if so, how bad...

[87turbodance]

Quote:

Originally Posted by c2xejk As options are considered, maybe the next step is to plasti-guage the bearings... That should show if they are worn and if so, how bad...

Very true. I don't know if it is the bearings or the oil pump. I will certainly plasti-guage a couple of the mains before I seal the motor up. Oil pressure is roughly 5psi at a hot idle but come up instantly with RPM. I'm going to dump some thicker oil in her for the next couple weeks while I wait for my parts to arrive

[lookin]

Since your oil pressure comes right up with RPM, doesn't that mean it is more likely your pump, rather than excessive main and plane bearing clearances?

Also, if anyone could tell me how fast oil pressure should rise with RPM, I would be grateful.

Hope it is just your pump.

[87turbodance]

Quote:

Originally Posted by lookin Since your oil pressure comes right up with RPM, doesn't that mean it is more likely your pump, rather than excessive main and plane bearing clearances? Also, if anyone could tell me how fast oil pressure should rise with RPM, I would be grateful. Hope it is just your pump.

It comes up but it still less than 10psi per 1000 RPM. At 2000 RPM I have like 15psi of oil pressure when hot. 3000RPM only has like 25psi. I'll be buying some thicker oil today for sure to hold me over for the next couple weeks because I have to drive the car everyday

[lookin]

Quote:

Originally Posted by 87turbodance It comes up but it still less than 10psi per 1000 RPM. At 2000 RPM I have like 15psi of oil pressure when hot. 3000RPM only has like 25psi. I'll be buying some thicker oil today for sure to hold me over for the next couple weeks because I have to drive the car everyday

Yep that is too low alright. The nice thing about the Toga is that it raises flow rate more aggressively with increasing RPM, and the low rpm pressure is also great.

One thing you mentioned earlier got me wondering. You say your oil pressure jumps up "instantly", and I wonder if that indicates that your oil passages are constricted with buildup.

I mean doesn't the pressure sensor measure resistance to oil flow?

Think about it. Your pump is probably weak, and yet your oil pressure jumps up instantly. Could that mean it may be time for Auto Rx, or something?

Just wondering.

[Ondonti]

My duster has about 20-25psi oil pressure @ idle with a shim'd toga pump.
It has been said on the 3/S boards that the stock pumps sometimes leak at the relief valve so a washer or two under the spring helps prevent that and increases idle oil pressure even though the relief valve is only meant to prevent "too much" pressure at high rpms. I only used 1/16" shim but Ive heard of someone doing 1/8"
I think 12psi is the bare minimum you should have at idle.

[87turbodance]

Quote:

Originally Posted by lookin Yep that is too low alright. The nice thing about the Toga is that it raises flow rate more aggressively with increasing RPM, and the low rpm pressure is also great. One thing you mentioned earlier got me wondering. You say your oil pressure jumps up "instantly", and I wonder if that indicates that your oil passages are constricted with buildup. I mean doesn't the pressure sensor measure resistance to oil flow? Think about it. Your pump is probably weak, and yet your oil pressure jumps up instantly. Could that mean it may be time for Auto Rx, or something? Just wondering.

I may have worded that bad. Pressure will rise smoothly with rpm. There is definitely a linear relationship. At a cold idle I have 80psi but that drops to 5 or less at a hot idle (800- 850 rpm on the factory guage)

[lookin]

Quote:

Originally Posted by 87turbodance I may have worded that bad. Pressure will rise smoothly with rpm. There is definatly a linear relationship. At a cold idle I have 80psi but that drops to 5 or less at a hot idle (800- 850 rpm on the factory guage)

Oh OK. Sounds like maybe a new pump may fix your op problem then. Hope it does.

Please tell us how things turn out.

[lookin]

Quote:

Originally Posted by Ondonti My duster has about 20-25psi oil pressure @ idle with a shim'd toga pump. It has been said on the 3/S boards that the stock pumps sometimes leak at the relief valve so a washer or two under the spring helps prevent that and increases idle oil pressure even though the relief valve is only meant to prevent "too much" pressure at high rpms. I only used 1/16" shim but Ive heard of someone doing 1/8" I think 12psi is the bare minimum you should have at idle.

Do you have a link to their posts about that? I never shimmed mine. This is the first I have heard about this.

[Ntrain2k]

Quote:

Originally Posted by 87turbodance I may have worded that bad. Pressure will rise smoothly with rpm. There is definitely a linear relationship. At a cold idle I have 80psi but that drops to 5 or less at a hot idle (800- 850 rpm on the factory guage)

I'm surprised it's not making noise. That's an indicator of excessive clearances in the bearings...

[87turbodance]

Quote:

Originally Posted by Ntrain2k I'm surprised it's not making noise. That's an indicator of excessive clearances in the bearings...

I know what you're saying. But, the motor is a quite as any 3.0 I've ever heard. It doesn't even make a tick. With the hook up the injectors are the loudest thing you hear. I wont know what's going on until I open it up, though. I'll have STD bearings and a new oil pump on hand hoping they will solve the problem. I'm definitely going to plasti-guage the crank and check for scratches. If anything looks wrong I'll have to bite the bullet and pull the crank and get it reground undersized.

[Tim_K]

You can't just "pull the crank" because of the oil pump and rear main seal and flexplate / torque converter, etc.

If the crank needs to come out, you'll have to pull the engine out to get at it.

[87turbodance]

Quote:

Originally Posted by Tim_K You can't just "pull the crank" because of the oil pump and rear main seal and flexplate / torque converter, etc. If the crank needs to come out, you'll have to pull the engine out to get at it.

When I said pull the crank I meant pull the motor and take the bottom end apart. I wish it was as easy as just "pulling the crank"