Oil Pressure Dropped On Rebuilt Engine

[TT_NS]

I finished rebuilding my engine a lil while ago and i took the engine up to 6k (engine just finished breaking in) and when i slowed down all the sudden the oil pressure droped. I stoped the car and checked for leaks. there were none. I checked the oil and it was perfectly filled. I turned the engine back on and noticed there was no lifters knocking and thought maybe it was just a wire. The Oil light was not on so i though it was ok. (the oil light works. it turn on with the other check lights.) I drove the car very carfully though. at idle the car shows almost no pressure as i take the car up to 3k RPM's the pressure build a little but it only made it half way befour the minimum pressure line on the guage. I checked the connection to the sending unit and it is good. And i took a multimeter and messured 12.6V at the connection. I was thinking that i was just the unit that messures pressure. What do you guys think. (by the way the oil pump is brand new. has about 1000 miles on it with the engine.) For a 91 Eagle Talon TSI

 

[talon1987]

did you install the main bearings correctly ... check for oil clearances ... possibly a bad pickup


-Pat

 

[TT_NS]

did you install the main bearings correctly ... check for oil clearances ... possibly a bad pickup


-Pat

yea i checked all that, the engine was put togeather correctly and runs great. i was thinking it was just that pressure sensore because the other one that connects to the oil light isent turning the oil light on even though the other pressure sending unit shows almost no pressure.

 

[TSIfreek]

I would first get a good oil pressure gauge like auto meters electric gauge. I would not run the engine untill I have a gauge that can tell me the accual pressure.
Im sure if you dont hear any lifter knock you are gettting oil pressure and should be fine, but just be sure with an accurate gauge. You can remove the oil fill cap and see oil coming off the rockers/cams as well.
You can test the stock gauge by grounding out the wire that goes to the sensor on the oil filter housing with the ignition on and it will spike way to the right indicating the gauge itself is ok if it doesnt move the gauge is bad. Also check the wire connection to the sender they are usually very loose and dont make contact with the sensor if taken on and off several times.
I hope I gave you some in site so you can sleep tonight.

 

[TSIfreek]

Also if you find that you still have low oil pressure the oil pump needs to be replaced.
Did you pack the oil pump gears with vasolene and lube as well as lubed the shaft?

 

[Defiant]

Your oil pressure sender's flakey.

 

[TT_NS]

i started the car up this morning and took it for a drive. the oil pressure went to the minimum oil line. but that was only because its cold out side. i did not drive the car long enough for it to warm up. but there was plenty of being thrown around under the valve cover. dose the aftermarker oil pressure guage come with the sensor or dose it connect to the same stock one?

 

[Red 2g GSX]

Get a real aftermarket gauge and put it on there. The stock gauge is worthless IMO get a real gauge and if the pressure is low then you have another problem. (bearing, oil pump, pick up tube, cloged gally. ect.

Vic

 

[TSIfreek]

i started the car up this morning and took it for a drive. the oil pressure went to the minimum oil line. but that was only because its cold out side. i did not drive the car long enough for it to warm up. but there was plenty of being thrown around under the valve cover. dose the aftermarker oil pressure guage come with the sensor or dose it connect to the same stock one?

The aftermarket gauge comes with a new sensor to match the gauge.

 

[StreetSleeper34]

Just a word of warning. After my timing belt snapped and the pistons/valves slapped, I decided to rebuild my engine as well. Went into great detail getting the best parts and trying to improve the performance and the whole 9 yards. Got it together and it ran great. But the oil pressure started to fade over the next couple of days. I ended up going out of town (75 miles) and finally she seized up on me. Ended up being the crank walked on me. There was no indication of wear before hand, and everything was done to spec, but for whatever reason it happened. So something to think about. There was no real symptom of it happening beforehand, except for the low needle on the gauge, but no light. Might want to check to see how much play is in the crank.

 

[ImportModder]

Personally, it sounds like bearings. Pop off a bearing and check. I'd check clearances, if okay, then move to replacing the oil pump. Perhaps it wasn't lubed when installed.

 

[Drifter27_04]

I have the same problem with my oil pressure as well.

My stock dash oil pressure gauge shows a strong reading at all time but as for my AutoMeter its a different story. When I am at idle it drops pressure but as soon I hit the pedal the oil pressure raises insanely and holds until I come to a stop.

I am thinking that it is the AutoMeter itself or could be in the line (dirty and needs to be flushed out).

 

[jasteel13]

i started the car up this morning and took it for a drive. the oil pressure went to the minimum oil line. but that was only because its cold out side. i did not drive the car long enough for it to warm up. but there was plenty of being thrown around under the valve cover. dose the aftermarker oil pressure guage come with the sensor or dose it connect to the same stock one?

just an fyi.. your oil pressure should be higher when the oil is cold... when it heats up it will drop