Oil Pressure drops

[Grundo Farb]

Hello, not sure whether this has been covered elsewhere but have recently purhcased an '85 Coupe VX :D and have been happily driving with no problems for 2 months. A couple of weeks ago I noticed the oil pressure gauge on zero, took the car in for a service, had the belts changed and the oil changed a couple of gaskets had gone so had them done as well.

Car now runs very well but the oil pressure falls off every now and then. I have been told by the garage that the gear that connects to the third shaft of some fiat engines wears down and can cause this, is this correct? Has anyone else had a similar problem?

[Hamish]

Grundo,
Yeah, we've touched on this topic before - it's not just a VX problem but across the whole Beta range :roll:
The problem comes in 2 parts:
1. The sump design is crap and when the car is driven with 'brio' the oil pump surges then comes apart wrecking the bottom end of the engine :evil:
2. The pump itself (although high delivery) is prone to wear - why I do not know.

The solution - well you could go dry sump if you're feeling rich :!: In everyday reality it could also be that the bearings need done on the engine. Every - and I do mean every VX engine I've had apart to investigate low oil pressure has needed new main bearings regardless of mileage :? Now this is a major job - but worth it long term.

You could fit a baffled sump (design for sump is in the Guy Croft book or contact him via his website www.guy-croft.com) which is in my view a must on any Beta, you will notice a big 'boost' in oil pressure and be happy in the knowledge you've done a better job than Lancia did on protecting the oil pump from surge issues.

As always with Lancias it's complex and costly to fix, but very much worth it 8)

[Grundo Farb]

Hmmm, just to clarify, it seems unusual for a pump to work one minute and not the next and to stop while running and then restart again don't you think? :?:

I was wondering whether it is more to do with the pressure sender and voltage drop on the gauge rather than anything else to be honest. As with other Betas that people have mentioned this one exhibits the classic votage drop problems. There seems to be an intermittant problem with just starting it with the pump coming on but the starter doesn't turn over (son't think its the starter either), I've had the suggestion of putting a relay onto the operating side of the starter to fix this and am wondering if the beautiful italian electrics are contributing to the oil pressure problem. Had thought of putting in a capillary pressure sensor to test it for a while.

The sump mod seems a good idea, although I had thought it was only if you were intending to welly it all the time rather than just drive to work.

[Hamish]

Hmmm, just to clarify, it seems unusual for a pump to work one minute and not the next and to stop while running and then restart again don't you think? :?:

I don't know... did anyone suggest that :?: As you know, Lancia electrics are, at best, idiosyncratic :roll: so it's possible there's a fault on that side of the system - more likely the readings are a fair indication on the state of the bottom end :evil:

As far as the electrics go, my best advice is to unplug the battery and strip and thoroughly clean the fuse box, replace relays and fuses. OK I'm sure all your relays and fuses look fine but unless you know their age change them.
Check very carefully the main feeds to the fuse box (black and white wire either end of fuse box) - the state of this connection is critical.

Next: if you follow the loom around the gearbox side of the engine you will find a round multi-connector. Seperate it then clean and re-assemble.

If you still have problems :? try checking the integrity of the ignition switch itself.

Wouldn't do any harm to put relays on the headlights and pretty much everything else remotely electrical :!:

Trust me on the sump issue - it's vital for any Beta.

[cthargiss]

Often the pressure sending unit will develop a leak in the diaphram, and show intermitent readings. If the gauge pressure drops but the warning light does NOT come on, replace the sending unit with a NEW one. If the pressure drop then persists check in the following order: Oil pump relief valve, oil pump drive bushing, main bearings, rod bearings, cam bearings, aux. shaft bearings.
Craig

[Grundo Farb]

Excellent stuff!

The voltage drop and elcetrical problem with the pressure sender was a suggestion from an Auto sparky, so I'll change the pressure sender and then do as you suggested Hamish on cleaning the fuses and checking the wires.

Once I get this sorted, (and the leaking water header tank, and the broken spring on the drivers door, and the...) I'll get onto the sump.

[Will]

..I'll concur with Craig's statement, and add that a hole in the diaphragm usually manifests itself as normal oil pressure on startup, and than falls off mystreriously. Also fluctuations i.e. downshifts sometimes register briefly.
-Will

[vvieri]

Fiat/Lancia electrical pressure gauges have always been unreliable and inaccurate. The best way to cure this, is to purchase a mechanical one.

That oil sump is a known weakness, even in newer FWD TC-equipped cars like Thema and Croma. Here is my sump, for Fiat Croma engine, though:
http://www.ele.tut.fi/~vvieri/tc/ecromatc.htm