# Jacobsen HR9016T Overheat and stalls



## Cptkuhl (Aug 19, 2019)

Hello,

I recently purchased a 2001 Jacobsen 9016 16’ mower with Detroit diesel 87 hp with 2900 hours to help keep my 17 acres mowed. 

I am new to diesels and would really appreciate any advise you could offer on my problem. 

With the PTO off, it seems to hold its temp well around 190 degrees. As soon as I engage the PTO, it will jump up to 210-215. When I start mowing, i get the overtemp alarm and temp goes north of 225. I know that a lot of my problem is that the screen gets clogged and I have to shut it down, let it cool and brush off the screen. I will start it back up and let it run to bring temp back down to 200 range before mowing again, but it quickly climbs back up. I recently changed the oil, oil filter, air filter and blew out the radiator and oil cooler. I also straightened out the fins. Coolant level is where it should be in the overflow tank. I notice black smoke from exhaust when mowing, seems like it’s laboring just mowing short grass at a slow pace. Any ideas how to get the temp under control or what’s causing my overheat issue while mowing? 

Also, when the temp gets to around 220, the engine just randomly dies. No stumble or hesitation, just a little serge, then shuts off immediately. It will start right up again and randomly just shut off again. Happens more often with the PTO engaged, but has happened a couple of times while just sitting there idling with blades off. Only stalls when the temp is high. I tried loosening the fuel cap, and it does the same thing. I cleaned up the seat switch and got it working again, but does the same thing with seat switch connected or bypassed. 

Hoping for some wisdom and guidance from the group of a place to start. I’m baffled by this. Thanks for your time!


----------



## Hoodoo Valley (Nov 14, 2006)

Welcome to the forum! How often are you cleaning / replacing the air intake filter(s)? Not too many hours but the radiator might need rodding.


----------



## Cptkuhl (Aug 19, 2019)

Thanks for the reply! I just replaced the air filter last week, but grass is really dry and it’s been dusty. Maybe a filter cleaning is in order. Wondering if the fuel shutoff solenoid is getting hot and losing power, causing the stalling problem. Thoughts? Thanks!


----------



## FredM (Nov 18, 2015)

you haven't thought of the thermostat failing, a faulty thermostat will cause your problem.

I too have the same problem when I use the belly mower on the Kubota, the fines will block the pre-screen and bingo, a steam engine,  but I would check the thermostat.


----------



## Cptkuhl (Aug 19, 2019)

Thanks, guess I assumed that the thermostat was good as it holds around 190 when it’s not under load. Definitely something to check out though. I do believe the fines clogging up the screen are my biggest problem. Not sure what to do about that.


----------



## FredM (Nov 18, 2015)

You will most likely be correct about the fines blocking the screen, and I have that problem also until I replaced the thermostat, but low!!, the last time I mowed the back paddock which was dry and lots of grass seeds, bingo !!, I had to shut the Kubota down because the temp was approaching the red mark, lifted the bonnet and the pre-screen was choked with fines, like you, I don't know what the answer is, maybe I will have to go back to mowing the back paddock with the zero turn, I don't have problems with that overheating.

Good luck with your endeavors.


----------



## Cptkuhl (Aug 19, 2019)

Seems to be a very common problem with these older mowers and tractors. I think Toro came up with a reverse fan that stops, and reverses to clear the screen when the temp reaches a certain temp. I thought about making some kind of secondary screen contraption with 12v fans attaches to blow the screen clear every so often as I have the room for it. Just a thought, but it’s a real pain to stop every five min and clean the screen with the current set up.


----------



## arcwelder (Sep 2, 2016)

On my Massey, I have to pressure wash out the radiator from the fan side out. Gets clogged up pretty regularly. I made a 90 degree head out of a male and female connector. It will try to rotate out of your hands though. 
Male: https://www.homedepot.com/p/Power-C...nector-for-Pressure-Washer-AP31039B/100664029
Female: https://www.homedepot.com/p/Power-C...nector-for-Pressure-Washer-AP31041B/100664033
Use a thick brass elbow. Lets you shoot straight through radiator without too much hassle.
Run tractor until radiator is dry or let set until dry before mowing.


