Aluminum radiator

[linjam]

Many say aluminum radiators cool better than brass/copper ones, due to providing more surface are, even though aluminum doesn’t conduct heat as well as copper. I’m considering trying an aluminum radiator to cool better.

Any thoughts out there?

 

[gsxr]

All W124 radiators are aluminum core, with plastic tanks. Make sure to use the proper MB coolant (G-05, or G-48) to prevent issues with the plastic getting brittle. The green stuff is no bueno.

With the cooling system all in top condition, a stock 500E shouldn't need additional cooling upgrades, for normal street use in USA.

 

[nocfn]

Define normal street use

 

[gerryvz]

As GSXR says, all .034/036 radiators are aluminum with plastic tanks on the ends.

You can go with a Behr or Nissens replacement. My original radiator failed about 5-6 years ago when I lived in Texas, so I replaced it with a Nissens that I just happened to have in my parts stock. It has worked well ever since and was a direct fit, with a minor tweak I needed to do to a bracket.

I detailed it here in this thread: https://www.500eboard.co/forums/index.php?threads/how-to-replacing-500e-e500-radiator.4212/

Radiator replacement is a DIY job. The radiator is specific to the V-8 W124 models.

 

[linjam]

Thanks, guys. Thought aluminum radiators became standard later than 1992. Apologies.

I don’t suppose an aluminum radiator like the one listed on rock auto would be any better?
https://www.rockauto.com/en/catalog...,5.0l+v8,1195051,cooling+system,radiator,2172
http://lilandglobal.com/product_catalog/1314aa/

I’d like to do whatever I can to reduce heat in my engine bay. I’ve just installed an acm fan clutch, and the car is fine when moving in 90 degree ambient temps but gets up to 105 when sitting in traffic. People on this site have said the acm “roars” a lot, but I don’t hear any roaring at all. It seems to pull quite strongly at idle, and my mechanic seems ok with that, but, again, I never hear it roaring like the misbehaving and inconsistent Mercedes one did.

Btw, Dave. My mechanic forgot I asked him to keep the old clutch for you. Sorry. But he did say the tang on it was cracked, so perhaps not of use to you anyway.

Maybe wrap exhaust in titanium or ceramic coating?

 

[speedy300dturbo]

The RockAuto aluminum radiator appears to be for a R129 500SL. You can also look into boron nitride spray for the radiator to help with heat transfer.

 

[gsxr]

I don’t suppose an aluminum radiator like the one listed on rock auto would be any better?
https://www.rockauto.com/en/catalog...,5.0l+v8,1195051,cooling+system,radiator,2172
http://lilandglobal.com/product_catalog/1314aa/ .

The Behr/Hella is OEM, but possibly now made in China (OE is made in South Africa, AFAIK). Nissens is the common aftermarket version. I've never seen the LIland all-aluminum unit but I don't know if it fits, their application chart shows it fitting both R129 and W124, which isn't correct... and the tabs shown at the top of the tanks would have to be cut off, at a minimum. All are likely the same core size and wouldn't offer improved cooling.

RENNtech used to sell a custom all-aluminum radiator for 400E/500E that was 50% thicker but this made it impossible to get the stock fan clutch out with the radiator in place. I don't know if the RT radiator is still available, but I doubt it.

I’d like to do whatever I can to reduce heat in my engine bay. I’ve just installed an acm fan clutch, and the car is fine when moving in 90 degree ambient temps but gets up to 105 when sitting in traffic. People on this site have said the acm “roars” a lot, but I don’t hear any roaring at all. It seems to pull quite strongly at idle, and my mechanic seems ok with that, but, again, I never hear it roaring like the misbehaving and inconsistent Mercedes one did.

If you are certain you know what the roar sounds like, and never hear it with the ACM, that is weird. No roar and 105C makes me wonder if the new clutch is working? Or if there's an airflow problem ahead of the clutch so it never gets enough hot air on the face to engage?

Btw, Dave. My mechanic forgot I asked him to keep the old clutch for you. Sorry. But he did say the tang on it was cracked, so perhaps not of use to you anyway.

D'OH!!!! Thanks for the update.

Maybe wrap exhaust in titanium or ceramic coating?

The exhaust already has thermal insulation from manifolds down to the catalysts. This isn't adding heat to the coolant though, exhaust wrap or coating would mostly be for appearance and not change anything functionally.

 

[linjam]

f you are certain you know what the roar sounds like, and never hear it with the ACM, that is weird. No roar and 105C makes me wonder if the new clutch is working? Or if there's an airflow problem ahead of the clutch so it never gets enough hot air on the face to engage?

