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Post Info TOPIC: W126 Monovalve Photos - Heater Problems HVAC Mercedes-Benz


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W126 Monovalve Photos - Heater Problems HVAC Mercedes-Benz


Recently I had a customer come in and win the award for the worst looking monovalve I have ever seen! LOL

Needless to say when your monovalve gets this nasty, your heater is not going to be so hot.

Feel free to show us your dirty monovalve photos!



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Hey SELLC,

I would think that there was / is no coolant present at all in this cooling system...If people are going to spend $50:00 or more on a good quality antifreeze, I would also suggest that an extra $10:00 spent on de-mineralized water will ensure many years of a problem-free cooling system...But when you see mono-valves in this condition, it leaves you wondering what will go wrong next and when...

Cheers,

Rastus

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Rastus wrote:

Hey SELLC,

I would think that there was / is no coolant present at all in this cooling system...If people are going to spend $50:00 or more on a good quality antifreeze, I would also suggest that an extra $10:00 spent on de-mineralized water will ensure many years of a problem-free cooling system...But when you see mono-valves in this condition, it leaves you wondering what will go wrong next and when...

Cheers,

Rastus


De-Mineralized water? Are you kidding me?

$50 on antifreeze? LOL!

I have to laugh every time I read this stuff... Regular water and regular GREEN antifreeze is fine with these cars providing it is serviced regularly.

Sure, you can buy/use Mercedes Antifreeze and feel good about it. You can also buy Mercedes oil too! But can you buy Mercedes-Benz Gasoline? Is the air going into the engine from Mercedes-Benz too?

The silliness you suggest is good hearted, but wreaks of the BW propaganda that see's people wasting money in vain.

But what do I know? 150,000+ miles behind the wheel of a Mercedes along with 10+ years of professional service. If you want to do your cooling system right, just service it regularly and all will be fine! If you want to use de-mineralized water and MB coolant that's your choice, but I have never seen ONE case where using regular coolant and water (timely serviced) has caused ONE SINGLE PROBLEM.

The rusty monovalve above is because it was removed from a cast iron block 300 SEL. The white particles on the other monovalve was pulled from an aluminum engine V8. They are screens and as such are designed to plug up in an effort to save the heater core. It's a wear item.

Now could you please explain to me how de-mineralized water or Mercedes-Benz coolant will prevent this problem? Or would you agree to say that in both cases, regardless what coolant was used, regular service intervals of the cooling system simply were not adhered to, which caused this build up.

Don't get me wrong... It's okay to baby your baby... It's okay to insist on nothing but the best, however don't think just because you did pay thru the nose for the de-mineralized water and MB coolant that you can leave it in there forever without service, because that would be false.

So at the end of the day it comes down to just ONE important tip... Service your coolant system regularly and folks who are spending less in fluids can service it twice as often for less than half the cost, which is by far better than trying to go twice as long on more expensive fluids. This holds true also for guys insisting on Synthetic oil and driving with it for 6000+ miles. Not a good idea, and counterproductive. With the exception of some areas that might have really crapppy watter, most of the industrialized world has water good engough for vehicles right out of the garden hose, but no one makes mention of that little fact.



-- Edited by SELLC on Monday 21st of January 2013 05:26:15 PM

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Yo SELLC,

Point taken, and probably 99% of all the people out there will no doubt use either water straight out of the tap or top-up their reservoir with whatever "antifreeze" they may or may not have lying around (LOL) ! Sometimes though, after you've just spent a large wad-of-cash to have repairs etc done, you don't mind having to cough-up a little extra for that piece of mind that everything is as "pure" as possible...Why ???

* Mixing antifreezes does turn your coolant acidic, causing in time, premature failure of everything.
* Water from your tap will have all kinds of toxins in it ranging from flouride, chlorine, metals and minerals etc etc.
* Stray-current from poor earth terminals etc on your engine block react with the metals and minerals in your tap water that promotes and speeds up the wear-rates of your cooling systems components.
* Typically your thermostat housing is designed to be a sacrificial-anode in an effort to prevent corrosion elsewhere. ( It is thought that by allowing this component to corrode, corrosion elsewhre is less-likely ).
* Coolant test strips ( and test kits ) have indicated that even after 8 years use with the correct proportions of coolant and demineralized water, the cooling water was still servicable and non-acidic with a Ph-level of 7.5, slightly alkaline. This means nothing has broken or corroded away, and that I've got nothing to maintain !

Luckily for us Benz owners that the quality of parts etc is well above the norm...I'll still be adding demineralised water to my cooling systems, just so I don't have to replace anything !

Cheers,

Rastus


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Yo SELLC,

I hope the last post didn't read too harsh, as it wasn't meant to...Things on your car can break at any-time as you only know too well ! Having worked for a while at an automotive air-conditioning / radiator repair shop, a lot of our work came to us from many different insurance companies, and you no-doubt know how tight those ###holes are. Anyhow, in an effort to save their money ( read ours ), they did a number of tests at one time to determine what was the best coolant / antifreeze etc to use as an aftermarket choice, as they were not going to fork-out for the cost of genuine replacement coolants for their clients ( read us )...As it turns out, most aftermarket coolants are nothing more than cordial, and radiators etc were needing to be replaced sometimes within a matter of months since the new component was installed, hence why they went to the trouble of testing these various coolants.
Anyhow, a quality antifreeze such as "Castrol" or whatever will do just fine, as long as it's known to be dependable or have a good reputation. Guys like yourself SELLC know what's good and what's garbage, and no-doubt you put quality coolant in your customers cars. I once worked for a guy who bought a batch of chemicals that apparently neutralized 2nd-hand antifreeze and was putting it in his customers cars at around $10 per litre...He had a couple of 44-gallon drums full of "brewing" 2nd-hand antifreeze !!!

