I am concerned about some deposits in my coolant bottle. Situation: 2000 PSD, no modifications, no tunes, 165K miles. Owned for 3 years, bought with 125K on it. Repairs since: Turbo pedestal, HPOP, new water pump, and used go pedal assembly - thanks again Clay! Oil changes at 7500 per OAP - thanks Blackstone! SCAs (green coolant) checked fine at purchase, and at water pump change too. Usage changed last January, when I lost my job. It will sit for several days, sometimes 2 weeks, but never fails to start. When I do use the truck, I drive it at least 100 miles to ensure operating temps get up there for a while. The coolant in the bottle stayed exactly on line at the MAX COLD line for at least 2 years. I took it out yesterday and in checking the MAX COLD line, it was down about 1/2 inch. No leaks, no coolant smell in the engine bay or the exhaust either hot after running, or cold this morning. Other possible related issues: Unburned fuel smoke for about 15 seconds, but only in cold weather (about 30 degrees F here on the Southern coast), but no indication of a missing cylinder. Unburned fuel smoke fades, and is replaced by steam in about 60 seconds, but only when cold, and no coolant smell. I noticed for the first time some black deposits in the bottle, and took a sample by scraping my finger around the inside of the mouth. When I changed the water pump a year ago, the bottle was very clean, so this has only started in the last year or so. Perhaps a picture might help, don't know if it will or not: I cannot see or smell any fuel, bubbling, frothing or other contamination in the coolant bottle, either. Any thoughts on what this is are greatly appreciated. Money for repairs etc is non-existent at this time, so I am particularly grateful for sound advice.

 

looks like dirt

 

Well, that is precisely what I thought it looks like as well. I am hoping someone is able to relate this to a previous issue they had faced - and solved. Again, thanks in advance for any assistance.

 

How does the coolant smell? Does it smell like fuel? A cracked injector cup will allow fuel into the coolant, where it will float and stick to the sides of the bottle. I suppose it might allow some coolant into the fuel, too, when the truck is sitting, and that might explain your lower coolant level.

Mark

 

I dont know if what i know is true;

I saw something similar once and the garage claimed that it was from the wrong coolant eating away at stuff.

Either that, or maybe the rubber hoses are rotting a little.

 

Rotting hoses would make sense for the color. Does it have a rubbery feel to it? Have you ever replaced the radiator or heater hoses? Ever have the coolant flushed and replaced?

 

you wil be able to taste the difference betweem runner/diesel/and oil. just put a little on your tounge.

 

that would work, but licking anti-freeze is a bad idea.....

 

naw i do it all the time, its ok in small ammounts.

 

could be hose bits - or oil. When the oil cooler goes you can get oil in the coolant. Usually looks like brown sludge but I've seen nearly black goo as well. Pull the dipstick & see if your oil has a brown "foamy head" on it - coolant is getting into the oil and vice versa.
If it does turn out to be pcs of the hoses I'd be putting a coolant filter on pretty quick - I put one on when my oem wp went @ 65k.

 

A couple of things to check:
1. How or what does it smell like?
2. Does a magnet attract any parts of the residue?
3. Put a sample in plain tap water and stir up. If there is a "film" that forms on top of
the water, then that might indicate oil of some sorts, or some type of petroleum
product.

Good luck,

 

I can't tell if it is oil or not, but if it is, it is most likely a leaking oil cooler o-ring.
I had black scum in my degas bottle and found a bad oil cooler o-ring.

Did your last oil analysis show any signs of potassium and/or sodium? That is a
sign of coolant in the oil. When an oil cooler o-ring leaks coolant and oil will mix.