oil pressure questions

[Pennywise]

I have searched but I got alot of different info on this. I just rebuilt my 91gst. it idles with the oil pressure at the L, once I give it gas it will shoot up to the first notch and will stay there until I let off the gas. NOW, I know stock gauges are not accurate most of the time. I also know that this is a typical problem in dsms with the oil pressure doing this. there was no shavings in the oil pan, I was suspecting a bearing. but is this about the norm for these cars? my car never goes above the first notch. car runs and boosted fine.

 

[project_tsi]

Your symptoms sound normal to me. Common with DSM's. I'd run an aftermarket mechanical guage to rid you of worries.

 

[nightspeed87]

my n/t 4g63 motor did exactly what you were saying. Did you replace the oil pump or the bearings when you rebuilt the motor, did you clean the oil pick up tubes and oil screens that may have accumilated gunk?? If not then those are all possibilities, but not to be pestimistic but Im sure its one of your bearings worn. Thats what it was on mines, oil pumps normally dont go out on cars unless they have crazy milage. Does your car run fast, and strong? I went almost a whole yr driving on my n/t with the low oil pressure at idle, when i idled too long the valves would tap. What I did is i just used 20w 50 oil and yea i know its kind of thick but it worked for me and its not a bad idea for older engines, also my valves stopped tapping since i put that oil and when it gets really hot its going to break down and loose viscosity anyways so it wont be as thick as 20 anymore once the heat gets to it, i keep that in mind, Just rev it here and there when you idle and make sure you keep the oil at the top line of the dipstick, with low pressure you have no room to run low on oil. * (Now when i wasgoing thru this it was n/t, but i imagen the oil system in the turbo would suffer more from low pressure )

 

[90gsxmesaaz]

You can also check the wiring to the oil pressure sender. I know on mine the wiring was so bad that it keep falling off. Just another idea.

 

[nightspeed87]

yea and hope its what he said because that should be the easiest to fix. I was also going to ask does your oil light come on? because that will tell you something right there if you have a real problem or not.

 

[Pennywise]

shop tried 3 oil sending units and it all read the same. no lights come on.

 

[Pennywise]

anyone else?

 

[nightspeed87]

hook up a mechanical gauge just to check what it is, but i still think its what i said, either one or more of the bearings are worn ( most likely ) or the oil system somehow has accumilated too much dirt and gulk and is detrimenting the flow, because at idle there are no rpms to work the pump and the gulk could be thick enough to knock off pressure at idle. As long as you dont here your lifters tapping to much then i wouldnt worry about it, because like i said ive driven on mines with the exact oil sympthoms as yours and no problems. I just kept 20w 50 in there and kept my oil constantly at the line on the dipstick and never let it go even a little low since I had bad pressure, and I would just rev it a few times at a light to keep pressure going but you dont have to do it excessively. I mean as long as after youve driven your car and if you unscrew the oil cap and look into the valve cover and see oil lubricating in there then your ok because most old cars have bad pressure and the point of oil is to lubricate so even though pressures low at idle the fact that when your driving it goes up will insure you that you wont have engine damage. Say you never got pressure even when driving then id say its a bad oil pump and your engines about to go, but dont worry youll be ok, jus listen for lifters tapping and keep the oil line correct and youll be straight.

 

[andymoraitis]

Frank,

You can run a mechanical gauge as Dan mentioned or pick up an electric which will indlude a new sender that wil mount in the front of the filter housing. I really wouldn't panic when using the stock gauge. Just for reference, the mechanical will run hot oil inside the car. Dan has his set up with copper tubing and it works great, but the electrical is a no muss no fuss type of deal. The fact that there are no shavings in the pan means the bearings are fine contrary to what you're being told in a few of these posts. You may want to clean the oil squirters or block them entirely and that will also increase oil pressure.

Andy

 

[nightspeed87]

For extra insurance you could take off the oil return line on the turbo and make sure oils flowing through there correctly and make sure no chaulking has started were burnt oil hardens in the tube, and if there is so get something straight and long and pointy and scrape it out . I even use to keep the oil slightly above the top oil line on the dipstick since i had low oil pressure i figured it wouldnt hurt to slightly over fill it. ( But very slightly not a lot over the intended line ) since dsms are somewhat starved of oil in the first place.
Just dont over fill it too much if you decied to try that because if you do and you like to rev high you will be burning up your rings and then youll be smoking as the oil passes in the combustion chamber. But like i said youll be ok good luck.

 

[Pennywise]

I hear no noises. I checked my head and there was oil. After I run this tank of gas i'm going to compression test it and then get a oil pressure gauge. so at idle i'm expecting about, 10-15 and driving about 50ish? thats what I have seen in most posts.

 

[andymoraitis]

Idle is good at anywhere between 15-25 and cruise RPM in 5th gear should be around 10 psi for every 10 mph. So at 50 mph you should see close to 50psi, etc. My readings are higher and yours may be a bit lower depending on how tired the internal parts are.

 

[Pennywise]

115k on the motor, NO BSEK. all stock.

 

[andymoraitis]

The ranges I gave you should work fine although BSE and blocked squirters will increase oil pressure. My stock 2.0 had 15 psi at idle and about 60 psi at 70-75 mph.

 

[Marc91GSX]

The ranges I gave you should work fine although BSE and blocked squirters will increase oil pressure. My stock 2.0 had 15 psi at idle and about 60 psi at 70-75 mph.

Andy,

What should a fresh engine read in your experiences? My engine's pressure is around 100 on start up, and at operating temp idle it is around 45.

 

[andymoraitis]

Marc,

I'm on a fresh rebuild and I run 85 cold at idle, eventually dropping to 25 when hot which is pretty normal. It doesn't vary much with different oil grades either. I can peg it to 100 by going WOT though. Your pressure sounds fine. Keep in mind that mechanical and electric gauges will read differently. If you've pulled the balance shafts and the squirters, that'll increase oil pressure significantly. I have no shafts, but I did keep the squirters. If you have an electric gauge, make sure it's at zero with the ignition on. I had some wiring issues with mine where it was showing 15psi with the key on and motor off and therefore skewing my readings. Re-wiring everything fixed that issue.

Let me know if that makes sense,

Andy

 

[Marc91GSX]

Marc,

I'm on a fresh rebuild and I run 85 cold at idle, eventually dropping to 25 when hot which is pretty normal. It doesn't vary much with different oil grades either. I can peg it to 100 by going WOT though. Your pressure sounds fine. Keep in mind that mechanical and electric gauges will read differently. If you've pulled the balance shafts and the squirters, that'll increase oil pressure significantly. I have no shafts, but I did keep the squirters. If you have an electric gauge, make sure it's at zero with the ignition on. I had some wiring issues with mine where it was showing 15psi with the key on and motor off and therefore skewing my readings. Re-wiring everything fixed that issue.

Let me know if that makes sense,

Andy

It makes perfect sense, I am running a N/T block with BSE and I am using a mechanical gauge. SO I think mine pressure is ok. THanks ANDY.

 

[nightspeed87]

in my n/t my pressure was really bad it was only at 10 psi at idle but leaped all the way up to like 75 under wot. Kind of weird. So removing the balance shafts actually increase oil pressure, I will have to reference that.

 

[nightspeed87]

And when you say blocking off the oil squirters you mention it as if there not really needed. Do you recommend not having them over having them or something?
( I have heard different opinions on this before. )
I have heard that the oil directed from the squirters could have better use flowing through the system else where?

 

[DSM8urVTEC]

Hey penny...you need to delete some of your messages in your inbox. I tried PM ing you and it won't let me b/c you're full. PM me if you see this.