OutdoorKing Repair Forum Forums Restoring, Customising and Modifying Tech Talk how do I fix my mower

My mower is leaking a lot of oil, but I would like to figure it out or fix it my self before I take it in to a service place and spending a lot of money

Hi charmaine, welcome to Outdoorking.

Please tell us what kind of mower, with what kind of engine - a picture or two would help a lot. If it turns out to be a Briggs and Stratton engine (most of them are, but there are several other engine brands commonly used), we need the very long series of numbers stamped on its top cowl. We also need to know where the oil is coming out.

I'm sure once we know what engine it is and where it is leaking, we can tell you how to fix it. That doesn't mean it will necessarily be easy to fix, or that you will have the tools required, but let's get to the bottom of it so you can have the choice of whether to do it or not. I agree that the cost of having a repair shop fix an old mower is often not worth spending.

charmaine,

One question.

Did you clean under the mower by tipping it over on the side?

ok so it's a 4 stroke rover i5500 mulch/catcher, model no. 14848, serial no. 3808100387. it's only 2 - 3 years old an it seems to be leaking from the side of the carbi?? at the front bottom. I may not know what it's called but I can figure out how to repair it as I'm a tinker but would like some ideas of what's wrong an what I may need before I pull it apart, as I've already fixed the (accelerator cable) and the pull start, replaced the blades and clean underneath after every use (to reduce build-up and unbalancing).

thanks for your help it is greatly appreciated.

Thanks for providing those details, charmaine. We still need some more, though. I now understand that you have a modern Rover, with Rover's Chinese engine, not one of the older ones with a Briggs engine. However because this is a largely undocumented engine, we will have to get the necessary information from you.

First, there is the point Bruce made. You said you have been turning the mower over so you can clean it underneath. Depending on how you are doing this, it is likely to result in a lot of oil leaking out. Generally there is only one way you can tilt a 4 stroke engine legitimately, and even then the machine will not enjoy the experience. Here is the way Rover's owner manual instructs you to clean underneath the mower:


The next step I recommend for your investigation of the oil leaking problem, is to follow Rover's instructions. Keep that mower the right way up at all times except when deliberately draining the oil as part of the required annual oil change service. Most likely the problem will then disappear, and the mower will run better as well. If this does not cure the problem, we will need pictures of where the oil is coming out, and your description of what you were doing to it at the time the oil came out.

Please note that the mower's engine oil must be maintained at the full mark on the engine's dipstick, just like the oil in a car engine. Since oil has been spilling out, the level will now be low and needs to be replenished immediately. To check the oil level, park the mower on level ground. Unscrew the dipstick from its housing, wipe it clean of oil, then rest it lightly in its housing without screwing it in. Then draw it out again and look at how high the wet oil mark reaches up on the bottom of the stick. Add a small amount of oil through the dipstick housing if necessary, and recheck the level until it is accurately on the full mark.

The oil only leaks when it is running. An use roughly 2lts each mow an it's starting to really tick me off. An get very expensive.
But you did not need to explain how to clean it or how to check the oil level. As it has been my chore since I was 8 an have been shown/taught most of what I need except for this one problem as it's not something I've had to deal with for I know it could be a cracked head.

Can you post some pictures please, charmaine? Once you have them in your computer's hard drive, just press the fifth icon from the left in the row of icons directly above where you type your posts. That will open the window - just press Browse, highlight the first picture, then revert to the posting window and press Add file from your PC, then Browse again, highlight the next picture, and so forth until you've selected them all, then press All Done. You can attach ten pictures to each post.

We need to see where the oil is coming out, and some detail of what your engine looks like. The Rover engine is a type of chonda, but we need to see exactly what it looks like where the oil is leaking.

Hopefully it is something simple. Lots of things go wrong with chondas, but not usually with the major parts, which are generally accurate copies from the Honda. Hondas rarely leak even a little bit of oil.

the last picture is where the oil is leaking from

Charmaine, is the oil coming out from under that silver cover which is held onto the top of the engine (the cylinder head) by 4 screws? If so, you can fix it in about 5 minutes.

