it is blister cold today with 20-30mph winds, truck runs fine the coolant temp runs around 175-180, I know it needs a thermostat. the oil temp never goes more than 10* more than the ect.. then tonight before work let out I started the truck up and ran it about 10 min. When walking around it to get in to leave i saw yellow fluid coming out of the tail pipe. it started right up no issues. went to check the degas bottle but could not get the hood open, froze shut. since my teps are in range of where they should be, shoud I be looking more at the head gaskets ? Per the Insight the boost under WOT it goes to 24-25psi and on the stock gauge it has never went any higher after the reflash in Nov. '09 . I will taking it to the dealer in the morning if any-one is there they all went home early to due to the bad weather 6-8 more tonight on top of the 5 last night.

 

Sounds like your EGR cooler is toast. I'd check that coolant level before driving it. You could hydrolock your engine if a cylinder fills up with coolant.

 

Are you sure its diesel and not coolant my 6.0 does that when its real cold and It was idling Looks like a yellow stain in the snow My 7.3 does it also every once and awhile and I know its not coolant because its got red ELC in it.

 

what would cause this to happen ? I just thaught that it was coolant. the truck ran fine the 30mi. trip home, now you have me really thinking.

 

Ya know the old saying . . . If it ain't broke don't fix it. Don't go looking for problems that might not even be there.

 

just made it out to the truck and got the hood open. the degas bottle is bone dry. for sure an issue, so much for that. should i turn it over by habd or just try to start it. the real concern is the oil temp never exceeded the 15* differance of the ect. could it be that it was ust geting weak and due to the cold it cracked and causing he issue ?

 

The EGR cooler can bust a seam even when the oil cooler isn't restricted. If your coolant was not at the proper concentration then the cold weather may have been a factor, but even if it wasn't, a small nunber of EGR coolers just have defects. Luck of the draw.

If it was mine I would not drive it any more than absolutely necessary. Coolant is going into your cylinders, and like PowerstrokeWannabe said, you could hydrolock. Even if you don't hydrolock, coolant will be forced past the rings into the crankcase and contaminate your oil. If there's a shop within a few miles of your truck you might be ok to drive it there. But towing it is safer.

 

If your coolant level drops too far the EGR doesn't get enough
coolant and will overheat regardless of the condition of the oil cooler.

So, even if the Oil cooler isn't blocked, not having enough coolant
is really bad.

the fluid in the exhaust "could" be condensation, but if the degas
bottle doesn't stay @ the correct level - it would seem you
have a big problem.

The temp delta test can only be used accurately when the t-stat
is working properly and then ECT is 190. If it's -20 outside
it will also effect the accuracy since things are getting lots of cooling.

* replace the t-stat (since the coolant is low, do it now)
* fill degas bottle to correct level.
* monitor degas bottle for a day or two
* monitor ECT vs EOT

 

1st. thing you have to do before adding a t stat is finding out why the coolant drop. You either have a hose leaking or the EGR cooler is shot, and from what you described with the liquid coming out the exhaust pipe, I would guess EGR cooler.

 

got the truck to the dealer today, and got it in right away ,but they had limited staff. they were thinking EGR cooler right off. They said they will be checking it out to be sure.
jeremy

 

dealer called me tonight before i left work, said that "all tested fine" ???
i then asked why the degas bottle was dry???? long pause and then " we thought that you filled it up, it is full now" . then ask what would cause that to happen?? " dont know, but why dont you drive it for the weekend and see what happens" I may-be crazy but I have been in the ag industry for 10 years now,this just does not happen normally to a engine.
when i checked the degas bottle there was no movement of any kind and no coolant to be seen. Other than at work I park on a black-top drive and have never seen a drop of any fluid. just dont know what to think now, but may need to find a new dealer. any help would be greatly welcome.

jeremy

 

Did they pressure test the cooling system? If so and it wasn't losing pressure then maybe you are ok.

 

I have not see the w/o but the said that they did pressure test it and it held it under pressure to spec. even if it was fuel coming out, with the amount that was coming out I would think that it would have been having a miss or at lest running ruff. It looked like a dog was marking my truck to keep his nuts worm.

 

Something doesn't sound right. I get some minor fluctuation of coolant level, but very minor. I've never heard of the resevoir being empty and next time it's checked, viola, it's full. Strange.

 

When mine did that it was cold as hell here truck idled for about 10 minutes. I took it to the dealer for an end of warranty check up made a list of things I thought was wrong with it inculding the yellow stain from the exhaust. He told me that it was unburnt fuel vapour from the idling carried out the tailpipe with the exhaust.When you think about it if it was the EGR cooler then color comng out the tailpipe would be black or look like oil because it would have a chance to mix with the soot in the cooler and the exuast pipe. MY 2002 7.3 has done the same thing a few times and the coolant is red in that one. My 2006 has only done it once.Next time that happens I would taste the yellow snow and see if it is sweet (coolant) or taste like deisel fuel or Bitter (dog PEE).