5W vs 10W oil

While our Jeep is sitting ready for our snowy & cold Chicago weather, I took my son's 2004 Impala LS in for a local shop oil change... The records show he has been using a 10W high mileage oil - 92k - However, the engine cap & manual indicate 5W should be used.

In surfing, it appears that 10W is recommended for older cars with looser engine tolerances.... and newer cars should use 5W with tigher engine tolerances.

So - is it only a viscosity thing ? Any issues with the 10W high mileage oil vs a 5W version ?

tnx -

Reply to
ps56k
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found this PDF among tons of other info -

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SO - for the Chicago winter, should I leave the 10W high mileage, or go back and get it replaced with 5W (as GM says) high mileage if avail ?

Reply to
ps56k

Yep.

Only in severe cold.

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I'm not a fan of the amsoil hype.

"depends" as in depends on how much oil you leak or burn. If you're not burning any oil with the regular 5W30 then why change. Besides, "high milage" is more of a sales pitch. A "high milage" engine can be in as good condition as a low-milage one.

Remember, the lower number is the viscosity when the oil is cold. The lower, the better it flows while your engine is warming up.

I use 10W30 for general weather but if the Jeep will be up in Colorado winter I switch to 5W30 synthetic. And it's a 93 with nearly 200,000 hard miles on the clock.

It also "depends" on where you are in Chicago. Last week Schaumberg was nice for the most part. South of O'Hare was a different story.

Reply to
DougW

Some engines require the 5W-xx type oils, since it isn't a jeep no idea about the Chevvie. One issue that *might* be a problem would be for the specific oil and type--it may be a bit too thick at Chicago temperatures to lube properly for the first few seconds at startup.

Reply to
Lon

Just as a point of info. Last week I put a motor in a Caddilac CTS. The extended warranty that the guy bought with the car(*not* a GM warranty)refused the claim because he hadn't been using the Mobil 1 that GM requires for that engine. Not saying the oil was the cause of the problem, just that the warranty company used it as a convienient(sp?)excuse to deny the claim.

Reply to
Old Crow

extended warranty that the guy bought with the car(*not*

I'm not sure they can actually do that. He needs to take the insurance company to court providing it simply wasn't a case of pure neglect.

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But then again I'm betting that warranty was one of those "as seen on TV" car insurance policies. 99% of which are simply a ripoff. BBB has tons of complaints against most of them, especially U.S. Fidelis.

We had one of our folks at work get ripped off that way. Tried to warn them but nooooo, the deal was just so good.... Now the idiot is mad at me for not warning him LOUDLY enough.... sigh, every villiage has at least one idiot.

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Shorter version of link above:
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Reply to
DougW

Which MAY put them in violation of federal law, but I suspect that what you call a convienient excuse in fact is just reality, the owner should have used the lubricant that the manufacturer specified.

Reply to
PeterD

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It was CNA, which is ordinarily pretty good about repairs. They ended up paying 1/2 the price of installing a wrecking yard motor. The motor they found actually had less miles on it than the original, and the car runs fine now. He's only had the car several months and when we changed the oil he didn't want to pop for the extra cost of the Mobil 1. The factory specifies M1, it's marked on the oil filler cap, mentioned in the owners manual, etc. The teardown and diagnosis was done by a Caddy dealer, but we did the repair because of the deal with CNA. I saw the old motor and all the bearings were wiped out as well as the heads(overhead cams with no bearing inserts). Looked more like an oil pump failure to me, but by the time I got it, it was a done deal.

To bring this back OT, I just used Castrol High Mileage 10w-30 in the '95 Wrangler YJ(115,000miles) I bought my wife for Christmas. I also started using it in my '94 YJ. The next oil change on this one is due at 300,000 miles. I think it actually cut oil consumption a bit over the regular Castrol GTX I used to use, but I have to get the valve cover resealed before I can tell for sure.

Reply to
Old Crow

they found actually had less miles on it than the

we did the

I'd have to suspect pump failure too, or starvation (broken pickup?). A slight difference in oil viscosity isn't enough to do that type of damage unless you are in the Arctic. There isn't anything "magical" about M1 like there is with some tranny and brake fluids. There has to be more to this story. Overtemp, starvation from overreving, oil additives or water in the oil.

I swear the valve cover in my 93 hates me. I'm >< this close to welding it on. Strange thing is it doesn't leak down the back, it leaks over #3 piston and there isn't bend one in it.. both head and cover are dead flat. Still using 10W30 Castrol Syntec with no real loss between changes. 162,000 and still under the blower. Just finished up getting the tranny output shaft seal redone. so it's one less spot in the driveway.

Reply to
DougW

Just checked the O'Reilly's web site. They list 2 different gaskets for the 6 cyl. Both Fel-Pro, one priced and $6.69, and the other at $45.99. I wonder if the expensive one is really all that much better? I don't think I'll be the one to find out.

