Oil Light / Strange Tachometer

[Moose]

1996 Disco I, 108K

What are some of the causes of these things happening?

1. Oil pressure light intermittently flickering. New oil (changed Sunday), new filter, recently ran Gunk Engine Oil Flush through. Doesn't always do it, then will flicker and/or be constantly on, especially at higher rpm's. Oil pump?

2. Tachometer not functioning for several minutes after starting engine. Operates fine after it starts, although the needle seems a little "slow" to respond to throttle changes, especially accelerating from idle.

Engine sounds normal, runs fine. I'm hoping that it's, for (1), a sensor or something simple, since I just put a new water pump on the truck. For (2) I'm hoping a loose connection?

 

[Moose]

OK, the plot thickens...

I get in my truck to leave from work, and notice the engine is knocking/tapping. Figure it's manageable, and begin to drive home (all surface streets, no highway thank God).

Long story short, oil light comes on solid, engine sounds like it's got pots and pans clanking around underneath. Get home, drain oil (which is pitch black and 3 days old -- Gunk must've flushed a lot loose!), drop pan, clean pan.

Tomorrow, cross your fingers for me -- hope that cleaning the pan and pickup tube cures the problem....

 

[AaronATX]

Hope that does the trick, but the reality of it is, low oil pressure = bearing wear.

And I was under the impression that you werent supposed to drive around with that flush in the oil.....I thought it was the sorta thing you add to the oil, get it up to operating temp and then change it again.

 

[Moose]

You're right -- I did drain it out each time. My wonder is if there was enough residual flush in the oil to affect lubrication. The pickup tube was pretty clogged and the 3-day-old oil was pitch black and sludgy....we'll see what a fill and drain today does.

 

[joey]

more than likely (as you already have found) the gunk worked loose alot of stuff, and this probably clogged the pick up tube.

 

[Moose]

Prognosis:

The patient is in "guarded" condition. I put everything back together, and refilled with oil, and things seem okay now. I'll be watching over the next few days for leaks and pressure drops, and noise. I'll update with more developments...

Andy

 

[joey]

After running on low oil for a while, I would recommend adding some lucas oil stabilizer (my personal preference), I am sure that other product work as well or even better (not sure on this), but it has always kept my engines running well.