Drove it about 25 miles at different speeds, mostly 50 ish...

jumped out with my infared thermo heat gun and got 109* on the head:confused:

I'm willing to try anything........remember this car on a 100* day will barley reach 90*c on a uphill drive at 4500' elevation

Take out the thermo and check it for operation in a pot of water with a thermometer . If you read much on this site you will find that many a new out of the box thermostat is bad.
JOHN M

New thermo works fine .. tested in pot before install. Old wrorks just as well. Think about it. My carpenter clamp became the thermostat when I pinched off the hose. Still no heat.. very little change observed.

The only thing I have not done is remove the fan blade ...maybe that's next!

I dont think the fan has that much effect when the thermostat is closed, does it? If it does I wonder if installing the fan clutch off of a 617 engine would help.

240D too Cool..check my theory?
 

As a few have read and helped... summary... I just cannot produce any heat out of the motor over 130*F
Long story short I changed and pretty much tried everything but parked it till spring.

I have a new theory on what the problem might be...?

I always felt a little low on power compared to my buddies 240d so I advanced the injection a little and got what I thought was significant increase. Still not as fast as his car but much better for me. I used the bubble method ( blow in the tube) tpo what I felt was to spec.
81 240D 130k miles , great compression, well taken care of car by po. Always serviced and valve adjust done recently.

My question..

could the IP timing be off so much that I am losing heat and power thru compression or exhaust stroke as to not have the complete cumbustion at the right timing? ... hence the power goes out the exhaust .. does this make sense to anyone?


thanks

bennett

Could you have a bad temp gauge or sender? And yes.. IMHO based on my small undersanding of diesels if you have poor combustion then an engine would run cooler. Good cumbustion produces more heat.

Try this idea. Use a sensor to measure combustion temps. Adjust timing till you get the highest temps. Some say you already have sensors.... "your glow plugs" More on that topic here:

http://biodiesel.infopop.cc/groupee/forums/a/tpc/f/159605551/m/1071029711/r/3361009911#3361009911

If you are running low power try adjusting the valves and run diesel purge.

If that doesn't work pull the injectors and if worn replace them with rebuilds.

Check the IP last.

For me, the most difficult diagnostic issues have always been ones that turned out to have more than one cause. Also, does your infrared thermometer have a fixed emissivity of 0.95? Many,if not most do. If so, your actual temperature will probably be higher than what the digital readout is. You can test this by coating an area with candlesoot (although I bet diesel soot would work well too:D ) and try reading it again.

If your engine is pushing the car down the highway then it is certainly making enough heat internally to boil water, provided the water is trapped by the thermostat.

I haven't read the other thread and will do so when I get the chance. If you are just idling, then yes, you may not generate enough heat to get very hot. But I presume you are running the car on the road and not getting interior heat.

After a highway run, lay your hand on the radiator cap. If it is too hot to hold your hand there for long, the water is getting plenty hot and you have a heater core issue, etc. etc.

We can solve this. The engine has to be making heat. Timing has some effect but not enough to cause what you're seeing.

Ken300D

OK, I have read your other thread.

It seems to me the first thing you have to do is trust your instruments, that is, the infrared thermometer. I wouldn't trust it. If it says your head is 130 degrees - why don't you just go ahead and touch it? :) 130 won't burn you.

Go ahead and try the exhaust manifold too. :)

So, do a few simple checks to make sure that temperature instrument you have is giving a reasonable reading. And there's nothing in the history of these cars that would lead me to trust the gauge in the instrument panel of the car. Those things read all over the place depending on such factors as the quality of the ground they get.

I think your first mission is to get the car to properly heat the coolant, then you need to worry about getting that heated coolant into the cabin and the heat exchanged with air. Seems like that is what you are focusing on properly.

I'll do a re-read, but I don't remember you telling us what your instrument panel gauge is showing for temperature. Is it moving off zero?

We can narrow this down and fix it.

Ken300D

summary of what I did
...Even in the summer I had difficulty hitting full 80*c on a hot day.
What I have done...
New bosch water pump ( weep hole was leaking)
Bosch 80* thermostat and in correctly
Ran diesel purge
I have cardboard and taped off the entire front of the radiator and this made very little change.
Head temps with Infared thermomoter reads 130 at best in these cold temps ( 20*f- 30*f) I am at 4500' elevation and low 20s at night and 30s in daytime.
no restrictions in the vents etc.. fan blows awsome.
Radiator( cooling system) pressure test at 15lbs... held over 1 hour and no drop
Dash Temp gauge reads 50*-55*cc and goes no higher even with cardboard.
I think my dash gauge is working correctly. Winter does not exceed 50-55C summer never exceeds 80* on a 100*f day uphill.

I agree with most coments There should be a relationship of exhaust temperature and combustion efficiency.For the person that asked about wether could touch the head and exhaust... I can touch and hold without burning me.
I feel my $150 Temp gun is calibrated properly...

It just about has to be the thermostat. Where did you buy it from, and what is the part number (still have the box?)?

You're not high enough or cold enough to be that much different from the rest of us with 240Ds. It should heat up, except in the case that water is allowed to flow in an unrestricted manner past the thermostat.

If you go so far as to remove the thermostat, please post a picture of it.

I'd recommend you do some research here by searching on "thermostat" and "problem" and read about the new ones that were no good. Seems to me it was partly a brand issue and partly a bad production run.

Ken300D

I'd really purchase another stat if I remotely thought it was the stat.

I now have 3 Motorad ( germany) Thermostats and they all work. Water tested and new one is in the Benz.

Again think about this... clamping off the radiator hoses is a simple duplication of what the stat does .. only more severe. It still did not heat up after driving in 30* temps for a 6-7 mile trip.

I'm probably not going to solve it since my buddies 240d (which is much faster and quicker take off) is as cold blooded as mine although his gauge reads near 80*+ shortly after startup on a cold day. I suspect a bad dash gauge on his. We are lucky to pull 60*F out of his heater vents at full speed on a 50 mile drive this week. Reminds me of my old VW heater .. just took the chill off at best.
Sorry If I'm beatin a dead dog .... the problem just bugs me cause I like to solve things. Can't get it out of my head.

thanks for the therapy

I'm sorry if there are too many threads.. I just wanted to revisit the issue. Someone must find it interesting enough to reply an learn as I am doing.

I'm not sure a 240 has a oil cooler t-stat does it? I re read the threads .. how did you suggest I test it?... Ir thermometer ?

Barry123400 posted this on the other thread.

"Also remember the oil cooler is thermastatically controlled as well and if oil thermostat is constantly open might do it. It is located in the filter container I believe but not sure. Find out at what temperature it is suppose to open and if your oil cooler rad is warm or hot under that temperature you may have it. Where else is there left to look anyways? The heat is going somewhere or is not being made. Since the 240d does not burn more than one litre per hour at idle and part of that is converted to mechanical energy you do not have a lot left if a fault exists like one of the above to lessen it.

you might be able to use the IR thermometer to gauge relative temps. The oil cooler should be cold until the engine warms up. If it warms up with the engine coolant, the oil thermostat is suspect.

Even if your IR thermometer is properly calibrated, it will not give accurate readings off hot objects that do not have a surface emissivity of 0.95. Typically inexpensive IR thermometers have a fixed emissivity.