B7100 Oil Pressure Lamp/Overheating

[Van Isle]

Short and sweet (long story to follow):

-Tilling my wife's grandma's garden with her B7100, I can work for about half an hour (maybe) before the oil pressure lamp starts to flicker on, increase in frequency, and it starts to feel very hot. When it does this I shut it down and let it cool down. It didn't use to get this hot or have this problem. About 4 years ago (or so) wife's cousin had it overheat (boilover) on him.

-I have made sure the radiator fins are clogged with dust/chaff (blown out and washed) and make sure it has good coolant in it (about a 60/40 mix).

-It does seem to lose a small amount of coolant, but the oil is not milky and the cooling system doesn't appear to be pressurized or bubbled when running. Coolant last changed about two years ago (and maybe 60 hours tops).

-Radiator cap rubber doesn't seem to be in great shape.

-When the coolant was changed I didn't do a flush or descaler because I read you can work stuff free and clock the thermo-syphon system.

-Oil changed every year (with not many hours) and new filter. Running 5w40 full synthetic.

So I would like to fix this for her, but I don't have a lot of my own time and money to throw at it and I don't think she has a lot of money to just throw at it, especially if its just guess work. I am sort of considering it a cooling problem, but maybe the oil pressure lamp is a completely different issue? Where should I start?

I was thinking maybe a new radiator cap, but if its not a pumped/pressurized system that probably isn't the problem is it?

I was thinking an actual coolant flush with a descaler might help? I heard to hook up a hose to force everything out backwards with some force?

Basically when I problem solve I try to do the cost benefit between the most likely causes and the easiest most inexpensive.

Thanks!!!



Long story: I use my wife's grandmother's B7100 to till her garden (about 50' x 100') and clear her driveway when it snows, that's about all it sees for work. I've been doing this for her for the last 5 years or so. My wife's grandfather was a heavy duty mechanic and purchased it new in the early 80's so I would imagine it was well taken care of until he passed away about 15 years ago. Then for the next 10 years either her tenant or one of my wife's cousins operated it for her, and I don't think it saw much maintenance in that time. Once I started using it, I dug out his manuals and did the maintenance on schedule.

When I'm tilling her garden, it doesn't take long for the oil pressure lamp to start flickering, and the air coming off starts to feel very hot. I used to be able to till the garden for a long time without any sign of it getting too hot. low range 1st gear, PTO on 2 and just go around in the hockey zamboni pattern. Soil is never very hard. About 4 years ago the wife's cousin was tilling the garden for her and it overheated. I did some reading and cleaned out the radiator fins (they had lots of dust and chaff in them) and replaced the coolant, and did the oil/filter and all that fun stuff. Seemed fine but slowly it has been getting worse and worse and now I can only seem to do a pass on 1/4 of the garden before the oil pressure lamp starts to flicker and it feels hot. Once it starts to flicker I just shut it down and let it cool down. With how bad it is now, progress is very slow and frustrating.

Edit: I know adding oil pressure and coolant temp gauges is a good idea, but I don't know if that money would be better spent at trying to fix the problem first rather than watch the problem?

 

[85Hokie]

Ok,

first question....
every checked the cam plug? IF you dont know what I am talking about - do a search for "cam plug b7100"

second - what oil you using? weight wise?

What is happening - the oil is getting hot, and thinning out - loosing pressure....

get a new radiator cap - 13 psi is the number you need. WITHOUT pressure here, it will boil quickly !

get a infrared temp gun - cheap - 20 bucks or less - tell us what the top neck of radiator is , bottom of neck .....

I would flush the hell out of the radiator - thermosyphon systems need to be clean to work well - then try straight water and see what happens.

the laser temp probe will tell us a lot.

 

[Jimc3165]

I would also advise to not be to quick to tear it down for the cam plug. I did because I was sure that was my problem, well it wasn't. I have not narrowed down what is causing my issue yet but I'm hoping the low pressure isn't low pressure but a bad sending unit. Also not sure I'd use 100% synthetic on an 80's model tractor. I think I'd stick with straight dino and it will save a few bucks. If you get yours to stop overheating and you still have the LP light then you will need a cheap gauge to see what actual pressure is. Good luck, I'm still working on mine.
Jim

 

[Repair]

Also not sure I'd use 100% synthetic on an 80's model tractor. I think I'd stick with straight dino and it will save a few bucks.
Jim

I get this question almost every day about using synthetic or regular oil, I can't remember the last time I had a call about a failure caused by the lubricating/engine oil.

I see a lot of Diesel engines destroyed by defective/neglected air filters.

The main reason for thinner oils is to increase MPG, a 5%increase in mileage means nothing unless you drive 100,000 miles a year or you think about every car and truck in the world, then it is important.

