How hot does your 116 run?

[pez]

Bleed bolt is on the top rear of the motor, attaches to the intake manifold near the head, I believe it's a 19mm bolt head, and is on the left top side of the motor. Left side is the side of the car if you are sitting in it - aka the driver's side for most of the world.

[Yesmar]

between 80c and 85c

[craigb]

I think I recently replied on here (or maybe another forum) about my M110 having trouble with air locks after draining coolant, and have also heard about the prob on 8's so I would definitely look for that bleed.

My M110 was running at 80C and the mechanic who did the lpg conversion said you need to have it running hotter for best performance so I asked the dealer and I think he said there was two thermostats, 75 and 85 from memory? So I took the 85 and installed it but no great affect. I had a sprint coming up so I just removed the fan altogether and disconnected the clutch wire on the air con so I could turn that front fan on without kicking in the compressor just by turning the fan and on cool. the car runs fine but I turn the fan on as soon as I cross the line and take a long route through the pits to keep things circulating.

I have left it that way for commuting and it hasn't been a problem (traffic not too bad in Adelaide) except climbing the hills on these really hot days sees the temp up over 100 but there are some downhill stretches in between that see it dropping right back instantly. I think the answer is to install another electric fan with a thermostat conected to it.

But performance wise there is a huge difference above about 87C. I have had mates in the car and gone to show them what she does and been dissapointed myself, looked at the guage at sub 85, pulled over to let it idle and bring the temp up and then have another go and the difference is massive! The mechanic did explain why the effect is but I can't recall now. He said it would run best at about 100 but 90 to 100 should be fine.

[koan]

I just removed the fan altogether and disconnected the clutch wire on the air con so I could turn that front fan on without kicking in the compressor just by turning the fan and on cool.

The way mine is wired (which is not to imply your's is the same) the refrigerant 62C over temp switch needs to close to get the fan to run with A/C on

koan

[craigb]

that sounds logical Koan, and maybe mine did in a past life but that may be bypassed now.

[WGB]

Once the car is converted to 134 the fan is usually wired to run any time the compressor is engaged.

Bill

[TJ 450]

Engine M100.985 also has the bleed plug at the top left rear of the intake manifold. It is right where the heater hose connects in to the manifold.

Tim

[koan]

Engine M100.985 also has the bleed plug at the top left rear of the intake manifold. It is right where the heater hose connects in to the manifold.

Is there any mention in the manuals of removing the plug when filling the cooling system?

Not seen anything in my books but doing so might make filling a lot easier.

koan

[jamesnb]

My 300SD runs at 175F (79C) pretty much all the time.  It has an oil cooler  which helps maintain constant temperature.  Plus the oil capacity is 8.5 L.

[transilvana]

My european 280SEL runs at 80ºC, last week I changed hoses, flushed the system and new thermostat, it runs cool.

[johnnyw116]

on my 1976 280SE i have an 79ºC,  thermostat and it runs always 79ºC/80ºC

[brettj]

A couple of weeks ago I replaced the water pump, thermostat 75 C, fan clutch, all hoses, coolant recovery tank, recovery tank cap and heater valve in my 75 450SE. My mechanic couldn't locate a heater hose so he created a make shift hose to replace the leaking hose. I had MB coolant installed as well.

Today the temp outside was about 92 degrees F. While waiting in line at the drive through window at McDonald's, I noticed my temp gauge rising above the normal 185 F to 200F. It stayed at 200F but dropped slightly to about        196 F while driving. Fortunately I only live about a quarter of a mile from Mc Donald's and drove straight home. I immediately opened the hood to check to see if the aux fan was on, it wasn't. The radiator was very hot to touch.

My car has never gone to 200F before. Since all of this work was done the temp has increased to the norm of 185F from the previous norm of 180F. I checked the service manual which states cooling water temp 70-95C, cooling water temp max 118C, thermostat opens at 75C. Do these figures mean that normal operating temp falls between the temps of 70-95C and overheating would begin at 118C?

I'm not sure if my car was over heating today and thought that maybe that make shift heater hose created a lack of proper circulation or perhaps my radiator is plugged? I've read in this thread about the bleeder valve which I can't find either. Anyone have a pic of this valve? How would you know if your radiator was plugged and needs to be rodded?

[pez]

Your aux fan turns on at 100C.  You did not reach that temp.  It is really normal for these cars to run between 80 & 95C.  Mine personally runs about 82C most all the time, but a really hot day stuck in traffic will get it up to 95C [a 40C day]. The bigger thing is if your temp drops immediately once you start moving, and the best way to test is to get it really hot at idle, then drive a long slow hill to see if it goes down. If it goes down, you're fine. If not, then you need to look at your cooling system efficiency.

Bleed screw is on left rear top of manifold, 19mm bolt.

[brettj]

Thanks for the testing suggestion. I'll give it a try tomorrow. Hopefully it was just the hot day that brought the temp up!

[brettj]

I tested my car out today. The temperature today was 84F. The temp gauge did not reach 200F. It hovered at about 185F which increased to about 190F when I put it through some stop and go driving. Once I began driving steady the temp did return to 185F. All of this new temp fluctuation concerns me. I thought maybe there is air in the cooling system. So I looked for that bleeder valve on the back of the motor and couldn't find it. I'm not sure if it does anything to release air from the cooling system but I opened the recovery tank twice. The first time the motor was cold so naturally no pressure was released but the second time the motor had cooled to a temp safe enough to open the cap. A good amount of pressure was released and I'm hoping any trapped air too!

The motor seems to be functioning well. I warmed the car up this morning and watch the temp gauge. The temp gauge moderately moved up as the motor warmed and as the temp gauge went up the air slide slowly deceased the RPM's from a high of about 1800 to the norm of about 800. So I'm still not sure if everything is OK or if I should look into purchasing a new radiator.