That cover (called the rocker cover) is just a piece of punched tin. Its job is to keep the oil in and the dirt out. If you clean around that area, then unscrew those 4 screws (from memory it's a 10 mm spanner, I always use a socket but a ring or even an open end spanner will do it) you can pull the rocker cover off. When you look at the other side, you'll see it has a black fibrous substance (it's called a gasket) running right around its perimeter. Look at it carefully, and look at the matching surface around the outside of the top of the engine (the cylinder head). The gasket may have come off one part cleanly, or it may have split and now be partly stuck to the cover, and partly to the cylinder head. Try to see why it was leaking - it may be out of position, or cracked or something. You will need to carefully scrape the gasket material off both the cover and the cylinder head, so both are clean. Don't let the material go inside the engine, where the mechanism is (the rocker arms, pushrods, and valves). Then take the cleaned cover to a Honda dealer and check that a Honda gasket will fit (it looks to me as if it will). Take the gasket home, lay it carefully in the recess around the outside of the cover, glue it in if you wish, then put the cover back onto the cylinder head, install the 4 screws and tighten them just moderately so the gasket is slightly squished. That's it, your first engine repair.

Post-edit: However if the oil is coming from well back from that tin cover, further underneath the cylinder head, the problem is almost certainly a blown head gasket. This is a bit harder to fix, though I feel sure you can do it if you choose to. Please tell us exactly where the leak is coming from, perhaps with a picture from a bit closer to it.

Well boys, that didn't fix the problem if not made it worse an your wrong about where it's leaking, not at the front bottom, but at the back bottom, husband thinks it's cracked an we can't afford to shop repair it. is there a type of putty or something we can use to fix it. Without having to pull the whole thing apart as I may not be able to get it back together again.

thanks

ps if need be I have a video of it

Is the oil coming from the joint between the cylinder head and the top face of the cylinder? You should be able to see that joint, with a bit of difficulty. These pictures of my spare Honda GXV120 base engine (peripheral items removed, just shows major engine parts) show the joint between head and cylinder circled in red:




The series of yellow arrows on your picture show where that joint face is:


We need to know whether that oil is coming out from the joint line between the head and cylinder, past the gasket. You can see the gasket edge-on in the third picture.

I'll offer all the likely causes of the problem in one go, rather than one at a time. You've covered the rocker cover gasket already. My previous post covered the cylinder head gasket.

The simplest item it could be - it could probably be fixed in less than one minute - is that the oil filler tube could be out of position - it is shown in the red oval below:

Because the mower base has a recess running around it, leakage from this tube would result in a pool of oil where you have shown it in your picture: that is the lowest point in the recess.

If it isn't that, the next item to worry about is the crankcase cover gasket, shown in the red oval in these pictures:



The last item to worry about (other than a cracked casting, which seems unlikely) is the bottom crankshaft oil seal, underneath the mower, circled here in red:

Oil flooding out from that seal might (it seems barely possible) result in a few splashes being thrown outward by the blade plate and ending up on top of the mower base, as in your picture. Most of the oil would simply be splattered around the underside of the mower, rather than getting on top of it.

So, my favourite possibility is that the bottom of the oil filler tube is now out of position, due to it receiving a bump somewhere along the line. If that has happened, chances are you just need to remove its attaching screw at the top of the tube, put it back where it belongs, and reinstall the attaching screw.

ok, so the last 2 pic's are a no, the 1st pic's I think are a yes, where you've put the arrows is where the oil is running to but take the last on the right and move it over more to the right between the cylinder and the small plate on the right, (added a green arrow to show)

Thanks charmaine, I think I follow what you have told me - now let's look at what it means. Here are some pictures of another (scrap, temporarily removed from the garbage) GXV120 with the cylinder head removed. I have put a red arrow on each view in the same position as you had put your green arrow:





Note the green oval on the third picture. That is surrounding the pushrod cavity: one of the potential sources of oil which could leak past a faulty cylinder head gasket. Note also the yellow oval in the same picture. That is surrounding the oil return passage: perhaps the worst possible place to develop a leak, because it would release a large quantity of oil.

