Engine Overtemp

[woodlandfarms]

So I am getting this out of the electrical thread as the problem is unknown.

2 weeks ago I was running the mower and the temp jumped to super hot. I quickly shut down, but the engine felt cool. On further inspection I found that the tab on my temp sensor had broken. Called the factory, received a USED sensor late last week to the tune of $50. Last night I re-installed. Went out to mow and the engine temp rose higher than it normally does under the same conditions previously.

I have a new sensor on order from Germany ($38) and it should be in within the month.

Here are some of the issues. Might be a guage grounding issue. Will work on that today or tomorrow as time allows. I used a thermal measuring tool (Harbor Freight temp gun). With the temp guage reading 235 degrees, the oil filter was at 280, the oil pan was 210 to 230, the head was 220 (where the injectors are under the cooler). The oil cooler (the Radiator as this engine is oil cooled, not water cooled) was cool enough I could put my hand on the hot side momentarily and hold it much longer on the cold side. 180 was the reading on the hot, 140 the cooler side.

Called Deutz today and no repsonse, I am sure it is the holiday. Went ahead and replaced the oil filter. Cut the original filter apart and no issue, it was in very good shape unless the top gasket was causing an issue.

If anyone is out on their diesel PT and working a sweat with it, and has a laser meter, would love to get an idea of how your machine reads.

 

[Coyote machine]

Your USED temp sensor could be reading different than your old sensor did. Why did you replace it? Did the broken tab make it unable to be connected to the gauge wiring?
Thanks for clarifying your sole method of cooling is the oil cooler. That being said, if your oil has been changed infrequently it's possible you have some sludge like buildup inside the oil cooler, but the 40* difference from in to out seems to support it working as it should. There aren't wild fluctuations between the readings, and the oil filter would tend to run hotter due to the need to filter as well as pass oil through its entire surface area and filter media.

 

[woodlandfarms]

Coyote, yes, the old sensor the tab was completely broken off at the base. Yes, I agree the replacement sensor, being used, is purely a stopgap. But in an effort to get a handle on the situation I have a difficult question to ask...

Where do I measure the temperature of the engine at? If I am to use a probe, or laser heat sensor, what is the ideal place for me to explore? Oil filter sounds like a bad idea. Oil pan is no where near where the sensor is (Sensor at top of head).

At this point the sensor is suspect. I understand the boiling water, test the thermostat method and I will give it a try and some point.

 

[marrt]

Where do I measure the temperature of the engine at?

Since you're in the film business, I suggest getting a FLIR IR camera and film the entire entire. Then you can identify hot spots and get a better sense of the overall thermal picture.

Actually, I have one of these cameras. They're very cool. One day when the tractor is hot, I'll try to take a couple images...just for curiosity.

 

[ponytug]

Marrt- And you have one, why?

Not exactly home video equipment. are they? As you say, really cool images. I've always wanted to have one. Last time I checked they were in the $20-40,000 range, unless you got one of the really nice ones which require certain levels of clearance and a DoD cosponsor...

Back to Carl's problem- Carl if your oil cooler is clean and your oil is semi-clean, and all four cylinder exhausts read about the same temp, then you are probably good to rock n roll. You are right that "the" engine temperature is actually several different temperatures that are related by load, rpm, external temperature, etc. Deutz has arbitrarily, or not so arbitrarily, defined it at the point where the sensor is. Run with it.

Might I suggest an alternate way to check the current sensor? Rather than the boiling water test, why not put your thermocouple on the temperature sensor, by the engine. Wrap 6-8 wraps of electrical tape around it for some insulation and and see what you measure? The numbers should be close. I wouldn't expect them to be the same: your sensor is measuring the oil temp, and the thermocouple is measuring the engine block temperature in the same location. It should be close, though.

All the best,

Peter

 

[MossRoad]

Take readings at many spots when the engine is cool, 10 minutes after operating take the measurements in the same spots, 30 minutes, an hour, etc... to get a benchmark of what gets hot and where. Ideally, there should be an oil temperature sensor on the engine somewhere attached to a guage. Take reading right next to it and correspond those readings to the guage readings, too.

 

[Coyote machine]

Coyote, yes, the old sensor the tab was completely broken off at the base. Yes, I agree the replacement sensor, being used, is purely a stopgap. But in an effort to get a handle on the situation I have a difficult question to ask...

Where do I measure the temperature of the engine at? If I am to use a probe, or laser heat sensor, what is the ideal place for me to explore? Oil filter sounds like a bad idea. Oil pan is no where near where the sensor is (Sensor at top of head).

At this point the sensor is suspect. I understand the boiling water, test the thermostat method and I will give it a try and some point.

If you have a thermocouple long enough stick it down the oil dipstick tube until it touches the pan, then bring it up an inch or so, so it's only in oil. Tape it to the dipstick tube to secure it and see what readings you get.

 

[TNgypsy]

hi there - while VDO ist a common oem in Europe, they do have a distribution office"stateside , however, no experience dealing with them.
my suggestion for VDO parts would be

summit racing

they do have most of the VDO lineup in stock at reasonable prices.

plus, monitoring oil temp by means of a simple aftermarket instrument plus sensor = replacement for oil pan drain plug is fairly easy.

 

[woodlandfarms]

So bringing this back up with what I believe is my solutions, and some warnings to all.

I bought the replacement thermostat as recommended. As a note, the plug for the thermostat is a size 12mm hex and do not torque beyond 50lbs. When I removed it, the outside had a film on it. Not oily but more sludgy, like the inside of an oil filter. I sprayed it down to clean it and as you will notice, there is quite a difference

View attachment 384067

On my new one, the little button was out, and it is clear the secondary cap was stuck in a bit. So I cleaned it all up and reinstalled. But I had not addressed the oil cooler. So I took it off as well. I grabbed my can of parts cleaner, flipped the cooler upside down and filled it up and let is sit for 20 minutes. Gave it a vigorous shake and poured it out. Definitly dark oil but no chunks. I then grabbed some simple green, poured it in and let i sit. dumped it and then flushed with water.

I then blew out and hosed the fins as I would if attached to the tractor.

That is when I realized my issue. Looking in between the fins, there was dirt. Now I look with a mirror and paper but you really can't see how obstructed the fins are unti you get your face right into it. But I had a certain amount of blockage. Out came the pressure washer and it took a number of passes to where I felt I had a good clean fin system.

Bolted it all back together and took the tractor down the hill for some serious road grading. Temp stayed way down. While i won't know until I mow, it looks like problem is fixed.

The big note I wanted to give in all of this was that the fins have looked clean to me for a while, but it wasn't until the cooler was in my hands that I really saw how congested they are even after normal air blowing.

 

[woodlandfarms]

Not sure why the picture did not come up.... Old on the left, new on the right