2015 Cat 305E2 Bogs down when under load.

Serial: H5M01334 Hours: 5200-5300, I am not near it at the moment. So, I haven't been using my 305 a lot recently, however I have been diagnosing the A/C issues its had. Lately I've been throwing a can of 134a into it when I need it and it'll get me a few days, which is cheaper than the evaporator it needs at the moment... ANYWAY, I've only noticed it when the A/C is on, and working, even if its not working well, you can hear that the compressor is on, but isn't blowing very cold at all. The engine will bog down under hydraulic load, usually two functions at once, or tracking once its up to temperature. I need to do more diagnostics on it, get coolant temps, and see if anything looks "out of place". I noticed the coolant gauge is above halfway, probably closer to 3/4 across the sweep, but not into the red. I want to say it was around 203, or 205 degrees when I checked it through the display the last time it did it. Either way, I am trying to source the issue of the bogging that it does. I've only noticed it after I have ran it for a while, and its at full operating temperature, and I have no idea if this is relevant, but its also when the A/C is on, the last time it occured, I turned the A/C off, and it did it again, but then I left it sit for about 5 minutes at idle, and went back to it and it was fine. I know when I first start it up, and attempt to perform any hydraulic functions, to say just move it out of the way for something else, it will bog and want to die at idle. Not every time, but more so when its colder, I don't know if thats related. I feel like its temperature related, the fuel filters are good, and I am not losing fuel supply either as the filter never gets drained of fuel as I am operating, so I don't think its the fuel pump. Hydraulic fluid is on the low side of full. There are codes stored in the computer, one is an overheat code, but its from a few hundred hours ago, before I even bought the machine. No warning lights come on either when it is bogging down. I'm trying to see if I am dealing with something serious, like a hydraulic pump, or something stupid, like belt slip, and trying to get direction on where to go before diving into it head first. Thanks!

When it does it again stop the engine and loosen the cap on the fuel tank then listen for a whooshing sound.

Another simple test is to run it off a Jerry Can of fuel and see if it still does it. Simon C

Thinking its vapor locking the fuel tank? Im going to be running it most of the day today, so I will give that a shot!

Take cap off and tape a good rag on top and Nige may of found it. Has to be ruled out before firing the parts cannon. Simon C

weareweird69 said: Thinking its vapor locking the fuel tank? Im going to be running it most of the day today, so I will give that a shot! Click to expand... Before you kickstart it for the first time take a moment to locate the drain underneath the fuel tank. Remove the plug or open the valve and see what you get out in the way of water and sediment.

Nige said: Before you kickstart it for the first time take a moment to locate the drain underneath the fuel tank. Remove the plug or open the valve and see what you get out in the way of water and sediment. Click to expand... I’ll try and find it. Is it under a plate or anything? I’m sure I’ll get a bunch of crap out of it. If it’s as simple as a new fuel cap. I’ll be tickled pink.

weareweird69 said: I’ll try and find it. Is it under a plate or anything? I’m sure I’ll get a bunch of crap out of it. If it’s as simple as a new fuel cap. I’ll be tickled pink. Click to expand... You have to start by eliminating all the basics before you go on to the expensive stuff. See the illustration below. It appears as though it's a plug in the bottom of the fuel tank. It does not appear to be under a plate but I wouldn't guarantee it. Regarding the tank cap try giving it a good clean inside and out with aerosol brake cleaner to make sure the vent is clear.

There is a hidden fuel filter, plastic mounted on backside of a bar in the right side compartment. Did u change that filter? I missed it first couple oil changes cause its kinda hidden

Thanks Nige, Looks like it’s an actual plug and not a valve. Yay… And, it’s full of fuel, and the plug is partially covered by the actual base of the house. So I’m going to have to run it down low and see if I can move the tank a little to get the plug out. mike holcomb said: There is a hidden fuel filter, plastic mounted on backside of a bar in the right side compartment. Did u change that filter? I missed it first couple oil changes cause its kinda hidden Click to expand... Yeah. That one is easy to miss if you’re not looking for it. but its fresh too

weareweird69 said: Looks like it’s an actual plug and not a valve. Yay… Click to expand... Bugger. Yes you need to do it when the tank is low on fuel. Meantime try the loosening the tank cap trick next time it bogs and see what happens.

Hopefully the cap does the job. When it’s low on fuel. I’ll try and get that plug out. Maybe when it’s back at the shop in a controlled environment lol

At whatever point you do drain it maybe look at installing a valve in place of the plug.?

weareweird69 said: View attachment 363141 Click to expand... Don't be scared, Allen on a extension, pull the plug. Being full and cap on it might hold a vacuum like. Most likely not but have a couple buckets ready and prepare to get a little wet lol

Nige said: At whatever point you do drain it maybe look at installing a valve in place of the plug.? Click to expand... That’s going to be on the list of things to do. mike holcomb said: Don't be scared, Allen on an extension, pull the plug. Being full and cap on it might hold a vacuum like. Most likely not but have a couple buckets ready and prepare to get a little wet lol Click to expand... Oh I’m not. But I can’t get it out. lol.

What’s the coolant temp supposed to be? Seems to start acting up around 200 degrees and I’m up to 208. It hasn’t done it bad enough or long enough to stop and check the cap.

Not sure but probably the thermostat opens around 90 DegC/195 DegF or around that. Have you inspected and/or cleaned the cooling package (radiator & hyd oil cooler) lately.?

I have recently cleaned it with air. But maybe it needs a good washing with water. I just ran it up to 226°. Left it on high idle and watched the temp drop pretty quick. I’d say I need a thermostat at the minimum. And a good cleaning of the radiator stack. In 6 minutes of idling on max throttle, it’s down to 208° The higher the temp got. The more it acted up. Wondering if it’s derating itself

I suspect that on a machine as small as yours the only way to adequately clean the cooling package might be to remove it and split all the coolers apart from one another. What you find may surprise you.

Nige said: I suspect that on a machine as small as yours the only way to adequately clean the cooling package might be to remove it and split all the coolers apart from one another. What you find may surprise you. Click to expand... Oh I’m sure it’s a disaster in between everything.