The last time I got my oil changed, the fella told me he'd like to put in 10w30 oil. I have a 2000 Saturn with just over 100k miles that's supposed to use 5w30. He said the reason was that the thicker oil was supposed to be better for cars with over 100k miles.

Is this true?

Also, I'm about due for another change, but within the last week or two, my engine has been acting weird. If I push in the clutch for while, for instance, to slow down for a red light, the engine idles dangerously close to shutting off/dying - ~3-500 rpm (Normally idles around 800-1200 rpm). The lights dim, if the heater's on, the fans slow, etc.

Could the thicker oil that my car isn't supposed to be using be causing this?

As a side note, I'm not a total car-tard, I've gapped a few spark plugs in my day, replaced a head gasket, etc.

That extra oil thickness isn't enough to cause any problems. The reason it's done is the piston rings start to lose their seal with age and wear and using a thicker oil helps to lessen the effects of this, acting as a band aid of sorts.

Your low idling problem could be a few things. When's the last time you've replaced the air filter or fuel filter?

guy who changed your oil's a tool, you should be using thinner oil, if anything different, with older cars, to put less stress on the engines. but since every old car has a leaky seal or two, you'll end up having to put oil in it more often when you go to a thinner oil, but as long as you consistently check the oil levels, you'll be better off with a thinner oil.

i drive an 88 camry with 160k miles (still gets 33mpg, holla) so i know my way around beaters

And this is my essential problem. Two people who sound like they know what they're talking about offering completely conflicting ideas.

Tell ya what, I'll do whatever the first person to offer their answer in the form of a lolcat tells me to do.

Also, wouldn't that be awesome if there was like an online Jeopardy game that you had to answer via lolcat?

lol, there's a reason that synthetics are used exclusively in racing, and it's because syn can give the same level of protection with a thinner base stock than mineral oil. Thinner oil is easier to pump and lowers the oil pump load losses as well as allows parts to move with less oil drag.

so, unless you're going to let the oil reservoir go dry, go thinner for better performance

The place I get my oil changed checks the air filter every time, and I get it replaced regularly. (I've been going to the for years and trust them pretty well)

As for the fuel filter, I'm not so sure. Sadly, my mechanic recently retired, and I don't have the equipment to do it myself. I guess I'll ask them about it the next time I go in.

It can be somewhat difficult to diagnose your low idling issue because there are several small things it could be. If you have the time, I would search for an internet forum that is dedicated to your car and do some searching there.

I would not recommend using a thinner oil under any circumstance on an older car. It is easier to pump through the system, but piston ring tolerances, and the tolerance of other lubcricated parts in general get looser with age, a slightly thicker oil will pick up some of this slack. A thinner oil will make the problem worse and result in increased blow by through the rings and burning more oil.

This is the opposite of every mechanic I've ever heard and also every article I can find on the internet.

Sounds like both sides are saying the same thing:
Thicker oil engine runs cleaner but harder.
Thinner oil engine runs easier but bluer.

You just have to pick.

This may sound like a good idea, but I know better. The extra "stress" put on the oil circulation system is negligible. As someone before me said the thicker oil acts like a gasket between the rings and cylinder wall which results in better power. Also my dad is a professional mechanic and has taught me a lot. BTW I've always owned beaters and have done all the work myself. I've never brought a car to a shop.

Oh, and screw your 160k camry. I have a 93 GMC pickup with 267k. That's right, over a quarter million.

And, your a tool for driving a camry.

all you have to do is ask

Low Key, I roll a 94 4Runner with 164K. I use the high mileage Synthetic Castrol. Its 10W30. You should go with that. Its more expensive, but cheaper then fixing tons of ****.

Wrong.

OP, listen to your mechanic or everyone in this thread except kkcountry.

sick

Low Key-
i have worked on cars since i was a kid...even tho i'm a girl, i learned from my dad then took a couple auto mechanics classes in college. I totally know this and agree w/all but KK. I have the same transport as Saltcracka..use same oil- w/o any problems. FTW.

Re: the way your car is running- sounds like your alternator and/or timing belt needs replaced or just timing adjusted. Your Saturn may have a serpentine belt- which runs it all, so check that.



mine is '93 and f-ing rocks. You went up in my book sir.

why is he a tool for driving a camry?

yeah, i don't mind admitting i'm wrong when it comes to the oil question (i guess i forgot we're not all driving formula 1 cars lol) but i totally don't get this either

I know a car isnt a person, but like a doctor you are allowed to get a second opinion from another mechanic.

The other thing, as others have said, could be any of a number of causes. Go see a mechanic ftw.

Edit: as in most cases, seeing an expert is infinitely better than asking the opinion of a bunch of anonymous people on a totally unrelated web forum.

I'm gonna set it straight for everyone here. Most of you are on the right track but have a few details mixed up.

A. If you're burning blue smoke out of the tailpipe, that means you're either in need of a re-ring, as the oil rings are allowing oil on top of the piston, where they are burned into smoke and expelled through the exhaust valve or,
B. Your exhaust valve seals are worn, allowing oil into the exhaust from the top of the cylinder head. You should never see blue smoke in the tailpipe under normal operation.

Thinner oil vs. thicker oil. It is highly recommended that you stick with the manufacturers oil weight rating for the most part. However, as an ASE certified engine specialist I have used THICKER oil in car with high mileage. When engines are built, the usual tolerances for gap clearance for your crank and rod bearings, generally fall between .003" - .005" but in rare occasion may be as loose as .007" and tight as .001". Depends on the maker. As time wears on, these gaps become larger, say .0005" for every 100,000 miles. The only time I switch to a thicker grade of oil for any given vehicle, is if I can still hear engine ping (which is a very light tap) right after an oil change. Old oil will start to ping in high mileage engines after about 1,500 miles. BOTTOM LINE - new engines have very tight gaps in the bearings that touch the crankshaft. If you have an oil consumption problem, (where blue smoke is coming out of the exhaust) Putting thicker oil in your motor will not allow proper flow through the gaps between crucial bearing surfaces on the crank. This could cause premature bearing wear due to inadequate lubrication and could lead to very expensive engine repairs down the road. The best thing to do in a blue smoke situation is to decide. Either you pay a mechanic like myself to find and correct the problem or, you deal with it and prepare to pay attention to your oil levels. And constantly adding oil to your engine does not substitute an oil change, even if you do change the filter every few thousand miles, as sludge still does form up.

Lastly, SYNTHETIC OIL - Synthetic oil by definition, is a lubricant made by man with little or no natural petrolatum. Synthetic oil molecules are much smaller and more uniform in size, allowing better distribution of forces and pressures that help to reduce friction between steel surfaces that make dynamic contact, (piston rings and cylinders for example) It is because of these smaller molecules that people commonly find more oil leaks, as they are capable of leaking down between smaller cracks and crevices. A good example to understand what I'm talking about is 2 jar of marbles. one jar has small marbles all the same size whereas the other, has all different size marbles. The jar with the smaller, same-sized marble represents synthetic oil. Obviously the other jar represents conventional oil, in which the larger marbles will sometimes plug tiny leaks. Oil weight has nothing to do with it. Weight is determined in a lab by SAE and defines the oil's ability to protect at certain levels of friction and temperature.

I think that about covers it. If I missed anything, feel free to comment.

The dates of the posts, apparently.

Lots of research though...

Sick bumpe.

I wish KK would post more.

lol, how on earth did you come to a 4.5 year old thread to give that advice?

Also, I thought any thread past whatever recent date the forum was upgraded was in the archives and not possible to bump anymore?

You should have said this oilier.

Yeah but then I might risk being wrong on the Internet more often than once every 4.5 years