W124 high temperature reading

[ash_2009]

Just flush out the system and it'll be fine. That temp reading is fine. I have 3 x E220 and they all do that.

I was actually thinking of doing the flush.

I have read some places to use mercedes benz citric acid for the flush and some posts have mentioned that using that they have actually got leaks so do be carefull.

Maybe I will just wash with distilled water and then fill with appropriate coolant.

Ash

 

[WDB124066]

Do not flush with acid MB do not recommend it. There is a flush kit that is available from MB that uses water.

 

[stwat]

Do not flush with acid MB do not recommend it. There is a flush kit that is available from MB that uses water.

MB sell a citric acid flush.

 

[ash_2009]

Just an update on this issue.

Firslty I had a look at the fuses for the fan which are located in the box behind the main fuse box and I saw a 5amp and 15amp fuse and both were fine (see picture). From other pictures I have seen online, this looks to be very different. I thought they would have been fuses on some relax box

Secondly, I had a closer look at the radiator from the outside and I noticed bottom left, this sort of rusting/breaking up going on. Rest of radiator looks okay although some signs of rust but no holes as yet. See picture. Do you think this radiator would be causing this high temperature or there is too little rust to have any effect

Ash

 

[WDB124066]

MB sell a citric acid flush.

Not for use on this engine in the coolant system is the advice I hear time and time again from MB Techs of the era.

There is a product they sell for ridding the system of engine oil from memory.

 

[brucemillar]

Just an update on this issue.

Firslty I had a look at the fuses for the fan which are located in the box behind the main fuse box and I saw a 5amp and 15amp fuse and both were fine (see picture). From other pictures I have seen online, this looks to be very different. I thought they would have been fuses on some relax box

Secondly, I had a closer look at the radiator from the outside and I noticed bottom left, this sort of rusting/breaking up going on. Rest of radiator looks okay although some signs of rust but no holes as yet. See picture. Do you think this radiator would be causing this high temperature or there is too little rust to have any effect

Ash

Ash it all contributes. What you see is classic signs of the rad starting to deteriorate. It is probable that the bits you cannot see are as bad if not worse. These are the very fragile cooling plates that do break up over time and with age. To be 100% certain you need to either replace or re-core your radiator. Replacement alloy ones are not to expensive - I just replaced mine on my 300TE for about £125. A re-core (if you can't find a replacement is around the £150 - £170)

 

[WDB124066]

Just an update on this issue.

Firslty I had a look at the fuses for the fan which are located in the box behind the main fuse box and I saw a 5amp and 15amp fuse and both were fine (see picture). From other pictures I have seen online, this looks to be very different. I thought they would have been fuses on some relax box

Secondly, I had a closer look at the radiator from the outside and I noticed bottom left, this sort of rusting/breaking up going on. Rest of radiator looks okay although some signs of rust but no holes as yet. See picture. Do you think this radiator would be causing this high temperature or there is too little rust to have any effect

Ash

That rad looks like it may have dirty fins as well as what you can see in the picture. It won't be operating at 100% efficiency like that. But it looks like a gradual loss of efficiency not the step change you are looking for...?

 

[ash_2009]

Ash it all contributes. What you see is classic signs of the rad starting to deteriorate. It is probable that the bits you cannot see are as bad if not worse. These are the very fragile cooling plates that do break up over time and with age. To be 100% certain you need to either replace or re-core your radiator. Replacement alloy ones are not to expensive - I just replaced mine on my 300TE for about £125. A re-core (if you can't find a replacement is around the £150 - £170)

Thanks Bruce,

I know there is an element of risk going for a replacement rather than new. New radiators I am assuming can be a little dear, genuine Behr ones of course, but I have seen a company called Nissens??

Anybody heard off or used them as new radiators

 

[brucemillar]

Ash. I think that the replacement alloy jobs are fine. Try ECP or even Merc themselves.

 

[ash_2009]

That rad looks like it may have dirty fins as well as what you can see in the picture. It won't be operating at 100% efficiency like that. But it looks like a gradual loss of efficiency not the step change you are looking for...?

Nope not...but looks like it might need a new radiator. I am searching around and rather go for new genuine one but I am also waiting for the wallet to get a might hit

Ash

 

[ash_2009]

Ash. I think that the replacement alloy jobs are fine. Try ECP or even Merc themselves.

Bruce, are you talking about replacement of the whole radiator or just the fins.

ECP dont have the radiator for my car, GSF do and its a Nissens, and complete I am assuming and not just the fins.

Ash

 

[A250 Bennyboy]

My A250 normally runs at 80, but sometimes goes up to 100 but soon comes back down to 5he 80ish mark

Had a bit of bother with my coolant system, it heated up to the point it flashed up a red warning tell me to turn off my engine, so the first time it went in they replaced a dodgy sensor and also replaced the thermostat as well as both are sisuated at the back of the engine, only had my car back for a week when it needed topping up with coolant? Took it back so they could presure test it, but to my surprise they just topped it up, so told them I'd be calling everyday for them to top it up.
In the end I had to get roadside assist out, knowing they would be paying for a hire car from Europe car.
Only took them a day to fix, the first time it went in it took them over three days to fix but I had no courtesy the first time they fixed my car, goes to show that if it's costing them money then they'll pull the fingers out to fix it as quickly as possible.
Hope you sort out your problem without to much hassle and cost.
By the way mine was all done under warranty phew

 

[darreningram]

My 95 E 280 temperature went above 100 today for first time ever- traffic and air con on full- amazing how quick it settled when hit 40mph

 

[hotrodder]

Nissens rads are good quality and usually extremely good value for money... dunno how much GSF were asking but i'd expect their price should be easy to beat as they play the same silly mind games as eurocraparts these days. Look up your car on SKS car parts or one of the European sites like MisterAuto, bestpartstore etc and you'll get MB part numbers as well as part # for Nissens, Hella, Valeo and/or whatever brands of rad they have in stock. Origonal, good quality aftermarket or cheapnese tat they're all ally cores with plastic tanks.

