Overheating Terex HR16

[michael Griffith]

06 Terex HR16, Mitsubishi S4L engine overheats when tracking and running bush hog attachment. (Both require a lot of hydraulic fluid)
1. replaced cylinder head, it had a crack and I thought I had found the smoking gun, but didn’t.
2. Radiator professionally cleaned
3. New water pump
4. Auxiliary fan to help circulate air.
5. Hydraulic filters changed.
6. Greased everything

It still overheats when used in warm weather doesn’t in cold weather. I am at a loss for ideas. I’m just over $2700 in on parts tossing and still no better off except the head was replaced.

It’s just tracking and bush hogging. I can live without the bush hog attachment, but would like to drive it more than 100yrds without having to stop and let it cool down. It cools as soon as I stop and let it breathe for 1-2 minutes.

I’m thinking worn hydraulic pump making the engine work too hard constantly pumping to keep up with the flow?

 

[Vetech63]

First thing you need to do is verify that it’s actually heating and not a faulty sensor. Do you have a IR temp gun? Compare the temp gun reading at the thermostat housing versus what is on the machine temp gauge

 

[SLK001]

You said that the radiator was cleaned. Did you check the thermostats? Did you flush the entire cooling system in addition to the radiator?

 

[michael Griffith]

I should have posted more. Yes u have used a heat gun and confirmed it’s actually overheating, also replaced with a cooler thermostat. Switched to a 175 degree. This thing really has me stumped. Fan clutch is good also. Thank you for the quick replies

 

[DDoug]

How about hydraulic oil temps ?

 

[michael Griffith]

Yes entire system was flushed with a parts store type mix. I caught what was flushed to examine. It was a very tiny amount of what looked like black sand. Less than a matchstick head, if that makes sense.

 

[michael Griffith]

How about hydraulic oil temps ?

Hydraulic oil temps with an infrared gun are 160-170 at highest when engine is at 210-215. Of course that’s a reading on the hydraulic cooler . It will dig with no issues, just tracking and bush hogging. It does seem to put a decent pull on the engine when tracking. I mean it pulls down the rpm’s and engine sounds like it’s under a harder pull. It’s as strong as can be , doesn’t get weak tracking.

 

[DDoug]

Hydraulic oil temps with an infrared gun are 160-170 at highest when engine is at 210-215. Of course that’s a reading on the hydraulic cooler . It will dig with no issues, just tracking and bush hogging. It does seem to put a decent pull on the engine when tracking. I mean it pulls down the rpm’s and engine sounds like it’s under a harder pull. It’s as strong as can be , doesn’t get weak tracking.

Are the track brakes releasing ?

 

[SLK001]

I would concentrate my efforts on the cooling system. Check your hoses for collapsing during operation - a hose can collapse on the inside and not be noticeable on the outside. Depending of the cost, it might be prudent to just replace all the cooling hoses on the suction side.

Drain the system and see if you get the specified volume of coolant out of it. Also, see how long it takes to drain out completely. A properly functioning cooling system should have no problem keeping your engine at the correct temp.

I have an engine that was overheating. I checked to see if the thermostats were bad. I found out that there WERE NO thermostats. This should have prevented the engine from getting to op temp in a timely manner, but it was still overheating. I started to pull off cooling components (pipes, hoses - I suspected bad hoses - and elbows). What I finally found is some previous owner had put a screen, sealed up with red silicone goo, over the intake to the radiator from the engine. Scale from the engine clogged this screen up every time the engine ran. My guess was that the perpetrator of this "fix" thought that it would keep the scale out of the radiator.

A cooling system flush that Caterpillar recommends, is to flush the system with 1 pound of Oxalic acid for every five gallons of water and run engine for an hour, then drain the system and purge all remaining acid with a flush of a half pound of sodium carbonate (washing soda) for every ten gallons of water and run this for a half hour.

Your statement of ...It was a very tiny amount of what looked like black sand. Less than a matchstick head... seems odd to me, as almost any older diesel engine should have some scale in the system.

 

[michael Griffith]

I would concentrate my efforts on the cooling system. Check your hoses for collapsing during operation - a hose can collapse on the inside and not be noticeable on the outside. Depending of the cost, it might be prudent to just replace all the cooling hoses on the suction side.

Drain the system and see if you get the specified volume of coolant out of it. Also, see how long it takes to drain out completely. A properly functioning cooling system should have no problem keeping your engine at the correct temp.

I have an engine that was overheating. I checked to see if the thermostats were bad. I found out that there WERE NO thermostats. This should have prevented the engine from getting to op temp in a timely manner, but it was still overheating. I started to pull off cooling components (pipes, hoses - I suspected bad hoses - and elbows). What I finally found is some previous owner had put a screen, sealed up with red silicone goo, over the intake to the radiator from the engine. Scale from the engine clogged this screen up every time the engine ran. My guess was that the perpetrator of this "fix" thought that it would keep the scale out of the radiator.

A cooling system flush that Caterpillar recommends, is to flush the system with 1 pound of Oxalic acid for every five gallons of water and run engine for an hour, then drain the system and purge all remaining acid with a flush of a half pound of sodium carbonate (washing soda) for every ten gallons of water and run this for a half hour.

Your statement of ...It was a very tiny amount of what looked like black sand. Less than a matchstick head... seems odd to me, as almost any older diesel engine should have some scale in the system.

Thank you for the advice, hoses will be checked and replaced if needed. I’ll repost after I chase down that lead.

 

[michael Griffith]

Are the track brakes releasing ?

Honestly I don’t know. I’m no mechanic and not really familiar with track brakes. I bought it used to use as a farm machine. How would one tell if the track brakes release?

 

[michael Griffith]

I appreciate everyone’s help. It has been discovered that exhaust gases are entering radiator. Head was replaced with a new one a few months back. It’s at the shop to diagnose the new problem. Probably a cracked sleeve.