What kind of motor oil do you use?

[Blue91Ex]

Very unlikely the cause of your leaks. Chances are, Promto used blended oil like the NAPA semi synthetic you were using. Mileage?

173k, as far as i know last owners kept up on maintenance fairly well. ive had it for about 20k

 

[swshawaii]

So that wives tale about synthetic oil in engines that have run non synthetic for decades, might have some truth. I had an oil change at prompto (usually do it myself) and I'm pretty sure they used synthetic oil, and now my engine is leaking out of like everywhere... Valve cover seal on driver side leaks, lower engine pulley looks like it is leaking, engine/trans area looks like it has a leak, it's not the filter or the drain bolt like I had hoped.. so yea. Worth considering maybe? After 3k miles I lost a bit more than a quart of oil. Never had this issue before. If you guys don't want this cluttering up the thread, I can delete it (of sorts) but I just thought a semi-brief follow up to my comment earlier might be helpful. I'm not saying this is deffinitely the problem.

May be time to switch to a high mileage oil that contains additives and seal conditioners to prevent leaks. Most major oil
manufacturers offer it, some full synthetic. Unless you rebuild the engine, something to consider on your next oil change.

http://www.pennzoil.com/motor-oil/pennzoil-high-mileage-vehicle/

http://www.valvoline.com/faqs/motor-oil/high-mileage-motor-oil/

 

[faco]

Why use 10W30 when it calls for 5W30? From what I have read, 5W is fine for summer, too, and it offers more protection during start up since the oil will flow easier than the 10W. if you are looking for more protection for the "summer heat", that change will not do it, and going to a heavier oil W+++ will rob you from start up protection while offering little "heat" protection.

Until recently, I have always used regular dyno oil and the recommended filter, at times a Fram. The oil was changed regularly. A couple of months back I pulled the valve covers to change the gaskets and found the engine to be immaculate, I was surprised that it looked that good at 160K. Still runs good.
However, since then, I am using high mileage synthetic (Mobile) as a precaution for seal maintenance. Will never be able to tell if the money will be wasted (since it would take two identical cars driven in the same way everyday, one with dyno and the other with syn to really have a better comparison), but it feels good in my head since I want to keep the car for a lot longer.

 

[Sweersa]

5W30 Valvoline conventional

Change every 4k

V6 4.0

 

[illinibbfan]

Amsoil Signature Series 5W-30, and some Purolator Synthetic filters I got on sale (they were getting rid of old model to make way for the new "BOSS" series).
Oil may be overkill, but I like the additive package to reduce engine wear so the ol' 2004 will keep running a few more years!

 

[Josh P]

I run Mobil 1 full synthetic. I use a napa gold 2 quart filter. 12K interval on the oil and 6K on the filter.

 

[Bulletslinger]

Valvoline Max Life Syn. Blend 5W-30 with either a MANN filter or Motorcraft.

 

[drdoom]

Motorcraft synthetic blend.

 

[LMHmedchem]

With my gen1, I used Valvoline Max Life and a Moblie 1 filter. With my gen3, I have always used Mobile 1 Extended Performance. I will be soon be switching to Mobile 1 High Mileage. I am also switching to the Motocraft filter since they look that same inside as the Mobile 1 and cost about 1/3 as much.

LMHmedchem

 

[kifferarri]

I've been using mobil 1 5w30 in both the ploder and mustang with motorcraft/mobil 1 filters (when I can get the mobils on sale anyways)

 

[cjben]

pennzoil platinum full syn in the manual recommended wieght for the vehicle in everything I drive or take care of(kids cars). 2005 focus(mine) 1996 f250 w/460( my old truck,no leaks with syn oil) 2004 4.6 4wd explorer(fiance's and people hauler) 2000 escort zx2(my son's car) 1999 escort lx(her daughter's car). I could just about open a full service garage just with family vehicles. lol

 

[rangermidtn]

Royal Purple and motorcraft filter.

 

[TechGuru]

Castrol 5W-30 + Motorcraft FL800S. $20 oil changes.

 

[BobRob]

Bertolli EVOO and a coffee filter.

 

[drdoom]

Bertolli EVOO and a coffee filter.

Human jet fuel baby!