View Full Version : Groundsmaster 4000-D Overheating Problems

04-13-2010, 07:43 AM
I have a Toro Groundsmaster 4000D with approx 1000 hours (bought second user). After approx 10-20 minutes of work, the motor starts to lose power and stall. The temperature guage climbs rapidly and the coolant starts to boil.

I have blown all debris free from the radiators and checked that the fan belt is correctly tensioned. I have flushed out the cooling system and replaced the coolant.

Any ideas?


The Toro Company
04-13-2010, 02:31 PM
Check the operation of the Fan Clutch. It should engage when the machine gets warm, and will cycle on and off. You can hear the fan when it engages.

For additional help and information, you can contact you local authorized Comercial Products dealer or the Distributor for UK. It is the Lely Company. Here is the link:http://www.lely.com/turfcare_uk/

Eric Baumeister
The Toro Company

04-18-2010, 08:30 PM
Sounds like a cracked head

shop manager
09-16-2010, 04:11 PM
can you tell me what degree thermostat the 4000D (60 hp Kubota) is supposed to have ?

what temp does the safety switch shut down the engine at..?

is it possible to change the factory temp gauge with a numerical one ..?

The Toro Company
09-17-2010, 06:28 PM
The thermostat starts to open at 160 deg F., then fully open about 180 deg F.
The safety Switch is calibrated to shut the engine down at 220 deg F. on the 2008 and older models. 2009 and newer utilize different systems. I assume you are requesting info for the 2008 and older machines.
We do not offer a mechanical gauge. If you so desire to change it, then you would need to source it locally.

As additional information, you can go to www.toro.com and download a free service manual if you desire. The manuals have all the information in them!

Eric Baumeister
The Toro Company

shop manager
09-18-2010, 02:39 PM
thanks.. i'll do that..

03-15-2011, 08:52 AM
Why did it take so many years before Toro's R&D people did something about the Groundsmaster's over heating problems on 4100D & 4000D? I have both and if you don't have great coditions you have trouble with over heating because of plugged screens in front of radiator.

The Toro Company
03-21-2011, 06:01 PM

An older Gm4000/4100 will operate normally without any overheating problems with proper maintenance. Depending on conditions this could mean the air intake screen will need to be cleaned more often due to debris accumulation. More times than not the radiator itself is partially plugged so debris on the rear screen adds to the problem because the radiator cannot work efficiently.

There are still plenty of Gm4000/4100 operating perfectly in the field that do not have a reversing fan.

The Toro Company

03-22-2011, 07:57 AM
Your right I almost forgot I was going to remove my radiators this spring and make sure (boil out) they are clean. I don't mow golf courses I do rougher work where the screen requires cleaning every 10 minutes under poor conditions. So yes you could be right but with rear discharge decks, dry conditions, dandelions, cottenwoods trees, and cutting at 4-5ins. with large amounts of clippings it can be frustrating.

Dodge Boys
04-19-2011, 04:46 PM
Sounds like a typical Toro.... Any of their Diesel units don't seem to hold up regardless of how rigorous your maintenance program is!!!! That's is definitely a head issue, send it out to get checked at your local machine shop!!! Been through this one, one to many times.... Just to bad I bought 5 units at one time..... Someone forgot to tell them they have to do more than just put a sticker on the units saying they are "commercial"!!!!!

04-29-2011, 03:14 PM
Well I did take the radiator off and had it boiled out and the flow is good, no roding necessary. It was dirty on the outside of the cores toward the bottom. Very hard to service without taking it all the way out to see just what is in around the cores. At least I now will know my cooling system is in shape for this spring and we will see if that makes any difference this year.
"Properly serviced" is an interesting phrase. Makes quit a difference who it's coming from, a guy at a desk or the guy having to make a living cutting grass.

Blades Buggies
05-31-2012, 10:38 PM
so I see that Clutch Fan was the first suggestion, cracked head was the second.
on mine, the water pump had gone bad, put a new pump and still have the same issue described above, 10-20 minutes it's in the red zone... let it idle for 2 minutes and she cools right down. I have purchased a new head gasket and head bolts, I'm guessing that the head needs to come off and be checked for cracks.
I've also tried a new thermostat as well as running it without one.. same timing on the overheating. It has shut down once on it's own but other times, I just don't let it get that hot before letting it idle. Kinda annoying cause it's a beast of a machine and I love it, just need to keep it cool

04-03-2014, 08:35 PM
I'm wondering where the guys are who modify the groundsmaster 4000d to make it "run correctly" ie...move oil cooler and mount sideways, and cut holes in hood, or extra electric fans (kickers) dry ice?...wtf? We have always had issues with ours as well..very annoying....especially when I watch Ryan/Jacobson WA mowers with cabs and heat/a/c flying all over town.