Twinspark Oil Pressure

[Badwolf75]

Hi all

New to the forum, and also new to Alfas - bought my first one only a few days ago  

It's an Alfa 75 twin spark (loving it), but I noticed tonight that the oil pressure gauge was fluctuating quite a lot. I know engine speed does have an impact on oil pressure, but at low RPM the pressure will drop right down (looked like 0.1 - 0.2 bar on the gauge), but at even quite light throttle application it will move straight back up to the healthy part of the range. I'd been doing a fair bit of low speed stop/start type driving at this point. Is this normal for a twin spark? Possibly a dodgy gauge or sensor, or something more sinister? Engine oil looks clean on the dipstick, and the level looks good too.

I'd appreciate any thoughts. As I said, I'm new to Alfas and would like to keep this one kicking for a while yet.

Thanks

[Darryl]

Sounds familiar. Give it an oil change and stick something thicker in it. See this thread http://www.alfaclubvic.org.au/forum/index.php?topic=5847.0 for some discussion/options. My personal view (elaborated on there) is:

Penrite HPR 40 is a good choice, SIN 10 if you can afford it and are worried about getting the oil flowing from cold startup.

Do you know what is in it now?

[Badwolf75]

Thanks Darryl. The guy that I bought it off knew his stuff and recommended those oils to me, but I'm not sure whether he had changed it in the time he had it. I'll check with him and if he's not sure I'll put some Penrite in it.

I've also read that using the right type of coolant is important in these cars - any recommendations on this front?

Thanks mate

[Barry Edmunds]

Badwolf76

Low oil pressure at idle is not unusual with Alfa engines, as long as it is showing a consistent reading under load. If you are really concerned about the oil pressue you could always change the sender unit.

One of the secrets to long engine life with Alfa Romeos is clean oil. Although oils have improved in recent years some Alfa Romeo owners still change the engine oil at 5k intervals and oil filters at 10K. This does depends on the normal useage of the vehicle and some might regard this as being a bit over the top and entirely unnecessary but compared to an engine rebuild because of component failure/dirty oil, oil changes are cheap insurance nd a whole lot cheaper.

[Typhoon90]

Don't forget also that oils should also be changed on time in service. An engine that does very low kilometres will sit around with lots of contaminants in the oil, and lots of condensation in the crankcase from just sitting there in teh daily heating and cooling cycles of the atmosphere.
  I find that I never hit mileage intervals on my vehicles due to having the choice of three every day and tend to change oil every six months in my vehicles. The fiance's car gets changed on mileage as she just drives that every day.

Regards, Andrew.

[MD]

Badwolf76

Get your sender and guage checked with a master oil pressure guage at a workshop. That will verify whether some or all of your components are faulty. ie, oil pump,sender, guage or wiring loom defects.

All reputable workshops have them.

A good rule of thumb when buying a used car from even you mother is to immediately change all lubricants, hydraulics and coolants then sit back and wait to see what goes wrong having done a basic service.

[Darryl]

In the days when this aluminium stuff was rather exotic and a large lump of cast iron didn't warp too easily if it got a bit warm from clogged cooling passages etc the idea that you needed to treat the cooling system with some respect was a bit foreign, just like the car... I don't think there is any need for any special care compared to modern motors - just change it every few years, don't mix coolants (top up with demineralised water or some spare coolant from when you changed it). A bit of tap water won't hurt to save it from overheating - just avoid using it often to avoid buildup of scale from hard water. Its the hidden damage that decades of abuse/neglect can do thats the problem - if it has a good history / PO you should be fine.

[Badwolf75]

Thanks for all your input guys. I just found out that the oil and filter were changed 1,500km ago (currently using HPR30), so that should be good for a while. I'm going on a long trip soon, so I think I'll flush and replace the coolant and see how it goes. Might use HPR40 at the next oil change and see if that stabilises the oil pressure.

Also, thanks to MD for the advice on the master pressure guage -  I'll definitely check that out.

[Anthony Miller]

20 yr old gauges are wildly innacurate, alfas especially. MD is right on the money with his suggestion of checking against a set of master gauges at your local alfa specialist. Personally I wouldn't worry to much about a low reading at idle, but I'd definately worry if I got a low reading under load. Just keep the oil up to it,always carry some spare, these cars do use a bit especially on a long run