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Discussion Starter #1
Gentlemen,

I kindly ask for your input about waht seems to be a complete failure of my oil pressure sending unit.

Background story:

My car (1600 GT Junior Engine type AR00536) was out to its acustomed dottore (garage) for new carb mountings, new engine mountings, oil change (20W50) + Filters (oil + Air), carb synchro, idle adjustment, ignition adjustment (advance), etc.

Prior to these works my oil pressure reading was always on the high side, and a bit lower on warmed up engine i.e. Normal

I retrieved the car from the mechanics last friday and drove a bit w/the car over the week-end. On this occasion I found that my Oil Pressure Reading, was completely nil / zero / Inexistant. Understandably I was a bit worried. I checked for all the connections to the sender unit (red/black wire) but all is connected normally.

The engine runs fine, with no unacustomed noises (knocking or the kind). The oil pressure failing light (the red one) does not light up.

So my question: Can these, notoriously unreliable & fragile oil pressure sender units, just die form one day to the other?

I just bought a new unit and will replace it hopefully this w-e, but I just wanted to retrieve opinions of the experts out-there..!

Thank you in advance for your input & please agree my kind regards

Thomas
 

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Yes, I think they can give up suddenly. Is the wire hooked up OK, not broken?
Does it have a low oil pressure light? Has that come on?
You can test with a mechanical gauge to get a check reading.
Andrew
 

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Richard Jemison
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Sending unit

You can test the sending unit`s failure by simply grounding the wire to it. If the guage moves to max pressure then the sending unit isn`t working.

With gear pumps, if the motor is running there will be pressure. If it is remarkably low then you probably have an issue.
If it is low only at low/idle rpm then most likely it is worn cam caps as the cause.
 

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Discussion Starter #4
Yes, I think they can give up suddenly. Is the wire hooked up OK, not broken?
Does it have a low oil pressure light? Has that come on?
You can test with a mechanical gauge to get a check reading.
Andrew
Hi Andrew,

1) Yes the wire is hooked up correctly aqnd No it looks allright (not broken)

2) Yes it has a low oil pressure light no its did not come on, yes I ckecked the connection to it (Grey cable on the right hand side looking to the back of the car, running to sender located on the the bottom center on the right hand side of the engine)

3) I'll check w/a mechnical gauge but only be able to do so this w-e

Thank you for the input and happy to read that these "senders" can die all of a sudden.

Kind regards
 

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Discussion Starter #5
You can test the sending unit`s failure by simply grounding the wire to it. If the guage moves to max pressure then the sending unit isn`t working.

With gear pumps, if the motor is running there will be pressure. If it is remarkably low then you probably have an issue.
If it is low only at low/idle rpm then most likely it is worn cam caps as the cause.
Hi Alfar7,

Thank you for your reply.

1) Ok I'll try your simple trick to ground the wire (pull off the cable from the sender and ground it to the casinf of the sender....correct?) :thumbup:

2) Are the mechanical oil pumps (gear pumps) prone to fail, in respect of worn out pump cams? I know that they come up for sale from time to time on the bay at ...well.... remarkable prices, and a new original pump impacts also the budget, I also know about aftermarket oil-pumps which are less expensive (of lesser quality). Do you have some experience there.

From what I know. The AR00536 engine is the "same" as the one used on the GT Veloce, and therefore has the deep oil pan....for the longer oil pump ...

Kind regards

Thomas
 

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Just a note regarding the oil pressure sender. Veglia and Jaeger gauges use different senders, a fact that some Alfa parts stores seem to forget from time to time. If you put in your new sender and the gauge immediately pegs to one side (I forget which, but believe it's all the way to the right), you have the wrong sender.
 

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Discussion Starter #7
Just a note regarding the oil pressure sender. Veglia and Jaeger gauges use different senders, a fact that some Alfa parts stores seem to forget from time to time. If you put in your new sender and the gauge immediately pegs to one side (I forget which, but believe it's all the way to the right), you have the wrong sender.
Dear Gary, thank your for your heads-up,

Yes I’m well aware that 2x sorts of oil pressure sender exist. My preferred supplier states that 1x version is for the “stepnosed” kind of Giulias’ GT’s and the second the “roundnosed” kind…, mine is a roundnose with the AR00536 engine.

On other suppliers website they tend to link it more to the instrument maker itself manufacturer “Veglia Borletti” or the other “Jaeger (Italia)”

In doubt myself I ordered both of them w/the firm intention to replace it over the week-end. And since I have plenty of willingness an courage I ordered also the “minimal oil pressure sender” (the one situated on the right hand side bottom of the engine block, and connected w/the grey cable)

Prior to tackling the replacement and first of all I went the easiest route and disconnected the Black&Red cable from the sender to short it against a metallic part of the carrozzeria… This evidenced that the needle indicator raised up all is way, conclusion to this the instrument in ****pit was OK. After a bit of cleaning I stuck it back to the sender and…

And then… well… ahem… my firm intention for replacement weakened, became less firm, and melted way totally, when…. I inspected more closely the actual location of the “oil pressure sender unit” and since I realized that I would have to remove the carbs… which have just recently be removed to replace the rubber intake mountings… my firm intention for replacement of the sender disappeared totally.

I then took the easy route and replaced the “minimal oil pressure sender” that had the age of the car and replaced it by the new part I’ve ordered. I reconnected it to the grey wire and started the engine …. Miracoli… Santa Maria mamma divina… the needle for the oil pressure resurrected from the death and came alive…. Tutti gli strumenti di misura funzunniamo perfettamente….

I suspect a bad connection due to some dirt and surface oxidation. Needless to say that I’m more than happy that I do not need to replace this ……. Sender.

Thank you for all your help and comments

Best greetz from Swizzera Toli0815 = Thomas
 

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Hi Thomas. Congratulations on the miracle cure! Alfas are living, breathing entities. Remember that and only speak kindly in their presence. :)

Regarding the oil pressure senders, all you need to know is the name on the oil pressure gauge, Veglia or Jaeger. Both senders will fit on 1600, 1750 and 2L engines. They just won't work if connected to the wrong gauge.
 

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Discussion Starter #9
Hi Thomas. Congratulations on the miracle cure! Alfas are living, breathing entities. Remember that and only speak kindly in their presence. :)

Regarding the oil pressure senders, all you need to know is the name on the oil pressure gauge, Veglia or Jaeger. Both senders will fit on 1600, 1750 and 2L engines. They just won't work if connected to the wrong gauge.

Dear Gary,

Got it!! Ok so I will just keep the Oil Pressure Sender for the Veglio Borletti instruments...

Kind regards & Thanks for the advise

Thomas
 
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