Switch to syn on high mileage GM?

[au13n0]

OK everybody, tried searching this to no avail---probably has been discussed to death but I couldn't find it. I have an '05 Chevrolet Colorado crew cab 3.5 I5 w/135,000 miles and have always used Valvoline dino at 5,000 OCI. Last several filters I've used K&N Gold. No issues or leaks with engine to date. Was thinking of going full syn at next change, or possibly Valvoline ML. Just thinking that a little extra protection couldn't hurt, but am kinda slow to pull the plug on what has been working. I've changed to full syn from dino on another truck but it was a 6.0 at 60k miles.
Anybody have experience/facts/intuition on this switch? Any insight would be appreciated.

 

[oilboy123]

Should be fine. It would be nice to do a run of RX to get the full benefit of the syn oil first.

I have switched a lot of cars with no problems.

 

[daves87rs]

Will be just fine....

 

[mrsilv04]

If you can get your hands on some MaxLife full synthetic, that's the route I'd go.

If not, use the MaxLife Semi-synthetic. It's a good stout, proven oil.

I use it in a Grand Am with 100,000 miles on it, and it works well.

 

[ARB1977]

I would stick to what your using now...why change if it isnt broke.

 

[ZZman]

Try it............love it.

 

[au13n0]

Originally Posted By: oilboy123
Should be fine. It would be nice to do a run of RX to get the full benefit of the syn oil first.

I have switched a lot of cars with no problems.


RX? I'm assuming you're talking about a treatment to clean out old deposits/sludge etc... before syn...sort of a mechanical laxative. What product seems to work best and how long to cycle? Thanks...

 

[SilverC6]

All the old wives tales regarding synthetic oil are dead.

Switch it without concern.

Many of the current synthetics, like PP, tout great cleaning ability.

I would let the new oil do your clean up work for you.

 

[Papa Bear]

I would have run syn to 135k then switched to dino for the autumn of it's years.

 

[ArrestMeRedZ]

I'm replying to "Watched Topics" this thread. I'm interested because I've got 2 '06 2500HD Silverados with close to 100k miles that I've just switched over from lube shop bulk to PP.

The trucks haven't been abused, but they are used commercially, and haven't had the attention (up to now) I give my personal vehicles. I know the oil hasn't been changed before the computer indicated the change was due.

 

[oilboy123]

Originally Posted By: au13n0
Originally Posted By: oilboy123
Should be fine. It would be nice to do a run of RX to get the full benefit of the syn oil first.

I have switched a lot of cars with no problems.


RX? I'm assuming you're talking about a treatment to clean out old deposits/sludge etc... before syn...sort of a mechanical laxative. What product seems to work best and how long to cycle? Thanks...


Even if you have run regular oil changes you will have some deposits. The synthetic oil will be trying to clean them out. Auto-RX gives you the most benefit when switching over to a syn oil. You start with a clean slate.
It cleaned out stuff on my car that had run most of it's life on synthetic. I now run a maintenance dose with synthetic oil.

 

[StevieC]

IMO GM vehicles have never had great luck keeping their oil where it should be. They generally are habitual leakers or burners once they start to see the higher mileages.

I would stick with what has worked for you up until now. Why change it if it isn't leaking?

 

[GMFan]

Do what you've been doing w/ the Valvoline dino every 5k miles and don't worry about it.

No real need to run Auto RX or HM oils IMHO.

 

[gfh77665]

Originally Posted By: Papa Bear
I would have run syn to 135k then switched to dino for the autumn of it's years.


Thats what I do. I switch to good dino (actually MaxLife syn-blend) at 175-200K miles.

 

[Triple_Se7en]

Use the Maxlife synblend -- then only drain the K&N filter at 5K - then reinstall the same used filter for another 5K. That K&N filter can easily withstand another 5K -- plus filter better the 2nd time around. I own the Colorado also -- same 3.5 engine from 2004.

I run synthetic for 7K -- using the factory, non-ADBV AC Delco PF-61. Your filter is an upgrade/step-up from the AC Delco.

 

[au13n0]

Thanks for all the input. Can't seem to find any auto rx retailed locally---looks like its a manufacturer-only item---and I hate to wait around for shipping. Is there a comparable cleaning agent that I can pick up at a local parts store? Thanks again.

 

[chevrofreak]

Originally Posted By: au13n0
Thanks for all the input. Can't seem to find any auto rx retailed locally---looks like its a manufacturer-only item---and I hate to wait around for shipping. Is there a comparable cleaning agent that I can pick up at a local parts store? Thanks again.


No.