Going to do the citric acid flush next week, quick question - Page 2 - PeachParts Mercedes-Benz Forum

vstech · #16 05-06-2011, 09:51 PM

Quote:

Originally Posted by mikethezipper

I don't know if anybody else tried this, but I found it much easier to flush the block not by removing the plug (mine was frozen and would not come out) but instead disconnecting the heater core hose and butting up my watering hose to it, and just run water through it till it came out clear from thermostat hose. This way you don't have to go under your car

this is a great way to flush your head, and the water pump, but it does nothing for the silt and sediment in the lower portions of the block.
to get the block drained, and cleaned, you HAVE to flush the block drain. it's really important on a gooked up motor!

MTUpower · #17 05-07-2011, 10:26 AM

Where's the pic of the location of the block plug?

frankengrant · #18 05-08-2011, 05:23 AM

...this really is an all day job.

Just finished most of the job, still have three flushes left but the engine has to cool down first.

I drained, via the radiator plug and engine block plug, and flushed with a garden hose through the top radiator hose, then filled with distilled water and drove around until it warmed up.

I then filled with 3+ gallons of DI mixed with 60oz of shout, drove for 10 minutes, drained via the radiator and engine block and flushed with a hose.

Filled with DI water, drove for 10 min with the heat on. Drained and flushed with a hose again....

Filled with 1lb citric acid mixed with warm DI water, drove for 10 min with the heat OFF and drained via the radiator plug and flushed with a hose in the upper radiator hose.

I then filled with DI water and drove for ten minutes, heat off still. I am letting it cool so I can access the engine block and flush everything out good so I can do 3 more DI water flushes before I fill. The 3 DI water flushes will be done with the heat on.

I didn't take the thermostat off btw, I didn't want to mess with that.

I bought 1 gallon of G-05, is that enough? How do I fill the system?

After the last drain, should I take the top hose off and fill there? Should the expansion tank cap be off while filling? Should I keep the top hose on and fill from the expansion tank?

sjh · #19 05-08-2011, 12:22 PM

Hello,

I filled through the expansion tank. My '90 300D has a 10 qt (or maybe 12, I don't recall) and I wanted 40%. Once I was done with all the flushing and I added one gallon of good anti-freeze, poured in my Purple Ice (purely optional, I got the idea from Jim's website about his SL) and then added distilled water.

Before I did all of this I removed the expansion tank and cleaned and tested.

I know I'm being anal (I can say that can't I??) but I've only had the car for 8 months, the last guy wasn't as bright as he thought he was (who is?) and I got 400K on my last 300D so this one with only 165K is just getting started.

Why'd you use Shout instead of some other detergent? Just curious.

frankengrant · #20 05-08-2011, 03:54 PM

I used shout because that was what diesel giant and a few posts here suggested, it was pretty cheap in the concentration I used it in too.

This job is a pain... haha just tedious

frankengrant · #21 05-10-2011, 03:04 AM

Finished tonight, added one gallon of G05, sjh, you ever have any corrosion problems with this low of an anti freeze concentration?

sjh · #22 05-10-2011, 04:52 AM

I've only had the car 8 months and the PO replaced the radiator recently.

As an educated guess I suspect that whatever additives the companies use that they are both buffered and over-designed.

I suspect that even at 10% AF the system would have an adequate amount of beneficial additives.

Recently there was a thread where someone mentioned testing for the acceptable presence of some AF additive by measuring the resistance to ground by sticking your meters probe into the water/AF mixture and having the other probe connected to the block.

He said it was in the FSM.

Please realize that I am giving you my best estimate and recollection and that I know something about some of the chemistry of these systems but not the specifics of AF design.

Anybody who claims to know more (besides some basic concept that I'm sure about) almost certainly does.

It is nice to be done and have good confidence that the car is in good shape.

Later.