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Andy, Truck Diagnostic Technician
Category: Medium and Heavy Trucks
Satisfied Customers: 1675
Experience:  International and Isuzu trucks , International, Maxxforce, Cummins and Isuzu engines, Diagnostic and electrical troubleshooting specialist , Hvac and truck /trailer refrigeration troubleshooter
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2005 freight liner sprinter van only raises temp to 120

Customer Question

2005 freight liner sprinter van only raises temp to 120 degrees at when started in morning and let run for 45 minutes. Will heat up to 185 when driving. I replaced the thermostat module and did not solve problem. Any ideas?
Submitted: 1 year ago.
Category: Medium and Heavy Trucks
Customer: replied 1 year ago.
I had the water pump replaced in May 2015
Customer: replied 1 year ago.
Replaced water pump in May 2015
Expert:  Wayne replied 1 year ago.

Hi I'm Wayne

I will try to help you with this

What engine do you have , Make and Model , Please

Customer: replied 1 year ago.
5 cylinder Mercedes
Expert:  Wayne replied 1 year ago.

Thank you for that

do you have a clutch Fan

check your clutch fan, make sure that it is not always on

let me know, please

Customer: replied 1 year ago.
Not the clutch fan any more ideas
Expert:  Wayne replied 1 year ago.

Hi ,

Sorry for long delay

Grand kids P/U from school

then make diner for them

so It always runs cold, did it always do this

we had MB in our fleet, issues was no heat

We had to re pipe the hoses,

so is your concern , Heat for the cab,

or engine, let me me know

Customer: replied 1 year ago.
Engine temp does not rise at idle but does increase to 185 degrees when driving about 10 miles.
Expert:  Wayne replied 1 year ago.


It is pretty common for a diesel to loose heat at idle

does the heater blow cold air at this time

let me know ,Please

Customer: replied 1 year ago.
Not after it gets to 185 temp does not rise when sitting only after driving
Expert:  Wayne replied 1 year ago.

Thank you for that

I will be honest with you

not sure what is causing that , other the a thermostat

I will opt-out and send to another expert

Sorry I could not help


Customer: replied 1 year ago.
Expert:  Jeremy replied 1 year ago.

My name is ***** ***** I will assist you with your question today.

I'm an independent contractor and I don't get paid until a rating has been made. No rate, site gets it all.

We can go back and forth as needed to help resolve the issue you are having. Follow ups are free after ratings, so rate in confidence!

Does the van only idle cool, but runs at normal temp all the other times?

I ask this because for that year of engine, they are designed to do that. In the 2004 US EPA engines, they were designed to only idle for 5 minutes and that is it. They idle cooler to keep the EGR gases lower to meet the EPA standards as well as the Euro standards for those engines were in both the USA and the UK. The UK requires low idle emissions where the US requires low emissions all the time.

I ran into the same problem a few months ago on a 2004 model and had a long talk back and forth with several Freightliner higher up people. What I was basically told is the engine is designed to start up, heat quick when you drive it (within 10 minutes) and then cool down fast for the 5 minute idle time to cool the oil in the engine and the turbo bearings. This was done to make the EPA happy so they didn't have to use a dual EGR system on the engine. A dual EGR system would have bogged the engines down like the large bore engines were, which have a lot of issues with them.

I replaced a thermostat in one and couldn't get it to warm back up. I thought the same issue was going on and I was told that if the engine idles warm, there is something wrong. They should idle around 160 degrees or less. Some idle cooler, but if it idles above 160, there is an issue with the cooling system. The reason it is cooler is as the engine is idling, the EGR valve is open and allowing the gases back into the cylinders to burn off the unburned gases, which creates less combustion and heat, so they idle cooler from that. It is not straight fuel and air going into the engine.

I know it seems a bit confusing for it was to me as well, but I'm told by Freightliner that if the engine is warming up within 10 minutes while driving and holds its temps, then cools down within 5 minutes of idling to 160 or less, then engine is operating normally.


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Customer: replied 1 year ago.
My van has never acted like that it would always warm up in the mornings at idle to 180 degrees and would remove frost from windshield within 15 minutes. Now it does not raise the temp over 120 degrees after 45 minutes to a hour only after you drive it does it get up to 180 and stays up to that at idle
Expert:  Jeremy replied 1 year ago.

If you're not getting hot enough to defrost the windows, then you will need a computer hooked up to see what the injectors are doing. You may not be getting enough fuel to the engine for you should be hot enough to defrost windows and heat the interior of the vehicle.

You may also have a coolant filter blockage or an imbalance of the coolant. I would test the DCA level of the coolant and change the coolant filter. Your coolant filter should be on driver side of engime next to the oil filter. It will be a drop in style filter.

Customer: replied 1 year ago.
All has been done at the dealership. No answers or luck to correct problem. They had my truck 5 days without results
Expert:  Jeremy replied 1 year ago.

I'm at a loss then. This will need more of a hands on approach versus an online approach.

I'm opting out to see if another expert might have an idea.

Good luck and good day.

Expert:  Andy replied 1 year ago.

Hi there ... My name is ***** ***** I would like a kick at the cat here . Did the unit ever have a winter front on it over winters ? And did we vaccum fill the system after any repairs that may have been done to the unit ? There could be air locked in the system somewhere ?

Expert:  Andy replied 1 year ago.

The fan wether engaged or not always carries air through the rad. Perhaps a winter front would help here . And we need to be certain that the coolant strength is set to -40f . If pure coolant in there , or too much water in there , theere could be blockage issues.

Customer: replied 1 year ago.
I replaced the supimintal pump on the coolant system and solved the problem back to the way it has always. Thanks
Expert:  Andy replied 1 year ago.

Oh I see ... a booster pump was added to assist and it has failed . Good find sir ! Well , thanks for letting me give it a try anyway . Thanks for giving us here at Just Answer a try at it . Hopefully you'll give us a try the next time you need something answered . Can't win them all I guess . Take care!

Customer: replied 1 year ago.
Not added replace part of the original MB equipment on the cooling system