Oil light on!!

[clemsonfor]

I have been useing my ym2000 a good bit this weekend. Today I had bushhogged a few hours and tdrove it down into the woods to cut a tree out of the road. When I got to the tree I brought it down to an idle and was going to leave it running. When I got to about 1000 Rpms or lower the light lit up. If I increased just slightly it went away. I thought the wire might be the issue it was a tad loose. I did what I needed to do. Went back up to house. Pulled the screw off and cleaned it and the connector till shiny. This made it go off when i started it up (although the last few times after I noticed when I started it it would take like 30 seconds at that rpm till it came on for whatever reason. This is on it warm and only been off 10 mins or so , so not enough time to cool down). So I left the tractor to idle at a tad under 1000 or so and did a few things. It states off for 5 or 10 mins at that rpm. Then I looked over and it was dim or just lit up I can't remember. Increase it slightly it went off. Now here is the difference, idle it way down and it went out too. The light was coming on at only maybe 800rpm lower or higher it was off. The place it lights up is the 5kmh notch which is below the 1000 mark on the top side. I guess it would be around 750 to 800 rpm.

Never has this light come on before. There is no difference in the way the motor sounds. I'm wondering if I have a bad sensor or maybe it got some trash in it? I didn't have time before I had to leave to pull it out and try to clean it or anything. I just plan to buy a new one and see if that fixes it. I don't have an external cause to try to see pressure. Maybe this will make me buy a tool for this.

California do you have a part number from a Nissan/Datsun that you found for one in all your playing around with these? I didn't some quick look ups a bit ago on some 70s nissan applications and didn't find anything that looked like it on advanced auto.

Other than this the tractor was flawless this weekend. I disked about an acre and a half of foodplots and bush hogged several acres.

 

[clemsonfor]

Messing around Rock Auto I found a 78 subaru Standard has a oil sensor with a tab. I can change my ring terminal to a female spade and use this one of I need.

I actually found one in their list that has the male spade secured by a screw so I could take it off, not have to cut anything and use the ring on it already. I can't remember the price but it was $4 other options are $2. Haha depending on eachs location and shipping I may buy the cheaper one and put a spade and keep my $2...hey I'm cheap!

 

[California]

California do you have a part number from a Nissan/Datsun that you found for one in all your playing around with these? I didn't some quick look ups a bit ago on some 70s nissan applications and didn't find anything that looked like it on advanced auto.

I went to Autozone and the counter guy matched it by eye. He said it was near universal across Subaru/Datsun/Mitsubishi(?) for that era, all the Japanese car companies that were likely to contract others for some of their components. A NAPA counter guy might be more experienced. Just match threads (eyeball, its tapered British Standard) and the pressure cut-in spec. You might have to add a slide-on terminal to your existing wire.

Sounds like you found my old thread, where I temporarily added a T and a water pressure gauge, like you see on a well pump, to judge if the problem was the oil pump or just a bad sender. (The T was needed to get clearance to thread in the larger-diameter water gauge).

 

[clemsonfor]

I read that post years ago, and remembered it. I read everything you write in the Yanmar forum. Well I should say especially every thread you start. A lot can be learned if you sit and listen when a wise man speaks. And you sir are a wise man!

 

[California]

And I have relied on your good advice many times, thank you!

I went and looked for that old thread. 11 years ago! Man was I long-winded as I explored all possibilities while I narrowed down the cause.

Here it is. I'm referencing it here because that was the only time I took, and posted, typical temperatures at head, pan, manifold etc. Somebody might want this information.

I see I named the sender I bought: "listed for 80's Corolla and 70-90's Subaru but is universal, with a blade added on top of a screw terminal".

This is one of the rare cases where the part is so inexpensive that starting diagnosis by swapping parts is justified.

https://www.tractorbynet.com/forums/yanmar/156109-low-oil-pressure-no-bad.html

And here's the photo of the water gauge that was temporarily installed. I used a brass American-thread pipe nipple into the block to avoid damaging the cast iron but actually neither were harmed by this mismatch.

Something else in that photo that I had forgotten - I had to replace the last few inches of wire after I tore it off, while rasseling a downed tree with branches that pointed in all directions.

Good luck with your project!

 

[clemsonfor]

Yep I found one with a blade attached with a screw. It's only $3 to ship it. I'm not usually a parts swapper. But I would spent the $6 on fittings if I don't happen to have the right one on hand to adapt the old well pressure gauge. And after all that mess I'll just parts swap. If it was $50 for the part I'd be troubleshooting. Thanks. I didn't even think of the well pressure gauge. I have an old one that I think is still good from working on the well a few years ago (if it was bad I would have tossed it). I think I remember now. The old one was bad. I ordered one and the fitting that came with it was split and Amazon just sent me another. So I kept the gauge cause it was good.

I also thought about maybe replacing the wire end. Thinking it may be internally corroded . I'm going to order the new sender and see what I get then go from there.

I'm going to re read your initial post later tonight as well.

 

[California]

I'm going to re read your initial post later tonight as well.

That should put you to sleep!