So we recommend regular oil.

 

[Bulldog]

I used 100% synthetic for years in my B7100. Had over 6000 hrs when I traded it in and still running fine. I don't believe the oil is the issue except I would go to either 5w30 or 10w30 diesel oil.

I would clean the cooling system out and try a new cap.

What brand filter are you running? Only problem I ever had was with a cheap filter. It stopped up and split the case. Fram in case you are wondering.

 

[Lil Foot]

I have tried both synthetic & conventional oils in mine, with no appreciable difference, other than cost. But I run 15w-40 in my older (1240+ hrs) diesel. But it's hot out here.

 

[85Hokie]

I get this question almost every day about using synthetic or regular oil, I can't remember the last time I had a call about a failure caused by the lubricating/engine oil.

I see a lot of Diesel engines destroyed by defective/neglected air filters.

The main reason for thinner oils is to increase MPG, a 5%increase in mileage means nothing unless you drive 100,000 miles a year or you think about every car and truck in the world, then it is important.

So we recommend regular oil.

Starting with this statement....... (I missed this in the OP text)

"Oil changed every year (with not many hours) and new filter. Running 5w40 full synthetic."

SO - right off the bat, the oil's viscosity is extremely low, not sure the engine was designed to run with that low of flow, despite the hours, it has wear. SO as the oil is getting hotter, the viscosity is getting lower all the time - it might protect like 40 weight oil, but it is BEHAVING like 5 weight - and here is the problem - the engine getting hotter due to radiator "problems" and the oil getting thinner and losing the ability to form pressure.

If I am not off too much - the light comes on at 7 psi???? Something like that? SO you have lost so much pressure (if you had a gauge it would show 40+ cold) that the light flickers.

This has nothing to do with synthetic or old dinosaur oil. It has to do with heat and engine oil viscosity once hot.

First thing that needs to be done - as I stated, was find out what is going on with the cooling system, IF this is not fixed - then everything is a waste of time.

Changing the oil to a more viscous oil will help in the short run but WILL not fix the problem.

The oil is a huge cooling point of the engine - if the water based system is flawed, the oil based will soon be flawed too.

As for the cam plug - it is either THERE or NOT THERE, based on the OP, year of purchase, THIS was the era of "bad cam plugs" - the newer models if you will did not have the same problem. AND since the light is working.....I would suspect that it is ok....and the oil is getting hot and the pressure is dropping.

I would highly recommend that you get some numbers together on the cooling system and see what is going on there before tearing anything apart.

 

[Van Isle]

Thank you all for taking the time to reply. Current plan of attack is to do a rad flush and replace the rad cap. If that doesn't solve it then probably look at just putting a cheap oil pressure gauge on and then either use a laser temp gun or put a coolant temp gauge on too. Then I will be able to see the real issue is temp, pressure, or both and go from there. I noticed that the fan belt is pretty loose but it doesn't seem to skip and the fan spins nicely.

I have to disagree with the 5w40 potentially being the issue. The only reason I run it is because I buy it by the 5 gallon pail and use it in my truck. It's a 40 weight oil and the manual calls for 10w30, so this is a heavier grade oil. In the winter it will 'behave like a 5 weight oil would' but the oil itself won't cause these pressure drops at temp. I was

I just got a flu so I slept all day today but will look into the cam plug issue. I definitely don't have the time to delve into that. I have a feeling that won't be the issue because it takes some hard work for the oil pressure to drop. I will know more with a gauge though. I would lean more to it being a bummed oil pump which I also hope isn't the case!

I will advise as I move forward. I like to 'close my case' on forums like this so anyone searching in the future knows how my situation ended. There's tons of threads out there where people solve their problems but don't say what is was!

 

[85Hokie]

Van - sorry you've been sick - get better quick!

but...........

"it's a 40 weight oil and the manual calls for 10w30, so this is a heavier grade oil. "

I think you need to study up on the oils - the first number is the weight, so you are using a lighter weight oil.....5 vs 10.....HOWever, the 40 weight will protect better as it gets warmer......

I hope you find the radiator is in need of TLC - it will fix all the problems!

 

[D2Cat]

I like your stroy. But I have no idea of your question.

I find it entertaining when a first time poster comes on a forum and makes a comment like yours.

Are you confused because you didn't see a question mark in the sentence, or just wanting to type something on a forum. If there was a question mark, my guess is you wouldn't have a clue what the solution might be!

Check you're spelling if you're so analytical.

Most folks on a tractor forum would understand what the original poster was saying by his topic: "B7100 Oil Pressure Lamp/Overheating".

Come back when you have something to contribute.

 

[North Idaho Wolfman]

Come back when you have something to contribute.

He won't be back...
Sneeky spam originator, clue was Location... America... Nobody in "america" says that.