Overheating on long hills

[Nautamaran]

Nautabox works only for T1N ?
The datalog doesn's seem too accurate.
Oil usually warms up 20 degrees behind coolant, when the log shows them even.
The sudden spikes in temperatures indicate big reading errors.

Yes, Nautabox is specific to the NAFTA om647 and logs the values read from the engine’s own sensors.

I have made and posted similar plots, and my experience is exactly the opposite of your assertion: the OM647’s engine oil sump temp seldom lags and often leads the coolant temp by several degrees. This makes sense when you consider that the engine has oil jets cooling the pistons, and that heated oil drops back into the sump immediately, where its temp is measured.
The oil goes through the oil cooler, where it’s temperature is brought closer to coolant temp, then through the engine block where it will reach whatever the block temp is, and at this point is very close to the same temp as the coolant, then hit the hot pistons. So the oil sump temp will warm up near or above the coolant temp, and often be several degrees above coolant temp due to the piston cooling.

The ATF temperatures also make sense when you consider that the fluid circulates through the COLD side of the radiator, so the transmission fluid temp being measured at the sump will often be colder than the coolant temp being measured at the engine thermostat, indeed this condition is pretty common with ambient temperatures of 50’F when the radiator can shed heat more efficiently.

-dave

 

[jackbombay]

The ATF temperatures also make sense when you consider that the fluid circulates through the COLD side of the radiator, so the transmission fluid temp being measured at the sump will often be colder than the coolant temp being measured at the engine thermostat, indeed this condition is pretty common with ambient temperatures of 50’F when the radiator can shed heat more efficiently.

-dave

I measure my ATF temp (with an autometer gauge) where it enters the cooler, so I am measuring it at its hottest point essentially. At 70˚ ambient temp (21˚ C) the trans fluid temp will be the same as the coolant temp at 70 MPH on relatively level ground. And change in ambient temp will reflect directly in the trans fluid temp, that is, at 50˚ the trans fluid will be 20 degrees cooler than the coolant temp, at 90˚ the trans fluid will be 20˚ warmer than trans fluid temp, at 120˚ F on level ground at 70 MPH my trans fluid will be 220˚ F. 70˚ is the neutral point, or cross over point if you will. Climbing long grades will of course put more heat into the trans fluid.

 

[Kajtek1]

Yes, Nautabox is specific to the NAFTA om647 and logs the values read from the engine’s own sensors.

I have made and posted similar plots, and my experience is exactly the opposite of your assertion: the OM647’s engine oil sump temp seldom lags and often leads the coolant temp by several degrees. This makes sense when you consider that the engine has oil jets cooling the pistons, and that heated oil drops back into the sump immediately, where its temp is measured.
The oil goes through the oil cooler, where it’s temperature is brought closer to coolant temp, then through the engine block where it will reach whatever the block temp is, and at this point is very close to the same temp as the coolant, then hit the hot pistons. So the oil sump temp will warm up near or above the coolant temp, and often be several degrees above coolant temp due to the piston cooling.

The ATF temperatures also make sense when you consider that the fluid circulates through the COLD side of the radiator, so the transmission fluid temp being measured at the sump will often be colder than the coolant temp being measured at the engine thermostat, indeed this condition is pretty common with ambient temperatures of 50’F when the radiator can shed heat more efficiently.

-dave

Never heard about the oil temperature phenomena before, but assuming it exist, the diagrams shows 20 degree drops in temperatures, only few seconds later to move 20 degrees up. That's evident reading errors
Several fluids follow the same pattern, what would indicate the errors in the reader, not in single sensor.

 

[calbiker]

The datalog doesn's seem too accurate.

The sudden spikes in temperatures indicate big reading errors.

You don't know what you're talking about. There are no sudden temperature spikes. The plot contains over 3700 timed measurements. Temperature moves quite slowly. If you compress 4 hours of driving, while taking data every 4 seconds into a graph a few inches wide then perhaps you would interpret the plot having sudden spikes. But you would be wrong.

As to data accuracy, it's probably accurate to a couple of degrees.

 

[Midwestdrifter]

A piece of advice Kajtek1, if you have zero knowledge of a platform, or if your comments don't even apply to the same vehicle class, I suggest you avoid posting. Or at a minimum learn from those with direct experience. Dropping into random T1N threads, and posting supposition, or worse making specific (and wrong) statements about the T1N platform does nothing but confuse those asking questions.