 

[clemsonfor]

Yep I found one with a blade attached with a screw. It's only $3 to ship it. I'm not usually a parts swapper. But I would spent the $6 on fittings if I don't happen to have the right one on hand to adapt the old well pressure gauge. And after all that mess I'll just parts swap. If it was $50 for the part I'd be troubleshooting. Thanks. I didn't even think of the well pressure gauge. I have an old one that I think is still good from working on the well a few years ago (if it was bad I would have tossed it). I think I remember now. The old one was bad. I ordered one and the fitting that came with it was split and Amazon just sent me another. So I kept the gauge cause it was good.

I also thought about maybe replacing the wire end. Thinking it may be internally corroded . I'm going to order the new sender and see what I get then go from there.

I'm going to re read your initial post later tonight as well.

Thanks for the reminder. Need to click it and read it.

 

[clemsonfor]

You know what. I found one like your talking about with the blade and also a screw. It's at rock Auto, no one local shows other than a blade that's riveted. With the slow Corona mail service now a days I don't trust if I order it it will get to my farm property bin 6 days for me to use. I had a part I ordered from a guy off eBay for my Cub. He lived in Kentucky, the part came to me a week and a half later via Puerto Rico!!!???
Anyway to my point. I forgot I have that 186 sitting in my yard. I doubt it's sender is bad. I will grab it to take with me in case I don't get the other in the mail. I'd rather not hack it to a spade connector. Why, I guess that's just me. It won't take 1 minute to do and not make any real difference but I'd rather keep it as is right now. I could even buy a blade connector from a local place to ha e that as a last resort....well probably won't. If the ordered one does not arrive it's not a big deal I will be there this time of year more often with deer season. I am almost to the point where I won't be useing the tractor much at all till next spring.

 

[flyerdan]

I doubt that the sender is at fault; it's just a pressure switch that opens the ground circuit for the oil light, and if it fails it usually results in a light not going out condition.
Since it pulses at low rpm, it's likely that the oil pressure is getting low either through a worn pump, main bearings not holding pressure anymore, or some debris in the bypass valve that's bleeding off some pressure by not allowing it to close all the way.
Swapping out the sender is the easiest and least expensive first step in the troubleshooting process though.

 

[California]

I doubt that the sender is at fault ....

This is one of the few idiosyncrasies of these elderly Yanmars. At around 40 years old the senders fail suddenly as he and I experienced, in my case right after an oil change. I've read in this Yanmar group of others too. So popping in an under $10 sender and hoping that fixes it, is a better diagnostic start compared to all the nonsense I worked through in that thread I referenced above where I started off suspecting worst-case and worked my way from complex to simple.

 

[kenmac]

If it's any help to ya. Before I sold mine, at low idle the oil light came on. I ordered a new sending unit and never had another issue

 

[clemsonfor]

I doubt that the sender is at fault; it's just a pressure switch that opens the ground circuit for the oil light, and if it fails it usually results in a light not going out condition.
Since it pulses at low rpm, it's likely that the oil pressure is getting low either through a worn pump, main bearings not holding pressure anymore, or some debris in the bypass valve that's bleeding off some pressure by not allowing it to close all the way.
Swapping out the sender is the easiest and least expensive first step in the troubleshooting process though.

After I cleaned it. It would be out below say 750rpm and out above it. Just seems strange. If things were worn it would show up as low pressure at 500 rpm just as much as 750 I would think? Anyway I'm just hoping.

Also if you read California post he had basically the same issue and had a bad sender. He verified with a huge as well. His sender was at fault.

I have one on the way. Says it will be at my farm Thursday so I will change it this weekend. Less than $8 for one with a screw terminal shipped to my house from Rock Auto. Don't even need to hack the wires.

 

[clemsonfor]

I suspect they may be getting trash in them or either just the connections breaking down or something overtime. As mentioned it's a 40 year old electrical part at this point in a very high vibration application. And if these are the same components that were originally designed for automotive applications, these have way less vibration. Smooth gas engine, suspension ride on asphalt. At least 5hats some of my thinking as well.

 

[clemsonfor]

Problem appears to have gone with a new sensor. I let it get warm at a high idle yesterday and the problem was there again at 750 rpm, not below or above. Today I swapped the new sensor in. Let it fastbidle till warm, maybe 15 mins or 20. Lowered it to 750 and lower , NO light! The old one the body of the sensor appeared to be loose in itself, the plastic part. Hopefully bit was just the old part wearing out, which it appears to be.

Here is a pic of the new sensor with application and part number listed if anyone wants to find it in the future. I looked through the various options listed for a universal one with the blade that could be removed and use the existing ring terminal with the screw on the new sensor. This brand from Rock Auto was the only one that appeared that way in the pictures of it.

 

[CoyPatton]

Thanks for the part no info.

 

[California]

Glad to hear the project turned out well!

 

[clemsonfor]

Glad to hear the project turned out well!

Thanks. Me too!

I bush hogged a few hours. Tractor was very well to operating temp it was in the 80s here today. I was in waist to chest high grass with the 5ft bush hog. Not light when I stopped and came down even to a 500rpm idle.