Engine does not reach 80 degs

[tom7035]

Talbir, I'm going to stick my neck out again here and suggest to you that making a standard spring (specifically designed for absorbing a given load in both directions - equal and opposite forces etc., remember?) shorter by simply cutting it renders it incapable of absorbing exactly the same forces without greatly increasing the risk of fracture - fewer coils and less material to absorb these forces than before. It is inevitable, surely?
Your observations this time would be interesting.
Mlc - I agree, but a slight correction on the subject of cooling. It is well known that an excess of antifreeze to water mixture does run somewhat hotter, i.e. given a similar ambient temperature where 100% antifreeze will grossly overheat plain water will not, so a happy medium has to be struck and this seems to be a 50/50 mixture. (Different of course where ambient temperatures differ from UK).
Cheers, Tom.

 

[W77]

My c180 reaches up to nearly 100 Celcius for city driving, is it normal or is it too high?

 

[mlc]

W77 - I think nearly 100 when stuck in traffic is ok. When you are at standstill you heat around the engine / radiator etc and it acts as insulation.

TOM 7035 - Thanks for the agreement. sadly I cant agree with your comment on running hotter with high anti freeze content. I think that info comes from the past when anti freeze had a methonal ( I think) content and the boiling point was lower, so if you had too much antifreeze you could get the car boling at "normal" temperatures. Modern cars ( I have more experience of Fords than MB's) have a high concentration and dont need a change for about 10 years. I really think that the cooling effect of the radiator is linked to the difference in temperature between it and surronding air rather than the contents of the radiator iteslf - but I coudl be wrong.

Mark.

 

[talbir]

MLC - oh dear - you NEED to be sure you are right before telling someone they are wrong.

"Fact - The concentration of anti freeze is unlikely to have any effect on running temperature. Too much is a waste, too little and the system rusts and may freeze on a cold night. "

INCORRECT - Anti-freeze DOES have an impact on the cooling system - that is why it's concentration is SO important. It is NOT just there to prevent freezing. Why do you think MB go to great pains to stress the CORRECT ratio of antifreeze and water ?.....

"Fact - Old radiators leak and get clogged up with debris, rust etc. both of which cause overheating. The chances of an old radiator causing excess cooling is zero. "

Go back and re-read my original post. I NEVER said an old radiator would cause cooling. I said it would cause problems - those problems being overheating. My POINT was that on a vehicle over ten years old is going to require renewal of these components sooner rather than later. A 10 year old radiator is going to have clogged elements and prevent the adequate cooling of the engine. So if one is overhauling their cooling system or addressing it, then this is one component that might as well be renewed on a 13 year old car. Not at any point in my post did I suggest that a bad radiator causes cooling. Re-read and understand.

"Fact - Running temperature is related to driving conditions and especially air temperature. The AA deals with lots of overheating cars (even MB's) on hot summers days - and very few on cold February days like today. "

Of course, ambient temperature has an impact but very little on a cooling system that is in optimal condition. The AA deals with overheated cars in the summer more often, yes, but those cars that the AA attend to have a problem with their cooling system...hence the call-out. On a car where all components of the cooling system are functioning correctly, the only difference ambient temp is going to make to operating temp is not much more +/- 10 deg C. And if you are correctly running at 90 deg C, then 80 or 100 is NOT a problem.

"Fact - The "Stiffness" of a spring is a function of its thickness, composition, hardness etc. and absolutley nothing to do with its length. This is called elastic deformation - just ask any half wit A level Physics student and they will explain it to you. What you are confusing this with is travel - if you cut a lump off a spring it will compress by less distance for a given load, but that doesnt make it stiffer. The idea that you think that just cutting a bit of spring off in the average DIY garage is frightening - I hope you dont drive the same roads as me. "

HOW incorrect ! The STIFFNESS of a spring is DIRECTLY proportional to it's length ! A spring is no different to a TORSION bar. Now imagine this. You are holding a long torsion bar, say 10m long for example, and you stick one end in a vice and you stand at the other end and twist the bar. IT will twist easily. Now cut that length of bar in half, stick it back in the vice and try twisting again - it will be MUCH harder to twist. Get it ? And a spring is no different to a torsion bar. If you believe that the stiffness of a spring has no relation to it's length, then go and chat to a physics lecturer or get some books out from the library. This is basic physics.

"Final Fact - In 30 years of driving, mainly working in road transport, the only occassions that I have witnessed cold running has been with either a thermostat jammed open or a cooling fan running all the time. I have however seen far more cases where the temperature sensor or gauge has been inaccurate. "

No arguments with your point above.

Finally you said "And then you claim that all this knowledge is due to your expertise in Physics. "

Please tell me in which post I claimed expertise in Physics. I NEVER claimed expertise in physics - I simply referred to the subject. I am not an expert in Physics - I am a mathematician and an Actuary. The physics of a spring as mentioned above are simple GCSE level physics. Again, do NOT suggest people made claims they never did.

