Apparent failure of head gasket on 6.7

[EB]

Long post



About two weeks ago I could smell antifreeze after I came in from a run late one night. The next morning the radiator was low and the overflow tank was completely full and I could see it had run over. I thought radiator cap, replaced it and took care of the coolant levels. The coolant gradually got lower in the radiator and the tank got fuller. All this is while the temp is completely normal for the loads I was pulling. The temp finally got up close to the 240 mark, I shut down for a while to let it cool off , then started it up and put water in and came on home with no problems. I took it to the shop last Thursday knowing what it probably was, but not believing that it could be the head gasket, and it tested positive for hydrocarbons in the coolant. Had to be the head gasket or possibly the EGR cooler. Pulled it down, the EGR cooler tested OK, looking at the head gasket, you couldn't see any "blow out" as such or feel anything. On the head you could see two places that were scorched outside the firing chamber. The head has been checked, it is flat, no warping, and has been magnafluxed (sp) and it has no cracks.

This should not have happened in my opinion. The truck is completely stock, and until this happened never got hotter than 210-215 max. It has been maintained correctly. It has been worked from day one, 90% of its 131,500+ miles have been towing a trailer, but this shouldn't have happened. I hope it is just a fluke. All the parts got in and the head got back today and it is going back together this afternoon. Should have it running and back to work tomorrow afternoon. It has been a long week wondering what was going to be found. I didn't post before now because I really wouldn't be able to answer any questions until I knew what happened. My other trucks went 419K and 345K miles without any engine problems. Like I said, in my opinion this shouldn't have happened. I hope it is a fluke, because it is an expensive fix. Give me a week after I get it back and I'll know if it is fixed.

 

[DPKetchum]

The part about not finding anything would make me nervous. Over the years the times all looked good and putting it back togather the problem was still there. Just about always ended up being a head issue.

 

[MMeier]

I think I would have at least had the head cut "just to make sure", or did they?? Hopefully they checked the block also?

 

[RVTRKN]

EB, just a thought, but what about the turbo? It is water cooled.

 

[HBarlow]

EB,



I'll be following this thread with interest.



My '01 developed the same symptoms around 250k miles. On inspection it was clear the head gasket had failed. Don't know why but it failed. The head gasket was replaced with a standard Cummins gasket and the truck still runs fine and loses no coolant at around 350k miles.



I hope that is all that was wrong wiht yours even no evidence could be seen on the gasket.



During a briefing today at May Madness I asked Scott Bentz of Cummins Rocky Mountain if he was aware of any problems like you experienced with 6. 7L engines. He said he has not heard of similar problems.

 

[betterthanstock]

Don't forget to replace coolant thermostat. They are cheap and some let go a lot sooner than others.

 

[EB]

I will be getting the truck back tomorrow, thought it would be today, but it will be tomorrow.

The block has been checked, the head was not "cut".

The thermostat has been changed.

I believe on the turbo the water is on the "wrong side" or so I have been told, to get into the water jacket. That, I don't know, just what I've been told.

I'll find out pretty quick if it is fixed, the trucks that have been running have been covered up with work, so I probably will run all weekend, and the temps got up into the 90's today. If it is going to leak water, I'll know in a day or so.

 

[EB]

Got the truck back Friday afternoon, got called for a short job Sat. morning. (thank goodness it was short) No change whats so ever. Was getting hot before I got to the location, 33 miles away. I loaded up, stopped and put a gallon of water in it before I got to the gate and started back. I had to stop and put another gallon of water in after 25 miles and got the load delivered. It was suggested to bypass the EGR cooler to see if that made any difference. I've got it bypassed but I need to know which electrical connector to unhook to disable the valve for the EGR. Anyone know which one that is?



The engine is running fine, smooth as ever, I just can't keep coolant in it. Unloaded (just the truck) there doesn't seem to be any problems. Put a load on it and build some boost and your water is gone in no time. I now think the problem is in the turbo. It is water cooled, could pressure from the turbo be getting into the water jacket? If so, what is the fix? New turbo?



I really think I paid for a head gasket job for nothing. I think they were guessing.

 

[DPKetchum]

When there wasn't a issue you could see with the head gasket I would have bet you'd be posting it wasn't fixed. Its either got a head issue or a Egr cooler issue. I'm just guessing and I know its apples to oranges but the Ford 6. 0 did the same thing when worked and it was a lot of EGR coolers replaced. Maybe the head is cracked. I use to send heads to DOVER cyl. heads and once in a while would get the dreaded nothing wrong with these heads phone call and I would insist to go over them again and THEN it would be found. Always got them back with this purple dye in the water chambers and faint cracks pointed out.

