[FishOn]

Hi Alfistis,

Unpleasantness this morning as the engine stalled while in a queue with a quick flash of "low oil pressure warning". Was able to restart without issue but then saw that the temp was rising, running unevenly and eventually smoke developed. Was able to pull over and thought I was low on oil - and also the coolant was running a bit low. Walked to a gas station, topped up oil + coolant (before checking if oil level was OK after resting - my mistake), but realized it wasn't needed and the issue remained. Got a car mechanic over who looked at it for 2mins, then switched off the AC and the issue was fixed... guess I should have thought of that.

Net: faulty compressor (or part thereof). What I still need to understand is how this might have triggered an intermittent low oil warning? Any expert that can explain it to me would be greatly appreciated - I own an Alfa to learn more mechanics, and boy am I learning

 

[David C]

Unpleasantness this morning as the engine stalled while in a queue with a quick flash of "low oil pressure warning".
....
What I still need to understand is how this might have triggered an intermittent low oil warning? Any expert that can explain it to me would be greatly appreciated

Low oil pressure because engine stalled.

 

[FishOn]

Thanks. And why would the engine stall due to a failed compressor? Was it that the engine didn't have power enough to turn the failed compressor at idle?

 

[warniegt]

Low oil pressure because engine stalled.

Yep, had this the other day when my foot slipped off the clutch when in traffic.

 

[FishOn]

Then the mechanic was concerned about driving around with the car - we had a bit of a language issue - but my understanding was that even with the ac off, it could still halt the engine. My guess here is that if the compressor belt completely freezes and not even allow it to be turned, this would also sieze the engine - is my guess correct?

Btw, when taking it to the Alfa garage he was not concerned at all as long as I don't turn on the ac... Hate conflicting info... Who's right?

 

[_The_Editor_]

AC compressor uses a clutch pulley I believe, so when the AC is turned on the pulley is locked to the compressor and drives it.. When turned off, the pulley freely rotates.

If the compressor is failing and causing more load on the belt/crank-pulley you might get some funny running of the engine, however I'd imagine the ribbed belt would have slipped before causing the engine to stall...

At any rate, if the compressor is borked then there's a risk that it'll sieze and cause the aux-belt to snap.. These have been known to take out the timing belt when they fail (rubber fragments getting inside the timing cover)...

Cheapest solution might just be to find a shorter ribbed belt and bypass the AC compressor all together if you don't need it...

 

[FishOn]

Thanks. I've booked a time for compressor change - but the garage didn't have time until the end of next week, so I'll guess I'll minimise usage until then. Strange that the Alfa dealer said it was ok to drive though...

EDIT: Rereading it - so it's only really dangerous if the clutch pulley has failed and locks to the compressor which also has had to fail.

 

[rgwm]

I'd agree that providing the aircon isn't switched on, causing the clutch to engage, you should be OK as the pulley freewheels.

 

[FishOn]

Thank you all. I'll give an update after the garage has had their say in 2 weeks (this being Switzerland, brace yourselves in terms of costs).

 

[Cuore_Sportivo_155]

if you disconnect the pulley, or the pressure switch, thepulley won't engage. or take the time to find the clutch fuse...

 

[FishOn]

Got a quote from the garage of Chf2400 (more than 1600 gbp)... Think I'll live without the AC for now and see if I can find and independent that'll like to take on a stray job.

 

[rgwm]

Its probably little more than an hour's work to change the aircon compressor, then you need to regas the aircon, so that sounds like a hefty bill..........Find a working second-hand compressor and any competent garage should be able to change it for you - or as you say, do without - haven't had working aircon in any of my cars, as far as I can remember

 

[FishOn]

Update: Now the compressor clutch must have failed - there's noise and a burnt rubber smell also when the AC is off... And the car heats up as well, I checked the belt and it is moving, but could it be that the belt is slipping so it's not cooling as it should?

Anyway, ordering new compressor+dryer and new belt +tensioner and idler (don't want them to start working only to discover something more is shafted - and the parts were rather cheap while labour here is not). The garage for my other car whom I trust said they'd install it for me. I'll just ask them to replace what they deem necessary.

 

[rgwm]

The auxiliary belt that drives the aircon (and alternator and PAS pump) doesn't drive the water pump, so I'm a little concerned about you saying its getting hot..........

How hot is it getting? Maybe its just been running too cool in the winter/spring due to a faulty thermostat?

 

[FishOn]

Great - now you're making me nervous
It got up to about 110C - and that's new, didn't happen before I had the AC compressor issue, very rarely above 90. I had the thermostat replaced a year ago or so when the engine wasn't getting warm. Btw, I did hear & see the fan kicking in just as was parking it when it was over a 100C, so that's working. And coolant level is as it should.
Until I have the compressor fixed though, not sure how much troubleshooting I can do on the high temp, but happy to get educated.

I'm heading on vacation (without Alfa) this weekend and don't think I'll be able to take it to the garage before, so update will follow in 2 weeks or so.

 

[FishOn]

OK, so just wanted to close this topic.
Ordered AC compressor with drier, new belt and tensioner and some other bits and pieces - had a garage I trusted install it and it now works just fine.
The only thing is that I'm left with some spare parts - apparently they couldn't change the drier as it was welded on?! It works fine and I'm not sure how many more years the beauty has left in it, so not really concerned about reusing the drier(and voiding any compressor warranty), just curios if anyone else knows about this or it was a previous owner that quick-fixed something.

So: is it standard to have the AC drier welded on?

 

[Cuore_Sportivo_155]

yes, part of the condensor. only the olderearly cars had a seperate drier.

 

[FranknAtl]

What was the part # and or brand and model # of the compressor on your 916? I have a 1996 Spider 916 and my mechanic said that the front seal is leaking. I saw the link to Amazon, but I need the specs. to match it up. Really would appreciate the help!