So... Guess I should have stuck with SAE 30?

[glum]

I have the same walk-behind lawnmower I've had since 1999. It has a 6.5 HP Briggs & Stratton "INTEK Edge" engine.

Until this year, I had always used SAE 30 in it. This year I had some SynPower 5w30 in the garage and decided to use it instead. They say synthetic 5w30 is OK, just that it might increase oil consumption.

Yeah, that it did.

Soon after the oil change, I noticed a lot of oil burning (i.e. blue smoke). The exhaust pipe and surrounding area also has a lovely coat of oil.

So, I changed back to SAE 30. This seems to have reduced consumption a bit, but it's still noticeable. I don't remember noticing this at all in years past.

You think the syn cleared out some pseudo-sealing gunk around the valve stem seals or something?

 

[greystone]

I did the same thing with a perfectly reliable briggs. Thru some Mobil 1 in it and slowly lost compression the rest of the summer until it would no longer start.

Had no problems on SAE 30 the 4 years previous.

 

[dparm]

You shouldn't judge a new oil formulation until it's been in there for at least one OCI. Many cars will see increased or even decreased consumption immediately after switching oils, but it will stabilize at the next OCI.

 

[justinf89]

Do you think the high temps of being air cooled caused it to shear? Now you have me worried. In my new honda gcv190 mower (HRX218) it says 30 weight can be used in hot weather but 10w30 for everything else. I just put 5w30 in because I didn't think it mattered but with 100F temps, I think I need to change it out a little sooner than normal.

 

[greystone]

I replaced mine with a mower that had a GCV160. The Honda engines seem to be designed for multi grade oil.

The briggs started burning oil almost immediately after putting in Mobil 1 and only ran 4-5 more times before it lost all compression.

could have been a coincidence but?????

 

[glum]

I don't think the problem was shearing. I'm researching the problem now. The manufacturer site says "Briggs & Stratton offers a Synthetic 5w30 oil that provides the best protection at all temperatures as well as improved starting with less oil consumption." I don't know who makes their oil but SynPower 5w30 ain't junk. My owner's manual says the syn 5w30 will cause increased consumption... Maybe their new engines are tighter or just more compatible with syn oil.

 

[Michael_P]

Tolerances vary greatly from one engine to another so results may vary. When I mean vary greatly, I'm talkin a thousandth or so.

 

[Stu_Rock]

I've had three B&S-powered lawnmowers, and they were always fine on whatever automotive 5w30 I had at the time. Including Mobil 1.

(why so many mowers? the deck rusted out on the first one; I sold the second one along with the house; the third one is running just fine--currently on Chevron Synthetic 5w30 from Big Lots in 2007)

 

[glum]

I'm wondering if the breather got loaded with oil when the mower was tipped. Seems like it would have worked its way out by now though.

 

[glum]

I must have been having a bad day when I changed the oil using syn 5/30. The owner's manual plainly indicates that syn 5w30 or 10/30 is only to be used up to 40F. Here, I had been using it at an average of 90-95F. So I guess I may have caused a significant amount of engine damage.

 

[Spazdog]

Hmmmm...

I've been using Quaker State Synthetic 10W30 in my Briggs and Stratton since 2006 in 100°+ temps.

I just switched to Green Earth Biosyn 30wt on the last change.

Then I dump the used oil in my 1996 3.5 B&S when I change it 'cause that one just pukes oil out of the exhaust anyway...there's no reason that thing should run but it still runs.

Maybe it was just your mower's time

 

[glum]

B&S makes a huge number of different engines... Some probably accept different oil than others. What I don't understand is that for conventional 5w30 and 10/30, they depict (in a chart) that it's only good up to 40F, but then add a proviso that if it's used at temps above that, increased consumption will result. But no such proviso for synthetic.

 

[TFB1]

Well I did a Mobil 1 0W-40 change on my '81 Snapper with a 3.5Hp B&S and it thew the rod two cuttings later...

Do I think the oil caused the rod cap to bust??? Nope not a chance... The crank journal was still perfect, apparent cause was a slightly loosened rod cap bolt... No the oil would not cause that either, most likely was due the years of heat/cool cycles... Even the engines of 30 years ago weren't built to last forever...

 

[Michael_P]

Slinger style lube systems don't seem to toss low vis oils as well.

 

[Superbuick96]

I noticed oil burning issues using Mobil 10w30 conventional in my 675 briggs, switched to Quaker State conventional 30wt...Havent ran it yet, hopefully it helps with the oil consumption

 

[deeter16317]

I just changed a newer 207 "cc" version B+S Intek from whatever the PO had to 5w40 synthetic...it produces no smoke (it smoked before), and runs fine...

Didn't even have a manual to read, just changed it over...I have about two hard hours of running on it, and it seems fine.

But reading this thread makes me wonder...I couldn't imagine a 5w30 weight oil being THAT different at operating temperature than a SAE30?

 

[glum]

^ That's what I don't get. I thought a 5w30 was supposed to have the same essential viscosity at high temp as SAE 30 would. I must be missing something...

 

[TFB1]

Originally Posted By: glum
^ That's what I don't get. I thought a 5w30 was supposed to have the same essential viscosity at high temp as SAE 30 would. I must be missing something...


It's been my experience over the years that a multi-vis oil is always consumed at a higher rate than a single weight oil, this is mostly referring to a engine that does have some consumption... The Mobil 1 0W-40 I put in the mower that blew the engine lasted only one cutting before it needed a add(I topped it off with some 30W AAP oil)... On prior changes it would go two to three cuttings with 30 or 40W before I'd have to add...

A couple years ago I had it over at my parents and it ran low on oil, so I added some type "F" ATF that pop had for one of their older cars... It ran fine but but swilled that stuff like a couple back alley drunks with a cheap bottle of wine...

 

[JTK]

Originally Posted By: glum
I thought a 5w30 was supposed to have the same essential viscosity at high temp as SAE 30 would. I must be missing something...


You're not missing anything. They're both 30wts at operating temp. I really don't think that oil, in and of itself was the demise of this engine. What ever happened just happened to take place in that particular time-frame.

They say multi-vis oils "can" cause increased oil consumption. I've never seen it. Once an oil burner, always an oil burner. In that case, going 'heavier' can slow it a bit.

 

[caprice_2nv]

I have a 1981 Mastercraft lawnmower with a 3hp Briggs. It has tons of hours on it, my parents had it since new and had to cut a very large rough yard with lots of rocks for it to hit. The last several years of usage it never got any maintenance, just topped off the oil once a year, it would be down a slight bit. Never any smoke.

Now were using it at my work since their old 90's Honda blew up. I did 2 or 3 oil changes with bulk Pennzoil 15w40 from our work to clean it out from the neglect. Then changed it with Pennzoil Platinum 10w30, then next time Quakar State Full synthetic 10w30. So far no problems at all.