None of my vehicles have cut springs - my W126 SEC's and SE have original AMG springs, whilst the Porsche, E500 and S320 have their original factory springs. And all sit perfectly.

BUT, if I had a car on which I wanted to adjust the height, I would not hesitate to cut springs to achieve the desired result. Because cutting half or one coil doesn't change the spring - all it does is give you a stiffer ride. Nobody has explained how the spring changes or becomes weaker etc if you cut off half or one coil......

Whether someone believes me or not is a matter of personal choice - but nobody is going to believe one who has their FACTS wrong. Period.


Talbir

 

[tom7035]

W77, nearer 90 would be more acceptable, but in extreme traffic conditions, continually waiting at lights etc., this can happen. Provided your fan is cutting in OK and the gauge comes down a bit when you get a move on I wouldn't worry. I assume you're not having to add coolant from time to time? If so this would indicate a problem. Cheers, Tom.

 

[talbir]

"I really think that the cooling effect of the radiator is linked to the difference in temperature between it and surronding air rather than the contents of the radiator iteslf - but I coudl be wrong. "

Yes, this is wrong. One can force the cooling system to run upto 15deg C lower by simply changing the content of the water in the radiator. This is achieved by adding a substance called 'Water wetter'. It changes the molecular structure of the water and helps achieve lower running temps.

The benefits of Water Wetter are more appreciated on high performance MB's. The E500 is a classic example, where the M119 naturally runs hot.

Do a Google search on 'Water Wetter' and you'll get plenty of technical literature on it's benefits.


Talbir

 

[tom7035]

CONCENTRATION may be defined as the total application of one's mind and body to a particular endeavour, to the complete exclusion of everything not relevant to that endeavour. (This should apply to every driver).

The only thing I've posted tonight which can't be argued with!!

Cheers, Tom.

(By the way Ben (tarmacsurfer), what was your question again? (LOL).

 

[mlc]

Talbir - I will read about water wetter with interest - although an initial check suggests that it aids heat transfer, no claim that it has more or less effect when used with anti freeze.

Two things - first is that common sense tells anyone that cars run cooler in cold weather than hot - anyone that drives know that!

Second - I have great respect for mathematicans - they are second only to we Physicists! However your explanation of bending a torsion bar and your analysis of what is happening and why proves just one thing. Sir you are no mathematician!!

 

[talbir]

" first is that common sense tells anyone that cars run cooler in cold weather than hot - anyone that drives know that! "

You seem to have trouble reading/understanding other pople's posts - that's exactly what I have said, that ambient teps can make +/-10 degC difference to operating temp. Again, I suggest you read.

"Second - I have great respect for mathematicans - they are second only to we Physicists! However your explanation of bending a torsion bar and your analysis of what is happening and why proves just one thing. Sir you are no mathematician!!"

Proves ? Please provide the proof disproving my statement about the torsion bar then - a feeble statement with no basis is of no value. You need to provide PROOF that one's statement is wrong -a simple claim that it is wrong is not enough.


Talbir

 

[squealinneil]

I like a good arguement.
Talbir, who services your SECs?

 

[tom7035]

Squealinneil, I think mlc looks after talbirs cars!!

 

[tom7035]

Water Wetter

Talbir, I note we are back on the physics thing again! Water Wetter seems to me to be simply a 'wetting agent' which has the effect of eliminating the 'surface tension' of the coolant. In other words expensive washing-up liquid with the foam taken out! I'm not suggesting it doesn't do what it claims, I'm just not clever enough to explain why it should. Wonder why they don't put a spoonful or three in every litre of antifreeze and thus eliminate the problem we have been discussing if it's so effective. What do you think? Tom.

 

[squealinneil]

tom7035



Joined: 22 Dec 2004
Posts: 34
Location: Dunfermline, Scotland.
Posted: Fri Feb 04, 2005 11:08 am Post subject:

--------------------------------------------------------------------------------

Squealinneil, I think mlc looks after talbirs cars!!
_________________
They said if we had women leaders there'd be no more wars. Then along came Maggie Thatcher - WRROOONNNNNNNNNNGGGG!!!!
1993 W124 200E 16V Auto, 123k. Metallic burgundy.


I don't know what "mlc" stands for. English please.

 

[talbir]

Hi Squealineal,

I look after my own SEC's , infact all my cars except the Porsche, since that is a rare model (only 1 out of 237 built to Special Request and so need to keep up the Porsche stamps in the book !).

My SEC's were featured in the article 'The Best SEC's ever' back in the November 2004 issue of 'Mercedes Enthusiast' magazine.

