slick willy

1 and 1 half qts. had 2 be replaced today. full service done 1 yr. ago. he is a retired mb dealership mech. very smart. known 4 years. he says ther is no leak. it might be a vacuum problem. any ideas ?

Plutoe

Whats the condition of your engine coolant!

oldsinner111

should be trans overfilling with coolant if rad. Is atf wicking up into computer box?

slick willy

i replaced the water pump,fan clutch,thermostat,upper and lower hoses,flushed with distilled water,added 1 gal. m.b. coolant 3 weeks ago. made a big difference. lower max temp. , colder a/c. what should i look for in my coolant ?

slick willy

where is the computer box ? is there a vacuum line i need to check ?

fabbrisd1

1, Plutoe is pointing out the W210 tranny fluid cooler can fail causing coolant and tranny fluid to mix - check coolant for "muddy" - gets worse contamination in tranny "sludging"

2. Tranny fluid level - needs to be correctly measured (1) MB level (2) with correct MB dipstick (or equivalent China correct dipstick) AND (3) measured at operating temperature - this is the ONLY way to have correct tranny fluid level.

3. FYI - not uncommon for "experienced" mechanics to complete job quicker - to refill cold at time the work is done and with "expereinced-guess" shortchange the fill cold - and frankly never admit that

4. Experienced W210 enthusiasts will replace the Tranny Adapter Plug ($14 OE MB/Mopar part only - China made non-OE not good) with every tranny service - since this part known to fail over time to cause internal tranny fluid seepage that "wicks up" inside the wiring harness from that plug to the TCM (Transmission Control Module) located inside the engine compartment.
If you are going to do the right thing - get the new plug - search for replacement instructions here - and after replacement pull the TCM board and see if fluid has gotten up there - which can be either 0-some-lot - use $9 can of MAF cleaner to hold/flood board both sides to clean and to clean board connector in that housing - air dry - no heat - reinsert board after air dry

oldsinner111

or drill holes in computer casket to let fluid drain.

Plutoe

You have been drinking to much Tennessee mash

oldsinner111

Naw common sense,if wires wick fluid just drill a few hole so box won't fill up.Simple,not everyone can lay under a vehicle,or afford a garage./

slick willy

i saved my coolant from the change 3 weeks ago. took some to my mech. he smelled it and said there is no tranny. fluid in the coolant. guess there is only one other place to look. need help. bobby.

ppatti

Following, as I have the same problem happening in my '95 W202 C220. 1 quart ATF has disappeared in the last 3 weeks and 300 miles, & there's not a single drop anywhere under the car. Trans fluid is pink not sludgy & does not smell burnt, coolant was recently changed and is clear MB blue.

Wondering if your (and my) vacuum modulator could be leaking (sucking fluid into the engine) & if so, how to test for that?

slick willy

ppatti. going to find out this week. just did a 300 mil. trip this weekend. the 320 ran like new. going to take it to my mech. will let you know if he finds anything.

ppatti

Thanks slick *****. Haven't been able to bring mine to the mechanic yet as its been raining and have been out of town - suspect it's the vacuum modulator though.

slick willy

where is the vacuum modulator ? i think the trans. control module is located pass. side, top, by firewall. right ?

ppatti

I think it's on the driver's side - clear vacuum line to the engine intake manifold, iirc. Still haven't brought the car in 'cause I'm out traveling for business this week - hope to next week 9/24/18.