So on behalf of a family member, who is technically savvy, he has a 2012 Wacker Neuson 28z3, S/N AG05746, somewhere near 500hours from new. After about 30/40mins the 28z3 sounds the engine temperature alarm, once i open the engine cover the alarm stops after a minute or two with the engine still running Diagnostics so far... 1. Blown out the radiator to ensure that it has airflow, radiator fins all in like new condition 2. Verified the radiator fan by verifying that a piece of paper will 'stick' to the radiator thus confirming airflow 3. Removed the thermostat and ran the machine to see if the condition re-occurs, which it does 4. I have confirmed it is a genuine overhead rather than a sensor issue by measuring the temp of the thermostat body when the alarm goes off...saw approx 235deg 5. When removing the thermostat did a visual check of the thermostat housing and inside radiator filler which did show any residue or debris inside the cooling system, it all looked just like new...the coolant was clear and like new 6. The engine cover is in good condition and the front and rear vent's are as designed and not blocked or modified The hydraulic filter was changed about 20hrs ago, the engine oil and filter changed 5hrs ago, and the air filter is clean. There are no obvious signs of any modification or prior repairs and the machine is fully functional..the machine is I believe 2012 and has 540hrs on it. The typical air temp during these time when the alarm sounds is 80-90deg I've pondered this and can't seem to figure it out... runs hot till the hood is opened...? *** Anyone seen anything similar?
Pictures? It's small, it's tight, it's all insulated, there's not enough venting of the engine compartment air. Is the muffler wrapped? Where is the air cleaner pulling it's air from, inside the compartment? Altitude? Air baffles all in place around the radiator? Those little Yanmar engines are usually bulletproof.
Message passed on... Pictures and more info to follow... Agreed in your last point, little yanmar engines are usually bullet proof! Altitude... It's in Sacramento area so not exactly super high.
No, not high, I would be looking for 10,000 feet before it started cooking usually. Is there a hydraulic oil cooler in front of the radiator? Is the hydraulic oil getting equally hot?
I'd really flush the radiator out good with a garden hose from both sides. Between the oil cooler and, ac cooler it is tough to blow them all out the way there stacked in there. You'd me amazed how much dust and dirt can pack in there that you might me missing with a blow gun.
I had one that would run hot with the hood closed ck every thing ended up the fan just was not turning fast enough even though it seemed to be I put a fan hub on it and it was fixed
Yair . . . It is obviously an airflow issue . . . anything changed where air exits the engine bay, a piece of insulation come loose perhaps and causing some obstruction? The point I make it doesn't have to be on the upstream side. If it has a viscous drive fan the first thing would be to lock it up and check belt has not worn down into grooves. It will be interesting to see the outcome. Cheers.
Make sure the fan is not on backwards and all the foam / gaskets around the radiator are good,
500 hours is a good time for the belt to get loose. Did the overheating start before the oil changes? or after?
Use to be a nearby company called "Huber reversible Fan Company", and they claimed you would reverse their blades for winter/summer. Can't really see it making a difference unless the airflow ran thru the cab.
The reversible fans have/had reversible blades. Turning a normal fan around won't reverse air flow, it just makes the fan horribly inefficient and you will have overheating due to low air flow. Something to look at, can't imagine a factory putting a fan on backwards, but you never know?
Radiator Has been flushed, Was clean inside visibly and clean to flush. Also has been run without a thermostat, Still overheats. The fan hub is fixed. The owner/operator has recently bought the machine and has no history on it... so really that is an unknown. The fan being fitted backward is something I suggested, on inspection it is offset and therefore can't be fitted in reverse.
Thanks to all for input so far!
I see the hood is adjusted as high as it can go in the hinge slots, is it sealing properly across the top and side when it closes? Also, is there a way to pull that air intake hose out away from the radiator a bit, looks to me like it's blocking air flow. That's so tight in there I think you're looking for a couple degrees at a time. Is the floor solid under the engine, or is there a provision for some outward air flow there?
Oops typing with elbows again....please dis-regard
man listening to all the things he has tried already, I would say the issue should show itself but it proves otherwise. Maybe try removing the screen in the hood. must be an obstruction somewhere
The hinges being at the end of the slot, and the dent right in front of the battery seem to go together. In one pic the right bolts look like they had been installed at the top of the slot previously and the left side is missing a bolt.
A few things to look at....belt tension is only supposed to be 8mm or roughly 1/4". Has the cooling system been pressure tested? test to 15psi. Confirm your rad cap is functioning correctly. test to 15psi. Your likely culprit is going to be the rad cap. BTW your coolant doesn't look very healthy. The Wacker machines don't come with the greatest coolant from factory to begin with so I would recommend changing that coolant. Every pound of pressure in the cooling system raises the boiling point 2 degrees. 15psi = 30 degrees. If the coolant turns into steam because of a bad radiator cap is will overheat rapidly. Opening the hood on the other hand is allowing more air flow through the radiator and its pushing air over the engine faster. Never seen a 28z3 overheat because of the location of the engine. One of the best placed engines in its class if you as me. Let me know what happens. I have worked on my fair share of those machines.
