2550 Melting hood!

[CCinCT]

...but the exhaust system really should not be on the lower end of the engine/frame.

On the 2006 models, the exhaust exits about midway up the front of the hood, and points forward. I think the browning grass problem was with 2005 and earlier models.

Has anyone noticed how high the underhood temps are on the later 2500 series?

Haven't noticed anything beyond what I would expect. Even after mowing for 2 hours in 80+ degrees, I've opened the hood and not felt like things were too hot. I usually idle down when I stop for more than 20 seconds, and I mow at close to full speed. So maybe those two things keep it under control.

 

[JSharp]

I know when owners say the heat off the exhaust will turn the grass brown if left idling, those things have got to be getting toasty under the hood.

Out of curiosity, what were the temperature readings? I know they check that sort of thing out carefully during design, so the engine temp range should be well within Kohler specs. Just not too good for the grass.

I know they make those sloped, tapered hoods to give better visibility when mowing, but the exhaust system really should not be on the lower end of the engine/frame. I have never thought too much of plastic hoods, but it's just what you are going to get today.

-Fordlords-

I was mainly interested in the possible oil temps so that's the only thing I tried to measure. I saw temps of 238ºF on the oil filter end cap, low 240's on the hottest part of the oil cooler, and 246ºF on the engine sump. Keep in mind my engine has an external Kohler oil cooler that I added and I wasn't working the tractor hard at all before I shutdown to make these measurements.

What bothers me isn't the plastic hood or the temps exactly. Engineering plastics are great things when used in the proper places and I think the tilt hood is preferable to the mult-part metal setup with too many parts, ill fitting tin, fasteners that don't fasten, etc.

What bothers me is the apparent lack of any thought as to how cool clean air can get into the engine and then be exhausted. The duct setup on the 3000 series is a lot better in that way IMO. With the current 2500 setup the engine fan is free to draw hot air from under the hood plus grass clippings and whatever else it can suck up.

Wonder what I would have seen without the added oil cooler and had I really been working the thing? It also got me later to wondering what the overall underhood temps actually are. We know relatively from the guys on the board how hot the air is that exits the underhood area - Hot enough to toast your grass brown if you sit too long.

I will say you have more faith in the "engineers" at Cub than I do. But you're probably right, Kohler wouldn't have allowed it and provided warranty coverage had the numbers been too out of whack. Then again, they know these engines in this application get used maybe 50-100 hours a year...

Sorry about the edit guys...

 

[JSharp]

On the 2006 models, the exhaust exits about midway up the front of the hood, and points forward. I think the browning grass problem was with 2005 and earlier models.


Haven't noticed anything beyond what I would expect. Even after mowing for 2 hours in 80+ degrees, I've opened the hood and not felt like things were too hot. I usually idle down when I stop for more than 20 seconds, and I mow at close to full speed. So maybe those two things keep it under control.

Mine's a 2006 and it toasts the grass brown if it sits too long in one place with the engine not at idle. I run the engine WFO when mowing of course but unfortunately my yard's too rough to have much ground speed...

 

[GreenQuality]

J-sharp where is your oil cooler located that pretty high on oil cooler. did you try to re-locate oil cooler in front of air intake by the fly wheel, it will bring those temps down. also try some exhaust header wrap with stand temps up to 2000 deg.

 

[JSharp]

I thought it was excessive myself.

The cooler is located on the shroud. You cut a rectangular hole in the shroud and mount the cooler to it. Then the engine fan blows cooling air through it. I'll see if can find a photo or take one if I can't. It has a massive amount of air blowing through it. Too bad it's the hot underhood air that the engine fan picks up instead of some cooler outside air...

Those temps I measured are telling us something about the oil temps and IMO they're plenty high. It certainly doesn't make me want to run inexpensive oil.

That might also explain why the Cub Cadet oil change interval is 1/2 ( 50 hours vs. 100 ) of what Kohler recommends in their engine manual...

There's a stainless steel guard over the muffler but I like the header wrap idea. That stuff always shortens header life but if it extends engine life it might be a good trade off...

