'02 C32 AMG - Where to start diagnosis?

[WadeLovell]

50k miles. Earlier this week the car started to rumble periodically like I had run over a bad patch of pavement. I notice it more going up hills and particularly right around the shift point at about 37 m.p.h. At first it was very sporadic. But in under 100 miles the frequency has increased. I also notice the car is jerking a little at constant throttle (this is so subtle there must be a better word than jerking). This is evident at neighborhood speeds (25 - 40 m.p.h.). I know at this mileage I should probably be flushing the transmission, replacing the intercooler and thanking my lucky stars every day there isn't a new problem BUT WHERE WOULD EXPERIENCED owners suggest I start? Thanks in advance, Wade Lovell

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[320 dreamer]

for me i would flush all fluids and replace the tranny filter. no need to replace the i/c unlkess you know its craked and leaking. check throttle position sensor and possibly cam sensor to start

[hammertime21]

Possibly Transmission Glycol(coolant) contamination... You need to find out if you have a Behr or Valeo Radiator. Behr = Good. Valeo = BAD.

[Panzerknacker]

Sounds kind of like glycol contamination, pretty common in the '02s. I bought mine with 70k on the clock and the problem had been adressed by the first owner so I have never experienced it, but sounds kind of like the symptoms. Flushing tranny and replacing the radiator before it is seriously damaged is the remedy if thats the problem.

[WadeLovell]

Will determine in the morning if this one still has the Valeo radiator in it. It was definitely manufactured before Sept. '03 so it certainly came with the Valeo. If so, I will do the glycol test.

If I have glycol in the system can I install the separate transmission cooler I happen to have next to the lift and plug the RH side of the radiator where the factory ran the stock cooler?

If not, what is the best aftermarket radiator to install?

Open to all suggestions but after hours of research, I am afraid those who have commented already have hit the nail on the head.

Thanks everyone,
Wade

[ML500K]

if you could hook your car up to a star diagnostics that would be the best way to check things out. Does your shift point increase? e.g. from 2nd to 3rd gear, ur tranny doesn't shift until almost 3000 rpm even though u are just tapping the throttle.

[W203Ramos]

[quote=ML500K;3794912]if you could hook your car up to a star diagnostics that would be the best way to check things out.
+1

[MountainStone]

Your local dealer can perform the glycol contamination test quickly and inexpensively (<$100); start there before panicking. Try a throttle reset before setting off tomorrow; see if changing the throttle response/shift points alters the symptoms at all. Have you ever replaced the spark plugs? The car is seven years old and the manual recommends replacement at 100,000 miles or five years; your low-speed symptoms could be fouled plugs (I think).

Regarding the 'best' replacement radiator, the OEM Behr units are not expensive.

[Trekman]

sounds like Glycol... Ticking time bomb if you keep on driving the car, have your car checked hope that the it didnt damage the tranny

[WadeLovell]

Went out in the beautiful light of dawn this morning to determine whether or not my C32 AMG still has the origianl Valeo radiator. I have plenty of pictures of what I am looking for thanks to the great people on this Forum BUT one has to uncover a lot of the radiator to figure it out.

BTW, thanks for the warnings and admonitions but don't worry, she is not going anywhere until I get to the bottom of this even though it means I have to drive one of the two POS cars I bought for the kids!

Hanna makes the HI 3859 glycol test kit available from epschemicals.com, 25 tests for $75. It is a simple yes/no test and takes a week to ship. Therefore, I am sending a sample to Blackstone Labs by rapid carrier.

I will put her in the garage on ramps tonight and start the teardown as if I am going to replace the radiator because if it is a Valeo, I am going to replace it even if it has nothing to do with the current problem. There is a great DIY radiator replacement write-up on this Forum {Tks Splinter!}. After I replace the radiator or, if I am so lucky it was already done, I will do the transmission drain and flush as written up on this Forum.

Once I have eliminated the risk of destroying the transmission due to cross-contamination, I will return to the diagnosis of the current problem if it still exists at that point.

FYI Pelican Parts has the following:
Behr Radiator 203-500-05-03-M6 $185.25
Mercedes Transmission dipstick (Tool) 140-589-15-21-00-M22 $65.00
Mercedes Seal Ring (10mmx20mm) 140-271-00-60-M22 $1.50 each
Elring Klinger Transmission Filter Kit 22-2043-140-M30
ATF cap lock pin 140 991 00 55 $1.50
Because I am ordering the genuine Mercedes Filter and the Woco pan gasket as well as the kit (in case the kit does not fit for some reason), my total at Pelican Parts with free shipping is just under $300.

I will probably go to the dealer for:
(2) 028 997 62 48 ATF tube o-ring seal
(2) 003 997 17 89 coolant hose seal
(1) Replacement plastic clip (on the transmission fluid hose at the top of the radiator)
(1) Replacement plastic clip (on the side of the radiator)
(14) Quarts of ATF.

Add in my Home Depot run and I am looking at $500 to avoid a potentially huge problem. Would more experienced Forum members go a different route? Am I losing it?

Yours,
Wade

[320 dreamer]

tranny tool 30$ on ebay filter kit 25$ ebay if you go to the chrysler dealer the tranny fluid is about 3$ per qt cheaper

[Trekman]

I got all my parts from RMeuropean.com they even sell the tranny fluid, coolant, and even the seals. I just did mine last weekend and I spent about $350 on all the parts. they will even ship it to you nextday for free

[WadeLovell]

Updated Parts Costs thanks to the great membersh of this Forum:
Behr Radiator 203-500-05-03-M6 was $185.25, purchased on eBay for $150.00 all in.
Mercedes Transmission dipstick (Tool) 140-589-15-21-00-M22 was $65.00, $30.99 eBay
Mercedes Seal Ring (10x20mm) 140-271-00-60-M22 was $1.50 each, RMeuropean $.89
Elring Klinger Transmission Filter Kit 22-2043-140-M30, RMeuropean $16.80
ATF cap lock pin 140 991 00 55 was $1.50, RMeuropean $.89

I will probably go to the dealer for: LMAO
(2) 028 997 62 48 ATF tube o-ring seal, STILL probably a dealer part, can't find it
(2) 003 997 17 89 coolant hose seal, RMeuropean $4.96 each
(1) Replacement plastic clip (on the transmission fluid hose at the top of the radiator). Need #.
(1) Replacement plastic clip (on the side of the radiator). Need #.
(14) Quarts of ATF. RMeuropean has the real deal for $11.23 per quart vs. $17.50 at the dealer!

Of course, Castrol Import Multivehicle ATF is supposedly up to the Mercedes 236.x standard but do I really want to be the one to find out for $6 a quart? I have contacted their tech support to see what they say. - Wade

[WadeLovell]

Originally Posted by Trekman

I got all my parts from RMeuropean.com they even sell the tranny fluid, coolant, and even the seals. I just did mine last weekend and I spent about $350 on all the parts. they will even ship it to you nextday for free

How do I get that deal? Or do you mean they ship the order the next day and it is delivered based on the shipping speed one pays for?