Serpentine belt or V style belt driving the fan ? The reason I ask is I have seen V belts get a hard glaze on them and no amount of tightening would stop them from slipping.
In answer to all feedback to date: All appears to be correct and serviceable... certainly nothing obvious. Some have mentioned the radiator cap, seems plausible, its the next stage. To be tested or replaced and re run. Thanks to all for feedback. Results to be confirmed.
They did not provide sufficient airflow through the engine cover. Made for Europe where it is cooler. You can remove the honeycomb grills on front and rear of the cover, and remove the insulating "noise reducing" foam from inside the cover and it should work fine.
I could understand that with a machine in located in Texas, but the machine the OP's having problems with is in Canada where I would imagine temperatures would be similar to what they are in Europe. I still think the comment about the hood adjustment being potentially out of whack and therefore not blowing all the air through the radiator has some merit.
Agree, but how does it help then to open up the hood ? Even though the O.P. has stated a garden hose flowed well thru the fins, if the hyd cooler is in front of the engine rad (which I can't see) and if the hyd cooler leaked a bit, and that red dust all over the air cleaner is the environment in which it has lived....Ther might be a coating of "Red dirt grease mud" all over the hyd cooler, letting the garden hose flow, but not nearly enough air. When opening up the hood, the fan might be able to now suck air from around the gap between the Hyd cooler, and the rad, when the hood is tightly down, it would make the air flow thru the whole assembly, (and be starved) Steam or solvent blast thru might clean things up proper like.
If the cooler is sandwiched right up next to the radiator I would agree with that, and the only way to really clean everything externally is to pull the unit out and separate the two radiators.
Nige, Sacremento, California's capital city is located in the San Joaquin Valley of California. It is often near 100 F there and the delta dust flood plain dirt is as fine a powder as can be found when it is dry, and if any oil in it it sticks like the dickens. You may see thru the radiatior fins but the crap is still coating the tubes. I think as digger doug mentioned that another cleaning of both hyd cooler and radiator is in order. For sure it won't hurt for the hyd to cool down.
It's funny at one point I was going to ask what possibility there might be of the red dust visible directly below the air cleaner dust valve on one photo could be getting blown into the radiator then it slipped my mind.
For reference, the hyd cooler is next to, not in front of the radiator... As for it being too hot (California) and European stuff is not built for it... Wouldn't have thought so... It's not that much hotter.
I assume you mean not much hotter than Europe..? Even though you've flushed the radiator externally using a hose I would still have a (careful) bash at it using a pressure washer TBH. That red dust around the air cleaner gets me a bit leery. In addition to that the way the hood hinges are set could be allowing some of the air that should be going through the radiator to escape through the gaps betwen the hood and the machine panelwork and that might just be the straw that breaks the camel's back where cooling is concerned.
Yeah, the way that's all shoehorned in there, the air has to flow properly out the back grille in order to move the radiated heat from the engine block and muffler out and away. Anything that leaks around the seals and recirculates through the radiator will be a killer too. It just doesn't look like there's much margin for error built into it.
I was in a similar situation with a generator, kept over heating despite a completly cleaned and fully functional coolant system. Here is what I did with a infrared thermometer and thermometer. Measure the top of the radiator (from engine), bottom of radiator (to engine), air temperature into radiator, and air temperature exiting radiator. Using these values, you can determine where there is heat, and where it is going. In my situation, it turned out to be air flow, the hot air off of the radiator was hitting a fiber fence and recirculating into the generator enclosure. Long story short, the air temperature going into the radiator was 130+ F, temperature exiting the radiator was 170 I think. The radiator wasn't getting enough cool air to keep the genset cool, had to cut a hole in the fiber fence to let the heat exit. I would do the same thing on your excavator, see where the heat is going. Based on your pictures, I gotta wonder if you are experiencing similar problems. Is there a air seal missing somewhere that allows hot air to re-circulate?
Report to date: Coolant system holds pressure, Cap holds pressure, All known trim pieces present and fit correctly, Thermostat removed (testing purposes), Coolant flushed and replaced, Radiators washed (external)... had a BS over the phone and that about covers it. I suggested (with hesitation) that it may be worth replacing the rad, cap, stat at this point just to rule them out. It is a reasonably cheap step albeit a little serious. (I will add I hate throwing cash at an unknown problem but sometimes...)
Had a hospital generator once with a heating problem. When the radiator exhaust ductwork (which it was engineered for) was connected it could not pass a load test due to continued warming under full load and overheating. After Cat worked on it at least ten times they discovered it had a faulty fan that flexed two much. Also is there any way to test how much coolant is being pushed thru the radiator. Gunked up or worn impeller in the water pump perhaps? The hood being open may let enough heat out to let a marginal system perform.
Just an observation really but why is the filter box so dusty when the intake is in front of the rad set? Is there something wrong with the box or its cover that is letting it draw air from the hot engine bay? :Banghead
After only 500 hours... I would not have thought so. If I recall correctly the intake duct/pipe has been recently replaced.
