I was driving at 65 and got passed by a new duramax ambulance doing like 80. It was puking white smoke that smelled like solid fuel. What is wrong with it? When the CR injectors fail, do they stick wide open or something? He musta been doing that for 30 miles.

Things are looking really green in that picture was that taken today? You guys must be a month ahead of us by the looks of things. Even though the weather has just started to break here it still looks like its in the dead of winter :mad:Sorry for the hijack

Yeah today. We've had some freak weather, lots of rain and now its 75F. Gonna head back to 30 in a few days but people already started mowing their lawns.

It was probably taken pretty close to this.

Yeah today. We've had some freak weather, lots of rain and now its 75F. Gonna head back to 30 in a few days but people already started mowing their lawns.

It was probably taken pretty close to this.

I had to mow my grass in NC this past weekend. I am in Terre Haute In right now, what do you know about over cooling problems?

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Cant help with the D'max though.

Too much flow = too much cooling. Thermostat opening too much possibly. I took my thermostat out and it wouldn't get over 120. Same as wind chill..higher wind speed sucks the heat out of your face faster.

Most likely a stuck open injector(s). I've seen the same thing on thee local school bus too doing the same thing.

Too much flow = too much cooling. Thermostat opening too much possibly. I took my thermostat out and it wouldn't get over 120. Same as wind chill..higher wind speed sucks the heat out of your face faster.

I am on tstat #6 and it keeps getting colder and colder even in 60 to 70 degree weather, with winter fronts installed.

Did you ever confirm the temp gauge was working accurately? Have you checked out the water pump? To be getting colder with each new thermostat is a little beyond me. Colder is more resistance though and a connection that is getting crappier and crappier would compound the problem, which sounds like what you are seeing.

I cant rule out an electronics issue, but there is no part of the cooling system I cannot grab and hold on to after I am up temp(gauge reading 165* maybe). I can grab the top radiator hose right at the tstat housing and hold onto it. I don't ever remember being able to do that before or on any other vehicle I have owned. The other day, right after shutdown, I noticed how cool everything felt and decided to open the radiator cap. It sprayed my hand with luke warm antifreeze. I know these trucks have very good cooling systems, but I would have expected the anti freeze to at least cause some discomfort to my hand if it was up to temp going into the other side of the radiator. A temp gauge is on the to do list, I just cant seem to get that far down the list just yet.

I wonder if something you are doing on installation of the tstat is shoving it open. Without a tstat the flow is so high I can never get over 120, as I said, but even with a tstat wide open it still has enough of a restriction to keep it from ever flowing that much. But the thermostats on these trucks don't just open, they open and close, constantly. With a trailer on a hill it might stay open but otherwise they should cycle. If yours doesn't cycle then it would just be cooling it the entire time, keeping the temperature lower. That's why I wonder if you are somehow installing it wrong or who knows what. Just seems to me that if it wasn't cycling it would give the exact symptoms you experience

It is cycling. The temp is constantly moving up and down. From 140 to a max of 170. Seems to like near 160* most of the time. I am assuming that it is opening when I see the temp drop to the low 140's and it is closed completely when it rises to 165 and occasionally 170. I went and bought another temp gauge today and while looking under the hood I leaned against the top radiator hose and it almost burnt me. It was to hot to hold for more than 2 or 3 seconds. I have not felt it that hot I while. Got in and turned the switch on and the gauge read about 168*, must of shut it down with the tstat closed. It cooled back down to 160 when I drove off. I'll hook up the temp gauge to night and see what it says.

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sorry about hijacking your thread on the hazing D'max. this temp thing is driving me crazy.

This is a wild swing at the fence but have you ever replaced your water pump? If you have is there an outside possibility it might be for a 6.7? I read somewhere a while back thathey're interchangeable and they have a substantially higher flow rate than the 5.9 Its almost impossible but not entirely that somebody at the parts counter grabbed the wrong pump? Thats gettin pretty desperate though!

Well theres a thought! Nice thinking diesel4life. No prob dripley, I think Mike answered it, I just didn't if they ever stuck open like that or not. I'm sure the engine was toast by the time they got it back

I did replace the pump about a year and a half ago. They appeared identical as far as the number of blades on the impeller and side by side nothing was noticeable that was different. The only catch is the problem started over 4.5 years ago. About 6 months ago it started getting worse to where I am now. I installed the mechanical gauge this afternoon. But much to my disappointment after installing the sender into the head, I let capillary tube and its pretty spring like covering cross the positive battery terminal:doh:. After that the gauge would not go below 160. I drove it home and it did go to 205* and right now is slowly cooling down. Glad I bought the cheapo Sunpro from Advance. Might go buy another tomorrow and see if my ignorant self can install it without frying it. What's another 20 bucks. I am reading the voltage on the signal wire coming from the sender and the gauge is reading 140 and the voltage is reading 1.55. earlier at 160 I was reading 1.2 volts. Mike posted an ohm reading but I must be doing some thing wrong. I cant read anything when I set the dvm to ohms. Did I mention electronics is my very weak spot. I aint afraid to take anything off this truck and replace it but electronics and I are sometimes in different worlds.

Well theres a thought! Nice thinking diesel4life. No prob dripley, I think Mike answered it, I just didn't if they ever stuck open like that or not. I'm sure the engine was toast by the time they got it back

Common Rails do some weird things including blowing the entire tip off the injectors.

I was driving at 65 and got passed by a new duramax ambulance doing like 80. It was puking white smoke that smelled like solid fuel. What is wrong with it? When the CR injectors fail, do they stick wide open or something? He musta been doing that for 30 miles.

I saw a Ford with 6.4L doing the same thing a while ago. He had a small trailer and was driving about 55 and leaving a trail of blueish/whitish smoke. I thought I read somewhere that a failing DPF could cause this. I maybe wrong though. I do know one thing, it sure did smell bad.

I forgot about that, I see the same thing all the time, maybe even the same truck and trailer