Did another 1300ft climb at 80-90% load today, average speed about 40mph. Ambient was 85F at the bottom, and around 75F at the top. Max coolant temp was 209F. At 65mph and around 75% load my coolant temps peak around 200F.

 

[Kajtek1]

I don't need to know the platform to read the diagrams.
Maybe my glasses are better than yours, but at about 60 minutes the temperatures jumps up and down over 20F within few seconds. That repeated several times later, beside slower temperature changes, what likely is result of driving on grades.
Such sudden temperature changes don't happen in real life. It has to be instrument error.

 

[jackbombay]

Maybe my glasses are better than yours, but at about 60 minutes the temperatures jumps up and down over 20F within few seconds.

You can't see a resolution of seconds on a scale of minutes.

It seems the T1N forum is your hobby, which would be reasonable, if you owned a T1N.

 

[Kajtek1]

Sounds like you are making T1N a good excuse for spreading bad information?
Is that some kind of religion for you?
you did not even notice, that I my comments apply to scanner, not to Sprinter model.

 

[jackbombay]

Sounds like you are making T1N a good excuse for spreading bad information?
Is that some kind of religion for you?
you did not even notice, that I my comments apply to scanner, not to Sprinter model.

Of the two of us, I can assure you that one of us is spreading bad information here...

 

[Midwestdrifter]

I tried to be charitable, but you are dumb. We literally explained how you weren't reading the scale right on the chart...

We have put the effort in you educate ourselves about the vehicles we own. You are an armchair cowboy who thinks his previous experience with other vehicles and "intuition" overrides literal data and first hand observation.

I will make this clearer. Go away. This forum is to help t1n owners, not let you assuage your ego and relieve your boredom.

 

[jrod5150]

The water pump that was installed was a GEBA and the gasket was metal. My mechanic said these are pretty good and he's installed them on a few dozen vans.

I plan on ordereding a new clutch and radiator cap today, should have those done in a few days.

Jrod5150 what do you mean by a late locker? I feel like my fan clutch is turning on at 225 and not the 210 or so it should be correct? Linden installed my fan clutch about 13k miles ago but I don't think it's turning on at the correct temp if it's even turning on at all. I noticed it for the first time in weeks come on yesterday at 225.

I've had two different places do a head gasket test in the past two months and both said no issue. Also the van is driving great, no noticeable issues other than heat.

I have resorted to blasting the heat to keep temps down and that seems to have a large impact.

Lastly I belive all of this started just a few weeks ago, before this I had no issue with passes in Colorado and can only remember one time I have seen it above 215.

Late locker as in when the fan clutch engages yes 225 is late. Cant hurt to throw a new one at it I personally change them on almost every van I rehab/resell. Shops typically use the combustion gas dye set up which I personally have had zero success with. A cooling system pressure tester should give you a definitive yes or no. Unless of course its so slight that it only pushes out under extreme load which should get progressively worse over time. Ive driven vans for 500 miles easily with a slight leak with no issues. Its the up a hill 100 degree day is when its an issue. Throwing another clutch at it isnt a bad idea but most t1n forum users wouldn’t have it since they changed it 13k miles ago and want to spend as little money as possible such as throwing an aux useless pump at a t1n thats overheating because its cheap Again if its a chinese pos myle it most definitely can be your problem

 

[jrod5150]

Not per my experience. I used to own 1998 MB E300 diesel turbo and at about 160k miles radiator broke due to PO driving over high curb.
Replacing radiator I notices the engine fan clutch was freewheeling and looks like it did for long time, so I decided to not put the fan back, depending on natural air flow and electric helper fan in front.
The car with fan removed would keep 78C engine temperature when cruising with 102F outside and only when stuck in traffic the engine temperature would go into 90's of C I had it to Las Vegas in 114F recorded at the time and never the engine temp went up above 100C.
I sold the car and become friends with new buyer, who lives in Long Beach. He was at my place a month ago, still driving 200k miles car with engine fan removed.

