L30 (gutless turd) Vortec in my "Grandpa Truck", here. Popped it's intake gasket -as they will all do eventually, and put coolant in the pan. My son had it, so he took it upon himself to change the intake gaskets.

When done, he was concerned with "some engine noise" it had apparently made on it's last drive before gasket work -I never heard it. Anyway, apparently, as a precautionary measure to this "engine noise", after the job, he dropped the old oil/coolant mix, installed a new filter and filled it w/20w-50. That's right...."RACE oil!" (j/k). But yeah, 20w50. It's still warm weather so whatever.

Anyway, I get the truck back right after this all happens and immediately, I learn that it has a pretty vicious lifter tick(s) on any start up. It was really loud....at times I debated if it might be a light rod knock, but it was definitely lifters, cyl 8 and it'd go away, but would take a while; 10-20 minutes. I could shut the truck off, hot or cold after lifter tick(s) went away, start it right back up and the tick process would start all over again....take 10-20 minutes to go away. Truck ran for 500 miles like this....it was annoying and concerning to me. I was beginning to think that somehow the lifter(s) got screwed up having coolant run through 'em?

Yesterday, I changed the oil back to this vehicle's typical M1, 5w-30.....lifter tick eliminated. Wha....? I started it numerous times, no tick. I drove ~100 miles, no tick. Hooked up my boat, towed it about 40 miles to winter storage, shut down, started multiple times....no tick. No ticks at all.

This isn't a problem needing solving; it's solved....but I just wonder how in the hell a thinner oil eliminated a lifter tick(s)?? How did a thicker oil NOT work to keep the lifter pumped up? And how, when HOT, the thicker oil didn't basically work (in the lifters) like the thinner oil is working, when COLD? Fuggin mind boggling, I say!

As my Auto Prof used to mumble unenthusiastically when he didn't care to answer a student's retarded question....."AMFM.........AutoMotive Fuggin Magic".

 

I am assuming that flow is more important than viscosity...

 

I agree....except that HOT 20-50 should still flow better than COLD 5-30. And, it ought to stay pumped inside the lifter, better. Should....

 

Does the L30 have tiny little oil passages feeding the lifters? I have heard of a different manufacturer's engine having notoriously small passages and the same thing happening, ticks with thick oil (regardless of temperature) and quiet with the recommended **** thin oil that seems common these days (in this case 5w20 recommended).

I won't mention the manufacturer, lest poor Sofa come in here, see it, and then gak all over your thread

 

I don't think so. L30 is a 305.

 

The internal clearences of the lifters were setup for 5W30 in the newer engines. Thicker viscosity oils can and often do result in what you see. The 2003+ Hemi's actually had a DTC that would set for the wrong viscosity. They called for 5w20 and thicker oils would cause the 8 lifters that shut off for the MDS system to become sluggish. Sluggish lifter = misfire transitioning back to V8 mode. The PCM would sense it was all 4 of the MDS cylinders and set the DTC for the sluggish lifter function. DTC for that is P1521 IIRC, seen it before as well on the Hemi's when someone feels the need to put 10w30 or 10w40 in them.

 

Well that's an explanation that makes sense...kind of. What's weird is that all the lifters didn't make noise. But more weird, still, is the oil viscosity vs. temp issue. According to THIS CHART, and others, the 20w-50 oil at 212°F is quite a lot thinner than the 5w-30 is, at 60°F (15.5C). Now the Grandpa Truck doesn't have an oil temp gauge, but I'm confident that the oil gets to at least 212°, climbing Little Cottonwood canyon, and Parley's canyon, both places where it's getting flogged....as hard ad Grandpa will take a flogging.
And then, of course, the lifters work fine with 5w-30 at 60°F (our recent weather for cold starts and running)....and they also work fine at 10°F -previous operating conditions. It's weird to me.

 

Are you looking at the cSt of the oils which is directly correlated to how they flow? Even two different brands of oil with the same labeled viscosity can have greatly different cSt ratings. Alot of the cSt data I have seen is at like 40C and 100C.

 

I'm looking at the relative numbers in the graph and the charts...and others. Even w/o charts and graphs though....I don't think there is any brand of oil where a 50 weight will be thicker at 212°F than any other brand's 30 wt oil would be at 60°F....or 10°F. Do you?

 

I had a set of GM Performanxe LS7 lifters bought in 2012 time frame that sat on a shelf for years in my 383. After it sat a while occasionally one or more collapsed. In extremely cold weather that morning sickness could last a fair amount of time because of the amount of time it takes to get the oil back into the lifters. This was at 12F, it hammered probably 30-45 seconds before it pumped back up. Actually have the top end torn apart changing the cam, lifters and intake manifold this weekend.

I will say in weather that cold running an engine on E70 is like a cold diesel starting up. It struggles to hit on all cylinders until it gets a little heat into the engine. If the temps had been negative might not have started with that weak battery especially and no block heat. It sounds like it is idling fast when the heater was blowing 100-110F because it is. The 0411 and P59 do a somewhat weird warmup routine in Park/Neutral in cold weather. If the engine is cold started with the IAT under 40F, when the engine reaches 110F on the CTS it will bump the idle up 150-200 rpm to help warmup the heater then drop back down to the normal idle table at around 160F. It is idling at about 1,200-1,250 rpm at that point.