TerexDemag AC50-1 overheating problem-URGENT HELP NEEDED

[ernstZA]

Hi Everyone

I have a problem with an AC50-1 which is overheating , climbing a hill it goes all the way up to 99'C and all bells and whistles goes off.

Today I had compression tests done - all good, we had the radiators out recently-all good, we had the hydr. motor on the cooling fan repaired, new temp sensor was fitted today- apparently the old one was no good.

The only problem the computer technician could find is that injector number 2 is over fueling. Now I don't know if that will have any effect on the temp. problem. I can replace it later as it is on its way to a job and can't be pulled off until next week.

Also I pick up small jerk movements every now and again

Any ideas for where to look/scratch from the experienced guys will be greatly appreciated.

Kind Regards

 

[lantraxco]

The temp sensor may have been your problem, if it was the sensor that controls the cooling fan. Just guessing, I know nothing about this particular machine. Yes, overfueling will contribute to heat so that's something you will want to address as soon as you can, not to mention I would assume a single injector overfueling would cause an imbalance which can't be healthy for the engine. Are you getting transmission overheat as well? If so you may have a torque convertor problem that's causing the engine to overheat, just a thought.

 

[ernstZA]

The temp sensor may have been your problem, if it was the sensor that controls the cooling fan. Just guessing, I know nothing about this particular machine. Yes, overfueling will contribute to heat so that's something you will want to address as soon as you can, not to mention I would assume a single injector overfueling would cause an imbalance which can't be healthy for the engine. Are you getting transmission overheat as well? If so you may have a torque convertor problem that's causing the engine to overheat, just a thought.

Lantraxco, thanks for the reply.
I am definitely going to sort out all the injectors next week.
Regarding the transmission,yes, it is also overheating but I thought it is mainly because the engine overheats and it is using the same radiator. What type of problems can I look for on the torque convertor that will make it overheat?

 

[lantraxco]

It's kind of a chicken and egg thing, which overheats first? Could be the transmission/torque convertor are throwing so much heat into the the radiator that it's causing engine overheat as well. Also, if the transmission is slipping or not shifting properly down into the correct gear, or the torque convertor is defective then the load on the engine will increase which also causes more heat. Do you know if the engine rpm's when pulling a hill are noticeably higher or lower than normal before the overheat alarms go off?

 

[ernstZA]

Not too sure about the rpm's will have to speak to the operator when it get back in to the yard. I will defnitely have a look at the TC. One thing we did not check is the external heat exchanger for the TC, this is fed with coolant from the radiator to cool down.

 

[dbl612]

if the engine is overheating the water supplied to the trans will not help cool it. id worry about the bad injector washing that cylinder and causing a ring to score the cylinder and overall oil dilution. does the crank oil smell slightly of diesel?

 

[ernstZA]

We sorted the injectors with new ones. We changed the filters and oil on the transmission. But did found that the transmission temp is definitely the problem. The transmission temp rise to about 97'C but the water temp stays cooler and also cools down quicker. I have put the crane on a one month job where it will mostly just stand and idle. After this job I will send it to ZF to get checked and inspected for a probable cause. Thank you for all the replies.