Dunno what the score is from MB but AIUI Behr maybe ain't what they used to be? It's Behr-Hella now and i'd take a Nissens rad over a recore of the origional or a new genuine rad personally... the Nissens rad i threw in mine a few years back fitted perfectly, the core was bare ally not painted black* like the origional Behr so cosmetically not quite as nice. On the flip side the inlet/outlets are a better design IMO, thicker wall where the hose clips fit that tapers smoothly away whereas the origonal Behr was thin plastic with a copper reinforcing ring stuffed inside the hose stub. The later makes a great stress riser and it's not unknown for them to break there although that's probably as much to do with hamfistedness (levering hoses off/overtightening jubilee clips in an effort to get saggy old hoses to seal etc) as the plastic getting more brittle with age

I'd buy a new (genuine) rad cap unless it was replaced recently too. They're under a tenner and even if the seals on the old one look good the pressure stage can get weaker with age which is something that's easily missed/forgotten about when pressure testing cooling systems as the cap is typically replaced with an adaptor for the test

* Contrary to the popular myth painting rads black doesn't make them more efficient because they work mostly by convection and conduction with very little heat transfer taking place through radiation


Dunno why some MB techs would be against citric acid (MB will be an insanely expensive source for the stuff compared to home brewing suppliers or the bay etc) flushing personally... citric acid is great at eating scale/lime deposits and chelating metal oxides. It's one of the major active ingredient in loads of cleaners, rust removers & aluminium brighteners and pretty much harmless to most things. The exception would be a rotten cooling system where scale depsits and the like may be plugging/masking leaks but that should apply to any active flushing agent...
Can't remember what's in their oil residue removing flush but i've got a vague recollection it's something a fair bit nastier... trisodium phosphate used to be fairly popular i believe but not so much these days and IIRC it's a fairly strong alkaline which are typically way better at eating aluminium than weak oxidising acids
Off the top of my head i'd have thought vinegar should be a safe & cheap flush... the acetic acid in it works like citric acid with regards to rust & scale but it's maybe a better degreaser albeit not as good as a proper oil emulsifier. Soap/detergent is popular in some circles but you want something that doesn't create loads of suds

 

[WDB124066]

They say there was a anti corrosive fluid coating applied, acid will take it off.

I've had the same question from three Benz 124 trained Techs, so I checked in the manual, there is no acid flush for 6 cylinder petrol 124's, only water with a kit. If anybody can find an MB instruction to use acid on a 124 then I'm in - boots and all.

 

[hotrodder]

I'm guessing they're talking about silicates from the coolant and silica packet (some models only?) in the header tank? If it supposed to be something done during manufacture i'd bet it's long gone by now

If it is/was silicates they're constantly being replenished if the things serviced properly... AIUI they work kinda (very crudely) like sacrifical anodes i.e. react with/stick to ally surfaces so the HOAT with silicates coolant gives better protection than silicate free 'straight' OAT coolants. Especially in areas subject to cavitation like waterpumps. Because the silicates sacrifice themselves and/or fall out of suspension after a while the coolant needs changing more frequently than silicate free OAT stuff

I'm no chemist but i wouldn't have thought citric acid (or any other flushing agent) would stop silicates from doing their thing once the system has been rinsed out. I can see it maybe killing the silica packet in the header tank but i suspect that probably died of old age years ago if it was the origional?
That said if the car's been serviced properly there shouldn't be any need for flushing with anything other water and/or maybe an emulsifer if oil has gotten into the cooling system at some point

 

[WDB124066]

I think it is meant to be a long lasting coating rather than a short term thing....

 

[WDB124066]

I think it is meant to be a long lasting coating rather than a short term thing....

 

[WDB124066]

I don't have much information on it apart from what the techs are saying here. Certainly interested in knowing more...

 

[hotrodder]

I'm curious too but i doubt it's something easy to get proper details on. There are various industrial sealants & coatings that are applied to pipelines, castings and the like but they're all designed to withstand whatever chemicals are put through the pipe, valve, tank etc. Stuff that's usually a lot nastier than some citric acid or vinegar

My take is that if the cooling system is scaled up or there's corrosion that's proof that whatever coating may have been applied is long gone. Citric acid or vinegar will both eat limescale and corrosion without etching sound metal* or dissolving rubber seals/gaskets/hoses. 5% acetic acid is a bit more corrosive to some flavours of rubber (nitrile & SBR are rated 'fair' while epdm, neoprene and silicone rubbers are safe according to the internet) but i think vinegar is more dilute than that? Definately will be when mixed with water

* the metals they'll come into contact with in the cooling system at least. Vinegar is very good at eating magnesium so don't try cleaning rocker covers with it. As an aside it's also a good way for confirming that a casting which feels to light to be aluminium is magnesium as a drop of vinegar will react with mag instantly; fizzing away as the reaction produces hydrogen. The refractory oxide layer on aluminium (including AlMg alloys) protects it and weak oxidising acids improve corrosion resistance of metals like aluminium and stainless as long as there's some O2 about