waaaahh, you are protecting my car from ME...

Good idea,

Thanks a lot,

The difference with a leak down test is, motion.

If the engine is running, the water pump is altering the flow, obscuring any air leakage, unless the gasket is totally blown.

A leak down test is with a stable slow air test, and minute fluid changes.

__________________
John HAUL AWAY, OR CRUSHED CARS!!! HELP ME keep the cars out of the crusher! A/C Thread
"as I ride with my a/c on... I have fond memories of sweaty oily saturdays and spewing R12 into the air. THANKS for all you do!

My drivers:
1987 190D 2.5Turbo
1987 560SL convertible
1987 190D 2.5-5SPEED!!!

1987 300TD
2005 Dodge Sprinter 2500 158"WB
1994GMC 2500 6.5Turbo truck... I had to put the ladder somewhere!

Will go and buy from HF the leak down tester,

And do the test,


Will report back,

Thanks again,

I have to kind of agree here. If the only symptom is that the radiator hoses are hard in the morning, I'd leave it alone until the symptoms progress to lost coolant, intermittent high running temp, or power problems. Run the head as long as you can, if it's already cracked you aren't gonna be able to fix it anyway.

__________________
Current stable:
1995 E320 157K (Nancy)
1983 500SL 125K (SLoL)

Gone but not forgotten:
1986 300SDL (RIP)
1991 350SD
1991 560SEL
1990 560SEL
1986 500SEL Euro (Rusted to nothing at 47K!)

Gone and wanting to forget:
1985 524TD 167K (TotalDumpster™) [Definitely NOT a Benz]

Why would you even consider removing the head when you have no problem? All you have is a concern, and perhaps misplaced. When it starts boiling over and you see a thick brown mousse floating in the coolant, then you have a problem. Until then, just keep driving and be happy your engine runs strong. If it stays under 120 C on the dash gage, you shouldn't be concerned about engine damage.

Re your title, "low on pollution?", you live in CA so can buy Propel's Diesel HPR which is made from bio sources. Thus, it is adds no net CO2 to the atmosphere. That makes you better than all-electric cars from the "climate change" perspective, which is the current main environmental concern. NOx is no longer much of a problem, even in the LA Basin where one can now see the snow-covered mountains from the beach, at least on clear winter days.

__________________
1984 & 1985 CA 300D's
1964 & 65 Mopar's - Valiant, Dart, Newport
1996 & 2002 Chrysler minivans

Thanks Bill Grissom,for you input,

I do drive with an eye on the temp. gage, and have a switch to turn the elect. fun on,

Before climbing hills, or hot days,

will try the leak down on each cylinder,

Thanks for the restraining words, to avoid un necessary work on the car,

I do not have Propel's Diesel HPR in my area, ( Ventura county)

thanks again,

In my case (1987 300TD with OM603 engine), I sent a sample of used engine oil for lab analysis, and they reported the presence of coolant in the engine oil. I immediately decided to replace the head. In retrospect, I could have driven the car for probably several more years before replacing the head. I was not loosing or using any coolant, and did not have a hard upper radiator hose in the a.m.

Note that after I got a good head installed (second try, what a pain) I had a pressurized upper radiator hose in the mornings. I was sad.

I kept driving the car. I drove it hard. I pulled a trailer from Charleston SC up to NC, in the mountains, bought a load of oak flooring, and hauled that back. In July. Mountains, and then long highway run. Engine temp climbed above 100 deg C and stayed between 100 and 115 for most of that ten hour day.

After that, no more hard radiator hose in the morning. I think the new head gasket was not sealing, but the long hard HOT "break-in" properly seated and sealed up the head gasket. That was about 40 or 50k miles ago, still going strong.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

Thanks Maxbumpo, for sharing your experience,

I learn something from your posts,

I thought that this OM603 is NOT for pulling trailer,(1987 SDL)

I do take out my rear seat, and use the car as semi pickup, (sorry),

In the U.S. of A., Mercedes decided that a luxury brand car should not pull a trailer.

In Europe, one could get a trailer hitch (or tow bar) installed at the dealer, in almost every model, especially the wagons and sedans. I bought my wagon's trailer hitch in Italy and brought it back in my luggage. Customs officer thought that was pretty funny! Rated for 1500 kilograms for a trailer with brakes, 750 KG for trailer without brakes.

__________________
Respectfully,
/s/
M. Dillon
'87 124.193 (300TD) "White Whale", ~392k miles, 3.5l IP fitted
'95 124.131 (E300) "Sapphire", 380k miles
'73 Balboa 20 "Sanctification"
Charleston SC

very interesting,

The 2,000 PSI is only for a very short period of time, the 100 PSI for a long period of time and will uncover any real leaks.

If there is a fixed size hole, 2 x pressure does not equal 2 x the flow. Think of a storm / screen door pneumatic closer. The door closes at a certain rate by it's self, push with 2x the force of the spring and it won't move 2X the speed, it will move at a somewhat slower rate than 2x speed.

There is a term for this that I can't recall right now, it is a fluid dynamics issue. Basically, a fluid or air can only move at a certain maximum speed before becoming so turbulent the fluid it's self causes a restriction.

On the engine that was using a quart every 4,000 miles, the head gasket looked perfect. There was only a very slight discolored area where coolant was making it's way into the combustion chamber. If I hadn't done a leak down test looking at the radiator level, finding where the coolant was being lost would have been impossible.

Doing a leak down narrowed things to a specific cylinder. Actually 2 cylinders, one on each side of a GM 4.3 V6. Rather than have the car down for a longer period of time, I sourced replacement heads, built them up then swapped. The head faces on both heads had a slightly low spot in the same place causing loss of coolant.

Thanks for your time, and sharing your experience,

I am getting the point,