[joew]

I have an 85 Spider Veloce and the oil presure comes up to around 60 PSI up until the engine reaches 180 -200. Then the oil pressure reading goes to zero or less than zero! Regardless of idle or 2000-2500 rpm -stays at zero.
As far as I can tell, the engine has oil in the top end (visula with cap removed) and the temperature never goes much over 180-200F (accuracy of the gauge?).

What can this be. I have no red warning light, 5w30W castrol oil, etc.

Engine runs fine??

Thanks,
Joe

 

[spiderserie4]

oil pressure sender - at least worth checking, swopping out, just to be sure!

 

[racer1958]

If your oil pressure drops to zero, your engine will make a racket.
You will know the sound!!!.
Pull the oil pressure sender, on the side of the block, and temporarily install a mechanical gauge in case you do not have another electric sender.
You can buy a mechanical oil press. gauge at Harbor freight it comes with metric couplings.

 

[joew]

If your oil pressure drops to zero, your engine will make a racket.
You will know the sound!!!.
Pull the oil pressure sender, on the side of the block, and temporarily install a mechanical gauge in case you do not have another electric sender.
You can buy a mechanical oil press. gauge at Harbor freight it comes with metric couplings.

Thanks Racer,
Is the sending unit on an 85 accessable from underneath the car or do I have to pull the entire plenum, hoses, rail, etc. out. I just put all this stuff back in after a recent head gasket job....major PIA!

Thanks Again,
Joe

 

[bianchi2]

5/30 is kind of light for our cars..i run 20/50 year around.. even in our very friddged cold winters here in california..

 

[ghnl]

The sender for the oil pressure gauge in on the right side rear of the block. Not easily accessible but you don't need to take the car apart to get at it either. That sender is known to be failure prone. If the low oil pressure warning light does not come on (and is known to be good) then it is likely oil pressure is OK. The switch for the warning light is on the left side near the bottom of the dipstick tube.

And 5W-30 seems quite thin. It may also be one of the "Energy Conserving" formulas that could also be low in the zinc additives our engines are said to need.

 

[144]

The oil pressure warning LIGHT comes on at 5 psi. That is minimum for idle according to Alfa. It's likely that your sending unit for the gauge is on the fritz.

When you first turn your key to on (before you start the engine), you get the low oil pressure warning light ON, right? Then it goes out after start. Right?

Use 10w40 as minimum. 20W50 in the summer.

 

[joew]

The oil pressure warning LIGHT comes on at 5 psi. That is minimum for idle according to Alfa. It's likely that your sending unit for the gauge is on the fritz.

When you first turn your key to on (before you start the engine), you get the low oil pressure warning light ON, right? Then it goes out after start. Right?

Use 10w40 as minimum. 20W50 in the summer.

Thanks Road,
The light comes on if I take the wire on the driver's side switch to (-) ground, the light comes on. It does not come on when I flip the "power on" switch to start the car.

Oh , did I mention that the ignition switch is missing from the PO. I am with a toggle "power on/off" switch" and a momentary push button to start the car
I have ordered a new ignition switch this week and will install this weekend. Gotta love those PO's!!!

I will also change the oil to a 20w this weekend.

What is the easiest way to change the sender. Remove the plenum only?
Any pictures? I like pictures. They got me through the head gasket job quite nicely!

All the Best,
Joe

 

[ghnl]

What is the easiest way to change the sender. Remove the plenum only?

You do not need to remove the plenum. You will need a short/thin wrench (14 mm come to mind but my mind doesn't remember so good anymore - perhaps it is 17mm?).

 

[joew]

You do not need to remove the plenum. You will need a short/thin wrench (14 mm come to mind but my mind doesn't remember so good anymore - perhaps it is 17mm?).

Thanks Ghnl
from the top or from underneath?

 

[144]

Need to get the low pressure light fixed. It's a grounding sending unit. When the oil pressure goes below 5 psi, the sending unit grounds and illuminates the warning light. There should be power to the warning light anytime the key switch is ON.

 

[joew]

Need to get the low pressure light fixed. It's a grounding sending unit. When the oil pressure goes below 5 psi, the sending unit grounds and illuminates the warning light. There should be power to the warning light anytime the key switch is ON.

Road,
That is my primary goal once the ignition switch arrives.
I agree completely that the redundancy that the switch provides to back up the less-than reliable sender is essential.

Thanks,
Joe

 

[gigem75]

Before you take the sending unit out ground the wire to it and make sure the guage pegs out, 99% of the time they do and it's usually the sending unit but it's nice to know for sure.
Some sending units are 17mm but most are 14mm and you will probably need to grind a cheap HF 14mm end wrench down so it will slide into the space between the sending unit and the block and onto the flats of the sender. Don't lose the copper sealing gasket. You will probably want to disconnet the battery too. One slip and you can have an exciting situation on your hands since it is right above the starter.

 

[vf31rhill]

joew,

If you need a new sender I have a new sender in the box for $45.00 and I will pay the shipping to a US address. I bought it but never needed it and never installed it - it is still new in the box. These sell for about $56.00 I believe. The open ended wrench which fits it is around 14 or 17 MM. I have a stubby one in my tool box and will get it out tomorrow and see the exact size. The problem with putting a wrench on the sender is that the space between the back of the sender and the engine block is very narrow. I got around this by putting the wrench on my bench grinder and "thinning" it up a bit.
You can get the wrench on the sender by removing the radiator overflow tank and coming in from the right while kissing the top of the intake plenum. Once you get the wrench on the back side of the sender, angle it toward the rear of the engind and use a hammer handle to drive it down and off. It is a great temptation to screw the sender off by twisting the body of the sender. Don't do this until it is quite loose on it's threads. It is easy to twist the outside casing of the sender in relation to the base, and if you do this you will break the wire inside which goes to the spade connector your gauge wire hooks up to. On reinstallation of the replacement sender, the final tightening can be done by leavering on the wrench with a tool against the firewall.

Look for a new post from me in the morning and I wil give you the exact size of the wrench and maybe a photo of the ground down wrench.

Robert Hill in Memphis, TN [email protected]

 

[spiderserie4]

if you don't have a bench grinder you can now find ultra thin headed open-ended wrenches, Stanley Proto do them for example, just 3/16 inch thick for a 17mm gives some idea just how thin. Useful to have a couple in the toolkit for jobs where acess requires a thin wrench (like the oil pressure sender!)

 

[vf31rhill]

The wrench is 14 MM. Attached is photo of slimmed down 14 MM open end stubby which will fit the oil pressure sender.

I also included a photo of the ground in half 10 MM box end wrench which allows access to the rear most nut on the heater control valve.

Robert Hill in Memphis, TN

 

[papajam]

The sender size, either 14mm or 17mm, depends on whether the sender is a Jaeger or Borletti. It can also depend on if the sender is aftermarket or not.
A 9/16" tappet wrench works perfectly on the 14mm senders.

 

[joew]

The sender size, either 14mm or 17mm, depends on whether the sender is a Jaeger or Borletti. It can also depend on if the sender is aftermarket or not.
A 9/16" tappet wrench works perfectly on the 14mm senders.

Thanks Jim,
What is a "tappet wrench". Please excuse my lack of knowledge on this one.
I understand box, spanner, ratcheting open end, etc.
Never heard of a tappet wrench??

 

[ghnl]

There must be a reason they're called 'tappet wrenches' but they are thin wrenches. Another source for thin wrenches is a bicycle shop.

 

[papajam]

Tappet wrench. It is an open end wrench that is about half the thickness of a standard open end. The name comes from their use adjusting valve tappets.