General Miata Chat A place to talk about anything Miata

No oil pressure.

Thread Tools
 
Search this Thread
 
Old 04-20-2009, 10:32 AM
  #1  
Junior Member
Thread Starter
 
Sleeper_MX5's Avatar
 
Join Date: Jan 2008
Posts: 269
Total Cats: 0
Default No oil pressure.

I just did a motor swap on my 95. After the installation, I turn the key switch to on and the oil pressure guage will go up to 90. When I crank the car up to start it, its back at zero. The engine starts and sounds good. but no oil pressure...did i forget to connect something? is there a pin for the oil pressure guage that i miss? if i did, where can i find it?
Sleeper_MX5 is offline  
Old 04-20-2009, 10:38 AM
  #2  
Elite Member
 
Laur3ns's Avatar
 
Join Date: Mar 2008
Location: Enschede, NL
Posts: 2,053
Total Cats: 12
Default

It cannot show 90psi without the engine running. Is it the switch type? Probably connected wrong.
Laur3ns is offline  
Old 04-20-2009, 10:41 AM
  #3  
Junior Member
Thread Starter
 
Sleeper_MX5's Avatar
 
Join Date: Jan 2008
Posts: 269
Total Cats: 0
Default

Originally Posted by Spookyfish
It cannot show 90psi without the engine running. Is it the switch type? Probably connected wrong.
How can i tell if its a switch type? I don't think i've ever seen whats behind the cluster. where can i find the connection?
Sleeper_MX5 is offline  
Old 04-20-2009, 01:27 PM
  #4  
Junior Member
 
the_man's Avatar
 
Join Date: Aug 2008
Location: MD/DE/PA
Posts: 333
Total Cats: 0
Default

Alright, let me think if I can drag out the memories of the various oil pressure senders... (somebody correct whatever information I **** up):

The 90-94 senders showed higher pressure as resistance decreased. Meaning that gunk on the connectors or whatever would cause a lower reading than you should see.

The 95+ "fake" sending units were an on/off switch that operated such that when you hooked it up to an earlier gauge, the gauge would show to the max on the scale with no pressure, but somewhere in the middle (or maybe the bottom) with pressure above 7psi. This sounds like your symptoms.

Basically, I don't know what sender you have on the engine, and what gauge you have in the car, and therefore can't say anything intelligent. Did the "fake" gauges have markings for actual pressures? Did a '95 have a "real" gauge or a "fake" gauge (I thought '94 was the last year, but I'm not sure) and did you retrofit something else? Methinks that your problem isn't a lack of oil pressure, it's a hodgepodge of bastardized components that don't know how to play nicely together.

Wish I could be more helpful, but I haven't been thinking about Miatas much lately. I also can't help you identify one sender or another- but what year motor did you put in and did you use the sender on that motor?
the_man is offline  
Old 04-20-2009, 01:52 PM
  #5  
Senior Member
iTrader: (7)
 
wes65's Avatar
 
Join Date: Aug 2007
Location: Southern Indiana
Posts: 1,369
Total Cats: -1
Default

Is your sender more the size of a quarter or a light bulb?
wes65 is offline  
Old 04-20-2009, 02:31 PM
  #6  
Elite Member
iTrader: (33)
 
RotorNutFD3S's Avatar
 
Join Date: Jan 2007
Location: Newnan, GA
Posts: 2,518
Total Cats: 30
Default

Originally Posted by wes65
Is your sender more the size of a quarter or a light bulb?
Let's put a picture into play, look above your oil filter but under the intake manifold, does the sender look like the one on the left or the one on the right?

RotorNutFD3S is offline  
Old 04-20-2009, 04:24 PM
  #7  
Junior Member
 
locomonkeyboricua's Avatar
 
Join Date: Sep 2008
Location: ATL GA
Posts: 295
Total Cats: -216
Default

the oil pressure guage on a 95 miata will show half way up when there is no oil in the car ,, WTF.. i think its just the diffrence in the year you got i would not worry about it much just make she checks her oil...
locomonkeyboricua is offline  
Old 04-20-2009, 04:30 PM
  #8  
Junior Member
Thread Starter
 
Sleeper_MX5's Avatar
 
Join Date: Jan 2008
Posts: 269
Total Cats: 0
Default

it looks like the one on the left
Sleeper_MX5 is offline  
Old 04-20-2009, 04:30 PM
  #9  
Junior Member
Thread Starter
 
Sleeper_MX5's Avatar
 
Join Date: Jan 2008
Posts: 269
Total Cats: 0
Default

it looks like the one on the left with the pin.
Sleeper_MX5 is offline  
Old 04-20-2009, 04:57 PM
  #10  
Senior Member
iTrader: (7)
 
wes65's Avatar
 
Join Date: Aug 2007
Location: Southern Indiana
Posts: 1,369
Total Cats: -1
Default

You either need to swap to the gimp sender that you can get for $5 at autozone, or you need to upgrade your gauge to the old "true analog" style
wes65 is offline  
Old 04-20-2009, 04:58 PM
  #11  
Senior Member
iTrader: (7)
 
wes65's Avatar
 
Join Date: Aug 2007
Location: Southern Indiana
Posts: 1,369
Total Cats: -1
Default

Oil Pressure Gauge
wes65 is offline  
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
stoves
Suspension, Brakes, Drivetrain
5
04-21-2016 03:00 PM
Aroundcorner
Miata parts for sale/trade
2
10-01-2015 03:20 PM
JesseTheNoob
DIY Turbo Discussion
15
09-30-2015 02:44 PM



Quick Reply: No oil pressure.



All times are GMT -4. The time now is 10:20 PM.