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RomSprinta
08-15-2016, 11:34 PM
Hey all, looking for some input and advice here on my 2006 long-tall 2500 (265k) van.
The engine has been running pretty consistently at 215F when driving on flat freeways at 65-80mph. Climbing a hill or mountain pass in the Summer it can get up to 230F, and then I turn on the heat, roll down the windows, which can bring it down to 215F if I down shift to 3rd or even 2nd gear. Going down the mountain it cools down to 180 no problem.
The radiator was replaced (it was actually stolen...long story) at around 150-160k. The coolant has been exchanged several times since then, due to repairs, replacement of head, replacement of harmonic balancer. So, the coolant isn't old.

Are these temps abnormal for flat freeway driving at ambient temps of 80F+...?

Any advice on how to clean, service, etc to get this puppy to operate a bit cooler?

EDIT: also, the aux fan comes on when it's supposed to (as far as I can tell, I hear it). And I've have the big/main fan replaced this Feb. It was running all the time, so it may have been over cooling...? Still confused....

Midwestdrifter
08-15-2016, 11:38 PM
Sounds like your fan clutch is worn out. Does the electric fan come on?

RomSprinta
08-15-2016, 11:51 PM
The aux fan does come on like it's supposed to. I've also had the big fan replaced in Feb. (I should've put that in the original post, I'll edit it now).
Thoughts...?

NBB
08-15-2016, 11:57 PM
Your thermostat and/or temp sensor may be incorrect, worn out, or of a cheap aftermarket variety. I would check these things first.

sailquik
08-16-2016, 12:02 AM
You had the large engine driven fan on the end of the water pump replaced or was the viscous
clutch on the end of the water pump what was replaced.
When the temperature rises to ~ 210-215 deg F. do you hear the big roar as the viscous clutch engages
and the big fan behind the radiator starts turning because the coolant temp has increased the temperature
of the viscous fluid to the point that it engages the clutch which makes the big fan spin up.
You can hear it.....if you don't hear it, then the viscous clutch is not working correctly.
When you hear the big fan kick in, the temp should fairly quickly drop back to the 180-192 deg. F range.
Did you replace the OEM fan and viscous clutch with OEM parts....or something else?
Hope this helps,
Roger

RomSprinta
08-16-2016, 12:27 AM
Hi Roger, thanks for your input. I had the whole fan and clutch replaced with MB/OEM. I do hear that fan, but it does not bring the temp down.
Before I replaced the fan and clutch it would run ALL the time, thus over cooling (or at least that was what I thought). Didn't notice the difference until the Summer ambient temps got up to 70F+. Also, the coolant level has not gone down, so not losing any coolant.
Could there be something else awry...?

Midwestdrifter
08-16-2016, 12:46 AM
I am assuming you cleaned between the intercooler radiator and AC condenser when you replaced the radiator? Crap tends to build up there.

With the engine running feel the air flow around the engine driven fan. Is the air more or less traveling axially out from the fan? If the air is paddling/circling or coming out perpendicular to the fan, you may have a restriction. Plugged up condenser/radiator/intercooler fins can cause this. Condenser fins can get bent up/plugged over time by sand/rocks/bugs.

What is the condition of your serpentine belt, tensioner, and pulleys? A weak tensioner or worn belt can cause the water pump to slip at higher RPMs. This can result in low water flow.

Finally, a thermostat that fails to open completely can also cause issues. If you have an IR thermometer gun, you can check the radiator hoses after a highway run (immediately after). With the coolant at 200+F the outlet hose should be 50F or more lower than the inlet. If it is not you likely have a flow restriction. Water pump, radiator clogged, thermostat stuck etc (assuming you have good airflow).

sailquik
08-16-2016, 01:20 AM
If you hear the big belt driven fan roaring, and the temp doesn't come back down pretty quickly to > 200 deg. F then
MWD''s suggestions are all valid and lead to correcting your issue.
Clean between the layers in the stack.....check the tensioner and the belt (might want to check that they put the serpentine belt
on correctly so the big fan PULLS air through the radiator).
And, since they don't cost much you may want to replace the thermostat although your temps are way above the thermostat temp
but if it doesn't open all the way that could be your restriction.
215 deg. F running on the flat in 90-100 deg. temps is not really overheating.
230 deg. F when pulling hills (at what speed and in what gear) is also almost normal if you are hauling
a heavy load (> than 2,000 lbs.) or have a heavy trailer (> 4,000 lbs) on the back.
If you are trying to run 75-80 mph all the time, you might want to slow back to 65-70 and see if the temps are better.
Hope this helps,
Roger

autostaretx
08-16-2016, 02:59 AM
Would one of the electric circulation pumps freezing up impede flow enough to elevate temperatures?