 

[franmech]

We are a Cub dealer and I can say that on all 2500 series we have been removing the center panel that blocks the louvers in the hood. Also you may want to check with your dealer on service bulletins. 2500 series built before August 2006 have an exhaust shield extension that can be installed to cure any hood and latch melting problems...................It's dry where we are and the air filters have been plugging solid within 15hrs. of use!! When this happens the engine uses massive fuel and burns oil, the engine has to suck in something and it will suck oil right through the crankcase breather...............

 

[JSharp]

Thanks for the tips franmech.

Mine is an early '06 so I'll check with my dealer about the exhaust shield extension. I've had no problems with the hood latch yet. I have seen the air filter issues to a lesser degree along with tons of crap in the fan after just a couple hours running. Unbelievable how much crap the engine can suck up when it doesn't have a decent place to draw air from.

I'm going to pull the upper louver cover before I mow the next time. Plus change the oil to a synthetic now ( tractor has 60+ hours ) instead of waiting until 100 hours, along with using a larger oil filter next time I change it.

What a nice engine the Kohler is. I won't see mine destroyed by the marginal environment it's been put in. I'll trade it for a Green one or an Orange one before that happens...

 

[JSharp]

I was out in the shed a bit ago and noticed, surprise, surprise, the hood on my 2554 is starting to melt too. Quite a bit of "sag" around the the hole cut for the exhaust pipe and the grill is looking bad.

Looks like it'll need a new hood and grill, plus the headlight reflectors are folded in too. I suppose the dealer might as well fix them when they replace the hood and add the heatshield franmech mentioned.

There's your Cub Cadet thermal "engineering" Fordlords...

Scabbing on a heatshield isn't a long term solution IMO. The engine will still be running with inadequate cooling and decreased life. The hood just won't melt.

I'm not sure I care to find out how this turns out. I do think I'll send an email off to Kohler and find out how they feel about providing warranty coverage when their engines are used in this kind of environment.

Then it might be a good time once it's all fixed to clean it up and let someone else be Cub's engineering and testing department...

 

[EuropaChris]

There's your Cub Cadet thermal "engineering" Fordlords...

Scabbing on a heatshield isn't a long term solution IMO. The engine will still be running with inadequate cooling and decreased life. The hood just won't melt.

The '05 and earlier 2500 series had a far superior hood setup. Yes, it's metal, can dent, etc. and can also rattle, it also has a much better setup to pull clean, filtered air through the perforated grill on each side of the hood as well as under the steering area. Keeps the blower clean and also ducts the hot air OUT of the engine well and to the front and down. Yes, they will toast the grass in short order from the exhaust, but it does a nice job keeping crud out of the cooling system.

Chris

 

[JSharp]

The '05 and earlier 2500 series had a far superior hood setup. Yes, it's metal, can dent, etc. and can also rattle, it also has a much better setup to pull clean, filtered air through the perforated grill on each side of the hood as well as under the steering area. Keeps the blower clean and also ducts the hot air OUT of the engine well and to the front and down. Yes, they will toast the grass in short order from the exhaust, but it does a nice job keeping crud out of the cooling system.

Chris

A friend has an older model and I can't say I care for that system either. The airflow is more correct but the panels are cheap and fit poorly, plus the fasteners don't hold the panels on well at all. So they're always loose and rattling. He said it's been that way since new.

So, maybe there's 3rd answer - proper engineering using decent quality parts...

To add to this little temperature lovefest, I mowed 3 hours today in 78°F degree heat. I first removed the center louver cover on my semi-melted hood. Then I used a digital thermometer and put the sensor inside the engine compartment in between the battery and the engine, about 1" down from the top of the battery.

It peaked at 145°F

Basically, this is the air temp the engine is drawing for cooling on a day that's not even all that hot.

Anyone who thinks the cooling air temp being this high isn't going to shorten engine life substantially, needs to sober up.

And just so the whole lack of cooling, hood melting issue isn't the only thing to mention today, I now have a "knock" in the deck when the blades spin down after disengaging the PTO. Yes, the deck has been cleaned and greased religiously since new.

Call me unimpressed on machine with less than 65 hours of moderate use...