I am potentially dealing with a head gasket and cracked piston issue on my LML Duramax in the middle of a cross-country trip with my fifth wheel trailer.
We are now at our longest stop of our trip in Halifax. The first full day here I spent the day on the phone trying to find someone to look at the truck.
His assessment is the worst news of any I have had via email or over the phone, and he's pointed out a few things that leads him to believe what he does about what's wrong with the truck:
- Coolant surge tank, he released the pressure, and then tightened it. The return line had bubbling in the tank, which he says indicates an exhaust leak in. I did not have the seemingly common hard upper rad hose after sitting overnight, common when the failure of the head gasket lets pressure into the cooling system.
- At idle, he removed the oil fill cap, and plenty of blowby came out, with a very clear and steady smoke stream, though not what I would call heavy.
I took my oldest son with me to the shop. Neither of us got a bad feeling. In one of the outer suburbs, and the guys seemed friendly, joked lots, and shared quite willingly a lot of the different things they've seen on the three brands of diesel 3/4 and 1 tons, and all seem to jive with what I know about the different trucks.
That said, a $15k repair bill has me wanting to be extremely cautious.
Here's more of a back story on the truck, and on the events that lead me to finding out just how bad of a problem I now have.
I'm the second owner, and I bought the 2013 truck in 2017. It had 160,000 km. I changed all fluids, except the coolant which had at that time, recently been done. I understood at the time that the DEF system was deleted. The truck has done two long haul road trips prior to this one with our over 10,000 pound dry fifth wheel, and many other shorer trips with it, not to mention the driving done hauling all sorts of things around, and just general driving around without a load when unhitched on a trip, or as a last resort second vehicle in town. In the entire time since I bought it, to before leaving on the trip, the coolant level dropped once around 2018 just enough to trigger the low coolant warning, and I topped it up, without any coolant issue since. My wife insists before the trip she told me there was a leak, but I also see the AC condenser drain is by the right wheel well, and I also had to change a glow plug and the fuel filter and both batteries before this trip. Not any sign that coolant was leaking then.
We started our trek from Edmonton hauling our fifth wheel (a small to mid size one in Alberta, though seemingly a rare behemoth once we hit Ontario). There were no issues, until just a while ago. As we were making our way from Quebec to New Brunswick, the coolant light came on after I had to stop to let one of my kids use the bathroom and I had the truck idling while everyone else also decided they needed to go. As I barely put it into drive and before taking my foot off the brake, the low coolant light came on. I could only get bottled water from that gas station, so topped it off and went to our next stop. The level was low again when we reached the stop and I checked after it cooled down, but attributed it to not being able to properly fill a warm cooling system. From this point on, I had the light come on several times (and other times had to top off without the light on), and I began to suspect issues. But no signs of oil in the coolant, or coolant in the oil, so it was a head scratcher to me, until I noticed while we are on Prince Edward Island on a day trip, that coolant was indeed coming out the right wheel well, and was also in many spots near the surge tank.
I began to seriously look further, and learned that a head gasket failure may not be evident from what I was used to as the symptoms, and that pressure could leak. I had figured out by this point the coolant was coming out of the overflow, which was supposed to be a symptom along with a firm upper rad hose after sitting overnight. And yet, the rad hose wasn't hard. So more head scratching, and other possibilities:
- EGR valve might be bad
- thermostats might be bad
- even the surge tank may not be separating the two sides properly, or that the cap isn't sealing
So, over a weekend, in a remote island with sparse population and virtually nothing open on Sunday, we needed to make it on to our current stop in Halifax, where I figured we would have some luck in getting it fixed.
I hooked up my OBD reader for the drive to monitor the real temperatures, which remained usually between 80C and 90C, and briefly hit a peak of 100C on a very long climb at freeway speeds over 100 km/h, which then dropped quickly on the descent to the 80 to 90 range again.
I then learned this is what would be expected on the engine, so that ruled out anything with the thermostat. I also found the diesel shops around here were all booked up, though I managed to find one guy who had an opening, though he had someone else he thought might come in later in the week.
Over the phone, before seeing me, he said his experience is that 95% of the Duramaxes he sees for head gaskets also have hairline piston cracks.
And so that's where I am now. I've been checking in with a mechanic friend back home who also has Duramaxes, and while he was initially skeptical, he looked into the LML and learned of the unusual lip on the LML pistons to trap in heat, which was revised by Mahle (the OEM supplier) in an aftermarket replacement version. So his skepticism faded somewhat once he found that.
Would love to hear from others what the take is on this. I gave him the go ahead to order parts this evening (which he will do tomorrow), and I bring the truck in Wednesday.
