Jump to content

Low oil pressure after highway trip


Recommended Posts

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...

Link to comment
Share on other sites

Members dont see this ad

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!

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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.

Link to comment
Share on other sites

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. 

Link to comment
Share on other sites

  • 2 weeks later...
  • 2 weeks later...

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...