Question for those in the north.... - Page 2 - PeachParts Mercedes-Benz Forum

bill murrow · #16 10-25-2005, 08:10 PM

My 300TD warms up faster than any diesel I've ever owned. No cardboard either....Throws tremendous heat too.

Sounds like a stat to me. Can't hurt to try it. Easy fix and the part is cheap enough. Don't forget the gasket, which may come with the stat.

Cheers,

Bill

ZackaryMac · #17 10-25-2005, 10:12 PM

I'd say your mechanic was talking just to hear himself. He wasn't making sense.

However, I can guess he gets this idea from smaller diesel engines that have a hard time producing enough heat in the cold (60F is hardly cold). I've owned 3 VW diesels, and they are small engines, so unless they are working, they don't make much, sometimes any heat. Driving around town on a windy -20C day, the engine will actually cool down without a rad block. Get out on the highway, and in 5 minutes the heat is rolling out.

Same for my diesel Sonoma. Most of my driving is at 80kmh, and when the temps get below freezing, I barely have any heat by the time I get to work, 20 minutes later. I have to block the front of the rad to get any heat. Yes, I've tried new themostats, coolant, etc. With the heater on high, sucking all the heat out of the coolant, and cool ambiant air flowing around the block, it just doesn't get a chance to get hot. I guess this is the trade-off for getting 45mph from a truck.

Guys with bigger engines/more cylinders don't have this issue. My fathers diesel Dodge never suffers from this. He laughs at my toy diesel truck (and my toy Kubota diesel tractor! Geez! I have no use for his Massey high-arch 165, so I guess we're even

).

Seems you guys make enough heat to not have this situation either. Consider yourselves fortunate.

Hatterasguy · #18 10-25-2005, 10:17 PM

My 300SD is doing the same thing it will never get above about 60C. I have a new T stat on order and plan on replacing it later this week.

btw I noticed last winter on a -5 degree night my SDL would just barly hit 80C if I kept the rpms up in 3rd. Diesels just don't heat up in the winter, even though that car still throws off some nice heat, the cabin was nice and toasty.

nckmsn · #19 10-25-2005, 10:30 PM

Quote:

Originally Posted by nhdoc

I think your experience is atypical. I've run 240Ds and other cars without thermostats in order to diagnose problems and they run very cool, never getting up to operating temps and the heat from the heater is minimal. Running them without T-stats would be even more "open than open" as there is nothing to impede the flow of coolant through the block and radiator...I can't imagine why having a "stuck open" T-stat would result in a higher operating temp...makes no sense.

The reason it would be hotter is because the engine is heating the coolant, and then the coolant doesn't cool back down because it is running straight through the radiator and then back into the warm engine. I had the understanding that the thermostat would need to close so that the coolant had time to cool back down in the radiator. did you drive your 240d hard to see if the engine got hotter? if you are sitting at idle or just driving around town at slower speeds, then yes, your motor will run cooler. What do you think. I'm not saying anyone is wrong, but this has just been my experience.

jaoneill · #20 10-25-2005, 10:32 PM

My Ford F800 has a 1" T-stat by-pass hose to ensure enough cooling under load in the summer and as a result carboard becomes necessary running empty at -30.

A few years ago in Eire I rented a diesel vw and damn near froze most of the first day on the road. It took me that long to figure out that the toy diesel would warm right up at 3500rpm. Drove it, well rev'ed and comfortably warm, for weeks.

But, the heater on my 190D, with the fan on low, will cook you after 3 minutes on the road at -30. Engine is right up to temp.....it is a beautiful thing.

Find a real mechanic before you have any real issues.

Best of luck,
Jim

t walgamuth · #21 10-26-2005, 12:19 AM

are bypass type. when the engine is cold they direct all the flow from the water pump directly back to the block wo passing through the radiator. when the car warms up and needs cooling it directs the flow through the radiator. in between it mixes the flow.

so if you run a benz wo the stat it will never warm up around town in cool weather and when it is really hot or pulling a hill it will overheat because most of the water will flow to the path of least resistance... back to the block wo going thru the rad to get cooled down.

so you dont want to run your benz wo a stat.

get a german made one and install it with the flat plate down and the pointy side up.

tom w

Pete Burton · #22 10-26-2005, 08:28 AM

Dang! As a direct result of participating in this thread, my thermostat just failed. It was OK yesterday, but this morning I noticed I didn't have normal heat. Sure enough, the temp gage was around 60C, not 80-85C.

bill murrow · #23 10-26-2005, 08:41 AM

Quote:

Originally Posted by Pete Burton

Dang! As a direct result of participating in this thread, my thermostat just failed. It was OK yesterday, but this morning I noticed I didn't have normal heat. Sure enough, the temp gage was around 60C, not 80-85C.

Karma always wins.

Better check mine I guess.....

Cheers,

Bill

RUN-EM · #24 10-27-2005, 01:45 PM

had the thermostat and did change it. Sparky the Diesel does now warm up to just a little over 80 degrees C on the guage. This is on a 70 degree day. I'll let it go through several heat/cold-cycles and continue to add anti-freeze if needed before I trust it though. Had a car with air bubble that later caused me to overheat and thus--lose an engine. So, I shall play it safe, rather than sorry. And I did fill the engine through the top radiator hose and then top off the fill tank.

Think my mechanic was just pullin my leg on the cardboard

Thanks to all.

Regards

Run-em

boneheaddoctor · #25 10-27-2005, 01:47 PM

Both of my Benzes warm up faster than my Honda does....basicly I am getting warm air in 5 minutes time roughly. Not hot air but warm air..hot takes a little longer.

biopete · #26 11-19-2005, 09:07 PM

So everyone has bashed this mechanic. Perhaps he is a bone head or perhaps he noticed other things the poster (sorry original poster ,I' m not going back to look up your name

) did not tell us. Such as the cooling fans are running all the time. Are there no other causes to overcooling to a constant <60C other than thermostat ? Sometell me and i'm off for a thermostat.

I have an 81 300D that overcools but both cooling fans run from startup all the time. The aux one shuts off sometimes. I' m wondering if the fans are the problem before i go and change a thermostat. I will start a thread on this as I think "Overcooling" deserves its own properly named thread.

boneheaddoctor · #27 11-19-2005, 09:11 PM

On a cold morning the interior fans should not come on immediately....there is always a few minute delay on mine as the coolant temps start to rise....then they come on...This is with ACC not the Euro manual controls.

BluEyes · #28 11-19-2005, 09:43 PM

biopete: radiator fans being on all the time is another problem (and could lead to the fans burning out and the car overheating in the summer) but would not cause overcooling with a properly functioning 'stat. See, when the stat closes, it bypasses the coolant back to the block, so it does not have a chance to get to the radiator and get cooled by the fans.
Also, then you're on the highway there is more air flowing through that radiator than the fans could ever hope to pull, and the engine should keep temp just fine.
If your car doesn't get up to temp, or takes a really long time getting there, you need a new thermostat. At least they are cheap to buy

Now, if you have manual heater controlls and have the heat and fan on full all the time, that could cause overcooling because the 'stat cannot regulate flow through the heater core.

t walgamuth · #29 11-19-2005, 10:35 PM

blueeyes has it right.

new stat needed.

tom w

whunter · #30 11-19-2005, 10:50 PM

Quote:

Originally Posted by SD Blue

Mercedes are manufactured in Germany and from what others tell me, it gets pretty frosty there in the winter.
In fact, my MB puts out heat faster than any other vehicle I've ever owned. As others have recommended, changing of the thermostat should resolve this.

http://www.about-germany.org/life/weather-in-germany.php
I book marked this link for the fun of it.