As replied to by others, your experience isn’t relevant in this scenario as you dont own a T1N as ive pointed out in other threads. You can read the complete service manual on a T1N and still not know how to fix common or complex issues. Pattern failure knowledge from owning/driving vehicles is crucial especially with a 15yo vehicle. This is why I rarely reply in the NCV forum because im still learning about them and my knowledge is limited. Even though ive owned/rehabbed /sold 5 and have 4 more in my inventory.

 

[calbiker]

Here's what's going on around the 60 min mark. The vehicle is slowing down at a stop light. At 60.2 minutes the vehicle has stopped. It is in first gear with 669 RPM. The clutch slippage is 681 RPM. ATF temp is 167 F while Coolant is 188 F. At 60.27 minute, the tranny is put into Neutral. Clutch slippage drops to 6 RPM. Heat stress to the clutch is removed. When in N, ATF temperature is no longer displayed. The ATF T data now displays Coolant temp. It takes a few seconds, but at 60.4 minute mark ATF T and Coolant T signals are equal (within a couple of degrees).

At 60.87 min. the vehicles is in 1st gear and ATF T shows 168F. BTW, my logging code doesn't record small quantities of LOD or TORQ. It makes a total mess when graphing them.

Time​

MPH​

LOD

TORQ

MPG​

Boost P​

FRCV​

EGR​

RPM​

S RPM​

Select Gear

Actual Gear

ATF T​

Coolant T​

59.73​

11​

44.51​

14.88​

44​

10​

829​

653​

Drive

2nd

167​

187​

59.8​

17​

67​

207​

4.6​

28.64​

47​

27​

2214​

140​

Drive

2nd

167​

186​

59.87​

24​

72​

120​

6.72​

26.9​

50​

6​

2420​

198​

Drive

2nd

165​

186​

59.93​

27​

53​

81​

13.2​

21.58​

36​

34​

1872​

62​

Drive

3rd

167​

186​

60​

28​

46​

26.72​

16.47​

32​

38​

1819​

97​

Drive

4th

167​

187​

60.07​

27​

35.95​

15.95​

24​

22​

1249​

370​

Drive

4th

167​

187​

60.13​

14​

0​

15.14​

24​

27​

680​

243​

Drive

3rd

167​

188​

60.2​

0​

5.13​

15.01​

25​

5​

669​

681​

Drive

1st

167​

188​

60.27​

0​

0​

15.02​

25​

25​

686​

6​

Neutral

-N-

167​

189​

60.33​

0​

0​

14.89​

24​

27​

682​

2​

Neutral

-N-

167​

189​

60.4​

0​

0​

14.86​

24​

26​

669​

1​

Neutral

-N-

188​

189​

60.47​

0​

0​

14.85​

24​

26​

681​

2​

Neutral

-N-

188​

189​

60.53​

0​

0​

14.85​

24​

26​

681​

2​

Neutral

-N-

188​

189​

60.6​

0​

0​

14.85​

24​

27​

684​

0​

Neutral

-N-

188​

189​

60.67​

0​

0​

14.85​

24​

27​

689​

2​

Neutral

-N-

186​

188​

60.73​

0​

0​

14.85​

24​

26​

672​

1​

Neutral

-N-

186​

188​

60.8​

0​

0​

14.85​

24​

26​

689​

2​

Neutral

-N-

186​

188​

60.87​

9​

63​

76​

1.52​

26.39​

44​

28​

2019​

98​

Drive

1st

168​

188​

60.93​

13​

69​

107​

11.63​

16.53​

35​

35​

1534​

246​

Drive

2nd

172​

188​

61​

13​

73​

170​

19.65​

16.31​

41​

10​

1509​

441​

Drive

2nd

174​

188​

61.07​

20​

88​

274​

4.99​

29.28​

52​

25​

1988​

53​

Drive

2nd

174​

189​

61.13​

29​

81​

233​

5.33​

34.45​

65​

37​

2819​

46​

Drive

2nd

176​

189​

61.2​

34​

77​

263​

9.03​

28.64​

53​

29​

2274​

60​

Drive

3rd

176​

190​

61.27​

39​

82​

256​

8.36​

31.97​

57​

36​

2510​

67​

Drive

3rd

179​

191​

61.33​

42​

73​

218​

9.96​

31.54​

62​

37​

2746​

60​

Drive

3rd

179​

192​

61.4​

44​

78​

261​

11.41​

29.26​

52​

27​

2142​

95​

Drive

4th

179​

192​

61.47​

46​

89​

291​

11.43​

31.23​

55​

28​

2180​

71​

Drive

4th

179​

193​

 