I realize they're magnetically-coupled rotors (more or less) floating free in the coolant ... but anything can jam (somehow).

--dick

RomSprinta
08-16-2016, 10:42 PM
Thanks for all the input here. I'm going to have the thermostat replaced this Thursday. I'll post an update.

designrmi
08-18-2016, 01:30 AM
I too have been seeing temps occasionally go 230+ on a recent trip to CA. ambient temps were
mid 90-100, and very some steep hills. On this trip i did throw a transmission related code 2511.
cleared code and changed trans fluid, before returning home, all seems fine.
but level driving in 75 degrees I see 180',normal. any incline or higher ambient and i'm at 210 +,
Twice in the life of my sprinter ive seen temps just below red line for a few seconds, how bad is this?

sailquik
08-18-2016, 02:31 AM
Pushing the "overheating limits" (250 deg. F) can be pretty bad.
Why not simply manually downshift to 4th gear, slow down a few mph (keep the revs in the 2700-3200 range and
I'd be willing to bet the temps will stay noticeably lower.
Probably need to check/clean the A/C condenser/Charge air Cooler/Radiator "stack" just to ensure you are getting
the maximum flow through the entire stack.
The manual downshift will get you a little better performance and better fuel mileage vs lugging along in 5th gear (Overdrive 0.83 :1).
Plus this gets the big engine driven fan running faster and when you can hear that big fan roar, your engine and transmission
should cool off fairly quickly.
Roger

lindenengineering
08-18-2016, 03:22 AM
I too have been seeing temps occasionally go 230+ on a recent trip to CA. ambient temps were
mid 90-100, and very some steep hills. On this trip i did throw a transmission related code 2511.
cleared code and changed trans fluid, before returning home, all seems fine.
but level driving in 75 degrees I see 180',normal. any incline or higher ambient and i'm at 210 +,
Twice in the life of my sprinter ive seen temps just below red line for a few seconds, how bad is this?

You should not be seeing temperatures like that!
In Colorado on a hot 90dgf day, pedal to the metal from Golden to Genesee on I /70 I don't want to see the needle past the 200 on the dash guage mark. In any case pushed hard onward up to LookOut mountain the viscous fan must trip in by 106 Celsius absolute tops on the scanner or its abandon the test and go fix!
Dennis

designrmi
08-19-2016, 02:40 AM
Yes I have been doing all that down shifting, to keep things a bit cooler,and going slower up the passes, thanks Dennis, I was looking for that reference, 90 dgf up the hill to Genesse, 200 on the dash. ok. fan clutch,

lindenengineering
08-19-2016, 04:59 AM
Yes I have been doing all that down shifting, to keep things a bit cooler,and going slower up the passes, thanks Dennis, I was looking for that reference, 90 dgf up the hill to Genesse, 200 on the dash. ok. fan clutch,

Yes fan clutch most likely but do clean the radiator especially behind the A/C condenser fan and the condenser first!

Use Dawn dish liquid (50% soap 50% water) spray it on all over (sounding like a Brut after shave advert! :laughing:) Then wash off with a gentle spray of water rinse from a garden hose then try the cooling system.
All the best
Dennis

designrmi
08-27-2016, 07:57 PM
Ok new fan clutch is in, yes i can hear it roar on occasion, seems to have cooled thing down, but of course the ambient temps are way down also.

Rock Doc
08-27-2016, 09:04 PM
I will further emphasize Dennis's recommendation to use a gentle stream of water to rinse through the radiator stack. A strong stream can/will flatten the radiators fins, thus blocking air flow and contributing to less radiator efficiency.

Rock Doc

glasseye
08-27-2016, 10:38 PM
I rode along with Dennis when he tested my 04 up that grade on I-70. It's a significant load and a great physical exam for the vehicle.

Frito passed with flying colours. :rad: