Heat issues? Maybe not? - PeachParts Mercedes-Benz Forum

Zerohour3k · #1 12-14-2005, 04:10 PM

Just a real quick question, and probably a dumb one at that. Is it normal for these old cars (I have an 84 300D Euro) to take a while for heat to come out, espically in ~12F weather? These mornings are really getting cold, and until I can get on the highway, the heat is mediocre at best.

Is this just the way these things are supposed to work, or is there a problem? Once the car is "hot", the heat blows out pretty well. Not scorching-hot, by any means.. but comfortable. And thanks to the iron engine, it holds heat pretty well, too. My climate controls are of the dial-type.. (one for fan), and two hot-cold dials for the left and right sides of the car. Has levers for upper - lower vents (which I like a lot better than the ACC's). So.. is this a problem, or just my car being old?

boneheaddoctor · #2 12-14-2005, 04:22 PM

Quote:

Originally Posted by Zerohour3k

Just a real quick question, and probably a dumb one at that. Is it normal for these old cars (I have an 84 300D Euro) to take a while for heat to come out, espically in ~12F weather? These mornings are really getting cold, and until I can get on the highway, the heat is mediocre at best.

Is this just the way these things are supposed to work, or is there a problem? Once the car is "hot", the heat blows out pretty well. Not scorching-hot, by any means.. but comfortable. And thanks to the iron engine, it holds heat pretty well, too. My climate controls are of the dial-type.. (one for fan), and two hot-cold dials for the left and right sides of the car. Has levers for upper - lower vents (which I like a lot better than the ACC's). So.. is this a problem, or just my car being old?

maybe your cooling system is showing symptoms of needing a proper flush...or a aux water pump on its way out...

Pete Burton · #3 12-14-2005, 04:22 PM

Because it is a diesel, it has less waste heat, especially at idle. They do take a bit to warm.

Zerohour3k · #4 12-14-2005, 04:35 PM

Well, the radiator was replaced *right* before I bought the car (the last owner apparently had a leak in the thing, and rather than patch it, replaced it with an OEM one). I'm guessing the coolant system was flushed when this was done, which was about 18,000 miles ago. As for the aux water pump.. um.. not even sure where that would be.

..Then again, at full tilt in the middle of summer, the car DOES get up to about 110C.. so I dunno?

barry123400 · #5 12-14-2005, 08:52 PM

Thinking the euro model may not have the pump. How about getting one off a junker if it does not and installing it. Or it might have one that is not working but think not. Make sure the auxillary pump still works as it is electrical prior to installation. It's purpose is to increase the flow through the rad core on north american versions and you could wire in a switch. Plus perhaps your heater on valve is getting a little tired. Others with more experience may help by commenting on the valve. I do not know if partial failure is possible or not. I would try the booster pump though as it should be easy and might help. Yet i do not think the 240ds in north american version have the pump either but could be wrong. Heat seems to be adaquate but on occasion some people post they are not getting enough.

#6 12-14-2005, 09:14 PM

How long does it take the engine to get up to temperature? Does it reach and remain at 80C, even in cold weather? Are you getting inadequate hear when the engine is at 80C?

kerry · #7 12-14-2005, 10:03 PM

My 85 3000td has a temperature sensor that keeps the fan from blowing when its cold out. It takes about 6 short city blocks on a winters day for the engine to get warm enough for the fan to overcome that lockout. It only varies about 100 yards in the distance it takes to reach that temperature. The air is just barely warm when it begins blowing. This is in temperatures between about 5 degrees and 20 degrees. I've never experimented with it in below zero temperatures although it was about 10 below last week and it did seem to take a little longer before the fan came on.

Zerohour3k · #8 12-14-2005, 10:52 PM

Quote:

Originally Posted by Craig

How long does it take the engine to get up to temperature? Does it reach and remain at 80C, even in cold weather? Are you getting inadequate hear when the engine is at 80C?

Once the engine gets up to 80C (Which is only on the highway, when I'm trekking along at 75-80mph).. it blows out nice, warm air. Driving around locally, the car rarely pushes 50C. On average, the car will run 45-50C once it's been "warmed up" (or taken on the highway, and then driven on local roads). Stop-and-go traffic, the car doesn't go near 80C, in this weather.

#9 12-14-2005, 11:10 PM

Quote:

Originally Posted by Zerohour3k

Once the engine gets up to 80C (Which is only on the highway, when I'm trekking along at 75-80mph).. it blows out nice, warm air. Driving around locally, the car rarely pushes 50C. On average, the car will run 45-50C once it's been "warmed up" (or taken on the highway, and then driven on local roads). Stop-and-go traffic, the car doesn't go near 80C, in this weather.

It sounds like a thermostat issue. The engine should get up to 80 C and stay there after just a few minutes of driving. Consider replacing your thermostat. Also, running at those low temperatures is not good for your engine.

boneheaddoctor · #10 12-15-2005, 08:00 AM

Quote:

Originally Posted by Zerohour3k

Once the engine gets up to 80C (Which is only on the highway, when I'm trekking along at 75-80mph).. it blows out nice, warm air. Driving around locally, the car rarely pushes 50C. On average, the car will run 45-50C once it's been "warmed up" (or taken on the highway, and then driven on local roads). Stop-and-go traffic, the car doesn't go near 80C, in this weather.

I agree with Craig...what you describe is a bad thermostat.......I just replaced mine last night as the last 2 days it never got above 60 C on the temp guage....now it stays between 80 and 90 C like it should..........80 around town 90 on highway.

Zerohour3k · #11 12-15-2005, 08:59 AM

Quote:

Originally Posted by boneheaddoctor

I agree with Craig...what you describe is a bad thermostat.......I just replaced mine last night as the last 2 days it never got above 60 C on the temp guage....now it stays between 80 and 90 C like it should..........80 around town 90 on highway.

Is the thermostat hard to replace? It's currently 15 degrees outside, so if it's an hour-long job in the freezing cold, I'd rather just have it done at a shop. I've never replaced one of these things before, so I don't even know what type to get. :\

Huh.. never knew that running *cold* would be a bad thing o.O

boneheaddoctor · #12 12-15-2005, 09:04 AM

Quote:

Originally Posted by Zerohour3k

Is the thermostat hard to replace? It's currently 15 degrees outside, so if it's an hour-long job in the freezing cold, I'd rather just have it done at a shop. I've never replaced one of these things before, so I don't even know what type to get. :\

Huh.. never knew that running *cold* would be a bad thing o.O

10 minutes on a cool engine....three 10mm bolts and a 3/4 gallon of coolant is all it takes. Running too cool increaces wear and shortens oil life too.....

Heres a hint.....a 10mm deep well 3/8" socket and ratchet is the perfect length to get at all the bolts...