[vanski]

@Kajtek1 , I’m sure your intentions are good.. please understand many of us have spent hundreds, even thousands, of hours beating our heads against the wall working through issues on the T1N platform. Do you 100% need to have spent this time to have a good understanding of these vehicles, I suppose not, but it doesn’t hurt. And sure, many mechanics have worked on enough vehicles across the spectrum to be able to understand issues quickly on just about any vehicles, but these folks are few and far between and they do this as their profession.

Just Thursday I completed an inspection for someone looking to buy a 2005 with only 95k miles. The seller only wanted $13.5k for it while similar Craigslist listings show value between $17k - $25k. Shoot, I’ve sold a few T1Ns with over 200k miles for more than $13.5k and that was during pre covid times. The potential buyer also brought a folder of receipts totaling in the thousands of dollars, and these receipts were just in the past year. What gives? On the initial test run the temperature shot up past 215F on a flat hard run and the outside ambient temperature was only 72F. Records and visual inspection showed the radiator and all hoses were replaced. But the thermostat was crusty and the viscous fan clutch was very crusty. It also had the incorrect coolant in it. The foreign auto shop doing this work billed at $150/hr and didn’t fix the over heating issue! So how can we dig into how badly this vehicle may have been over heated? Through my experience on working on T1Ns, I’ve correlated injector seal leakage with over heated motors as well as gross oil leaks which you wouldn’t expect on a vehicle with such low mileage. Neither was present.. of course the head gasket could have been compromised if the motor was over heated as well. I tested for a head gasket leak which wasn’t present either. Oh and the fan clutch assembly passed the cardboard test but that doesn’t mean &&@? in my experience. After further discussion with the potential buyer it turns out the seller is a close friend of hers... ut oh... talk about the possibility of ending a good friendship.. okay, let’s call the seller and drill into this a bit more. Seller not only knew of the over heating but also communicated that it would run hot to the buyer. Seller also communicated he would pull over and run the heater when it got close to the red. Okay great. No one is trying to pull the wool over anyone’s eyes, the seller also didn’t just melt the thing, and the buyer just wanted me to earn my $150, fair enough.. So what was my final communication to buyer.. hey, the thing runs hot and most likely there has been at least a few instances it was over heated. Does this mean the motor is bad? Not necessarily, but there is risk. How could it be bad?? Head could be warped although the gasket hasn’t failed yet. Pistons and rings could be compromised. Block could even be compromised although I would expect to see other items fail first if that happened. But the normal things I typically see on a motor that’s been severely over heated are not present; gross oil leaks all over the place, injector seal leakage, head gasket leak. Can she fix the over heating issue?? Yes, most likely with a new Mercedes viscous fan clutch assembly, but let’s go ahead and replace the thermostat, do a coolant flush, and put in the right coolant as well. No record on the belt tensioner, belt, idler pulleys either... let’s take care of that. There’s always the water pump, but let’s save that one. Although the harmonic balancer was replaced and I personally would have done the pump and the other items listed above then. Isn’t that what mechanics charging $150/hr are supposed to recommend and do?

anyhow, I now own a 2017 4x4 and I’m starting to learn that platform. Every now and again I’ll try to add VALUE to a discussion on the NCV3 forum, but usually in the form of a question and definitely not with any kind of authority.

I am and will forever be a student always learning and although I have a couple brain cells working I know there are those who are not only smarter than me but also have a lot more correlated experience in the subject I’m trying to learn.

 

[bored]

I tried to be charitable, but you are dumb. We literally explained how you weren't reading the scale right on the chart...

We have put the effort in you educate ourselves about the vehicles we own. You are an armchair cowboy who thinks his previous experience with other vehicles and "intuition" overrides literal data and first hand observation.

I will make this clearer. Go away. This forum is to help t1n owners, not let you assuage your ego and relieve your boredom.

I would love to see people include their mileage included when showcasing data from their scanner. Also include if this is the original motor and if not how many miles did the other one die at.