I do all mechanical and interior work myself - I've been tinkering with MB's since I was 16 yrs old.

cheers
talbir

 

[mlc]

Talbir,

I can see that you are getting quite excited about this post. You are described as a Senior member and that carries certain responsibilites, including only giving advice as "fact" if it really is. It sounds as if you are a very capable chap with repairs / maintenance etc. Perhaps you could get away with cutting springs for instance. What I can confidentaly state is that if my 18 year old son read your item he be out their this weekend hacking bits of the springs of his Ford Ka to acheive the desired look. All four corners would be at a different level and the car would be in the ditch at the first corner. I have a friend that performs miracles with restoration, he has a Rover P5 that started life as a four door saloon and is now a two door convertible. The results are perfect, but I wouldnt recommend that anyone trys this at home!

I have reread all the posts to this thread and I dont think I have been unfair. Springs are hardened, a scratch - such as the slip of a hack saw blade will create a weak spot. If you have got away with it - well done - but its still a risk.

As far as having to prove your wrong about your torsion bar. I dont have to - you presented a totally flawed agrument. A long bar deflects more than the equivalent short one because the deflection is related to the load AND length, thats what elastic deformation is! Thats why cutting a bit off a coil sping means that it compresses less. It doesnt means it stiffer or weaker - just shorter.

Quad Erat Demonstrandum.

Mark.

PS - I've had enough of this - lets call it quits!

 

[talbir]

"As far as having to prove your wrong about your torsion bar. I dont have to - you presented a totally flawed agrument. A long bar deflects more than the equivalent short one because the deflection is related to the load AND length, thats what elastic deformation is! Thats why cutting a bit off a coil sping means that it compresses less. It doesnt means it stiffer or weaker - just shorter. "

In the above, you stated : "because the deflection is related to the load AND length"

Doesn;t that contradict your earlier posts AND in the process say exactly what I have said all along, i.e. a springs stiffness is directly proportional to it's LENGTH. On the torsion bar example, I assumed the same load before and after cutting...because that's the same with cutting a spring. The load, i.e. the weight of the sprung components remains the same.

Moreover, I am not out to contradict or be difficult or prove anyone wrong. Through these discussions we all enhance our knowledge. I have presented a point on springs with technical explanation to back it up. I'm only trying to have a meaningful discussion - it'd be the same if it was down the pub over a couple of pints. I mean, no-one takes this stuff personally do they ?

Hope not - it's all constructive discussion from my point of view.


cheers
talbir

 

[mlc]

Talbir,

I think the confusion is between stiffness and spring travel. I agree completley that if you judge the stiffness of a spring by the travel avalable then cutting it in half means that their is less to compress. But using the same argument means that as a tall building will sway several feet in the wind and my house only moves a very small amount (I Hope!) means my house is stiffer than the tall building. The tall building has a much higher torsional rigidity, which I think this is all about. My (very limited) knowledge of sports suspensions over the years tells me that when the car has a "sports" suspension, which in most cases means firmer, the changes are - lower suspension, shorter AND stronger springs and thicker anti roll bars.

In terms of taking it personally - sadly some people do! But far more worring is that some assume that every thing they read is gospel, so we all have to be careful in getting the facts as accurate as possible.

Finally - not sure if that was an invie for a pint or two - but im in Manchester so I have to say thanks but no thanks. We can however offer world class Physics tuition at all of our universitys if you feel the need

Cheers

Mark.

 

[joe bloggs]

Great stuff, been dipping in and out all day, although rather busy looking after 25 technicians and the days problem vehicles.

Ok to return to the poor blokes question it would seem that a new thermostat perhaps would be worth doing at some point, a road test would answer the question for me though, i.e. I would be looking to see how quickly the temp settled at its current normal, whether too low or high, checking the heater output etc, just to get a feel for the car, and to make sure we were not looking at a faulty guage / sender etc. Watch those plastic thermostat covers though, prone to breaking off at the top hose if the clip is done up too hard, best to fit a new aluminium one while it is off.

Ok yes if correctly done by an engineering shop springs could be cut, although if you look at most MB springs the upper coils are flattened and wedged to give a squared off profile, but also the lower coils are bent slightly to give the spring a flatter surface, if you place them on the ground either way up they will stand up, as opposed to a cut spring which would fall over.
as MB springs are prone to snapping at the best of times, not to mention the current epidemic of 210 front spring cups breaking away, (see if your dealer will honour your corrosion warranty when he feasts his eyes on those freshly cut beauties) I would still recommend the correct size / strength spring from a dealer, not least for the 2 year warranty, and the peace of mind of a proper job done. Remember to wax them up thoroughly, and fit the sacrificial anodes to the bottom, (ask the dealer for them).

Kind Regards to you all
JB FIMI Senior MB Diagnostic Technician.

ps. Note re someones comment about xenon headlamps, the height of the vehicle is calculated by the rear sensor only, as this is all that is required to tell the ecu the angle the car is currently adopting, i.e. if the back is down the headlamps will point at the sky, would you like the MB schematics??

 

[squealinneil]

What I want to know is who made me a senior member?

 

[LNM]

I took my thermosat out to try and kid myself the head wasn't knacked. Needless to say, it didn't work.