oil gage

[akc]

OK i just replaced my heads on my subie the before I replaced them the car overheated and the oil gage was pegged out. now no water leak no oil leak but the oil pressure gage is under 0 like it is not working or something is not working. the car sounds great. is running good but I am a little worried about the gage at 0. any ideas??????????? I replaced the oil pump before it overheated. the oil is swishing around and seems to be flowing. What would you do???

[Uncle Ed]

What I did was to put a manual gage on my 86'. You take the sending unit off, cut the threaded end off close to the can. Then drill and tap the cut end for 1/8" NPT. You'll then be able to have a good idea of what you oil pressure really is.

Regards

Ed

[Niku-Sama]

just try a few pressure sending units from the junk yard.

 

if you got a replacment pump i am guessing you got a replacment sending unit, i bet its one thats about 3 times bigger than OEM, they fail real easy.

alsmot as if they get accustomed to a certian pressure and/or flow and when you do something or fix something to get better flow/pressure it cant handle it and dies

[akc]

Yes I bought a not OEM part so that is probably the problem. Maybe??? it did not like it when the engine overheated?

Edited October 25, 2009 by akc

[clunkerbob]

Apparently from reading all the complaints on the forum , the gauge readings are a big problem . the oil and temp gauges are dead in mine too . They go up just a tad after running awhile .... but barely over zero .

 

I test grounded the wires to the senders and the gauges pegged , so looks like the transmitters on both are shot . The Sube factory units arent really cheap , but seem to be the only ones that hold up , so in the long run be cheaper than buying aftermarkets .

 

I like the idea of a mechancal oil pressure guage . Somebody had put an underdash one in my Brat but never hooked it up . I'm going to get some 1/8 " plastic tubing and finish the job they started .

 

Overheating the engine wouldnt effect the oil pressure unless you totally fryed it ... and it would be knocking . But like the other guy said ... it might have cooked the guts inside the oil transmitter .

 

( mine has one of those big clunky things on the oil pump housing too ) aftermarket stuff ... now dead

 

Bob

[akc]

I meant overheating the engine must have fried the sending unit not the engine. (although it did fry the gaskets for the head). It seemed to work till the car was turned off (after it overheated) and then It stayed on pegged out until we drained the oil and now it will not move (oil gage) even up to 0.

[akc]

Changed the sending unit still cannot get it to work. I was sure the oil pump was good..... The engine sounds good. Still tagged under 0 all the time.

[Redcap]

Have you tried using a mechanical oil pressure gauge to verify you actually have oil pressure or not?

[akc]

Finally got a oil gage (mechanical one) and tested the oil pressure from the pump. It reads I think 60 at start up. My car has always had higher oil pressure at start up and then after it warms up it goes down to about 30-40. I did not have time to run it a long time last night so I do not know if it went down as it warmed up. I think I will just put a mechanical gage under the dash unless anyone has any clue how to fix the gage on my dash as it seems like it is the issue here (I replaced the spending unit. ) That is one area I have not dinkered with cars. Usually though it has been the speedometer or fuel gage on our Chevy or Dodge cars. I feel weriod driving a car with no oil and another with no temp gage. (my car the temp works my sons is the one without the temp gage. ) Of course the temp gage did not help when he blew the gaskets. (radiator drained too fast.).

 

Now the compresser for my AC went out. will this ever end. I think I will just disconnect that. It squeels pretty good now. Also my volt meter is down to about 10 sometimes 8. I cannot remember where it used to run but I know it was higher before. The pullys and belts seem to be lined up where they go and the car sounds like it is timed right. sometimes I feel like putting this car out of its misery but then i could have messed up somewhere putting them back on. it looks right and sounds right.

[GeneralDisorder]

I understand your frustration, but one thing you have to take note of - the engine still runs despite the problems with the gauges, and the accesories. One thing that Subaru's are known for - despite multiple failures of accesory systems they still seem to get down the road one way or another. Mechanically they are very sound.

 

Understand that the wiring is 20+ years old at this point and the effects of time and corrosion are just something that has to be dealt with. On a lot of the older Subarus the wireing wasn't very well protected against corrosion around the connectors. You may have a bad connection somewhere.

 

If you ground the wire from the sending unit to the block, the gauge should read max pressure. That's a good way to check the gauge. If you get no reading then you probably have a wireing problem. The gauges themselves aren't very accurate but they rarely actually fail. It's very easy to get to the back of the cluster once you pull the surround off. You might try running a new wire from the sending unit to the cluster.

 

Mechanical gauges are ok as well - although I don't like the cheap plastic tubing they use. I prefer to put in a 90* elbow to the pump, run a stainless braided pressure line to the firewall, and mount a new sending unit (or 1/8" copper tubing if you are doing mech.) for like an Autometer gauge, etc. I have an Autometer three-gauge panel on my lifted wagon that has volts, temp, and oil pressure. The sending units are less expensive than the stock one's and the whole setup was like $65 plus maybe $40 for the 36" braided SS line. Works like a champ.

 

I have also done the $10 Walmart oil pressure gauges but you have to buy a longer peice of tubing for them. My local VW aftermarket house carries VDO gauges and they had a tubing kit that was better quality and plenty long enough for a Subaru (designed for an air-cooled VW with the rear engine). Total cost on that install was maybe $40. I cut the threaded end off the stock sending unit, tapped it for 1/8" NPT and installed a 90* elbow and then the tubing fitting. I would only do that on a road-going car though as the tubing is fragile and it would easily get ripped off by brush off-road.

 

GD

[akc]

I think you are right the wire off the oil pump is yellow and has some discoloration I believe from heat as it lays across the engine in 2 spots I would not be suprised if it got fried somewhere and no longer has a good conection. Would that explain why the gage pegged out after it blew the head gaskets (I do not think it had high oil pressure) and then when he took everything apart it went down to 0)Or maybe it came undone somewhere along the way.

 

you are right it is amazing that the engine still runs despite what it has been through in the past year. A summer of overheating (leaking hose and a bad radiator plus the weber conversion plate leaking under it) the oil pump going and me driving it about 60 miles without oil pressure, my son driving it with out water for at least 5 miles. It is a miracle it still works. despite what we put it through. I think I have all the water lines replaced now though. Your right I should not complain that the AC toasted. I can just get by without it besides one does not really need it in washington and next summer will be cooler compared to me driving this summer with the HEAT on. while we tried to find all the leaks. The one under the weber really had me stumped.

 

Thanks for putting me back on track and the good advice you obviously Love subarus. I will try grounding the wire and see what I can find and go from there. a new wire would beat wiring and installing a new gage. I do like the little beast. I guess i am a still a little upset that at my son for blowing the head gaskets. It is not the subarus fault she was trying to tell us she had a water leak we just could not find it.