 

[calbiker]

While we're on the topic of long hills, around 100 minutes the vehicle is going up a long hill in cruise control (heading west on I10 out of Palm Springs). I am not manually downshifting. The tranny does it when necessary. Select gear remains in Drive. Noteworthy:

Despite downshifting two times the vehicle remains at max load. Some say to never stay at max load, but rather manually downshift. They obviously do not own a T1N Sprinter motor home.

Downshifting does not drop ATF, Coolant or Oil temperatures. They actually rise.

Time​

Speed​

LOD​

TORQ​

MPG​

Boost P​

FRCV​

EGR​

RPM​

Slip RPM​

Select Gear

Actual Gear

ATF T​

Coolant T​

Oil T​

96.93​

57​

96​

314​

12.52​

33.48​

60​

29​

2259​

75​

Drive

5th

199​

201​

244​

97​

57​

99​

322​

11.69​

33.19​

60​

34​

2246​

66​

Drive

5th

199​

201​

244​

97.07​

56​

99​

320​

11.5​

34.34​

72​

36​

2622​

109​

Drive

4th

199​

201​

244​

97.13​

56​

99​

314​

8.91​

33.34​

69​

50​

2615​

55​

Drive

4th

199​

202​

244​

97.2​

56​

99​

315​

9.11​

33.45​

69​

52​

2637​

58​

Drive

4th

199​

201​

245​

97.27​

57​

99​

316​

9.01​

33.87​

70​

50​

2655​

56​

Drive

4th

199​

201​

246​

97.33​

56​

99​

316​

9.07​

33.87​

69​

49​

2639​

61​

Drive

4th

199​

201​

246​

97.4​

57​

99​

318​

9.24​

33.8​

71​

49​

2660​

65​

Drive

4th

199​

202​

246​

97.47​

57​

95​

293​

9.75​

33.15​

70​

49​

2700​

63​

Drive

4th

199​

202​

246​

97.53​

57​

95​

305​

9.71​

33.71​

71​

44​

2688​

62​

Drive

4th

201​

202​

247​

97.6​

57​

96​

300​

9.59​

33.93​

71​

45​

2690​

63​

Drive

4th

201​

202​

248​

97.67​

57​

95​

305​

9.92​

33.74​

71​

44​

2686​

60​

Drive

4th

201​

202​

248​

97.73​

57​

98​

307​

9.22​

34.19​

71​

45​

2682​

60​

Drive

4th

201​

203​

248​

97.8​

57​

87​

273​

10.63​

32.73​

70​

44​

2703​

64​

Drive

4th

201​

203​

248​

97.87​

57​

94​

308​

9.98​

34.39​

71​

41​

2682​

59​

Drive

4th

201​

203​

249​

97.93​

57​

99​

317​

9.64​

34.02​

72​

47​

2675​

55​

Drive

4th

201​

202​

249​

98​

57​

99​

317​

9.34​

33.54​

71​

50​

2666​

62​

Drive

4th

201​

202​

249​

98.07​

56​

99​

315​

9.64​

33.58​

70​

51​

2647​

60​

Drive

4th

201​

202​

249​

98.13​

56​

99​

314​

8.96​

33.68​

70​

51​

2632​

59​

Drive

4th

201​

202​

249​

98.2​

56​

99​

314​

9.03​

33.73​

70​

51​

2640​

64​

Drive

4th

201​

202​

250​

98.27​

55​

99​

313​

9.46​

33.7​

70​

51​

2623​

56​

Drive

4th

201​

202​

