I have a 2011 6.7 and have been having an issue lately. While driving the coolant temp will drop 20 to 30 degrees then cabin heat will go out for around a minute. The temp will then spike up to around 220 and the heat will go back out then the temp will stabilize. My coolant overflow tank moves a little bit. Maybe an inch or so. I used a block tester for exhaust fumes on the overflow many times and directly on the radiator as well. 1 time the fluid did turn to a little bit of a bluish green when it was directly on the radiator. I changed the thermostat and the rad cap already. I also did a coolant pressure test and it held steady at the pressure I put it up to. I have 80k on it and h&s programmer with no head studs. Any insight? Also no coolant in oil and no oil in coolant.
I did it 3 times on the radiator. I am going to do it again tomorrow. 2 out of 3 times no change in color at all and that 1 time is was a questionable bluish green. I guess if it's leaking its a very small leak for now.
I did the thermostat after I was having these initial symptoms just going with the cheapest things first. I have been using the bleeding screw on top where the egr cooler used to be. Seems as if there is an endless supply of air.
Well this may not help if it is the gasket. I usually just refill the system, fire up the engine with the rad cap off, let it get up to thermostat temp, you'll see the coolant start moving through the rad, keep adding as needed, watch for a few minutes to ensure its full, install cap, top off overflow. Check overflow a couple times over the next few heat cycles.
You may have to use the exhaust brake and high idle to get the engine up to temp if its cold where you are.
Napa sells a kit that chemically determines oil in the radiator coolant or coolant in the oil. Both tests are accurate but the dye never goes away once put into the system. A leak down test at the radiator is the only way to determine if you have a busted HG. I tested mine at 20# and it bleed off in 20 minutes to under 17#.
Just went out after letting it sit all night. Took the radiator cap off and coolant was so pressurized still it shot out of the cap. I guess it has to be the head gasket. It should have been a vacuum by now. Are Victor reinz head gaskets ok to use? Heard mixed reviews.
no it shouldn't, but being pressurized and letting air into it, you should also be seeing bubbles in the overflow and a rising level there. but since you aren't seeing those things it led me to believe your cap was possibly bad. cheaper than a head gasket if that was all it turned out to be. Any white smoke or anything?
How long did it sit? Did you try my suggestion on bleeding it? Also be certain you have the correct rad cap they have few styles of caps, one for a non remote res system and one for it. The later has an internal valve that opens when coolant starts to cool to pull it from the res back to the rad.
Here is what Wiki Answers has to say about it:
Look at the bottom of your radiator cap. There are two seals. One that seals at the top neck and one that seals at the bottom of the filler neck. As the fluid heats up it expands. It eventually over powers the primary spring in the radiator cap.
The bottom seal is broken as the pressure exceeds the spring force of the cap and the cap rises. Fluid then enters the overflow tank until enough pressure is relieved to allow the spring to force the bottom seal back into place.
You'll also find on the bottom center of the cap that there's a brass or stainless circle plate. That circle plate actually creates a one way check valve. When the engine cools back down the coolant shrinks in volume. As that happens the pressure in the coolant system becomes a vacuum pulling down on the bottom circle plate and thus opens the check valve.
Once the valve opens the fluid is drawn in through the tube that leads to the bottom of the reservoir and refills the system. The system is actually self burping in that it evacuates air on each temperature cycle. Air is pumped out when the system gets hot and fluid is then drawn in when it cools.
I have no white smoke from exhaust. I can try to bleed it again but I doubt it will do much. There's no way I should have had that much pressure after sitting for 16 hours.
Does anyone have any tips for this head gasket job? Such as draining oil first then coolant? Also I will be going to a machine shop to get the head decked. I have also heard some people will hone the top of the block with a Honing stone as well. And I should be chasing the threads for the head studs with a chaser before installation as well?
No reason to drain the oil. Was just wondering what tuning or settings are you running on your mini max. Timing, fuel, any defuels? You can get all this work done and still come back with the same issue if you're tuning is improper.
I run it on performance. I haven't done anything custom on it. Ran it like that for 40k before the head gasket went and the guy that had the truck before me for the first 40k probably did the same.
Honestly it has been so long since I've looked at that I couldn't tell you. Whatever h&s uses as their default default and timing on their performance tune. Not sure what it is.
Nope, that's just the thing, that's the reason for my question.:nerd: LOL
So, have you been running the stock fueling at times?
You add any Defuels on top of that and.... well...
You only have to hit your thumb with a hammer once to get a black nail. Especially on a cold motor. I will ask one more time, as I'm trying to help , are you running any defuels?
Custom tuning or timing @2 fuel at tow or street.
Preformance would be timing 3 or 4. Never ever, ever any Defuels as it does not knock back your timing. Only fuel. Less fuel more timing= complete burn before TDC. Wrong time for the power stroke. Result is high cylinder pressure.
ok so after 5 hours the cylinder head is off and i cannot find the smoking gun on this gasket. does anything stick out to you guys? i wasnt blown out in any spots. maybe it just corroded and started a small leak or something?
Do all of the piston tops look similar? On the 3rd pic is that just oil residue around the sealing ring? The rest look fairly clean but that one does not.
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