Briggs Intek 20HP Using Oil

[Mr. Shamrock]

You will find it is a lot like a motorcycle or any engine yes it can burn oil and not smoke. Seeing you have a lot of carbon around the valves and not smoking I would still be checking the valve guides. When the intake opens you have vacuum around the valve head and if the guide is loose you are sucking oil down pass the loose guides. On cars or truck they have valve stem seals but I never came across that on mower engines but maybe there is such a thing?

Well I don't claim to know it all about motorcycles but I am a pretty damn good wrench. I am always up for learning new things though and a good tech will admit that he learns new things on a regular basis. Can you explain how an engine can burn oil and not smoke it out. I know some slight leaks aren't seen until the RPM's are high. GM has an issue with the newer vortec engines burning oil at high rpms that the driver will never notice because it is so slight, but we are talking about 1/2 to a full quart in 3000 plus miles. I am burning at least 1/2 a quart every couple hours. That should be very visible coming out of the motor somewhere. Please teach me something new.

 

[reynoldston]

If it isn't leaking oil and using oil now it has to go someplace. I would say it is burning it up clean and if you had white smoke would be not burn up oil. Ever see a cold diesel start and a big white cloud of smoke come out it till it gets warm. That is unburned fuel oil. The same thing for the motor oil. It gets hot and burns clean. I don't know what else to tell you other then valve guides and the next step would be rings. Unless some other reason the oil is getting into the combustion chamber like a vacum line or vacum leak. Now some one said leaking into the transmission, but with that wouldn't the transmission be over full in time. Besides that I don't think to two of them come together. The best of luck on this.

Nick

 

[Sammy the Red]

One time, I bought some brand name oil that was on sale. Changed the oil in my truck and my girlfriends truck. Both were V-8's, both in good condition. Her truck started to using a quart of oil every day. She was not happy. The very next weekend I bought the brand of oil her truck had been used to and changed oil and filter. It stopped using oil when it got what it had been used to. My truck, never made a difference.

Some engine manufactures say that using a multi grade oil will increase oil consumption.

Go back to using the B&S 30wt oil or a quality brand name 30wt oil and see if oil use is reduced.

 

[reynoldston]

One time, I bought some brand name oil that was on sale. Changed the oil in my truck and my girlfriends truck. Both were V-8's, both in good condition. Her truck started to using a quart of oil every day. She was not happy. The very next weekend I bought the brand of oil her truck had been used to and changed oil and filter. It stopped using oil when it got what it had been used to. My truck, never made a difference.

Some engine manufactures say that using a multi grade oil will increase oil consumption.

Go back to using the B&S 30wt oil or a quality brand name 30wt oil and see if oil use is reduced.

Now that is another good idea:thumbsup:

 

[Mr. Shamrock]

Now that is another good idea:thumbsup:

I thought of that and the last oil change which was only a couple months ago is when I used B&S 30W oil and filter. Now this was before I replaced the breather valve and got some of the carbon out of the motor so who knows. I have to work until about 3:00 today and then I am going to get a new filter and oil again. I also plan on doing a leak down and vacuum test. Does anyone know how much vacuum I should pull? Thanks for all the input - I will definitely post my results.

 

[ILENGINE]

RobertBrown the engine and transmission are two separate units so its not going between the two. Reynoldston the briggs does use a seal on the intake valve.

 

[reynoldston]

I thought of that and the last oil change which was only a couple months ago is when I used B&S 30W oil and filter. Now this was before I replaced the breather valve and got some of the carbon out of the motor so who knows. I have to work until about 3:00 today and then I am going to get a new filter and oil again. I also plan on doing a leak down and vacuum test. Does anyone know how much vacuum I should pull? Thanks for all the input - I will definitely post my results.

Sure sounds good, but just what is a leak down and vacuum test, and what is it going to tell you? I am guessing how much vacuum in the intake manifold when the engine is running for vacuum test? It seems like I have seen a test where you put compressed air into the the cylinder too see how much blow by you get by the rings or check for a blowen head gasket. Never heard of a leak down test. Is a leak down test vacuum in the crankcase to see leak bypass the rings?? It seems you would want the valves open for that test. You must need some kind of vacuum pump for a test like that? So just what information are you going to get from this test for oil consumption? ( Does anyone know how much vacuum I should pulll) From where ?

 

[reynoldston]

Sure sounds good, but just what is a leak down and vacuum test, and what is it going to tell you? I am guessing how much vacuum in the intake manifold when the engine is running for vacuum test? It seems like I have seen a test where you put compressed air into the the cylinder too see how much blow by you get by the rings or check for a blowen head gasket. Never heard of a leak down test. Is a leak down test vacuum in the crankcase to see leak bypass the rings?? It seems you would want the valves open for that test. You must need some kind of vacuum pump for a test like that? So just what information are you going to get from this test for oil consumption? ( Does anyone know how much vacuum I should pulll) From where ?

I googled a leak down test and my first guess was right. Compressed air into the cylinder and a no more then a 10% lost of air going out. Not very clear on how this 10% is measured? You must have the right equipment for this test and it will tell you a lot without a tear down. good luck

Nick

 

[ILENGINE]

Small engines are measured in inches of water vacuum not mercury like most things. It is preformed with the engine running with using a water mamometer or the special small engine vacuum gauge. Briggs talks about crankcase vacuum testing but doesn't publish what the correct amount is. I did one on a briggs intek twin a couple of years ago and got 10 inches which according to tech support is too low.

The measuring apparatus is hooked up with a modified dipstick cap with the engine running to measure. It using a water mamometer you have to clamp off the line going to engine when you start it to prevent the water from being sucked into the engine.

The leakdown test is preformed at top dead center with a special leakdown gauge that has green,yellow, and red areas with the amount of air loss measured on the gauge. Most are calibrated at either 90 or 125 psi input air. The you find out where the air is leaking from. The rings, head gasket, or valves.

 

[reynoldston]

What does this crankcase vacuum test telling you that you had only had 10 in.s ? Now remember we are looking for oil consumption. Maybe the crankcase vent isn't working right or piston ring blow by? This all sounds like a good test to me. I have to say I do the pressurize cylinders test at line pressure to find a bad piston, valves or head gaskets.