251​

98.33​

56​

99​

313​

9.41​

33.73​

70​

51​

2624​

62​

Drive

4th

201​

202​

251​

98.4​

55​

99​

312​

9.33​

33.61​

70​

51​

2609​

60​

Drive

4th

201​

203​

251​

98.47​

55​

99​

312​

9.59​

33.7​

69​

51​

2599​

59​

Drive

4th

201​

202​

251​

98.53​

55​

99​

310​

9.23​

33.84​

69​

50​

2614​

57​

Drive

4th

201​

202​

251​

98.6​

55​

99​

311​

8.83​

33.51​

68​

51​

2588​

64​

Drive

4th

201​

203​

251​

98.67​

54​

99​

311​

9.36​

33.51​

68​

51​

2561​

60​

Drive

4th

201​

203​

251​

98.73​

54​

99​

310​

8.95​

33.67​

68​

50​

2564​

65​

Drive

4th

201​

202​

251​

98.8​

54​

99​

310​

9.01​

33.52​

68​

51​

2560​

56​

Drive

4th

201​

202​

252​

98.87​

55​

99​

310​

9.11​

33.68​

68​

51​

2569​

59​

Drive

4th

201​

202​

252​

98.93​

54​

99​

311​

9.45​

33.57​

68​

50​

2563​

55​

Drive

4th

201​

203​

252​

99​

54​

99​

311​

9.79​

33.38​

67​

51​

2532​

56​

Drive

4th

204​

203​

252​

99.07​

53​

99​

314​

9.18​

33.57​

66​

48​

2500​

54​

Drive

4th

204​

203​

252​

99.13​

52​

99​

316​

9.34​

33.58​

65​

47​

2493​

59​

Drive

4th

204​

203​

252​

99.2​

52​

99​

320​

9.83​

33.61​

64​

44​

2437​

62​

Drive

4th

204​

203​

252​

99.27​

51​

99​

321​

8.98​

33.74​

64​

43​

2402​

62​

Drive

4th

204​

203​

252​

99.33​

50​

99​

319​

9.82​

33.29​

63​

44​

2375​

63​

Drive

4th

204​

203​

252​

99.4​

49​

99​

322​

9.62​

33​

62​

46​

2340​

378​

Drive

4th

204​

203​

253​

99.47​

49​

99​

307​

7.24​

33.83​

73​

38​

3227​

48​

Drive

3rd

201​

203​

253​

99.53​

50​

100​

308​

6.57​

33.61​

74​

37​

3277​

49​

Drive

3rd

204​

203​

253​

99.6​

51​

99​

304​

6.69​

33.39​

74​

36​

3354​

46​

Drive

3rd

204​

203​

253​

 

[vanski]

Here's what's going on around the 60 min mark. The vehicle is slowing down at a stop light. At 60.2 minutes the vehicle has stopped. It is in first gear with 669 RPM. The clutch slippage is 681 RPM. ATF temp is 167 F while Coolant is 188 F. At 60.27 minute, the tranny is put into Neutral. Clutch slippage drops to 6 RPM. Heat stress to the clutch is removed. When in N, ATF temperature is no longer displayed. The ATF T data now displays Coolant temp. It takes a few seconds, but at 60.4 minute mark ATF T and Coolant T signals are equal (within a couple of degrees).

At 60.87 min. the vehicles is in 1st gear and ATF T shows 168F. BTW, my logging code doesn't record small quantities of LOD or TORQ. It makes a total mess when graphing them.

