low oil pressure after aftermarket install...

[CampbellsChunkySoupra]

we just installed my new megan racing electric oil pressure guage. all was fine and working well. it was at about 20-30 psi[which i dont know if that is normal or not]

anyways, i got on it pretty hard in first and i felt a pretty large jerk [something like that of a intercooler pipe blowing off at high boost] then a large poof of smoke came out the back end. it boosts fine for the most part and sometimes cuts out. now my oil pressure gauge reads 0 psi.

it didnt read 0psi until after this "jerkage" happened.

any help? ive got a good amount of oil in the car so that part is good. what can i check for the pressure?

oil pump/screen?
oil pressure sending unit? [it is brand new]
oil pressure regulator?

thanks!

-Tyler

 

[johnathan1]

Check codes...I wouldn't drive it until you figure out what the problem is...

 

[CampbellsChunkySoupra]

alright. we will be doing that tomorrow. i hope its something silly and easy to fix... god oil pressure is important.

 

[Jaguar_5]

Holy crap that sounds bad man, if the gauge is brand new, and working, you have no major visible oil leak, and you felt something wrong happen with your engine, along with a cloud of smoke, followed by a reading of 0 psi oil pressure? I hope for your Supra's sake that you shut it down immediately!!! Good luck man...

 

[CampbellsChunkySoupra]

yeah, ive driven it as little as i have been able too. its still my daily driver. what could be the problem that went wrong and have it not reading any pressure?

what are normal oil pressure readings in the rpm ranges?

 

[Jaguar_5]

I'm no expert, I'm not sure what could've happened, i would stop daily driving it if you don't want rodknock, though if you really have no oil pressure it could very likely be too late already...

You want about 10 psi for every 1000 rpm for any engine

 

[jetjock]

Makes me wonder about the sender or how it was installed. It'd be the first place I'd look.

 

[mk3ftMFw]

^ i was gonna say the same. Dont drive it until your sure you'll end up in my boat. And my boat is at the bottom of the sea.

 

[Burntz]

I'm no expert, I'm not sure what could've happened, i would stop daily driving it if you don't want rodknock, though if you really have no oil pressure it could very likely be too late already...

You want about 10 psi for every 1000 rpm for any engine

So at 7k rpms id be at 70 psi? Seems a bit much for me haha, As far as I've noticed, I hit 40 ish when I get on it, and it stays thier. Its at like 20-25 at idle, and like 30 and climbing at part throttle

 

[CampbellsChunkySoupra]

ok. so there is more to add to the story...

i got back in the car and started it up after i checked the oil once again and [apart from the normal oil leaks, there was nothing under the car] the oil was at the level it was before. it was all clean too....definatly a good thing, lol..

next the gauge decided to work alittle bit. it was right about 15-20 or so during idle and then it fluctuated based on throttle. this was of course up until i got to cruising speed for the hwy. at 3200 rpms and 55 mph, i was at 5 psi. i doubt that the actual engine oil pressure was 5 psi, it must be the sender. tomorrow we will check for codes as well as re-install the sender unit. gonna try to retorque it down. ill keep u posted. it seems to be running fine for the most part.

this is an improvement for the stock gauge never working since ive owned the car, so at least at some point my new gauge is reading around 20psi. is it possible that the pressure can fluctuate from 20psi to 5 psi at the same engine conditions?

-Tyler

*edit- 500th post!

 

[dbsupra90]

where did you install it?

i had this problem on an aftermarket elec gauge. it was the sending unit causing the problem. what would happen is once the car warmed up from driving the sending unit would get heat soaked and go all to hell. it would read 3psi at idle, then 12. then would read 30psi while crusing then 10psi.

what was recommended to me by the people that made the gauge was to remote mount the sending unit away from the stock location to avoid the heatsoak.

 

[jdub]

You want about 10 psi for every 1000 rpm for any engine

So at 7k rpms id be at 70 psi? Seems a bit much for me haha, As far as I've noticed, I hit 40 ish when I get on it, and it stays thier. Its at like 20-25 at idle, and like 30 and climbing at part throttle

Note Jag said for "any engine"...the 7M-GTE is a bit different in this respect in the way the cooler circuit works. The cooler relief valve functions at ~40 psi to direct oil flow to the cooler, then to the pan. As a result, you will not see much above 40 psi on a turbo motor. As a general rule of thumb Jag is correct...you want to see oil pressure rise ~10 psi per 1000 rpm.


Tyler - I'm with JJ...something is amiss with the sending unit. How was it installed?

 

[CampbellsChunkySoupra]

oil pressure sending unit was just screwed into the block after we went to the local parts store and verified that it was indeed the exact same thread pitch and size.

it screwed in and we got it as tight as we could. however, we did not put the stock "little plastic grey cover thingy" back on the new one. last night i checked the wire that goes to the top of the sending unit and it was still snug. so i dunno.

 

[dbsupra90]

they are not the same size. real close, but not the same.

the sending unit is 1/8 npt (1/8x27) and stock is 1/8 bspt (1/8x28). i suppose its possible the sending unit is 1/8 bspt, but ive never seen one.

i still say heat is part of the problem. they arent designed to be that close to the turbo and manifold heat. stock is.

 

[CampbellsChunkySoupra]

alright. well how can i check to see if the actual unit itself is defunctional?

i was driving the car today and it had 50psi of pressure at 55mph and 2200 rpms. 5 minutes later at the same conditions, it was down to 5 psi. so that at least means that hte pressure sending unit works part of the time. so i think the oil pressure is ok. ive driven it probably 50 miles since the install of the guage [not to mention all of the miles i drove it prior to the install where i had absolutly no knowledge of the oil pressure] and there is no engine problems yet.

-Tyler

 

[ImperfectSupra]

i have the same problem on my 87 turbo. i just did the knock sensor rewire, is there a wire for the oil pressure gauge on my ecu that might have come loose cause my gauge doesnt move at all. where is the sending unit anyways

 

[CampbellsChunkySoupra]

congrats on the search function by the way

oil pressure sending unit is located under the CPS. the easiest way to get at it is by removing your accordian pipe and your upper intercooler piping. u should be able to reach down and feel for it right by the turbo manifold. its there, just feel for it. there might be a rubber grey cap on it.

update* i have kept driving the car and about 80% of the time, i get good oil pressure readings. i think there is a fault in the sending unit.

-Tyler

 

[ImperfectSupra]

sorry, i did do a search and your thread was the first one that came up and u have the same symtoms that i have. i found the sensor and fixed the problem. it was the wire connection. it works fine now. the gauge gives me peace of mind. thank u very much.