Lou275

Hi everyone, I have recently (4 months ago) bought my first car - a 2004 CL600 biturbo (US model, now being driven in Europe). It has ~138,000 km and I want to preserve it as much as I can (that is extend its fully-working condition life).

Introduction

I have already made some fixes as follows:

1. Serviced immediately after purchase.
2. ABC system - valves replaced, checked oil and filters.
3. Fixes to the transmission valve body - when it became colder (<7 C) the car had some kind of pull back in the rev range between 1200-1600 RPM in first gear, after the car warmed up it was gone; after the fixes it drives much better and the issue is gone, even when temps are -8 C.
4. Trunk issues - the trunk could not close properly, I had to assist with my hands to make it close and lock; now I replaced the vacuum pump, the shocks, the right hinge and will be replacing the locking mechanism because it doesn't work well (locks after 3-4 tries).
5. Two times change of the transmission oil.
6. New brakes (Brembo) - rotors (in the front I took the 345mm as I am not quite sure if I can fit the 360mm, as in the European versions, without any modifications) and pads.
7. It had some unknown 19" rims with terrible tires so I wanted to get rid of them - I got the following:
   a) AMG III - Front: 8.5Jx18" 44ET with 245x45 tires / Rear: 9.0Jx18" 46ET with 265x40 tires [Summer]
   b) AMG I - Front: 8.5Jx18" 44ET with 245x45 tires / Rear: 9.5Jx18" 46ET with 275x40 tires [Summer]
   c) Mercedes-Benz Albireo: 8Jx18" 44ET with 245x45 tires / Rear: 8Jx18" 44ET with 245x45 tires [Winter]
8. (Appeal) Unfortunately, the previous owner fitted a CL55 AMG (kompressor) exhaust by cutting the rear bumper, so I had to get a new bumper and rework the tips of the exhaust by fitting them in a Y-type of pipe and tips from CL500. In any case I am missing the mufflers (items 260 and 270 here (make sure you click #2 on the top)).
9. I will be changing the 24 spark plugs on time to preserve the coil packs soon.

Apologies for the long introduction.

Questions

Now I am moving to cooling.
For a start, from what I read, it would be good to replace the coolant pump (item 10 here). I am thinking of getting one of the following:

1. Bosch 0 392 022 010
2. Pierburg CWA50
3. Pierburg CWA100 (RennTech)
4. EMP WP29
5. Kleemann

Which pump should I choose from the five in order to enhance the cooling capabilities of my currently stock system as much as possible, without having to worry that the water/coolant will move too fast through the system - that is, it may not have time to cool off? Do you guys maybe have any other suggestions in order to improve the cooling of this M275?

Do you have any advice on what else I can do to extend the life of the car (e.g. are there any specific brand of sports filters I should buy or replace the intercoolers)?

brucewane

You'll want to read through the sticky at the top of this forum, "Understanding Intercooling, Charge-Coolers, Heat Exchangers and Circulation Pumps". The basic points I got from that are 1) the M275 intercooler system will benefit from a larger heat exchanger along with a better pump; 2) the M275 intercooler cores are pretty well sufficient and 3) getting the M275 intercooler system properly filled with coolant and no air pockets and keeping it that way can be problematic.

Regarding point #3, the M275 intercooler system really must be vacuum filled using an HVAC vane pump to assure no air pockets. Additionally, keeping it that way is a problem because the system lacks an expansion tank; this causes the system to expel coolant when it heats/expands, and then draw in air when the coolant cools/contracts. So the system gets air pockets, which results in reduced intercooler system performance, higher intake air temperatures, and a reduction in boost/overall performance.

The later M279 intercooler system has an expansion tank which can be retrofitted to your car, or you can fabricate an expansion tank using aftermarket parts.

For the factory M279 approach, read this thread.

For the aftermarket approach, read this thread.

Lou275

Thank you and apologies for the delayed response, I am just working on many things on the car simultaneously. I began reading the sticky thread by Nick but have not yet finished and thanks - there is a lot of great information!

Based on what you have sent me and what I have been reading around the forum my cooling improvement project will consist of 3 main parts:

1. Expansion tank for the intercooler circuit - here I liked a lot the m279 approach as shown by Mooks and successfully implemented by others.
2. Larger radiator (heat exchanger) for the intercooler circuit - now I have not yet decided which one I will add there, I like pmercury's approachbut I am probably looking for something that will fit without too much modifications. I am looking at w220 S65 or c215 CL65 radiators, which as far as I know are substantially larger than mine (I think I read this in Nick's thread) and since the body is the same should fit fairly easily. Anyway, I am still researching and all suggestions are more than welcome.
3. Better pump: If the radiator is larger, then I assume I should get something better than the Bosch 010 or the Pierburg CWA50. I am thinking of the Pierburg CWA100, EMP WP29, or Kleemann (just not sure about the performance metrics of the Kleemann).

Also, I don't have much experience with bleeding the system so before I begin I will find someone who knows well how to do this or ask MB to do it, or in last instance just learn how Mooks or someone else here does it (probably this is the best option).

pmercury noted later in the thread, among other remarks, that a removal of the engine cover (it is essentially like mine but just by Brabus, it is not the AMG one) leads to significant improvements in temperatures (10% !), given the newly installed radiator and pump; and also removed the ABC radiator. I will think about the engine cover, but I don't think I will be removing the ABC radiator as there is no evidence on what is the long-term effect on the ABC system given that its absence.

brucewane

As far as the heat exchanger, you might want to consider leaving the factory unit in place and adding an additional HX that mounts under your bumper bar, like this one from Wiestec, or this one from VRP. Niether of those are specifically listed for the CL, but this bumper mount method is very common so there's lots of other companies out there making this style heat exchanger for all kinds of cars so you can probably find one that would work for you.

As far as the pumps, IMO the Pierburg CWA100 is likely the best option. I'm pretty sure the Kleeman is just a re-branded CWA100, it looks an awful lot the same. The EMP WP29 is probably more than up to the job, but keep in mind that it has a 1" inlet/outlet, so I don't know that it would acheive it's published performance in our application since our hoses and pipes are .75". From what I've seen the EMP is more expensive than the Pierburg, so I don't know that it's worth the extra expense or trouble of adapting to the inlet/outlet size. Both the Pierburg and the EMP are brushless motors, so both should live a lot longer than the original Bosch or the Bosch 010, especially if you're going to wire the pump to run full time.

Lou275

Hi everyone, I know it has been a while but I have been extremely busy. Anyway I have managed to do the upgrades I wanted:

1. Pierburg PWA 50 (chose 50 instead of 100 because I was afraid of coolant frothing) instead of the stock Bosch [thanks to Nick for the useful threads];
2. CL65 AMG C215 heat exchanger (took a while to come to Eastern Europe from the US) in the place of the stock CL600 one [thanks to Nick for the useful threads];
3. M279 intercooling system overflow reservoir [thanks to MooksM275 for the useful threads];
4. Wrapping of the intercoolers, pipes, and the voltage transformer in aluminum foils [thanks to BenzNinja/pmercury for the useful threads];

IMAGES

I have also done a few more fixes around the car:

1. Reed valve clean up, interestingly I found inside a plastic push rivet, still need to figure out from where it is;
2. Replaced the sparkplugs (NGK) and the sparkplug boots;
3. Replaced the left and right valve cover gaskets;
4. ABC system flush and change of the ABC filter and power steering filter (as prescribed used 10 liters to flush and 1 of each filters);
5. New engine radiator;
6. Rebuilt the steering rack;
7. Washer fluid reservoir replaced;
8. New air (K&N), cabin, fuel filters and replaced oil with Motul 300v 5w40;
9. Rebuilt the rear ABC valve block;
10. Replaced all 4 ABC accumulators;

I am overall happy with all the upgrades and maintenance done, except for the rear ABC valve rebuild, which didn't actually have to be done but I did it as a preventative maintenance. Now the rear right wheel sags when I leave it for a day on the default height. I will be driving it back to my mechanic to take a look at that valve block, I assume (hope) no threads were damaged in the process.

Lou275

If anyone wants part numbers for any of these just let me know.