5-20/5-30 synthetic too light on 90k???

[k gee]

So when I got the Tahoe a couple months ago, I immediately changed the oil out for some 5-20 or 5-30, I can't recall because I have 4 vehicles and had a bunch of quarts filled with old oil. I found a few new 5-20 though.

My girl drives the Tahoe, and had told me the check gages light had been coming on. I drove it last night and noticed it did come on, as the oil pressure gage dropped to 0 right after I let off the gas pedal. So I checked the oil and it wasn't even registering. Hopefully nothing is messed up. Checked the coolant and no oil in there (as far as I can tell) and added over 2 quarts last night.

Now, it has been at least 5k miles since we changed it (wow she drives too much). Should I go to a 10-40 or something heavier that won't burn as quickly? I've never seen such oil consumption in anything I've driven. Is it a sign of something going bad? Or was it just because the oil was too thin/light?

 

[grimm]

I recently posted a somewhat similar issue about my oil pressure gauge. Basically it was dancing all over the place and would drop to zero when I braked hard, or accelerated hard, but was getting the proper reading at idle, under load, and at cruising speeds. At first I thought the oil pump or oil pressure sending unit was going bad, but as it would turn out, after changing the oil and filter, to the correct amount, everything was okay.

Make sure you have the proper amount of oil, should take roughly 5 quarts. These trucks will consume some oil here and there, especially with higher mileage. Also, I recommend using a high quality synthetic : 5w30 and 10w30 are both acceptable as stated in the owner's manual. I'd try going to 10w30 and take it from there. In the process it wouldn't hurt to check your gauge and the sending unit. If those things are fine and new oil does not help, you might want to check your oil pump for correct pressure. If all that checks out, you may have a leak somewhere, if not something visible on the outside, maybe internally.

 

[crmzendrgone]

I have always had the understanding that the higher the mileage the thicker the vicosity.
Like here in AZ hell I run 1030 in winter and 1040 in the summer but I have 170+ thousand miles so. . . . But what grimm says sounds like good advice.

I do think 520 synthetic would be to thin!!!!

 

[TahoeJim]

Bearing clearances and the rest of the engine weren't designed for use with thinner oils like 5w-20 or 0w-20. I'm at 93,000 miles and have very good oil pressure with 10w-30.

 

[TahoeJim]

Noticed your location....LA. No need for 5w in your truck. I ran 5w-30 during the winter when temps were consistently below freezing and often in the single digits.

 

[k gee]

So I should run 10-30 sounds like.

Yeah she was running it 2 quarts low. I guess it burned off.
Everything else checks out good. Running Mobil 1 Syn.

And yes I do live in Los Angeles.


Thanks

 

[haks310]

LoL

I'm running 5W-30 Mobil1 Syn right now with no issues. Switching over 10w-30 soon though.

 

[AtomicHoe094]

yea you should be fine with 5w30 without a doubt. But then again it doesnt matter which you use. you wont tell a difference.

 

[faze]

In real life there is no difference between a 5w30 and a 10w30 unless the temp drops below zero....below zero the 5w30 will thin down below a 10w. Above zero both will be around 10w. If I lived in LA I'd probably consider a 10w40 for the summer.

0w20 seems to be a ford wierdness...my brother's mustang runs that oil so they must be tight engines or have really good oil coolers because he runs it in Toronto summers (80-90F).