2G Low oil pressure

[Midnightride]

2G, 95 TSI automatic

Ok so today finally got around to having someone help me tune the car. Driving and tuning is not the safest and buddy of mine has more tuning knowledge experience than me. Either way we start the car up, idles fine runs fine. We notice the oil guage is reading low. We cruise around the apartment complex and notice it goes up but not much. we put the car in neutral and raise the rpms to 5k the pressure rises to the first line but never crosses it. Then we I start ot let off the low oil light flickers on and off but then stops. Never came back on.

Oil is full and clear. I used the synthetic blend 10w30.

The motor was just put back in. It has the balance shaft removed so the oil pressure should be higher than normal right. The front care was also replaced by previous owner of the block.

As for timing, since the balance shafts were removed the oil pump sprocket didnt need to be ligned up ( I ligned it up anyways).

What do I need to be looking at? To me it sounds like a short or wire not contacting completely. I dont wanna go on the street and take a chance of blowing or locking anything up. Need to the oil pressure guage back to working order.

Before the motor change the guage always read fine.

 

[winterftbl]

Is there a cut in the line? Other than that I guess its time for a new oil pressure gauge.

 

[Midnightride]

there is no oil leaking so no cut in the line. Perhaps the sensor unit wire is crimbed or needs attention. I'll be checking that today or tomorrow.

I can see the reading being off, but why would the oil light flicker? Are they both on the same sensor? Or does the oil light come on at a certain point?

 

[winterftbl]

The reason why i said it might be cut is because I was in the same boat. My oil pressure was low and my line looked like it was cut in a few places, I taped it up and the reading went back to normal. Well yoour oil light should only come on when you have low oil, so I really dont know, it might be your sensor. Best thing to do is check it just to make sure.

 

[absolute_DSM]

Was the engine rebuilt or just taken out and put back in?

If it was rebuilt, you should have primed the oil pump before you started it, or packed the oil pump with grease so it wouldnt be trying to suck air into your oil passages.

 

[fourreGsixty3]

Our coolant, and oil pressure guages aren't the most accurate. Some constantly read on the low side, when aftermarket oil press. guages read oil press. is good for RPM range.

Here are some threads that you cou;d have read...and probably figured out your problem:
http://www.dsmtuners.com/forums/newbie-forum/255293-oil-pressure-gauge-what-normal.html

http://www.dsmtuners.com/forums/cylinder-head-short-block/274786-oil-pressure.html

Or...you could scroll through ALL 20 pages of related threads... http://www.dsmtuners.com/forums/search.php?searchid=3835287

Someone is bound to have a similar situation that was fixed...

 

[Midnightride]

I got a bottom half and top half and put them together. When it was all done I put the motor in. I pulled the main fuse and cranked it over to prime everthing with oil

 

[Maglin]

Did you turn the 2 balance shaft bearings on the front of the motor? That would be the right side if you are looking at it from the back (flywheel) of the motor. If you put the new ones in and lined the oiling holes up that would be your problem. The last motor I did a BS removal on I also used a FFWD forward facing oil filter housing which they pre drill and oil press was perfect. I only ever see very high oil press with that housing when it's above 8K RPMS.

 

[Midnightride]

2G with the balance shafts removed. Just put the engine and tranny back in. Started up fine etc...

after a few days or so I notice that the oil pressure is low after complete warm up. I installed a mechanical oil pressure guage since. The previous owner of the block I'm using said the oil pump worked fine for him.

Here is what I'm seeing.

After the car gets warm at 3500 rpms it is at 80psi oil pressure.

900 rpms= 20 psi

after letting it sit for a bit or driving it around the complex, and it starts to read low on the stock guage, its will say 900 rpms= 5-7psi.


When it gets to that point and i put it in drive it will say 0-5psi.

when taking the rpms to 2300=42psi
3500rpms=68psi and egt is 1200

Then right before I turned it off it went to about 1-2psi and the oil light started to flicker.



If the oil pump was bad why at start up would it read right or higher and after about 30 minutes or so start to drop? (cause the oil got thinner after warm up?)

Some of you have said a oil pressure valve being stuck open? Does the oil pump have to be removed for that? Thoughts suggestion?

Car has 4.5 quarts of new oil. 2 quarts 2.5 quarts of 10w30 and the other 2 are 10w40.

As for the balance shaft install here is what the previous owner said:

"
I did do the balance shafts right as i sent you in a pm, rotated to block the holes that where there...
The block offs were installed properly, its runs 1/2 to 3/4 on the gauge, i ran this block for a good while with no problems..
Did the block off and did the rod bearings both, its done right..
"

Thoughts/suggestions?

When the pressure starts to drop, the rpms stay the same.

 

[DSMULATOR]

The oil pressure relief valve is part of the oil filter housing. Usually you have to take the timing cover off to do it tho. Where are you tapped into to get the pressure readings? If its in the head, try tapping into filter housing, as close to the pump as you can get to make sure your not loosing pressure in the block or head.

 

[Midnightride]

I took the front allen bolt out of the oil filter housing(the one facing the front of the car).

