I was wondering if some temperature fluctuation is normal when driving up mountains? I have a 2006 158" 2500 and the coolant temp goes up some when driving up inclines for more than a few minutes. Once the terrain levels out or I go back down the coolant temp drops back down rather quickly. I wasn't sure if this is normal as I have never owned a vehicle that has a visible temperature change on the gauge. Thinking of going on our first overnight trip in the rv project to the blueridge pkwy in a couple of weeks but I wanted to know for sure prior to leaving.
Is temperature fluctuation normal on hills?
- Thread starter tonbab
- Start date
sailquik
Well-known member
tonbab,
It's absolutely NORMAL for the temperature to rise going up grades.
You can mitigate the amount of temperature rise by downshifting to keep your 2006 T1N (OM-647) in it's most efficient power range.
If your RPM gets < 2400 RPM, it's time to manually downshift (tap the gear selector lever to the left) and get the RPM up into the 2700-3250 RPM range where your Sprinter has it's most efficient pulling power.
Take a look at your Operator's manual and it suggests that "overheating" occurs around 240-250 degrees.
At around 210 degrees you will hear the big engine driven viscous clutch fan kick in and that will bring your temperature right back down to near normal.
A Scan Guage II would be a good addition so you can tell what's really going on with your Sprinter.
% engine Load will tell you when your engine is straining/lugging and you can downshift manually to get better mileage and help your engine to live significantly longer.
Hope this helps,
Roger
It's absolutely NORMAL for the temperature to rise going up grades.
You can mitigate the amount of temperature rise by downshifting to keep your 2006 T1N (OM-647) in it's most efficient power range.
If your RPM gets < 2400 RPM, it's time to manually downshift (tap the gear selector lever to the left) and get the RPM up into the 2700-3250 RPM range where your Sprinter has it's most efficient pulling power.
Take a look at your Operator's manual and it suggests that "overheating" occurs around 240-250 degrees.
At around 210 degrees you will hear the big engine driven viscous clutch fan kick in and that will bring your temperature right back down to near normal.
A Scan Guage II would be a good addition so you can tell what's really going on with your Sprinter.
% engine Load will tell you when your engine is straining/lugging and you can downshift manually to get better mileage and help your engine to live significantly longer.
Hope this helps,
Roger
Thanks Roger! I came here with the exact same question as the original poster. I've also never driven a vehicle where the temperatures fluctuated at all, except in the direst of situations. I find that my Sprinter very quickly gets up above 200F while going up hills. Even lightly loaded and on cooler days. I do downshift manually and have an ultragauge, so I can watch the engine pretty closely.
surlyoldbill
Well-known member
Try the drive from Lone Pine to Furnace Creek if you want to see some wild fluctuations...
No harm to check your radiator for obstructions: https://sprinter-source.com/forums/showthread.php?t=12434&highlight=radiator
Many vehicles employ non-linear meters/sensors. In the Honda I had, the needle wouldn't change from180F to 220F, then it would start moving. It's done to keep people from getting upset. On the T1N, it's a real temperature gauge, but even in the the desert, climbing mountains, I've never seen it over 215F.
The aux electric fan kicks on at 221F engine coolant temperature. The hash mark above 180 is 215.
There's some more info here.
https://sprinter-source.com/forums/showthread.php?p=253246#post253246
vic
There's some more info here.
https://sprinter-source.com/forums/showthread.php?p=253246#post253246
vic
This is good info. I always wondered why my sprinter temp gauge was 'busier' than other vehicles' gauges. It is like a yo yo on the hills. Honestly, it runs the same at 100 as 215, without the gauge it would be hard to tell. Chalk that up to excellent engine management controls I guess.
lindenengineering
Well-known member
Guys
Temperature rise can be mitigated by cleaning the cooler matrix's of first the condenser, charge air cooler and then the radiator core!
A/C condensers
Taking a look at the A/C condenser which is the first obstacle for the incoming air to get through, its dense pack nature is a big trap for dust/dirt and debris like grass hopper guts!
There are dead zone areas especially behind the Aux fan on TIN models.
This build up is such that if you remove the tin plate bracket supporting the top of the aux cooling fan assy and ease it forward against the lower rubber mounts you will often a huge mound of dirt collected behind the electric motor area.
In any case as a side bar this is highly advisable because the Aux fan tin plate mount brackets are very flexible and as the lower mounts deteriorate over time it causes the whole fan assy to vibrate against the A/C condenser core eventually abrading a hole in the core dictating replacement not to mention the abrupt loss of A/C refrigerant..etc etc.
A new condenser from MB source is around $450, you can get an aftermarket unit from suppliers like 1 800 Radiator which do a very comparable job for around $150.
For some reason this year I have replaced no fewer than 8 condensers on TIN models exhibiting this problem. Worth taking the time at a service interval to check this problem in the making.
Charge Coolers
I got some feed back this year from operators after frontal collision repairs where there were done. Reports of more power and cooler running on both NAS models were mentioned. I investigated by going into the scrap pile of the shop "Christmas box semi precious metals"
and digging out the alum coolers we had replaced.
First dense pack road dirt trapped inside the cooler matrix was evident! This is easily overlooked on both models. Furthermore I did note a lot of carbon and oil deposits inside the coolers of TIN models which can only be removed by total removal of the unit and tanking it in a bath. This was evident on particularly on two units which were TIN models had had covered about 250,000 miles before suffering frontal collision damage.
