I picked up an oil pressure sender for my 455 at an auto parts store. The round body of the sender is too wide, doesn't clear the block to let me screw it in. Can I just use a 1/4" nipple and coupling to extend the pipe on the sender and allow it to fit? Will this still give accurate pressure reading? Did they just screw up and give me the wrong sender, are there a lot of models? Thanks for any help.
Dave
That is how i have mine installed. It never occured to me, but maybe that is why my oil pressure never goes over 30.
everybody says to make sure that it is at least 40 lbs, but have never seemn that. I use an electric VDO oil pressure gauge w/ that HUGE sending unit.
I don't see why it would cause a pressure drop, but maybe. What oil do you run?
As long as your sender is seeing engine oil pressure it will work fine, your nipple should have no affect. The critical thing with senders is that you have the proper one for the gauge you're using...VDO gauge - VDO sender that matches etc. Some senders cross over to various gauges, some do not. Depends on the combo. I can tell you that an incorrect sender will many times give you an inaccurate reading on the gauge.
Also if your sender is the type that grounds through the sender body, I've seen teflon tape interfere with that connection and cause an inaccurate reading. Brass will normally seal pretty well on it's own if the sender is the proper tightness. If your sender is the 2 wire type (not as common) you probably don't need to be concerned with this.
Now that you mention it, go figure. I have the bell looking unit, and it has a brass 45 degree piece to keep it away from the block. I had tried the long slender one ( I guess thats what Olds calls for) and it made my pressure reading spike off of the gauge. I don't think though that a fitting would be able to reduce a pressure reading like that unless there was some serious blockage between the block and the pressure sending unit.
Thanks, Mike! Its a one wire sender. I already bought the fittings, got brass for corrosion reasons anyway and won't use any tape. As for if its the right one, the boat has some older gauges, not sure what brand, so I thought I'd try the stock sender for gauge (not for idiot light).
Since we're talking, I wanted to get a Beede Alert oil pressure gauge, it lights a light when pressure drops below 10 or 20 psi. Gaffrig also has one but the Beede gauge matches the look of my other gauges more closely. Anyway, I tried a number of places including Beede directly and I can't get one, Beede has some pretty strange minimum order and stocking rules. Any thoughts? If I buy a new gauge of whatever brand I'll get the sender the manufacturer recommends with it.
Dave
One of the hugest problems I had with the oil pressure gauge was matching a certain manufacturer gauge, (teleflex), to a sender unit on the block that was made by another manufacturer, (Napa).
I had terrible oil pressure readings and I couldn't figure out why. In a last ditch effort, I bought a new gauge and sender, (autometer), from the performance shop for about $50 and after this small investment, I found I didn't have to pull the engine to replace the oil pump.
You might want to try the same thing. Good luck!
Yea I know Beede's a little difficult. We do business with them but don't stock any of their regular Beede stuff and they do have minimums. Perhaps there's a distributor locally that we can get one from that stocks them. If your interested just give Bob here at Rex a call on Monday and tell him I suggested it on the Hot Boat forum to you.
Sender mismatch is the most common problem we see in gauges not working or not being accurate.
you will not have any problems i had the same issue, put an extender. what i acually did was, i put the extender then split the 2-way. one was a mechanical guage right on the block. and the other was the sender. sometimes you might see the guage on the dashboard fliker. thats because its a bad sender or you have a short in ur wireing system, or your alternator is doing something wrong. but anyway's you will be fine extending it "i did it to my 455 olds well on my last boat that is" and i never had a problem
good luck
eric
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