All I'm getting at is that if you've just spent over $1,000:00 for a water-pump, hoses, and labour, what's another $50:00 to make sure that the coolant and waters the best ?

Cheers,

Rastus

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Rastus wrote:

Yo SELLC,

I hope the last post didn't read too harsh, as it wasn't meant to...


 Too harsh? LOL, that was pretty funny.

No, I do agree that in some areas the water quality could be poor and it is a known fact that minerals and such will deposit in this case, however using de-mineralized water is not usually the "norm" although like I have said in some areas including well-water it could serve as a valid argument. In my area we seem to have pretty good water and I have never had a problem, but then again I don't usually take my coolant past 30-40K.

It is VERY true that you should not mix certian coolants and I guess to someone not in the know could make that mistake. If you are topping off an existing cooling system I would highly recommend using the same coolant that is currently in the engine. The big "scare" back in the 90's with GM's "Dex-Cool" turning to jelly when mixed with conventional anti-freeze is what really hit home to many but since then it seems that formula has been retired, although they do still sell DexCool most off the shelf antifreeze is made to be mixed with any coolant and the bottle will even state so, usually this coolant is of a yellow color.

The newer BMW's use a blue coolant, which almost looks like washer fluid and I have seen this blue coolant sell from a company called "BeCool" (an aftermarket performance radiator company) for almost $60 a gallon!

For someone doing their own coolant flushes as it pertains to the M116 and M117 420/560 engine I have used regular water and green antifreeze for over 100,000 miles with no problems, but again I do change it every other year and I am not mixing the green stuff with existing fluids. If you do make the switch, best to make sure all the old coolant is out anyway. I am in no way saying that one should avoid the OE coolant, or demineralized water, just that I have been happy with the less expensive green coolant and regular water.

An example of mineral build up can be seen in an old inlet pipe of a hot water heater (redundant I know, they should really just be called water heaters). Looking inside the feed pipe of an older household appliance such as a water heater will give you a very good idea of what mineral deposits look like and will do over time. For that reason people choosing to spend more on de-mineralized water can feel good about their investment. 

There are however some areas I don't play around, like for instance Fuel, I only buy Premium. Another area I don't play around is with oil, I use Castrol GTX @ 3000 mile intervals. Some folks like synthetic and that's even better but them same people will also try and squeek more miles out of it and on an older engine that is just not wise.   

I think as a car ages you will find many of them to have green coolant, but if you are flushing the coolant on newer vehicle it may be best to stick with the manufacture's suggested anti-freeze in an effort to maintain any warranty coverage. Once out of warranty you could however do as you please, providing you do the work yourself.

If I have a customers vehicle that needs a flush I will only use the suggested brand, but that's because it's not my car and I won't proclaim to know more than the manufacture when it comes to someone else's baby. But on my almost 25 year old Mercedes I have and will continue to use Green antifreeze at regular scheduled intervals of 30-40K. I might add my Mercedes is driven every day in both summer and winter and she has been DAMN GOOD to me.



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I was online looking for monovalves the other day and noticed this thread was at the top of the list! LOL

Just figured I'd add this photo to show where the rubber rips that causes these units to go bad.

I am having to pick up a few extra mono valves for my Mercedes' but if you start to notice your heat falling off at RPM's above idle, it's probably this.

I also wanted to mention that if you just need to replace the monovalve as shown above, you don't have to pull all the piping off like is shown at the start of this thread. I had a few off parts cars at the time they were taken and I wanted to give a better view of the system at hand. If you're just replacing the monovalve you can do this without removal of that entire hose assembly. Just undo the two Philips screws on the foam firewall to move over the diagnostic port and you have full access to the 4 flat head screws that need to be removed to gain access to the monovalve insert. Be sure to mark the exact orientation of the shims as they must go back on in the same way or you could have problems. This is usually pretty easy as there are just a few and they don't usually fall off. The entire job could take someone an hour their first time, but from there on out maybe a 20-30 minute job. Here is a photo of me changing mine on the fly during a cold winter day... It's just that easy folks!



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SELLC wrote:

I was online looking for monovalves the other day and noticed this thread was at the top of the list! LOL

Just figured I'd add this photo to show where the rubber rips that causes these units to go bad.

 


 LAST TIME WE HEARD OF A TORN RUBBER........ 9 MONTHS LATER REX WAS BORN!!!!!!!!!!!!!!!!!!!!! AHHAHAHAHAHAHHAHAHAHAHAHAHAHHAHAHAHAHAHAHAHAHAHAH!!!!!!!!!!!!!!!!!



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I apologize for the use of terminology Stoma...

For guys like you and Chealse Manning, I suppose a ripped "diaphragm" would be more suited to your sexual orientation.

Carry on!



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