Hi All,

I have a 96 Sport, and I changed the oil the other day, and added some of that STP honey stuff, since I figured that when it gets really cold, it will be not to not have a dry start (we are in new england)

and maybe this is a coinscidence, but now the truck seems to run a bit rougher - including the idle.... almost more of a vibrate than a miss...

when I hit the gas, it's a bit louder too, and seems to vibrate more than it used to... almost like the engine is working harder than it has to...

So, I guess my question is, can too thick an oil cause the engine to run like that, or am I just going nuts?

just changed all the plugs and wires 2000K ago, and ran ok until this oil change...

could I have a plug that is started to foul out?

Thanks

 

it might be a concidence, but i NEVER add anthing "magic" to the oils, weather it be engine , transmission, or axle.... you need a friction modifier in the axle to assist the slip clutch, but as far as im concerned everthing for the engine and transmission is snake oil and will at best do nothing, and at worst change the addative package of the oil as it was designed from the refinery-- for the worst. drain it out and change to see what happens. when it gets really cold, you for sure dont want honey in the motor!

 

In the winter you want a lighter oil. A thick oil takes longer to flow through the passages and build pressure, so its actually worse as far as dry starts are concerned. Many people are under the impression that a thicker oil will stick better, and to a certain extent it does. But over a 24 hour period, I feel that just as much thick oil has drained off the parts as the thinner oil.

If you really want to protect from dry starts, use oils like Royal Purple, Amsoil, or Redline. These high quality ester based oils have very strong surface tension and that causes them to stick better without being thicker. True synthetics also tend to be more thermally stable, so they will maintain a lightweight viscosity better in cold weather.

 

yeah, I love Amsoil, but never used Royal Purple...

would that honey stuff with 10w/40 make the engine run rougher though? that is my question... maybe I'm just paranoid....

I never stalls, and seems to shift ok, so I guess I shouldn't complain, but still, it would be nice to figure out if the oil caused it...

would 10w30 be better for winter? it's still a 10w oil - I have always run 10w40 in all 3 of my v6's, and they seem to like it year round... including my Aerostar...

does anyone have a solution for the 3.0L engine that's in my aero, to get rid of first 5 mins of a stuck lifter? it's louder when it's colder outside.... but after like 3-5 mins, it seems to go away... I tried the lucas stuff and the seafoam - still doing it...

 

Can I switch to say, Mobile One synthetic right now without changing the filter? (do they mix?)

in other words, if I just pull the plug, and do a drain, and then add royal purple without also changing out the filter, which would still have the organic oil in there, will that hurt anything?

or should I just drain it, and replace it with 10w30 (instead of 40) or switch to a 5 weight oil?

I don't know the word on mixing a good synthetic with the 10w40 valvoline that I used...

 

I run 5W30 year round in my '94. Not sure why you would run a 10W30 or higher. I believe your '96 recommends 5W30.

 

If you are going the oil brand, you should change the filter as well. I don't think any of this explains why the engine is running rougher.

 

10 weight is better for the hotter weather, and with older engines because it increases oil pressure...

I'll have to drive it some more to see if it's just me, or what, but thanks for all the tips - I'm still curious though if the synthetics are mixable, that is, if I have mostly 10w40 in there now, can I top off with a good 10 weight synthetic, etc... or should I drain it all and start over?

 

Drop the idea of using 10w oil. Your motor hates it. Run a good 5w oil instead. 10w oil is for older engines, not old engines. Ok, that was as clear as mud. Heavier oil is for like 80's and 70 era type engines or engines that are excessively worn, not the new breed that came out in the mid to late eighties and 90's. The new engines have tighter tolerances and require lighter oils. A heavy oil will just overwork the pump and cause dry starts. Heavy oils will also cause more heat build up and reduce the engines efficiency. A heavier oil does reduce consumption if you have oil leaking past rings or valve guides, but it is more important to get adequate lubrication than to seal the engine.

I would switch to a good 5w30 oils and use it year round. You could use a 5w40 in the warmer months if you wanted to.

And yes, you can mix the synthetics with regular oil, just try to get most of the old oil out. The main point about mixing oils is that you should mix different oils together to save money or alter the chemistry. I know that some people would try making their own synthetic blends by mixing synthetic and regular oil in an effort to save money. But oil is a weak link thing. If you have a blend, the oil won't last longer than conventional oil, since the conventional oil starts breaking down first. The exception is when the blend is carefully engineered and the correct additives are added. Even then, it won't last nearly as long a good full synthetic.

So to sum up, your engine is not an older engine yet, I have a '94 and I run 5w30 through it, yes you can mix it with regular oil (just plan on changing it in about 3,000 - 5,000 miles), and so long as your oil pressure is good, you do not need a thicker oil.

 

I have a 2000 explorer with the 4.0 SOHC and it recomends 5w-30 year-round in the manual so thats what I've been using for about 70K miles. I've been putting in Mobil 1 full syn for about 55K now and my engine seems to be loving it. I found it to work well and so im not changing it!

 

I always thought that a thicker oil would give you better compression, thus more power, and better MPG, plus of course, less wear, because of the thicker film between moving parts.

Plus, with a thinner oil in the summertime, (non synthetic) I always heard that the higher heat would break the oil down, and cause premature wear...

I used to run 5W oil in the winter, and 10 in the summer, but then my intervals got all screwy, and so I just stuck with 10 all the time....

Everyone seems to swear by Mobil 1 syn for everything... I guess synthetics have come a long way since the early slick 50 days :-) -

maybe I will just try a good 5w30 in there for now, esp since it's getting colder, and see if the engine likes it better :-)

Thanks Bear