Time​

MPH​

LOD

TORQ

MPG​

Boost P​

FRCV​

EGR​

RPM​

S RPM​

Select Gear

Actual Gear

ATF T​

Coolant T​

59.73​

11​

44.51​

14.88​

44​

10​

829​

653​

Drive

2nd

167​

187​

59.8​

17​

67​

207​

4.6​

28.64​

47​

27​

2214​

140​

Drive

2nd

167​

186​

59.87​

24​

72​

120​

6.72​

26.9​

50​

6​

2420​

198​

Drive

2nd

165​

186​

59.93​

27​

53​

81​

13.2​

21.58​

36​

34​

1872​

62​

Drive

3rd

167​

186​

60​

28​

46​

26.72​

16.47​

32​

38​

1819​

97​

Drive

4th

167​

187​

60.07​

27​

35.95​

15.95​

24​

22​

1249​

370​

Drive

4th

167​

187​

60.13​

14​

0​

15.14​

24​

27​

680​

243​

Drive

3rd

167​

188​

60.2​

0​

5.13​

15.01​

25​

5​

669​

681​

Drive

1st

167​

188​

60.27​

0​

0​

15.02​

25​

25​

686​

6​

Neutral

-N-

167​

189​

60.33​

0​

0​

14.89​

24​

27​

682​

2​

Neutral

-N-

167​

189​

60.4​

0​

0​

14.86​

24​

26​

669​

1​

Neutral

-N-

188​

189​

60.47​

0​

0​

14.85​

24​

26​

681​

2​

Neutral

-N-

188​

189​

60.53​

0​

0​

14.85​

24​

26​

681​

2​

Neutral

-N-

188​

189​

60.6​

0​

0​

14.85​

24​

27​

684​

0​

Neutral

-N-

188​

189​

60.67​

0​

0​

14.85​

24​

27​

689​

2​

Neutral

-N-

186​

188​

60.73​

0​

0​

14.85​

24​

26​

672​

1​

Neutral

-N-

186​

188​

60.8​

0​

0​

14.85​

24​

26​

689​

2​

Neutral

-N-

186​

188​

60.87​

9​

63​

76​

1.52​

26.39​

44​

28​

2019​

98​

Drive

1st

168​

188​

60.93​

13​

69​

107​

11.63​

16.53​

35​

35​

1534​

246​

Drive

2nd

172​

188​

61​

13​

73​

170​

19.65​

16.31​

41​

10​

1509​

441​

Drive

2nd

174​

188​

61.07​

20​

88​

274​

4.99​

29.28​

52​

25​

1988​

53​

Drive

2nd

174​

189​

61.13​

29​

81​

233​

5.33​

34.45​

65​

37​

2819​

46​

Drive

2nd

176​

189​

61.2​

34​

77​

263​

9.03​

28.64​

53​

29​

2274​

60​

Drive

3rd

176​

190​

61.27​

39​

82​

256​

8.36​

31.97​

57​

36​

2510​

67​

Drive

3rd

179​

191​

61.33​

42​

73​

218​

9.96​

31.54​

62​

37​

2746​

60​

Drive

3rd

179​

192​

61.4​

44​

78​

261​

11.41​

29.26​

52​

27​

2142​

95​

Drive

4th

179​

192​

61.47​

46​

89​

291​

11.43​

31.23​

55​

28​

2180​

71​

Drive

4th

179​

193​

sure is nice to have this data for analysis!

 

[calbiker]

sure is nice to have this data for analysis!

Not as fancy as a Nautabox, but it gets the job done.

 

[Nautamaran]

I notice your road speed drops a few MPH too...
Engine RPM has a direct impact on coolant pumping rate, so I wonder if your radiator was a bit more heat soaked, increasing the rad’s cold tank temp and this reduced ATF cooling a smidge? My last “big climb” was in fog/mist at about 40’F and the ATF temp remained solidly below my coolant temp, which I attribute to the radiator being able to shed heat effectively before the coolant reaches the ATF cooler. I NEVER hear my fan clutch grab below around 80’F ambient.

To @dan717 : I would take a hard look and listen of your fan clutch. It should be roaring like a hurricane once the radiator becomes heat-soaked and the exit air temp is above 215’F or so.
If you can’t hear it (those who know, know) then replace the clutch. There don’t seem to be any brands completely immune to premature (or even initial?) failure, but the parts desk at MB or Freighter have less tolerance for poor quality parts.
Also be sure that your a/c aux fan (front of cooling stack) is spinning in the right direction when active. Reports are that the connector plug is reversible, and accidents happen... the fan is triggered by the ATC module at 221’F coolant temp, and having it blowing air forward presents an obstacle, rather than the assistance intended, to the airflow through the stack.
Finally, check that your thermostat is opening, and opening completely. This can be simply observed with a IR thermometer gun on the top hose, but this won’t detect a partially opening unit so a more complete test is to remove the assembly and observe it open in a hot water bath on the stove.

Good luck. You are not the first to have these problems, and hopefully you’ll get it sorted.

-dave

 

[Kajtek1]

As replied to by others, your experience isn’t relevant in this scenario as you dont own a T1N as ive pointed out in other threads. You can read the complete service manual on a T1N and still not know how to fix common or complex issues. Pattern failure knowledge from owning/driving vehicles is crucial especially with a 15yo vehicle. This is why I rarely reply in the NCV forum because im still learning about them and my knowledge is limited. Even though ive owned/rehabbed /sold 5 and have 4 more in my inventory.

I don't want to judge your reading skills, but my comments above apply to temperature reading.
When that happens to be on T1N, the temperature sensors and readers are the same on T1N and your digital baking oven.
You comment is missing the point.