Low oil pressure after highway trip

[Viterbo]

Today I drove the car with no highway road. Did a few pulls, today the idle was a bit lower than usual and the light didn't turned on. I assume it's temperature related (oil thickness) but still I think it shouldn't happen.

In 3 or so weeks I'll have the gauges...

[Clapped out]

The only reason why I suggested the oil, from past experience rallying the Christ out of the little k motors with cheap oil it couldn't hold pressure at idle even with a freshly rebuilt motor, when you look into different brand oils with their technical charts, a lot of conventional oils have a particular temperature threshold when hot before the physical integrity of the oil starts to fail, more specific/quality brands have a higher temperature threshold thus hold up far better/ don't thin out as much,

 

cheers!

[Viterbo]

13 hours ago, Clapped out said:

The only reason why I suggested the oil, from past experience rallying the Christ out of the little k motors with cheap oil it couldn't hold pressure at idle even with a freshly rebuilt motor, when you look into different brand oils with their technical charts, a lot of conventional oils have a particular temperature threshold when hot before the physical integrity of the oil starts to fail, more specific/quality brands have a higher temperature threshold thus hold up far better/ don't thin out as much,

 

cheers!

 

I'm using Total Q5000 15w40 (mineral).

I'm tempted to change to a 20W50.

[parrot]

I've always had the understanding that "old" motors are meant to use higher viscosity mineral based oils, and I only use 20W50 oil in the K & T motors.  But I grew up in the era when that was all we had and that's pretty much what they came with from factory, at least in Australia where most of us are only aware of snow as something you see on TV nature documentaries.

Have never really understood why thinner, synthetic oils with friction modifiers and so on are so "bad" for these types of motors.  I have this vague notion that it has to do with tighter tolerances in "modern" engines.  But as to whether there is a basis in fact I couldn't say.

Mind you, when the 4AGE first appeared in 1985, it was said to be a non rebuildable engine, and all us K & T engined people wondered why you would ever buy a car with one.

[ke70dave]

On the contrary my wifes subi forestor takes 0-20w. Its like bloody water. We were on a holiday amd i noticed it was a bit low, all the servo had was 15-40w so i put about 1L in to top it up. It did not like it at all. Idle was a bit funny and generally not running quite right. Spoke to a mechanic friend amd he reckons the vvti oil operated things cannot deal with yhe thicker oil and that was probably what i was experiencing. Dumped the oil when i got home and filled it with 0-20w again and it ran perfectly. 

The subi actually burns oil like crazy to. Burns whatever full to empty is on dip stick in about 5000kms. Mechanic friend reckons all modern cars burn the super thin oil, but they use the super thin oil to get the fuel economy. So we are burning oil to save petrol.....hmmmm.

So if thick oils makes modern engines play up, i guess you can assume too thin oik on old engines isnt advised?

15_40w is a pretty safe bet on old engines. My beema specifies 20-50w and it seems to be quieter with it compared to 15-40. 

[Viterbo]

I'm going to wait for the sensors and gauges to come and see what's happening inside the engine. 

With that I'll think about the oil. Maybe a 10W50 or 20W50.

Mineral 15W40 do about 5000kms and it's my oil it's not far from that.

[Viterbo]

As said in another topic I found my timing was way retarded (around 10/15 degrees ATDC, yes, AFTER TDC). Now I set it correctly and been pushing the engine without oil pressure issues!

[ke70dave]

ignition timing? 15 after? how on earth did it run? was the exhaust manifold glowing red?

[altezzaclub]

"Cough".. dizzy assumed to be turning the opposite way, points set on the wrong side of the shoulder....

An easy enough mistake to make.

 

[Viterbo]

I was cheated by the vacuum advance and by my lack of experience.

Check it here.

 

[Mal31443]

If you need to increase oil pressure it's faily easy pull oil pump out remove circlip and spring and insert a washer replace and off you go.

 

[Viterbo]

Just now, Mal31443 said:

If you need to increase oil pressure it's faily easy pull oil pump out remove circlip and spring and insert a washer replace and off you go.

 

That only works when revving. At idle it does nothing.