mark kibort

I was monitoring my oil pressure during the race at Fontana, but noticed the oil pressure was a little TOO good.. turns out its stuck at full scale when the key is turned on.
any ideas where to look first? could the sending unit be bad? or bad connection?

thanks,
mark

Mrmerlin

if it was working perfectly then all of a sudden started reading full scale I would check the 14 pin connector for shedding insulation and shorted wires first,
then if no joy ,
check the sender for shorted wires,
no joy ,
replace the sender

Speedtoys

Failed sender. Sometimes they heal..but its fail(ing) all the same.

IcemanG17

mark kibort

Really?

I did some testing last night. its pegged with the key on .. then, i tap 14pin connector (10 from the left) and it goes to zero. turn the key off, it goes to zero. turn the key on, it goes up a few mm...... start the car and it peggs to 5 bar.... turn the car off, and its stuck at 5bar..... tap the 14pin connector, and it falls back. did it a few times and its still pegging at start, but falls to zero after turning off.

oil pressure sensor?
sender wires look nice and covered. wires in good shape, connections good and tight. insulation good.

Bigfoot928

Problem is Amsoil. Pressure is too high. add some mobil one 0-50 and you should be good.

mark kibort

hahaha!!

OTR18WHEELER

I don't know about Amsoil, but pretty sure any synthetic oil will solve the 5 bar oil pressure reading over time., ....

FredR

I had a similar sounding problem with my 3 pin oil pressure sender installed. Found I had shredded wires from the 14 pin connector so replaced the wires, fitted new sender, still had strange behaviour. There is some kind of characteristic about the VDO gauges such that if there is an earth fault they do full scale deflection. Sean suggested fitting a two pin early type oil sender unit- did that and the problem disappeared and better still, my regular oil pressure the S4 motor originally demonstrated [5 barg when warm] reappeared [it had been showing 4 barg since I put the S4 motor is the GTS chassis]. No idea what sender you have installed but probably the earlier or so I suspect.

mark kibort

I have the two wire sender. the wires look perfect. could it be the gauge itself in the dash, or is it the sender. as i said,when it was full scale with the ignition on but car not running, i could tap the #10 from left, 14 pin connector and it would fall to zero. start the car, and it went full scale again.

how hard is it to pull the sender with the engine in the car? never touched this stuff, unless the engine was out.. i heard that those weird pickle fork open end wrenches (i guess you need a 22 or 24mm) can get it off.
sounds like thats where im headed.

thanks,
Mark

FredR

I found it very easy to remove the sender - you need an open ended spanner. Cannot remember whether I did it with the oil filter off to give a bit more room to work with.

James Bailey

Does it not concern you that "tapping on the 14 pin connector" changes things ???? Generally speaking good solid electrical connections and wiring are by design not effected by vibration or TAPPING...

mark kibort

it doesn't change anything when power is applied , only when it is removed. the connections of that 14pin are like new looking.. i don't know why the tapping makes the needle fall after it has gone full scale. but then start the car and it goes full scale anyway.. it doesn't change when tapped then... must be some capacitance in the system that is released when tapped.
someone else talked about this too. with a new sensor, the problem went away. i dont even know if that is the right 14 pin connector. maybe its the entire fuse panel... ill look it up on the schematics right now

Mongo

How about the solder joints? Is there enough on each pin to wire connection?

mark kibort

yes, all looks really good and clean at the 14 pin.. at the engine oil sensor side, also nice.. nice rubber boots, all solid.