Hey guys, I need help! I had my oil changed about 150 miles ago and I have since developed a small engine knock! I found out my mechanic used 5w-30 oil in my 03 discovery, 101,000 miles on it! Doesn't this vehicle call to 10w-30 oil?! Please tell me this is why this small knock has started and that I haven't caused damage yet! What do you think?

 

5w-30 gets real thin when hot, you probably dropped oil press, not uncommon, but if the oil guy was a mechanic, he wouldn't have put that oil in it.

Most of us use 10-40 or 15-40(I do)

luck,greg

 

They confirmed for me that it was 5w-30 oil...its being changed to 10-w40 as I speak. I will be pissed if this caused engine damage!

 

changed the oil to 10w-40. ive only drove it maybe 3 miles since the change, still a slight knock, maybe better classified as a tick.

 

Sounds like lifter noise.

 

That's what I'm thinking. The knock speeds up with higher RPM's. Is this a problem that should be addressed immediately?

 

There is no difference between 5w30 and 10w30 at operating temp. 5w30 is fine in your truck and did not damage your engine. That being said I would recommend you use a 5w40 HDEO like Rotella T6 or Mobil 1 TDT. Sometimes a certain oil will just be noisy in an engine and usually the thinner the oil the more noise. I would not sweat it unless it gets worse after the 10w40. Also just a thought change your own oil it is easy and much cheaper.

 

went ahead and did an oil pressure test...just trying to be pro-active here, since i do own an 03 (in the bad VIN range) go ahead and look at what figures came back and let me know your thoughts. i cant really read this invoice, haha. hopefully you can. but i was told everything came back good.

Pressure at idle - Minimum: 0.7 bar (10 psi)
Pressure at 2000 RPM: 3.4 bar (50 psi)
Relief Valve Opening Pressure: 3.4 bar (50 psi)

the operating temp figures were good as well, however the receipt/invoice they gave me did not have a spot where they could key the info for me. i was told that all my numbers looked great.


i might add that this knock/tick is fairly quiet at this point. it does not start till the disco gets to operating temp. and the higher the rpm's, or the faster i go, the more rapid the knock gets. once i get going 20 mph+ i cant hear it at all.

 

If it were mine, I would do a top tear down and inspect the rocker shaft, arms, push rods lifters and cam lobes for wear. Most likely this will only get worse and the sooner you catch it the less expensive it will be.

 

I'm ASSuming those were hot pressures, the idle I'd like to see a little higher, (it's still above 8#, tho')

While I don't disagree with Mike, your reality may be that you have to drive it.

If so, the minimum I'd do is mount a known good guage to monitor oil pressure.

There's also a huge potential difference between a knock (even light) and a tick.

I've said it b/4, If you put a piece of hose (1/4 - 3/8" x 2') to your ear, you can isolate nearly any noise.

Then you'd know if it's coming from the bottom end, oil pump housing, or oil pan area.

luck,greg