The oil pressure relieve valve, is that where the big bolt is on the back of the oil pump? Right by the stock oil pressure sending uint?

 

[Big Woo]

Well there are several possibilites:
Many oil pumps may look good or ok, but if one was to measure one, it will most likely tell a differnt story.

According to Mr. Haynes the 2.0L oil pump tollerances are as follows.
Tip clearance
Drive gear 0.0063 to 0.0083 limit 0.0098
riven gear 0.0051 to 0.0071 limit 0.0098
Side clearance
Drive gear 0.0031 to 0.0055 limit 0.0098
Driven gear 0.0024 to 0.0047 limit 0.0098

Oil pressure relief spring length free 1.835
load 13.4 @ 1.579 inches.

When these clearances get out of specification the oil pump has difficuly maintaining pressure because, effectivly there is to big of a leak in the system.

Other potential problems would include:
1: oil pressure relief valve problem
2: overheating problem with the engine or oil system
3: out of specification oil clearances for the main/rod/cam bearings
4: loose, damaged or leaking oil squirter
5: bad front cover/oil pump gasket or use of silicone as a replacement for the front cover/oil pump gasket.
6: Poor oil return to pan.
7: internal oil leak from various sources, I.E. balance shaft bearings, balance shaft stub shaft etc.

 

[Midnightride]

anyone know how to check to see if the oil pressure relieve valve is stuck open? I tried searching on here and didn't come up with anything.

Some directions and pictures of where it is located would be greatly appreciated.

 

[BUCK]

The OPRV is on the rear of the OFH - The big Brass ACORN NUT looking thing is the Oil Temp Valve - I personally purely HATE Mechanical Oil Pressure Gauges so for purely personal reasons I hope your "gauge" is crap & your indications are bogus - That said the OPRV is where I'd start - Below is my favorite OFH Thread...

http://www.dsmtuners.com/forums/new...pressure-gauge-installation-merged-1-8-a.html

 

[Midnightride]

well I installed the mechanical guage only cause the stock guage read low. I took my old pressure sending unit of my old block and put in the newer block. The guage still showed low pressure. So then I bought a mechanical gauge and the guage shows the same as the factory gauge. Low oil pressure after a while.

The thread you posted, I have read that before. You actually merged my first question about installing the gauge a week ago or so.

Now I just want to make sure my pressure issue is resolved. I looked through that thread again, but I didnt see anyone mention the pressure relieve valve. I just want to make sure I go to look at the right thing. Also what to do to get it unstuck or test it.

thanks!

 

[Midnightride]

Is the part circled the oil pressure relieve valve? I read somewhere it was a large bolt that is hard to get loose. If so, one's I loosen it, whats the next step?

 

[tqmx1]

It is one of those that it looks easy to get to but there is no easy way to get a wrench on it . I just took off enough bolts off the timing cover and pried it back to get the last bolt for the OFH and took it off to work with it on the bench.

 

[Midnightride]

I noticed you said you took the hole oil pump off, did you do this without removing the timing belt and such?

I might just remove the oil pump and put my old one of my block on. I didn't have any issues with it.

Someone mentioned you can't take the oil pump off without taking the timing belt off etc.

*** I take it by you answering to this topic that you had the same issues or the part that was circled is the OPRV?

 

[tqmx1]

No I just ment remove the oil filter housing. The oil pump stays in place.

 

[Midnightride]

gotcha

 

[BUCK]

Is the part circled the oil pressure relieve valve? I read somewhere it was a large bolt that is hard to get loose. If so, one's I loosen it, whats the next step?

YUP that's it - the other more forward ACORN NUT looking one is the Oil Temperature Valve for you Oil Cooler.

& I'm actually kinda liking the setups where guys are putting a Mechanical Oil Pressure Gauge in the Engine Bay off the Head or whatever...

 

[DSMULATOR]

Hey, if your taking the oil filter housing off, now's the time to port the relief valve to relieve some of the oil pressure created by the b-shaft block off bearing...just a thought.

 

[Midnightride]

If I dont have to take it off I wont. but if that is the only way to remove the bolt then yes, I might do that.

I sure hope that is what is causing the low oil pressure. The valve being stuck.

 

[pickens]

Its weird that it makes good pressure when cold. What weight oil are using? You may just want to up it to 50w if the engine was built w/ loose tolerances.

My engine does this to some degree, when cold the pressure is pretty high at around 1500 RPM, then as I drive it, the pressure will settle back to normal (the normal line on the stock gauge). When cruising (3k RPM) warm, the pressure slowly rises back to just below the first high mark. If I start the car when its hot, the pressure is below the normal line at idle. If I blip the throttle it goes to normal again.

 

[Midnightride]

Car has 4.5 quarts of new oil. 2.5 quarts of 10w30 and the other 2 are 10w40.

Using the thicker oil didn't help much.

having the good oil pressure is good at every start up and last for a while till after the car has been driven around and put back in park. As described above.

If the oil pump was bad, wouldn't you notice it at start up as well?

I'm certainly going to look at the OPRV and hopefully that was the issue.