Synthetic Blend Oil

[pbm]

My Daily is a 2000 Buick Century with the 3.1. It had 24k on it when I inherited it 5 years ago and has 108k on it now. It gets 5w30 High Mileage SynBlend in different flavors. Valvoline Maxlife, Castrol GTX, Providence (rural king). OCI’s are 5k. Engine doesn’t use any amount to speak of.

Like was mentioned before any SP/SQ is far better than what it would’ve gotten when new. Pick one and enjoy.

Has your Century had the intake manifold gasket replaced....the OE gasket were known to fail. I would do a UOA and check for coolant
and if present have the gasket replaced with an upgraded gasket.

I had an 02’ Buick century with the 3.1 in it and I only ran Valvoline MaxLife in it and it was a great oil with zero issues.

I also had a 2002 Century and ran just about every type of oil (dino, blend, syn.) without issues. It was a great car and regularly got well over 30 mpg on long trips (32 to 34 being normal). I did have to have the intake manifold gasket done but IIRC GM sent me a check for the cost. I would change the ATF every 30K to keep that 4T65 running well.

 

[MuzzleFlash40]

Has your Century had the intake manifold gasket replaced....the OE gasket were known to fail. I would do a UOA and check for coolant
and if present have the gasket replaced with an upgraded gasket.

Had the LIM done at 88k. Now at 115k the transmission is starting to get the firm shifts between 1-2 and 3-4. I’m going to try and squeeze by a little longer before I have it rebuilt.

 

[NavyVet88]

Has your Century had the intake manifold gasket replaced....the OE gasket were known to fail. I would do a UOA and check for coolant
and if present have the gasket replaced with an upgraded gasket.

I also had a 2002 Century and ran just about every type of oil (dino, blend, syn.) without issues. It was a great car and regularly got well over 30 mpg on long trips (32 to 34 being normal). I did have to have the intake manifold gasket done but IIRC GM sent me a check for the cost. I would change the ATF every 30K to keep that 4T65 running well.

The engine was replaced as soon as I got it because of that gasket. Long story short, I got the car basically for free just to help the previous owner get it out of his yard. I bought a used motor from LKQ for $750 and swapped it out. The gasket had long since went bad and it was milkshake city in that motor. The original motor that was in it had 199k on it.

 

[Japanese]

Had the LIM done at 88k. Now at 115k the transmission is starting to get the firm shifts between 1-2 and 3-4. I’m going to try and squeeze by a little longer before I have it rebuilt.

Would you risk the transmission with the new revolutionary Valvoline Restore and Protect ATF?
I think it will be worth the risk.
https://shop.valvolineglobal.com/products/valvoline-restore-protect-automatic-transmissionmission-fluid

 

[pbm]

Had the LIM done at 88k. Now at 115k the transmission is starting to get the firm shifts between 1-2 and 3-4. I’m going to try and squeeze by a little longer before I have it rebuilt.

I sold my 2002 Century with nearly 140K and it was running great at the time.....I just wanted something new. I had dropped the pan and changed the ATF (using Mobil 1 ATF) approx. every 35K and added a few extra magnets. I do recall reading that a 'shift kit' can fix the hard 1-2 shift (a rebuild may not be needed).

Here's what 'google' just told me when I asked about installing a 'shift kit':

"Yes, a shift kit (such as TransGo SK 4T65E) is a common and effective fix for the hard 1-2 shift (often code P1811) on a 4T65E transmissionmission. It works by recalibrating the accumulator system, reducing shift times, and managing high line pressure, which prevents the harsh, jerky shifts common in these transmissionmissions."

PS: I used to tease my daughters that I would leave them my Buick to which they would reply..."No thanks....it's an old man's car". HaHa.