----------



## XLENDI (Jul 22, 2019)

Pleas advise model Detroit.
cheers.
Alex.


----------



## Cptkuhl (Aug 19, 2019)

I was reading to stay away from washing out the radiator, but I think the air only does so much, so I will give it a try. Thanks!


----------



## Cptkuhl (Aug 19, 2019)

XLENDI said:


> Pleas advise model Detroit.
> cheers.
> Alex.


It’s a D704LT. If anyone knows how I can get my hands on a manual for this engine, you would be my hero! I can’t find anything about this motor, especially a manual, which would be very helpful!


----------



## XLENDI (Jul 22, 2019)

OK this is a later model Detroit, there is a strong possibility that she is a Kubota or VM.
As you are a mower do you have an oil cooler , this will be in front of the radiator, pls check as the air will pass though this prior to the radiator, if your fan is the suction type. If you have suction fan you will need to check oil cooler fins, compressed air is the best way to clean the fins out , always clean opposite direction of air flow. Look at condition of radiator cap , if necessary have it tested , they can cause over heat. When engine cold , do not remove radiator cap check radiator hoses to see if either has sucked in Are you losing coolant during operation out of the over flow pipe just below the radiator cap. CHECK IF YOUR COOLING SYSTEM HAS AIR BLEED TO PREVENT AIR LOCK IN THE COOLING SYSTEM. Air lock *will prevent cooling flow* through the system. A common problem overlooked. There are many reasons for over heat , check all the simple things.One of the first things you check is your fan belt is tight, cooling fins radiator and oil cooler, bubbles in cooling system, thermostat opening temp. When thermostat opens you will notice bottom radiator hose will become as hot as top hose. Worst case is the hydraulics maybe stressing the system due to a fault. Good luck .Cheers. Alex.


----------



## Cptkuhl (Aug 19, 2019)

XLENDI said:


> OK this is a later model Detroit, there is a strong possibility that she is a Kubota or VM.
> As you are a mower do you have an oil cooler , this will be in front of the radiator, pls check as the air will pass though this prior to the radiator, if your fan is the suction type. If you have suction fan you will need to check oil cooler fins, compressed air is the best way to clean the fins out , always clean opposite direction of air flow. Look at condition of radiator cap , if necessary have it tested , they can cause over heat. When engine cold , do not remove radiator cap check radiator hoses to see if either has sucked in Are you losing coolant during operation out of the over flow pipe just below the radiator cap. CHECK IF YOUR COOLING SYSTEM HAS AIR BLEED TO PREVENT AIR LOCK IN THE COOLING SYSTEM. Air lock *will prevent cooling flow* through the system. A common problem overlooked. There are many reasons for over heat , check all the simple things.One of the first things you check is your fan belt is tight, cooling fins radiator and oil cooler, bubbles in cooling system, thermostat opening temp. When thermostat opens you will notice bottom radiator hose will become as hot as top hose. Worst case is the hydraulics maybe stressing the system due to a fault. Good luck .Cheers. Alex.


Awesome reply, thanks for taking the time! It does have an oil cooler in Front of radiator, which actually folds out for easy cleaning, which I’ve done. I’ve also straightened bent fins on both radiator and oil cooler. The fan belt is tight and in good shape and the fan has a heavy suction from the backside of the radiator. I will take a closer look at the radiator cap and see if the hoses collapse. I thought about air in the system, how would I bleed the air out to eliminate that scenario? Start cold with cap off and leave it off until it reaches temp, or is there a better way? I do know that just running the mower spikes the temp about 15 degrees, and when I start moving, it’s just a matter of minutes before it’s headed towards redline. So you might be on to something with the hydraulics stressing the system, but I’m clueless as to what could be the stress point. Thanks again!