When I’m driving consistently at 30 or 40 mph plus, the temp stays between 85C and 89C. It only rises like that when sitting in traffic. It was getting up to 110C, but after my mechanic bypassed the washer heater coil (which was malfunctioning and blocked — he says they are badly designed parts which go bad often and that he reduced temps in another customer’s car by 10-15 degrees Celsius by bypassing it) the temp seems to be better by 3-5C.

My mechanic has ordered another upper fan shroud. He says mine is missing a flap on the side which helps direct the air, but when I looked at it today, it looked like all three flaps were there. Admittedly, it was dark and difficult to see.

Yes. I remember distinctly the roar of fan with the old fan clutch but don’t hear it with this one. Unless there is some other reason the fan could spin as fast and make less noise?

The exhaust already has thermal insulation from manifolds down to the catalysts. This isn't adding heat to the coolant though, exhaust wrap or coating would mostly be for appearance and not change anything functionally.

It wouldn’t add heat to the coolant, but it would reduce the engine bay temps.

 

[linjam]

The RockAuto aluminum radiator appears to be for a R129 500SL. You can also look into boron nitride spray for the radiator to help with heat transfer.

Boron nitride spray, eh? Any specifics on what it does or how much it helps? I'll search it.

 

[gsxr]

When I’m driving consistently at 30 or 40 mph plus, the temp stays between 85C and 89C. It only rises like that when sitting in traffic. It was getting up to 110C, but after my mechanic bypassed the washer heater coil (which was malfunctioning and blocked — he says they are badly designed parts which go bad often and that he reduced temps in another customer’s car by 10-15 degrees Celsius by bypassing it) the temp seems to be better by 3-5C.

I have a very, very hard time believing his claim...

My mechanic has ordered another upper fan shroud. He says mine is missing a flap on the side which helps direct the air, but when I looked at it today, it looked like all three flaps were there. Admittedly, it was dark and difficult to see.

The purpose of the flaps is to seal the shroud when the fan is engaged, so it pulls all the air through the radiator fins, and prevent it from pulling hot air from the engine compartment in through the space where a flap is missing. The flaps are not sold separately by MB, but sometimes you can find someone selling them used. Check with a flashlight.

Yes. I remember distinctly the roar of fan with the old fan clutch but don’t hear it with this one. Unless there is some other reason the fan could spin as fast and make less noise?

If there's no roar, and you know what it sounds like, something is fishy. Next time the engine is 95C+ and you are stopped, put it in P or N, and rev the engine slowly to ~2000rpm or so, with the window open. It should be plenty loud, even with the hood closed. Do you know what brand clutch was installed, i.e. was it really ACM, or some other brand?

It wouldn’t add heat to the coolant, but it would reduce the engine bay temps.

I understand what you are thinking, but I honestly believe the heat reduction would be so small it wouldn't make any difference. And, the labor involved in pulling the exhaust manifolds to swap out for coated ones is $$$$. Not even sure it could be done without pulling the engine? Never tried. For the record, on an inline-6 Mercedes engine, I had the manifolds JetHot coated and wrapped the exhaust downpipe. Looked great but I don't think it reduced heat under the hood one bit, and certainly had zero effect on coolant temps. YMMV, etc.

 

[linjam]

If there's no roar, and you know what it sounds like, something is fishy. Next time the engine is 95C+ and you are stopped, put it in P or N, and rev the engine slowly to ~2000rpm or so, with the window open. It should be plenty loud, even with the hood closed. Do you know what brand clutch was installed, i.e. was it really ACM, or some other brand?

I bought it from FCP Euro for $150, and the invoice said ACM, but I did not look at the actual fan clutch to see what was stamped on it.

I understand what you are thinking, but I honestly believe the heat reduction would be so small it wouldn't make any difference. And, the labor involved in pulling the exhaust manifolds to swap out for coated ones is $$$$. Not even sure it could be done without pulling the engine? Never tried. For the record, on an inline-6 Mercedes engine, I had the manifolds JetHot coated and wrapped the exhaust downpipe. Looked great but I don't think it reduced heat under the hood one bit, and certainly had zero effect on coolant temps. YMMV, etc.

Well, I don't know. I hear conflicting things and don't know what to think.

 

[nocfn]

The roar is unmistakeable in my E500 and Dad’s E420.

 

[gsxr]

BTW, for summer / city use, you can remove the belly pan under the engine to get some additional airflow. Doesn't make a huge difference, but may move the needle a bit.

 

[linjam]

The roar is unmistakeable in my E500 and Dad’s E420.

You have ACM fan clutch?

 

[gerryvz]

BTW, for summer / city use, you can remove the belly pan under the engine to get some additional airflow. Doesn't make a huge difference, but may move the needle a bit.

Yeah, you can be like Hoovy !!