How to diagnose any possible engine damage from overheating

No I said it is high temperature that destroys the lubricating capacity of some oils.

That only indicates that the engine does not run as hot. they don't all run at the same temperature B&S does recommend different oils for different engines and the essential difference is the maximum operating temperature characteristic of a given model.

It ran fine before he changed the oil. He was told by the service department that B&S recommended against using that type of oil in that engine. You can't infer anything at all from using the same oil in some other model of engine. He never tried to use the recommended oil. Yet he blames the manufacturer whose recommendations he ignored.

My push mower has gone 10 years using the recommended straight weight oil and I have never had to add any oil between changes. Many people get many years of service out of these engines without even knowing they have oil in them.

-jim

Dont put words in my mouth. I did not see anything saying not to use the synthetic...I was told that after the failure, and that was word of mouth.

When the engine was rebuilt, I went back to standard dino oil...The rebuild didnt last longer than a few hours...maybe 8-10.

There are some excellent castings made outside the US, from folks like Honda and Husqvarna. There are, as I point out, also some pretty dreadful ones.

Well, it sure wasn't cast iron.... the stuff was outrageously soft.

--scott

cheap checks are remove the oil filler cap and sniff the oil does it have a burnt sort of carbony smell ? also now youve changed the radiator keep an eye on the coolant (water) level if you are still loseing water then this would suggest a blown head gasket or worst case cracked or wharped cylinder head or block, but you would have to be pretty unlucky to have these. Chances are it will be ok. Best regards

hls wrote:

Whether you were aware of it or not - you ignored their recommendation. And it would seem even now you prefer to preserve your ignorance rather than find out what exactly what is/was recommended or why it is recommended. Instead you prefer to make up facts out of thin air about metallurgy and machining methods to explain what happened.

Well, standard dino oil was not likely what they recommended for that engine either. Whatever you put in the second time may have been even worse than what you put in the first time. What originally came with the engine was probably a synthetic. Briggs uses their own brand of synthetic that they claim is especially formulated to withstand much higher temps than other synthetics. And Briggs doesn't say use only their oil (I don't think they legally can). What they do say is if you choose to put 10w30 in the engine make sure you check the oil often. These engines will run a long long time even when they are at the point of adding a cup of oil with each tank of gas.

If you had asked the dealer or any place that sells and services push mowers with Briggs engines, you would find out that many people get years of use from the same engine and they do no maintenance at all. In fact, that is the targeted consumer for these cheapo mowers. They are designed to be used and discarded and the engine will generally last as long (usually longer) than the rest of the mower. It's likely that the carb has no adjustment for your engine so after your rebuild it was probably running extremely lean which contributes to making the engine run even hotter than it did before. Everything you have said indicates that heat was the root cause of your problems. And probably by the time you were done with your rebuild the grass was getting pretty tall which doesn't make it run any cooler either. The fact that someone else has an engine that doesn't run quite as hot and thus survives proves nothing at all about what happened to your engine. I suspect that there are thousands of purchasers that bought the same mower at the same time you did and who have done nothing at all in maintenance still have a running lawn mower. But getting back to the original poster's question and my answer to it. If you had put what most people are using in their cars today (5w30 petroleum oil) the type of failure you experienced in that type of engine would have been almost a sure thing. That's because the critical temperature where that type of catastrophic failure occurs is lower for standard 5w30 than it is for 10w30, which in turn is lower than a synthetic like Mobil 1. The OP didn't say what type of oil he uses. but in any case changing the oil after a overheating incident is cheap insurance just in case the oil reached the critical point where serious engine damage like you experienced can occur. That doesn't mean that high temperature definitely was the cause of your engine failure, but the facts as you presented them, point to nothing else.

-jim

Well, Jim, it is clear that you havent a clue what went on, and just want to demean me..

I make mistakes just like everybody else, but listening to you will not be another of them.