High running temperature & Oil in water

Hi fellow sprinter owners.

My apologies if this is covered elsewhere, however I have trolled for a few days and not quite found what may be a solution to my problem.


Firstly:
I recently bought a Sprinter 312D People Mover (5cyl Diesel Auto). My mechanic noticed oil in the water system upon inspection immediately thought head gasket problem... The the seller tells us that was because he had blown the oil cooler about 18mths ago, which subsequently contaminated the water. His mechanic, and service records support this, however his mechanic also says he had at every subsequent service attempted to flush this out of the system without 100% success. The previous owner has been running the vehicle without concern or problems, so it didn't seem to alarm me, and my mechanic was also happy with this. It has me wondering though... Is this a normal occurance, and what is the best method to flush the system.

Secondly:
Yesterday I was driving the van, did maybe 150kms just around town etc, temperature sitting between 80 degrees celcius to 90 degrees celcius... This appears quite high, but Mercedes dealer says they are known for running hot and anything around the 90's is not uncommon... They also said an alarm will come on if it begins to get too hot. Heading home had to go over the mountains, which is perfectly normal road and accessible driving - nothing our 4cyl cars and other people movers worry about. Temperature then rises to about 110 degrees celcius whilst maintaining 70km/hr at 3000rpm, and that sort of concerned me slightly more (particularly as we recently blew up a toyota engine with overheating issues - so you can undersatand the worries). Suddenly I see steam coming from the engine bay. Immediately pulled over, and looked under the hood... Engin smelt very hot - that typical water boiling on metal smell - Heaps of coolant spilling under the vehicle. Went to remove the radiator cap - no pressure release which was odd however radiator was full to the top.. water in top of radiator not even hot, just warm enought to bath in really! All other fluids oil etc good too. Found a crack in a heater hose and obvious that this is where the water was leaking from. Shortened it, put it back on, and drove it to the nearest water source carefully - temp at around 90 degrees C. Managed to cool engine for about 30min, and went to fill with water / new coolant, but only way I could do it was to remove radiator hose from engin block and fill direct into there... took maybe 5-6 litres at a guess.... With all this in check... we drove again today, and mostly the engin ran between 78 degrees & 85 degrees through the city, climbed to about 90 degrees along the highway, and crept up to just under 100 degrees going over the mountain range. No water spillage when i parked it, and certainly no steam !

Is this normal to operate up to 100 degrees ??? Outside temperature maybe 32 degrees!


Further when removing the heater hose, to shorten it, I notice the inside of the hose had thick oily sludge in it - obviously from when the water got contaminated back when the previous owner had the oil cooler blow up. Could this be part of the temperature problem ?


Sorry for the long post, nny suggestions would be great and advice muchly appreciated.

True on road tests backed by diagnostics reveal 65c at 2200 rpm 78c at 3000 rpm under-high acceleration mode. Temps running at an outside ambient temperature of 40c reveal an increase of 2 to 5% above normal operating conditions Brisbane tests, town running will show a higher temp if caught in gridlock between Spring hill to the Gold coast.
If on a run through the Beerwah mountains the temp's drop back to less than 65c as your running at lower rpm's and a higher and cooler elevation, and will only increase to 80c if running hard at acceleration above 3300 rpm/There are tests that can be done on diagnostics via the control unit CR for evaluation based on engine speed, coolant temperatures, intake air temperatures, oil temperatures, oil quality, oil level, boost pressure and including rail pressure, atmospheric pressure, and including fuel pressure.
Any thing above 85c is suspect and needs a though diagnostic check and engine service.
Richard
I meant to add if repairs are done the entire block and radiator need to be power flushed for 20 minutes a hose does not work, coolant 50/50 use only MB fluids.

It pays to fill to the brim as the excess reaming disturbed oil type sludge contaminates from block and radiator will show at the top of the tank, run for two hundred kilometers and then drain some out back to the black mark in the header tank as in doing so an increase of 1 to 2 Celsius will restore correct engine temperature operation.

If oil sludge is continuous 1/2 inch thick at the top of the tank after a power flush, then you have an internal engine problem.

My engine temperature is pretty constant at 84 degrees once warmed up. The highest I've ever seen it, (accelerating up a long steep hill) was 88 degrees. Outside temperature seems to have little effect on final engine temperature other than the time to get to normal running temps.
This is also a 5 cyl automatic.

Not your engine, but sounds similar to your experience:

https://sprinter-source.com/forums/showthread.php?t=22965

The writer also had rebuilt the oil cooler, but later found the oil contamination continued and was coming from another source. He has not reported the final disposition.

Normally I'd say it looks like your thermostat has stuck closed, which can happen usually after a car has sat unused for a while. But in your case I going to say it sounds like the bottom of your radiator is badly blocked with sludge. So the sprinter was boiling into the heater circuit. Ignore that 65 degree thing, it should run at 85.

Get it seen to before you do any more serious damage.

Hi all...

Thank you for your comments and advice. I've just had the cooling system completely flushed out at a radiator specialist. They used some oil stripper solution, and said that quite a lot of gunk camp through. They did a complete pressure test, and the system is super tight they said.

They didn't seem to have any concerns that the vehicle had any temperature problems for them. It was idling at 80 degrees C for them, Thermostat opening fine, heaters functioning well etc... They did specifically stated though that I should replace the hoses incase another goes, but other than that said that all was good.

In terms of operating after this, I didn't notice any change in temperature than yesterday... 80-90 degrees around the city & highway, climbed to 100 degrees going over the mountain ranges, but dropped to 90 degrees when heading down the hill. For me still seems quite high, but the radiator place said that with the coolant in the system, and under the pressure it is - the water isn't really boiling until it hits about 130 degrees, so anything under the 120 mark on the guage is fine ! "As long as it's not loosing water, you'll be right"

Still has me worried. Can anyone confirm this as normal?

I just read in the owner's manual:

"If corrosion inhibitor/antifreeze is present in the correct concentration in the coolant, the coolant temperature will be between +85 degrees C and +120 degrees C, depending on operating conditions. If the needle reaches the Red section, do not continue driving the vehicle".


I guess that it must be normal ?????

Did they check the fan was working properly?

Thomas.
I suspect that your tempreture sensitive clutch on the fan is not functioning. to test it, after a drive open the bonnet and see if the fan is spinning at the speed that is almost the rate the belt is moving. then spray a ligh mist of water on to the radiator and the fan should slow down, stop the water mist and throw a large cloth over the grill and the fan should speed up a gain. If none of this happens replace the clutch. Eric

Temperatures are too high i suspect the oil contamination has stuck shut the engine thermostat

So... I took the bus in to get a service yesterday. Got a clean bill of health. Asked the mechanic to have a thourough look at the cooling side of things.. didn't seem concerned at all. Fan OK, thermostat opening as it's suppose to, hose temperatures all in spec.

He did say he wasn't a fan of the sprinters, and mose Euro cars for that matter as they are known to run hot.

He did notice a bit of an oil leak though, but couldn't seem to work out where from. suggested possibly from the front head bolt, and to keep an eye on it.


Anyone here from a HOT region... I'm in Cairns FNQ.