Yair . . . simonsrplant. Just a clarification mate . . . is this overheating a new "out of the blue" carryon, has it gradually developed, or has it been a problem since new? You have mentioned five hundred hours on the little jigger. Cheers.
I think that answers your question Scrub. 500 hours, no history, could be anything, but I'm still suspicious of the hinges and that dent.
Well - There are a couple of other things to check. Fuel - Is it running lean? Restricted Exhaust - How is the muffler? And some others
I still don't see how a mis-aligned hood could hurt it, seeing how the solution (at the present time) is to "throw wide open the doors". Yes, I understand in proper operation, it's a baffled wind tunnel. Precisely designed to channel air to the proper places. Might the exhaust be leaking ? Manifold gasket, manifold crack, or just upstream of muffler ? That would dump some heat in the area, that removing the cover is somehow fixing..
Have you verified coolant flow? Water pump issues?
I missed this post :drinkup
If the hood is not sealing properly around the perimeter, the air flow could be escaping around the edges instead of pushing the heat out the back of the enclosure... it's a reach, but when you have overheating without obvious cause on a near new machine, you gotta consider all the possibilities....
Exhaust, from what I'm told is all in perfect order... The machine was working again today... Same fault. Good temp profile over rad 180 top 160 bottom, and hydraulics at 180.
The top of the radiator should be a lot more than 180 WHEN the thermostat is this hot. The 180 sounds like the thermostat wasn't fully opened yet??? Edit: give us the numbers on the radiator when the alarm is going off, and the air in front of and behind the radiator, like a sheet metal surface in the airflow on each side. The fan blade doesn't work, that will be much hotter.
I'm a bit confused too, if the thermostat is running 235, why is the hot water to the radiator only 180? Too little flow to the radiator? Wondering if the impeller fell off the water pump? I've seen it happen.....
Mr lantraxco, surely if the impeller had fallen off it would not cool with the hood open? And sorr ygentlemen for some vague facts on the machine... I'm sharing via emails and calls from a relation in California. Mr delmer, request sent for high temp figures.
Hard to tell for sure from the pictures, but the fan appears to be to far in the shroud. I have experienced this in different applications. The fan blades need to split the shroud to transfer the air as efficiently as possible . A fan to far in the shroud will just keep a lot of the same air going round and round and round. I would take that additional stoop off an try like that to see if it improves. Also make sure engine is running at recommended rpm . I have found just a few many rpm to cause a heating issue, again on different applications .
Shows how easy it is to jump to conclusions and why it's necessary to get ALL the relevant info. I was assuming the machine was located in a much cooler climate in Canada based on your indicated location .......
Seems to me that since it is an unmodified machine with only 540 hrs, the least costly attempt for a fix would be to replace the fanbelt to ensure the fan is turning at rated speed, and split the radiators to ensure no blockage.
Sstocker31: Radiators are side by side but back to back, they have good flow. Also, the fan belt is in good order with no slip. Not spoken to my relation for a week or so... He is in China on business. He has been in touch with Wacker regarding this so they are now aware of a young machine with a seemingly simple, or not, fault. I'll update with information when I can.
One of our 966c's with a 3306 ran for quit a while with the impeller broke off the shaft before we figured it out, symptoms were no heat out of cab heater and heating up when stalling torque converter, other than that it just ran a little warmer than normal, Temps across radiator were about what you mentioned but engine hotter, I wouldn't rule it out. It was just using the old thermosyphon!
So a long while later, a bit of cash and a lot of emails... New rad,water pump, stat, flushed system, fan, (fitted and re fitted backwards to check) more emails,testing and temp probing... determined that the hydraulics were possibly overlooked. Pressure and load testing a confirmed one side of the pump was overloaded. (Surprisingly to me) Sufficiently enough to overload the motor to overheating point. Reset pressures to factory standard seems to have cured all issues.
Wow. Wonder what number on the 'what now' checklist that was? At least it's sorted.
That one took a long time to sort out. Any idea if the relief on one side of the pump was set to high from the factory or after the fact? Or did the factory just have it lowered because of insufficient cooling capacity from the start? I would be curious of the before and after relief pressures.
Not sure and not sure... it's odd that it's a rental unit with low hours and seemingly little use... initial observations made us think that the pump has not been adjusted or changed as it still had paint markings, possibly factory and the overall painting had not had nuts removed. It's possible it was bad from new, or that it had been played with. We shall likely never know.
Just saw this, we have a JD50 that has been heating for a while. Turns out that Isuzu, or deere speced it, a 2 piece pully with a rubber ring, like a damper on most engines. It was slipping and finally got so bad the fan would slow down when rpms were called up. The new pulley is solid steel. No more heating.
water pump operation can be checked with a pressure gauge in the system close to the output of the pump. from the pics the fan is correct. if you grab the fan blade and try to turn it, does the belt slip easily? tighten and/or replace the fan belt... thats my bet