Hi All,

 

there's been a lot of good advice on the subject of my duff oil pressure sender (at least I hope it's the sender and not an expensive hole somewhere). Thanks to all who posted.

 

The answers raised the difference between a mechanical gauge (capilliary tube between engine and gauge) and an electronic one (sender installed in engine, electrical leads to gauge).

 

One view says that mechanical gauge is the only reliable one, other view says modern electric senders are OK.

 

What's your experience?

 

(I didn't bother to have an option in favour of the stock sender / electric gauge as everyone told me they're rubbish!)

 

Cheers - Gio

Personally I'd rather have to replace an electrical sender every few years than have hot oil running into the cockpit!! But that's probably just me :D

I'd second that :)

I'd go for electrical every time. People I've spoken to in the past all reckon mechanical are better but I think that's just a hangover from the days before electrical were reliable.

At work all the pressure instruments we have are electrical and apparently they're much more accurate and reliable than the old pneumatic/mechanical ones.

My dad asked this question to a person who works on oil rigs. He said that electrical is better. The quality of the electronics has become far superior than the old days.

 

People say that the senders do start to give off false readings over the years. Well they do, the accuracy does start to go after many years of use.

 

But no one has pointed out that Mechanical ones do too. Mechanical ones work by un-coiling a spring with the pressure of the oil water or boost. When a spring is squashed and pulled a lot, like when the needle moves, the spring will start to lose tension making it easier to squash and pull. Then the needle starts to read higher as the tension in the spring goes.

 

Its like when the suspention springs, they start to go after a while.

 

But when the accuracy goes on a mechanical gauge, the only way to fix it is to replace the dial, at the cost of £40-50 each, and that is if they still make style.

A new sender will cost you £6-£10

 

Electrical you just change the sensor.

 

Also with Mechaical expecially with water and oil ones, the temperature of the water is read from right behind the dial. By the time it travels up the hose to the dial, it could have lost heat or pressure. Granted it may not be that much, but I would rather know the values of the water and oil as close to the engine as I could. So the water temperature is taken from teh top rad hose, the oil pressure from near the sump and not read from a sample after 8 foot of hose.

 

People who like mechanical have mechanical. People who like electrical go with electrical.

 

I personally would go with electrical because of the following reasons and the other reasons already mentioned.

 

One thing I do like about mechanical, they use about 270 degrees of a dial when electrical tend only use 160 Degrees or so.

 

But there are electrical ones which will use the whole dial but will cost you a little bit more

 

Stuart

Mechanical choice for me!

Originally posted by MAC 1

Mechanical choice for me!

 

Luddite ! ;)

Would you stand with your face over a deep fat fryer? No me neither, electrical! :D

had a few older "sports" cars with mechanical and none ever failed or leaked oil. Anyway its pressure that works the oil one and the temp one.

Thanks gents - great replies (esp Stuart).

 

I shall toddle off to Harry's to see what they've got.

 

Cheers - Gio

Originally posted by AndyP

Luddite ! ;)

 

Ok Concorde or the new Boeing 737-700s

:tongue:

Gio,

 

 

Personally I wouldn't use a oil pressure gauge!

 

The big ends on a Zed are not a prevalent problem, I presume you wanna use the space for the three gauges in the din panel?

 

I would fill them with, Boost pressure, water temp and oil temp gauges, I think these are the most valuable on a zed!

 

Lets face it, if your oil pressure is down, you check your oil levels. If they are ok then it is time to for an engine rebuild or replace the faulty stock oil pressure sender!

Hi TopLess,

 

this all started when my stock oil pressure gauge started going wobbly. Gave me a nasty shock, I can tell you "WTF has all my lovely oil gone? :eek: ". But from the diagnosis and advice, it seems that it is probably just the sender (one on order).

 

(not losing any oil, no smoke, good pressure when cold, only goes haywire after about 10 mins, reading comes back intermittently)

 

But I hated the feeling of doom the first time it happened - so was thinking of fitting a backup!

 

Proper set of gauges will probably have to wait for someone to pay an invoice!

 

Cheers - Gio

Gio the only way to go is with the indicator being a digital

not analogue device , analogue uses moving parts hence wear and tear and then hysteresis "inaccurate readings" ( "slogger" in instrumentational terms ) go digital read out and electronic sendor , mechanical gauges are only used in industry these days because they are cheap and intrinsically safe to use in hazardous areas and offer fairly reliable pressure indication however they do need re calibration at least once a year to remove zero and range errors which are attributable to the aformentioned slogger ( wear and tear in the moving parts )

 

Steve

If you want The Gauge, go for Defi!

 

Completely black out when ignition is off and come to life when you turn the ignition on!