In short heat rejection is reduced when this get plugged up and it robs power gradually over time. In any case dirt restrictions presents less ram air flow to the radiator which is at the back of the pack! As a result all engine overhauls get a tanked & cleaned charge cooler. Cheap repair addition since its on the floor!
Radiators
Apart from a radiator cooling flush at 120K I have concluded that we should never use tap water for coolant strength dilution. Solids suspended in tap water simply separate out and plug up the core tubes. Again breaking open the cores of collision damaged radiators show appreciable deposits on units having done more than 250,000 miles.
Cleaning the radiator matrix is difficult at best, but I use a home made hose probe made out of a 3ft length of 3/8th copper pipe closed at the end. The cut two hacksaw blade slots at the tip to limit the pressure jet expulsion of water when connected to the shop water hose bib. This tool can be used down between the matrixes to clean out the dirt etc without bending the cooling fins which are delicate. I do use foaming coil cleaner from ZEP but a good household cleaner in a spray bottle with often dislodge dirt before the hose treatment.
Remember wide variations of cooling top pipe temperature can distress the head gaskets and we know that that brings.
Cheers Dennis
Temperature rise can be mitigated by cleaning the cooler matrix's of first the condenser, charge air cooler and then the radiator core!
A/C condensers
Taking a look at the A/C condenser which is the first obstacle for the incoming air to get through, its dense pack nature is a big trap for dust/dirt and debris like grass hopper guts!
There are dead zone areas especially behind the Aux fan on TIN models.
This build up is such that if you remove the tin plate bracket supporting the top of the aux cooling fan assy and ease it forward against the lower rubber mounts you will often a huge mound of dirt collected behind the electric motor area.
In any case as a side bar this is highly advisable because the Aux fan tin plate mount brackets are very flexible and as the lower mounts deteriorate over time it causes the whole fan assy to vibrate against the A/C condenser core eventually abrading a hole in the core dictating replacement not to mention the abrupt loss of A/C refrigerant..etc etc.
A new condenser from MB source is around $450, you can get an aftermarket unit from suppliers like 1 800 Radiator which do a very comparable job for around $150.
For some reason this year I have replaced no fewer than 8 condensers on TIN models exhibiting this problem. Worth taking the time at a service interval to check this problem in the making.
Charge Coolers
I got some feed back this year from operators after frontal collision repairs where there were done. Reports of more power and cooler running on both NAS models were mentioned. I investigated by going into the scrap pile of the shop "Christmas box semi precious metals"
and digging out the alum coolers we had replaced.First dense pack road dirt trapped inside the cooler matrix was evident! This is easily overlooked on both models. Furthermore I did note a lot of carbon and oil deposits inside the coolers of TIN models which can only be removed by total removal of the unit and tanking it in a bath. This was evident on particularly on two units which were TIN models had had covered about 250,000 miles before suffering frontal collision damage.
In short heat rejection is reduced when this get plugged up and it robs power gradually over time. In any case dirt restrictions presents less ram air flow to the radiator which is at the back of the pack! As a result all engine overhauls get a tanked & cleaned charge cooler. Cheap repair addition since its on the floor!
Radiators
Apart from a radiator cooling flush at 120K I have concluded that we should never use tap water for coolant strength dilution. Solids suspended in tap water simply separate out and plug up the core tubes. Again breaking open the cores of collision damaged radiators show appreciable deposits on units having done more than 250,000 miles.
Cleaning the radiator matrix is difficult at best, but I use a home made hose probe made out of a 3ft length of 3/8th copper pipe closed at the end. The cut two hacksaw blade slots at the tip to limit the pressure jet expulsion of water when connected to the shop water hose bib. This tool can be used down between the matrixes to clean out the dirt etc without bending the cooling fins which are delicate. I do use foaming coil cleaner from ZEP but a good household cleaner in a spray bottle with often dislodge dirt before the hose treatment.
Remember wide variations of cooling top pipe temperature can distress the head gaskets and we know that that brings.
Cheers Dennis
lindenengineering
Well-known member
Boater
Wise move, strangely here in the US/NA tap water is softer than the stuff we get/I got on your side. Coming "frum the Cotswolds" you could hardly get any harder than that. Basically its what BMW got its knickers in a twist about and demanded HOAT coolant and de-ionized water a few years ago! AND that prompted the Japanese to follow suit! I suppose if you ever get to disect a voltage converter on a Prius you can see why.
The tiny narrow coolant passages that pass under the heat sinks and printed circuit boards would undoubtably clog up with hard water in the coolant mix. That would cause it to overheat and stop the thing dead in its tracks!
Still going back to Sprinters, the laugh of the day a few weeks back was an owner that though we had left the AUX cooling fan off of his 2010 Sprinter as we were fixing it after a fender bender!
It was an OMG moment!
But soothing words and the fact that it doesn't have such a device! The lecky clutch engine fan does it all! AND that wire & socket hanging down here is ONLY for the horn mate!
Who says fixing cars isn't fun--At times!
Cheers Dennis
Yeah, used to live in N Wilts, I remember hard water - tastes good, but impossible to get soap to lather and limescale gets everywhere especially on kettle elements but even cold water stuff like toilet cisterns. The water here in Scotland is a lot softer, my kettle never furrs up but I'm sure there are plenty of other impurities and chemicals in the water. In the more remote highland areas even after UV filtration to kill the nasties a lot of the water retains a brown tinge from the peat....
crazyswede
Member
When I tow my temp goes back and forth between 180 and 215 (1/2 mark and 3/4). Marj on gage...no worries