Running a heavier oil

[Rollybear1]

Hello everyone, 98 GMC K1500, 5.7, 184K miles. My Truck runs well but has the annoying lifter tick. When I cold start it, it doesnt tick at all. After approx 10 minutes and the engine temp starts getting to 175 or so the tick starts.
Im 99% certain its not a leaky exhaust gasket. Sound is coming from center of engine and well, under the intake. Pretty much where the lifters sit.
I'm thinking of running Marvel Mystery oil through it and then trying a heavier oil.
I live in utah so winters are cold, so I was thinking a 10W-40? Does anyone know if a 5W-40 Diesel oil will hurt anything? and what exactly is the difference between diesel oil from gas engine oil?
Any other suggestions? Like I said it runs good but is just an annoyance with the tick, tick, tick at stop lights and in parking lots.
thanks!!

 

[Supercharged111]

Try the MMO first. I run 0W40 all year in my trucks. No need for anything thicker.

 

[95 Tahoe]

Diesel oil has more ZDDP in it. It will kill your cat. Lifters usually make noise while cold. Mine was doing the same thing before the rebuild. It would sound fine cold and once it got up to temp it had a constant tapping. I think mine was piston slap though. It went away after the rebuild. Now it just taps on cold starts for about 20 seconds, which I'm fairly certain is a lifter leaking down.

 

[SAATR]

Been using Rotella 5W40 for years, works perfectly.

 

[lbeninger]

Hello everyone, 98 GMC K1500, 5.7, 184K miles. My Truck runs well but has the annoying lifter tick. When I cold start it, it doesnt tick at all. After approx 10 minutes and the engine temp starts getting to 175 or so the tick starts.
Im 99% certain its not a leaky exhaust gasket. Sound is coming from center of engine and well, under the intake. Pretty much where the lifters sit.
I'm thinking of running Marvel Mystery oil through it and then trying a heavier oil.
I live in utah so winters are cold, so I was thinking a 10W-40? Does anyone know if a 5W-40 Diesel oil will hurt anything? and what exactly is the difference between diesel oil from gas engine oil?
Any other suggestions? Like I said it runs good but is just an annoyance with the tick, tick, tick at stop lights and in parking lots.
thanks!!

If your lifters are making a noise, there's a deeper issue that needs to be addressed . Use what the OEM suggested unless you have altered the base engine to other specs. The only addition I would suggest is using full synthetic.

 

[SAATR]

Diesel oil has more ZDDP in it. It will kill your cat. Lifters usually make noise while cold. Mine was doing the same thing before the rebuild. It would sound fine cold and once it got up to temp it had a constant tapping. I think mine was piston slap though. It went away after the rebuild. Now it just taps on cold starts for about 20 seconds, which I'm fairly certain is a lifter leaking down.

Given that the current crop of API CK-4 diesel oils have zinc limits on par with the oils specified for these trucks at their time of production and up until API SM (2004), any damage caused by ZDDP to the catalyst is already done. If they're the OEM catalysts on a '98 truck with 184k miles, they're well beyond their design life anyway, and are more likely to be (already) damaged by misfires and operational issues than the oil's zinc levels.

 

[Astro]

My engine seems to be happy with rotella t6 15w40. Been running it a while with no issues.

 

[Komet]

Whatever-40 after 180k miles is fine if you like seeing the needle go up more. Maybe don't run it if it's below freezing out. MMO might fix your lifter tick, the thicker oil won't. Diesel oils have a different additive package that isn't appropriate for your motor but you can run it anyway if you like. Snake sauces only sometimes work on the right kind of neglect-related issues, and never on mechanical failures.

 

[evilunclegrimace]

I have been running 15W40 in my trucks for over 36 years and have had zero problems ,on the occasion it is not available I run 10W40.

 

[jhornsby3]

Outside of the diesels, I run the 10w40 in everything. Mowers call for it. All three engines in the two boats calls for it. And the pick ups call for it. The pick ups get a full synthetic, The boats will be getting it this year. So the lawn mowers will be getting full synthetic next year. I put the, still good, oil from the boats in the lawn equipment.

The only difference between the motors in the boats and what is put in a GM vehicle is the block color and the marine add ons. The long blocks are the same.