Im about to have all 4 o2 sensors replaced with NTK ones, the front and rear main seals replaced, the optispark and water pump, the oil pump and oil pan gasket along with the oil level sensor. I was wondering if I should go with conventional oil or throw in some royal purple or some other synthetic? If so which one do yall suggest? The engine has 111k miles

 

What oil have you been running up till now, conventional or synthetic?

 

conventional is whats been in it. i bought it a year ago and left that in it til i got the engine work done. no since in good oil pouring out on the ground lol

 

Complete waste of money to put new O2 sensors behind the cats. That position does NOT affect engine performance so the only time they should be replaced is when they throw a code. At that time I would take one from in front of the cat and put it there and put the new one in front of the cat.

The ones in front are for feedback to the pcm, the ones after the cat only tell the pcm whether the cats are functioning.

Far as oil, it really does not make much of a difference. If you want the best based on measured data in THIS engine then Castrol Syntec specifically 0w-30 labeled "made in Germany" is it.

I have not kept up on it in awhile but when I did Royal Purple was good for racecars but not so good for the street. The running joke was "sheared out of grade pouring from the bottle". Meaning you dumped it in as a 5w-30 but when sampled and tested after use it was 5w-20.

 

So basically its pointless to spend the extra money for synthetic

 

royal purple is a waste of money. I can't find the article I was looking for but heres some info on it from a forum http://forums.tdiclub.com/showthread.php?t=244401

 

Guess Ill stick with Havoline 10-40

 

Hey has anyone found Castrol Syntec made in Germany local?

I can never seem to find it and lately have been running Amsoil Synthetic in my engines I care about...

 

Autozone and Pepboys are the only places I've found the German Castrol.

 

i always choose sythetic when i do an oil change, Cant really tell over time whats better unless you own the car since day one and you have a lot of miles and compare it to a car with gen oil. I used royal purple in my past car and with everyone saying how you can tell the diff is retarded. I couldnt tell a diff at all, except the color. I just purchased a car and put sythetic in with a bottle of Lucal oil stabilizer since thats what the prev owner was using. My advice is to just get some good oil that is on sale at Autozone or whatever you prefer. I think the most impportant thing is the filter anyways

 

Been using the AC delco filter

 

I always use a fram

 

Fram filters actually have been proven to be a less than ideal filter.

And I had a friend blow a Ford 351 from a faulty Fram. Manufacturing defect that left him with zero oil pressure. Combine that with an idiot mechanic he took it to who let it idle in the parking lot too long ... and it ended up being a toasted short block in about 15 minutes.

I use K&N, the good Purolater, or Mobil filters. Whatever is on sale.

 

well faulty filters I believe can happen anytime. Ive seen purolater and i will trust a fram over them anyday. As far as K&N ive heard bad things about them also.

 

Research it. MANY people have had trouble with Fram. And they don't filter as well as other brands. It has been proven test after test after test. Their just not good filters.

I am not saying you can't get a failure in anything... I had a Purolator filter fail on me (pin hole in side of filter - could not even see it but it sprayed oil everywhere when under pressure)

And the K&N and Mobil are made at the same plant, same filters. Only difference is the K&N Brand gets the 1" nut on the bottom (which is convenient - all brands should do that). I have never heard of anyone ever having a K&N or Mobil filter collapse inward on itself, or fail, causing lack of oil pressure.

There are a ton of great filters out there.

Actually WIX is a kick *** cheap filter as well.

Joe