is my SDL low on pollution ?
 

Dear all,

In the morning before driving, the radiator hose is hard,

pressure in the overflow coolant tank,

Testing for exhaust gas in the coolant tank,

car is very hot on top of the hill,

not loosing coolant,

oil one quart very 1500 mils,

rough idling for three minutes ,on cold start,

than drives like a running elephant ,

When testing with the diesel test for ten minutes in the coolant tank ,

it stays red!!!????( if detects exhaust gas, turn yellow),

I try and test at the muffler pipe, Takes long to turn a bit yellow,

Anybody with experience or explanation?

thanks in advance

I can hazard a guess.

Are those kits made for gas cars?

Maybe they’re looking for CO or some combustion product that you don’t find in diesel exhaust.

Just a guess.

Try holding the solution in front of a gas car’s pipe. Maybe that won’t work either post cat? I guess it would be best to call the manufacturer and see what they’re looking for.

the bottle says it is for diesel,
 

Did clean out the cat, it is empty, (did restrict my engine)

it changes color to half yellow, at the tail pipe,

My guess is that in the coolant, the amount is so small.

No idea what you're asking for. Low on pollution? For 1986, probably. For today? Doubtful.

What should be more of a concern to you is the pressure in the cooling system when the engine is cold. On an OM603, that's a BAD sign. If you're lucky, it's a blown head gasket. If you're unlucky, it could be a cracked head.

You are right, the cylinder head is my concern,
 

Trying to sniff the combustion gas in the coolant tank,

to verify leak in the cylinder head,

before I take the head off,

thanks for your kind replay,

A quart of oil in 1500 miles is probably a head gasket breach into #1. Cooling system pressure, gauge going straight to red, still running strong... well... for my #14 head it was terminal cracks.

Sixto
98 E320s sedan and wagon

Not loosing coolant, not heating up,
 

most of the loosing oil is from the turbo area,

should I spend the money?and time,

Or find a newer car,

So you didn't really answer the first question, does your tester specifically say that it works with Diesel engines on it? You need a kit that does.

The test kit is for Diesel engines
 

Lisle 75630 Special Indicator Fluid for the Lisle Combustion Leak Detector,

saw on youtube how it changes color from red to yellow in seconds,

I am looking for some strong indication, to open the cylinder head,

the pressure in the cooling system was for years,

I thought it is a good sign, that the hoses and the cooling system is good shape,

only lately I read that it could be an indication for hopeful a head gasket,

Gross polluter?

Pressure in the cooling system while running or shortly after isn’t a problem. Residual pressure overnight in a stone cold engine is a problem. My SDL had the latter.

Figure on $2500 to buy and install a good used head yourself. A new base cylinder head casting is about $2500. Dump the car instead of paying a shop to do it unless it’s in showroom condition.

But your cylinder head might be fine.

Sixto
98 E320s sedan and wagon

The only reliable way to test for combustion chamber to coolant leaks is to do a cylinder leak down test. This is where you remove a injector or glow plug, install an air hose, turn the engine to piston at top , both valves closed then apply about 100 PSI air. Keep the radiator cap off and look for coolant rising or bubbles.

The chemical test you are doing is for a quick test only, doing a leak down on every cylinder is the only definitive test.

will try the leak down test, thanks
 

will try the leak down test, thanks

Leak down test is not to check cooling system integrity if I understand correctly. It is to check the rings and cylinder wall. Also it is only 20psi. Am I missing something? No way you will see air bubbles at 100psi, even much more.

He is checking for a cracked head where combustion gases are finding a way to the coolant hence the hard coolant line ober night. 100 psi is used to make hearing or seeing the leak more pronounced.

??

Please read up leak down test. If you see bubbles at 100psi the head is a goner and I doubt the car can be driven as described by OP. What is the pressure when combustion happens?

Did the engine see a lot of heat? Because if it didn't the head isnt just going to magically crack. You probably just have a bad head gasket. I'm so confused on your post as well.. Why are you concerned about pollution? It was good in its time, but with all the green freaks and modern cars it's most certainly not up to standards. But if that's your concern, I wouldn't mind buying an SDL if it's clean otherwise. ;)

Sorry for my poor English attempt to express the situation,

I am probably better with my hands,

I am debating/hesitating before I take the head off, check to it my self,(gasket, visual ,straight edge,),

if I want to spend the money, and take it to Metric, in Canoga Park,Ca,

Car did not heat, in the last 150,000 miles I drove,

Once it drives, it loves the 70-80 miles, for hours,

only at night time it gets the hard radiator hose being hard,

Few days ago, it stop happening, NO hard radiator hose,

I change the coolant Tank cap, and the pressure came back, and made the hose HARD,

Could not see any wrong with the old cap,

but it leads me to believe, that the combustion gases are penetrating,

Time to take the Cyl. head off,

Thanks for your kind input,

It helps,

Long way for clarity,

Lisle 75730 is labeled for Diesels. 75630 isn’t.

https://www.amazon.com/gp/aw/d/B000I16L90

But you mentioned red fluid which is for Diesels vs blue for... it doesn’t say.

How did you get test fluid into the combustion chamber? There is no engine vacuum to draw it as the instructions suggest.

Sixto
98 E320s sedan and wagon

it says diesel on the bottle
 

it says diesel on the bottle,

One temporary trick is to leave the pressure cap only on the first latch, not fully closed, so cooling system cannot build pressure. Cooling capacity is reduced so watch the temp gauge but coolant can flow better because the pump isn’t fighting full pressure all the time.

Sixto
98 E320s sedan and wagon

it is Lisle 75730,

I think I will put the old cap back, till I fix the problem
 

I think I will put the old cap back, till I fix the problem

Thanks Sixto

Please listen to 40 + years of experience building engines. Any experienced engine guy knows what I'm talking about. A leak down test encompasses more than just piston rings.

We don't care about leak down percentages in this case, just if the air ends up in the cooling system.

100 PSI is typical and plenty in finding a combustion chamber to coolant leak that means anything. In fact, if you get a cylinder head pressure checked at a machine shop, they to use 100 ish PSI.

I generally fill the rad to the top then look for the level to rise. If the level goes up, there is a slight leak. Bubbles are a sign of a larger leak. I've worked on engines that used a qt of water every 4,000 miles, when doing a leak down, the level would slowly rise. A qt every 4,000 miles is very slight and the leak down test found it.

Any rise with a pressurized cylinder = combustion chamber to coolant leak. This could be from a failing head gasket / cracked head / cracked cylinder.

Thanks for the enlightenment. What i meant is seeing bubble is very serious. Is a qt every 4000 miles acceptable? I really don't think the OP has a serious issue and warrant a head removal, IMHO.

thanks a LOT for your response, and input,
 

I do tend to agree with Ah-Kay,

The car drives like lion, love 70-80 MPH, climbs hill,

Turbo 12 psi,

No loss of coolant.

Filled the coolant tank, till the top, NO bubbles, no change in coolant level,

While engine is idling,

The pressure in the cylinders is almost 2000 psi,

So why should push 100 psi, down the injectors, to see bubbles,


Still hard radiator hose in the morning,

Might go tomorrow to a shop with combustion sniffer,

Live and learn,


Thanks for your kind support,

If leak is so minor, maybe re-torque of the head,
 

If leak is so minor, maybe re-torque of the head,


Might reduce the leak,

Don't touch it. Just enjoy the car.

the saying here applies.. "if it ain't broke don't fix it"

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.

Thank you Vstech, you are right,
 

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.

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.

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.

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.

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,