All of this is consistent with your problem being a faulty cylinder head gasket, provided the oil is coming from the joint between the cylinder head and the cylinder/crankcase. I need you to look at that joint in the area in the red oval shown on this picture, and see if oil is coming out from it:


Then look at that joint in the area of the yellow arrow in this picture (underneath the cylinder head, adjacent to the oil return passage) and see if that is the source of the oil:


If we can verify that the oil is coming out from the gasket-edge surrounded by that red oval or above that yellow arrow, we will know you have a failed head gasket, and that is the source of the oil leak.

Here is why I have been harping on the subject of cylinder head gasket failure for some time now. I think I have already described your Rover engine as a made-in-China imitation Honda. Imitation Hondas are in some respects accurate copies, and in other respects, some corners may have been cut. Here are three replacement-part cylinder head gaskets for the Honda GXV160, which is the engine which inspired the design of your engine:




All three of these gaskets have provision to keep them from leaking gas from the combustion chamber. This is the raised-up ring surrounding the cylinder (the large round hole in the center). However only two of them have sealing material around the oil passages - the third one does not. Because of the raised-up ring around the cylinder, if there is no sealing material around the oil passages, there is a risk of it leaking oil - the cylinder block and cylinder head may not be touching the gasket anywhere except right around the outside of the cylinder.

ok, that's pretty much the right spot but I haven't pulled the whole thing apart as I still need to use it at the moment. An the last 2 pic's with arrow's aren't loading so I couldn't tell you. I think we might just put up with till we can afford a new one.

If you can verify that the oil is coming out from between those 2 surfaces - between the cylinder block and the cylinder head - then we can talk about what it takes to fix a leaky head gasket, and you can make plans. We need to be clear on whether that is the problem, before we can go any further.

Ok so I think I've figured out that's actually 2 issues, 1 is the gasket at the bottom (the one with crankshaft?? below, but not underneath where the blades are) and no.2 is the gasket where you've marked with the green circle. Only thing is I'd have to pull the whole thing apart to fix. Anyways what sort of gaskets am I needing to replace, with part/serial numbers etc or will I have to take them to a place to get them 'fitted' (size an shape)

Let's be clear on which gaskets/seals we are talking about. You have said it is leaking from the cylinder head gasket, in the area I have the green oval around in a previous post. That is the same area I have shown with a red oval in the next picture in the same post. Is it leaking from there? It isn't just some splattered oil from somewhere else, it is coming out from the joint between the cylinder head and the cylinder/crankcase casting? If it is, you need to replace the cylinder head gasket, the part I have shown three examples of, some better than others. The part is not all that expensive - about $6 for an unbranded one, and perhaps twice that for a genuine Honda one. You would need to remove the cylinder head, and take it to a Honda dealer, to verify that a Honda gasket will fit. I do not recommend using a non-genuine one if a genuine one will fit: you have already been bitten once by that gasket leaking.

Let's be clear on where your second leak is. Do you mean the crankcase cover gasket, shown circled in red here?


Or do you mean the crankshaft power take off oil seal, circled in red here?

yes it's the first pic, the crankcase cover gasket, that is one spot of leak which I didn't notice until today. the other leak which I first started this post off with is (Second lot of pic's) the green oval on the third picture. That is surrounding the pushrod cavity (where I pointed out with green arrow)

Thanks for clearing that up, charmaine. Now, you can replace both those gaskets, but the crankcase cover one in particular is a fair amount of work. Also, you may not be able to get spare parts from Rover, and because two of those parts are leaking, we have reason to suspect that they may not be top quality anyway. Furthermore we can't be sure at this point that Honda parts will fit. I've already referred to the way I would proceed with this. I would remove the cylinder head, clean up the joint faces, take the cylinder head to a Honda dealer to check whether a Honda GXV160 head gasket was a perfect fit, and if it did fit, I'd use one of those. I wouldn't actually reinstall the cylinder head at that point though. I'd remove the engine from the mower, then unbolt the crankcase cover from underneath the engine, clean up the joint faces, and take the cover to the Honda dealer to see if the GXV160 crankcase cover gasket would fit. If it did fit, I would reassemble the engine with both Honda gaskets and refit it to the mower.

If you decide to make the repairs, I can help you along the way with details from the Honda service manual for the GXV160. I don't think there are any service manuals for chonda engines, including the Rover one, especially in English rather than Chinese, but I could be wrong about that.