We are now at our longest stop of our trip in Halifax. The first full day here I spent the day on the phone trying to find someone to look at the truck.
His assessment is the worst news of any I have had via email or over the phone, and he's pointed out a few things that leads him to believe what he does about what's wrong with the truck:
- Coolant surge tank, he released the pressure, and then tightened it. The return line had bubbling in the tank, which he says indicates an exhaust leak in. I did not have the seemingly common hard upper rad hose after sitting overnight, common when the failure of the head gasket lets pressure into the cooling system.
- At idle, he removed the oil fill cap, and plenty of blowby came out, with a very clear and steady smoke stream, though not what I would call heavy.
I took my oldest son with me to the shop. Neither of us got a bad feeling. In one of the outer suburbs, and the guys seemed friendly, joked lots, and shared quite willingly a lot of the different things they've seen on the three brands of diesel 3/4 and 1 tons, and all seem to jive with what I know about the different trucks.
That said, a $15k repair bill has me wanting to be extremely cautious.
Here's more of a back story on the truck, and on the events that lead me to finding out just how bad of a problem I now have.
I'm the second owner, and I bought the 2013 truck in 2017. It had 160,000 km. I changed all fluids, except the coolant which had at that time, recently been done. I understood at the time that the DEF system was deleted. The truck has done two long haul road trips prior to this one with our over 10,000 pound dry fifth wheel, and many other shorer trips with it, not to mention the driving done hauling all sorts of things around, and just general driving around without a load when unhitched on a trip, or as a last resort second vehicle in town. In the entire time since I bought it, to before leaving on the trip, the coolant level dropped once around 2018 just enough to trigger the low coolant warning, and I topped it up, without any coolant issue since. My wife insists before the trip she told me there was a leak, but I also see the AC condenser drain is by the right wheel well, and I also had to change a glow plug and the fuel filter and both batteries before this trip. Not any sign that coolant was leaking then.
We started our trek from Edmonton hauling our fifth wheel (a small to mid size one in Alberta, though seemingly a rare behemoth once we hit Ontario). There were no issues, until just a while ago. As we were making our way from Quebec to New Brunswick, the coolant light came on after I had to stop to let one of my kids use the bathroom and I had the truck idling while everyone else also decided they needed to go. As I barely put it into drive and before taking my foot off the brake, the low coolant light came on. I could only get bottled water from that gas station, so topped it off and went to our next stop. The level was low again when we reached the stop and I checked after it cooled down, but attributed it to not being able to properly fill a warm cooling system. From this point on, I had the light come on several times (and other times had to top off without the light on), and I began to suspect issues. But no signs of oil in the coolant, or coolant in the oil, so it was a head scratcher to me, until I noticed while we are on Prince Edward Island on a day trip, that coolant was indeed coming out the right wheel well, and was also in many spots near the surge tank.
I began to seriously look further, and learned that a head gasket failure may not be evident from what I was used to as the symptoms, and that pressure could leak. I had figured out by this point the coolant was coming out of the overflow, which was supposed to be a symptom along with a firm upper rad hose after sitting overnight. And yet, the rad hose wasn't hard. So more head scratching, and other possibilities:
- EGR valve might be bad
- thermostats might be bad
- even the surge tank may not be separating the two sides properly, or that the cap isn't sealing
So, over a weekend, in a remote island with sparse population and virtually nothing open on Sunday, we needed to make it on to our current stop in Halifax, where I figured we would have some luck in getting it fixed.
I hooked up my OBD reader for the drive to monitor the real temperatures, which remained usually between 80C and 90C, and briefly hit a peak of 100C on a very long climb at freeway speeds over 100 km/h, which then dropped quickly on the descent to the 80 to 90 range again.
I then learned this is what would be expected on the engine, so that ruled out anything with the thermostat. I also found the diesel shops around here were all booked up, though I managed to find one guy who had an opening, though he had someone else he thought might come in later in the week.
Over the phone, before seeing me, he said his experience is that 95% of the Duramaxes he sees for head gaskets also have hairline piston cracks.
And so that's where I am now. I've been checking in with a mechanic friend back home who also has Duramaxes, and while he was initially skeptical, he looked into the LML and learned of the unusual lip on the LML pistons to trap in heat, which was revised by Mahle (the OEM supplier) in an aftermarket replacement version. So his skepticism faded somewhat once he found that.
Would love to hear from others what the take is on this. I gave him the go ahead to order parts this evening (which he will do tomorrow), and I bring the truck in Wednesday.
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