----------



## XLENDI (Jul 22, 2019)

The blocking radiator fins , if constant problem , can or is it possible to fit Velcro tape to side of radiator , then do the same to some mosquito wire , when blocked take of shake and put back.
OK, bleeding the cooling system , does your turbo have a water jacket, if yes this is the most likely place for a bleed nipple , if not look to the highest point on the cooling system , if there is a bleed nipple it should ?? be there. If there is a bleed nipple , running with radiator cap of will not get rid of the air. How many mowers do you have on your machine, can they be operated individually. If yes will the operation on one cause you to over heat , pls check , lets see if one of the drives is stressing,, with a 87 hp engine she should take up load with very little sign of stressing. Like any pump if they can suck air , they will not perform, but should not cause a power drain problem. You mentioned that the engine when hot will just cut out, pls be most careful, you do not want a scuffed piston. When you go to the doctor , he can mostly figure out what is wrong with you by what you tell him. Ok had you had any work done to you machine of any kind prior to the problem. Did your radiator have coolant inhibitor when you purchased it or plain water. if plain water , your normal water supply is it soft or hard water. It is all a process of elimination, essay , easy catch the monkey, you do not run after the bugger you creep up on him. Slow but sure, must be others in the forum with hydraulic savvy, that can help out.


----------



## XLENDI (Jul 22, 2019)

*No disrespect* , do you know how a radiator cap works, it has 2 functions


----------



## Cptkuhl (Aug 19, 2019)

XLENDI said:


> *No disrespect* , do you know how a radiator cap works, it has 2 functions


Great post, and that gives me a lot to think about. No disrespect taken, if I was a mechanic, I wouldn’t be on here asking for advise. I have basic understanding of most things, but the devil is in the details. I’m open to an education. I agree with your statement of slow and steady, one thing at a time and process of elimination. I just received this machine and don’t know any of it’s past maintenance history, other than it was city owned. I haven’t dug into it much yet Mainly because of time restraints. But I can say that I’m not too surprised that it’s overheating as it’s been over 100 degrees out and the grass has is very dry and dusty right now. I think the first step is to thoroughly clean the radiator, oil cooler and air filter. My stalling problem only seems to happen when it’s hot and I’m leaning towards the fuel stop solenoid. I will check the wiring on that and maybe look into a temporary bypass to narrow it down. Thinking that could be a wiring issue, a problem with the safety’s (which I know I have issues there) or possibly just a bad solenoid. Thanks again for the thoughtful and detailed reply!


----------



## Joe Babbs (May 22, 2018)

I'm endowed with an abundance of ignorance on many matters, including this one. But I was wondering if you overheat when the PTO is turning, but without the mowers attached.


----------



## Cptkuhl (Aug 19, 2019)

Got my problem fixed and wanted to provide an update and thank everyone for taking the time and for your expertise! 

Overheating issue: I blew out the oil cooler and radiator. Didn’t make a difference. Bought the “radiator genie” online and washed out the radiator and oil cooler. Amazing how much crud came out of there! I then rigged up an old house window screen to act as a prescreen of sorts to prevent the fines from getting to the oil cooler and radiator. 

I mowed the front pasture today and it ran 30 degrees cooler and never got above 195 degrees while mowing. This also fixed my stalling problem, so I’m guessing it has a heat sensor that would turn off the engine if it got too hot. 

Also, I couldn’t find anything about my Detroit Diesel D704LT. As suggested in this chat, turns out it is a VM Motori Detroit Diesel and was able to find the manual for it! 

Thanks again for all of your help! I certainly appreciate it!


----------



## XLENDI (Jul 22, 2019)

Great news and a big worry of your mind, quite often always the simple things.
Engine would be real happy if you did an oil and oil filter change , oil has been working overtime to protect your engine internals with the over heat shut down. if oil has been working overtime , the oil smell will give it away Always stay with a good quality oil , pays dividends when you have over heat problems. I am of to my farm next week , blew a track adjuster on my baby dozer, blew the seal,s clean out when i went over some roots. Cheers. Alex.


