Oil pressure gauge

[bijou22]

I have a VP 4.3GL 1997 Wellcraft 21sl and was wondering about the oil pressure gauge. Everything works fine on the boat (thanks to i-boats) but the oil pressure gauge is always reading to its max position when the engine is running. It does not overheat so is this normal, what should it read?

 

[Laddies]

Re: Oil pressure gauge

Normal oil pressure fo a GM 4.3 is about 40#. That sounds like a bad sender or short wire remoe the wire from the sender and see if it goes to 0 if so replace the sender

 

[bijou22]

Re: Oil pressure gauge

Not sure what you mean by this, where is the sender located. Could you explain in more detail the procedure please.

 

[Don S]

Re: Oil pressure gauge

Remove wire from sending unit.
Make sure end of wire doesn't touch anything.
Turn key to run position.
Look at gauge, if gauge reads ZERO, sending unit is bad.

Also check the gauge, does it have a good power and grouind connections

 

[bijou22]

Re: Oil pressure gauge

Thanks Don, can you tell me where the sender is on my boat and what it looks like?

 

[Don S]

Re: Oil pressure gauge

On the engine block back by the distributor. Blue wire to it.

 

[loonies123]

Re: Oil pressure gauge

I'm having a similar problem with my 1987 4.3 alpha. I originally had a problem with the gauge in that it was erratic and moved up and down. It also would show increased pressure when I turned on the dash lights. I checked the wiring to the gauge and found that one wire was loose so I tightened it. Now the pressure is stuck at 70 lbs. I tried disconnecting the sending unit and it still doesn't budge. It still shows an increase in pressure when I turn on the dash lights. My guess is that there is a short in the gauge but I'm not sure how to test this.

 

[bijou22]

Re: Oil pressure gauge

Can someone help me find the sender, I don't even know what it looks like, a picture would be great. Don said it was near the distributor with a blue lead going to it, I think I have it but really need confirmation, and how to remove it also.

 

[Bondo]

Re: Oil pressure gauge

The Sender is Usually a small round metal canister, about 2" in Dia.,+ about 2" long, with a single wire Stud in the end......

After the wire is removed,... It just unsrews from the motor......

It can Possibly be in 1 of 2 places,......
Either right next to the Dist. as Don noted,.....
Or,....
Just ahead of the Oil Filter on the Lower Port-side of the Block.......

Loonies123,.......
My Guess is,......
Either your Gauge is shorted out,.... Or there's a short in your Dash Wiring......
You can Test your's as stated by Laddies, above.......

 

[bijou22]

Re: Oil pressure gauge

Think I have it, many thanks guys.
Does anyone know the part number, in case I need a new one?
Doug Russell quotes 2:
1. Oil Presure Sender - 872064
2. Oil Pressure Sensor - 3853800

Not sure what the difference is though?

 

[Bondo]

Re: Oil pressure gauge

You'll need the Sender,...... Not the Sensor....... They are Different.....

 

[loonies123]

Re: Oil pressure gauge

My problem turned out to be a defective gauge.

Many thanks!!!

 

[Don S]

Re: Oil pressure gauge

You need the 3853800 sensor, the 872064 is for dual station.

Bondo.
Volvo uses sensor and sender for the same part. It's a Swenglish problem. (Interpretation from Swedish to English).

 

[bijou22]

Re: Oil pressure gauge

Took the wire off today, and turned on the electrics, the gauge did not move. Guess this means I need to get a new sender and if so any advice on installation would be great.

 

[Don S]

Re: Oil pressure gauge

Yes, you need a new sender.
Unscrew the old one, put some thread sealer (NOT Teflon Tape) on the threads of the new one and screw it in. Tighten down firmly, but don't break things. It's pipe thread.

 

[bijou22]

Re: Oil pressure gauge

Replaced the sender today and it maked no difference to the gauge, it still reads at full when the engine is running.
Anything else I could try?

 

[bijou22]

Re: Oil pressure gauge

Does anyone know a quick way of checking the gauge?

 

[sea wolf]

Re: Oil pressure gauge

You can purchase a remote oil pressure gauge at any auto parts store for less than $20. If the pressure on the remote gauge is normal, then it's probably a faulty gauge, sending unit, or wiring issue. More than likely, you need a new gauge.

 

[bijou22]

Re: Oil pressure gauge

Just to recap, if have taken the wire off the sender, turned on the ignition and it has not moved. Fitted a new sender due to this and gauge still reads the same.
Do you think I need to replace the gauge, or how can I test its working?
Is there a certain part number for the gauge on my boat that someone knows of?

 

[searay3]

Re: Oil pressure gauge

Replaced the sender today and it maked no difference to the gauge, it still reads at full when the engine is running.
Anything else I could try?

If the guage goes from zero to full swing with just the turn of the key, engine off, there is a problem with the wiring. You already checked the sender. If it is at zero and swings full after the engine starts, it's probably normal. Heavy cold oil will max a 60 lb guage until the oil warms....these guages are not that accurate, they are more of a guide. A true mechanical (master ) guage is what is used in a shop to determine true oil pressure...