Reply to
Old Crow

Nor will I. 46$! Thing must be made of gold or painted rice racer yellow.

My 93 I6 is supposed to use a form-in-place gasket. Basically a bead of RTV like stuff that is supposed to be "reusable" but hardly ever is.

Reply to
DougW

From the pics the expensive one appears to be a silicon "spaghetti" type while the $6 one is cork. This'll actually be the first time I've done this particular one, but then it's the 6th Jeep I've had so it's not like it'll be the first one I've ever done.

Reply to
Old Crow

Check your tightening order. Mine finally quit doing that when I got real picky and made sure that I snugged the one over the leak point (#3, just like yours) then got all the rest finger tight. Started at the leak point and worked both ways going about half a turn on each bolt until all were tight. PITA to do it that way but that gasket has held tight for over 5 years now.

Reply to
Will Honea

If you have the plastic type cover, beware getting crazy and overtightening it. Makes the leaks worse. This is a 95, where the gasket material may be different.

Cork gaskets are nice, but if over compressed don't recover as well as silicon or synth rubber ones. Not that whatever is under the mopar cover does either... Someday I'll put a hesco aluminium one on.

Reply to
Lon

Many modern engines just dont work well with non-synth. e.g. the variable displacement hemi where it appears many early problems with mds were owners and even a few mechanics who "knew more than the designers" about proper oil.

Pure synth doesnt seem to have any negative effects on the old I-6 even with high mileage, but thats another matter best avoided before the ams*1l loons grep in and clutter up the froup.

Reply to
Lon

up getting the tranny output shaft seal redone. so

the leak point and worked both ways going about half a

I'll do that next time. Generally I work my way out from the center in a couple of runs but doing it in one shot might work better.

The 93 has an aluminum valve cover and uses a bead of sealant that is supposed to be reusable (factory applied) but it long gave up. Last time I tried cork it leaked down the back so I went back to using just permatex form-a-gasket.

Reply to
DougW

I wasn't sure which you had - that plastic is a leak-by-definition AFAIAC. My son had a 94 XJ with the aluminum cover and wanted something to hold "for one trip" - you know those kinds of fixes I'm sure. We pulled the cover, cleaned the cover and head with brake cleaner, then took a tube of hi-temp silicon (sensor safe type) and laid a heavy bead all around it. Took a putty knife and tapered so that it filled in a triangle from the inner lip to a fine line at the outer edge. He had some 3/16 doweling on the bench so we cut some lengths and stuck it in the 4 bolt holes for a guide (as well as keeping the holes clean) and set the cover on while the RTV was still wet. Pressed lightly just to get it in place then let it set for 3-4 hours before putting the bolts in and tightening them with a screwdriver handle and a socket. That set overnight and he took off the next day - Colorado to CA back to Texas and home to CO. No leaks and it was still holding when he sold the XJ about 4 years later. I'm not sure what was more important: really clean surfaces or getting it down so that the bolts applied just a little pressure to the semi-cured RTV to compress it. Mike Romain always swore that the clean surfaces and silicon was the solution and thought the gaskets were useless so we tried it.

Reply to
Will Honea

Having worked for GM as a service tech for over 20 years, I'd vote for the clean surfaces. I've had to virtually destroy oil pans that were installed correctly with silicone to get them off of engines. In fact, this is probably the method I'll use to repair mine when I get to it. I get to spend over a grand in parts after the holidays to repair all the little crap that's gone wrong on the Jeep my wife's been driving for the last 5 years. With my luck, after I get it done she'll want it back and leave me the '95 4 cyl I just bought her. Either way, I'm OK, both the Wranglers have better heaters than the '61 F100 I've been driving.

Reply to
Old Crow

LOL! We drove one of those for years before Dad died - he bought it new. Same problem after a while. Yanked the heater core, threw it in the tank and soaked it for a few days. Sucker was plugged almost solid with the accumulated gunk from using well water in the cooling system and the annual flush never got any of it out.

After a loooonnnngggg soak, it would run you out of the cab. Lots more comfort than you'll get out of fixing the wife's Jeep.

A little off topic, but do you know of any solvents for that silicone/RTV stuff? A local outfit that refinishes bath tubs and such actually refuses to work on any appliances in a bath that has been sealed with silicone - claims he can't get it off and any trace screws up his finish.

Reply to
Will Honea

I saw a mechanic split seals with spiderwire fishing line between two dowels, just like a garrote. That was on a diff cover though. Dual purpose tool.

One other tool that works is a cut down trowel. Just turn it into a flag looking contraption and sharpen it like a draw knife. It will need a better bead on the shaft to hold it together.

Reply to
DougW

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