----------



## John A Moritz (Apr 20, 2020)

Happy your HR9016 is running cooler, I have two HR9016s on in Florida both had the same problem. I changed to aluminum radiator and have two 12vdc fans pushing air through the oil cooler to assist the engine fan which pulls air. I also change the front so the air is pulled from above not the dirty air with grass and crud from the sides of the machine. Have been running in Florida 90+ days with air conditioner on and my normal operating temp is 185.


----------



## josephrubio411 (May 1, 2020)

Cptkuhl said:


> Hello,
> 
> I recently purchased a 2001 Jacobsen 9016 16’ mower with Detroit diesel 87 hp with 2900 hours to help keep my 17 acres mowed.
> 
> ...


Hello. I recently purchased an identical jacobsen hr9016t mower (2001) with the Detroit deisel engine in non running condition. I am having trouble diagnosing the problem. I believe it may have to do with the neutral or brake sensor due to the drive linkage missing. All I get when I turn the key is a beeping sound. The lights on the control panel come on but no start or even turning of the engine. I can get the mower to turn if I. Jump the solenoid but the engine does not fire. I don't know if the fuel solenoid is working. Is there a way to bypass the safety switches/sensors? Any help would be greatly appreciated.


----------



## John A Moritz (Apr 20, 2020)

josephrubio411 said:


> Hello. I recently purchased an identical jacobsen hr9016t mower (2001) with the Detroit deisel engine in non running condition. I am having trouble diagnosing the problem. I believe it may have to do with the neutral or brake sensor due to the drive linkage missing. All I get when I turn the key is a beeping sound. The lights on the control panel come on but no start or even turning of the engine. I can get the mower to turn if I. Jump the solenoid but the engine does not fire. I don't know if the fuel solenoid is working. Is there a way to bypass the safety switches/sensors? Any help would be greatly appreciated.


1). Yes you can jumper the interlock switches, do you have copy of Parts Maintenance manual?
2). If K2 is not pulled with power on pin 30 of K2 the fuel solenoid will not pull and engine will not run
3). I made a male blade terminal to male blade terminal jumper to assist in troubleshooting, so i can bypass a relay.
4). Machine must see parking brake off, you in seat, transmission is neutral, pto off, and proper outputs from key switch to start


----------



## John A Moritz (Apr 20, 2020)

josephrubio411 said:


> Hello. I recently purchased an identical jacobsen hr9016t mower (2001) with the Detroit deisel engine in non running condition. I am having trouble diagnosing the problem. I believe it may have to do with the neutral or brake sensor due to the drive linkage missing. All I get when I turn the key is a beeping sound. The lights on the control panel come on but no start or even turning of the engine. I can get the mower to turn if I. Jump the solenoid but the engine does not fire. I don't know if the fuel solenoid is working. Is there a way to bypass the safety switches/sensors? Any help would be greatly appreciat





John A Moritz said:


> 1). Yes you can jumper the interlock switches, do you have copy of Parts Maintenance manual?
> 2). If K2 is not pulled with power on pin 30 of K2 the fuel solenoid will not pull and engine will not run
> 3). I made a male blade terminal to male blade terminal jumper to assist in troubleshooting, so i can bypass a relay.
> 4). Machine must see parking brake off, you in seat, transmission is neutral, pto off, and proper outputs from key switch to start


Correction for item 4)
Parking brake: ON
Transmission: NEUTRAL
PTO: OFF
Seat: OCCUPIED
Key Switch: outputs depend on S/N of machine


----------



## Arnie3000 (Aug 17, 2021)

John A Moritz said:


> Happy your HR9016 is running cooler, I have two HR9016s on in Florida both had the same problem. I changed to aluminum radiator and have two 12vdc fans pushing air through the oil cooler to assist the engine fan which pulls air. I also change the front so the air is pulled from above not the dirty air with grass and crud from the sides of the machine. Have been running in Florida 90+ days with air conditioner on and my normal operating temp is 185.


Do you have any pics of your setup


----------