 

[EB]

I'll have to disagree with you on the head issue. If the head were cracked, it would leak into the cylinder when it cooled off. When you tried to start it you would either have a miss or rough engine or it would try to lock up. Could be the EGR cooler although it was pressure tested at a radiator shop with a good reputation. No leaks. I believe it is the turbo, but I have no idea how you can check for that without replacing it.

 

[Bigwhitehd]

i have a 6. 7 turbo for sale. Only 3000 miles, please pm for details.

 

[sag2]

EB, see the photos in this link for reference. Your Chassis Cab should not have the EGR bypass valve (with the cables on it) but should be same other than that. Looking at the two right 6. 7 engine photos, 2nd from right photo shows the EGR connector is right in front of the brake fluid reservoir. Coolant bleed is in right photo with the yellow label below it.



http://www.gorowan.com/2007ram/mods/index.html

 

[DPKetchum]

I've seen dozens over the years that did nothing but loose coolant. Some would have a spotless cylinder,no carbon on nothing in it. Ran fine,started fine but lost lots of coolant. Bad intake gaskets on G. M. V8s always ran good but needed a gallon of water/coolant a week. How much changes were made to the head from the 5. 9 to 6. 7. I do hope its not the head and you find out what it is quickly for your sake. What a pain this can be.

 

[betterthanstock]

Are you sure it's not the water pump, a hose, or radiator? With engine running, it's hard to see steam as the fan can blow it off.



I would buy a rad cap tester that pressurizes the system, maybe hook it to an air compressor regulated to 25 or so PSI. Let it sit pressurized until you see a puddle, or it hydrolocks (ouch).



It could also be a hairline crack that only opens when hot, or a leaky freeze plug, or how about a leaky heater core? You smelled antifreeze, so it could be right there in the cab. There is a drain hole for the condensation. If it's a leaky heater core, it will fog up the windows more than usual.



The 6. 7 block is siamesed (no coolant between cylinders), not the same as the 5. 9, so no one knows how they hold up long term.

 

[Coalsmoke]

I'll have to disagree with you on the head issue. If the head were cracked, it would leak into the cylinder when it cooled off. When you tried to start it you would either have a miss or rough engine or it would try to lock up. Could be the EGR cooler although it was pressure tested at a radiator shop with a good reputation. No leaks. I believe it is the turbo, but I have no idea how you can check for that without replacing it.

EB, I am not a certed mechanic, but have been in enough engines to feel comfortable and would tend to agree with your above thoughts. Given the miles you have on it, and with that significant of a coolant leak, if the head was pulled to do the head gasket, if that much water was going through only 1 or 2 cylinders I would think that it should have been evident. The turbo could make sense if you are not having any issue when bobtailing. If the cooled bearing housing on the holset VGT were to leak, I can't help but think it would end up either on the exhaust side or the oil return. With the DPF it might be less evident though if you are making trips long enough to keep it up to temp. If it were my truck I'd start by with pulling the turbo and taking a good look. The water cooled EGR system is new to me so I defer to others.



I've been following your 6. 7 threads ever since the fall of 06. Sorry to hear of your troubles.

 

[EB]

Just got a call from the dealership and was told that technical services told them the first thing that should have been done was to change the EGR cooler. When told that the EGR cooler was checked at a radiator shop and was OK, they said that they can't be just pressure checked like a radiator. I'm getting this second hand from the service writer, the tech talked to the tech services people. Apparently there is a special way or procedure to check them. Anyway, there is one on the way, it is a restricted part so it will be a few days getting here, $800+ for the part, not counting labor,bringing it up to well over $3200 for the total repair if this fixes it. Any suggestion, if this fixes it on what to do about the first $2400 in repairs that might not have been needed. First time I've run into anything like this.

 

[PToombs]

IMO, the shop should eat the labor cost of the 1st repair. The parts are in there, so you kinda own them. At the least, they should do something for you.



I've been following your adventures since you have gotten this truck. I'm glad you have had such good luck with it, up 'til now. I hope you get it squared away, and get on the road again.

Good luck!

 

[grasmo]

Could the turbo share coolant on both sides hot and cold???... ... if yes then could the hot side have a small crack/leak into hot exhaust and if yes ... . then could it be small enough to not affect the sensors in the exh???? I know it is a stretch. But I'm hoping to trigger some out of the box thinking. Still waiting for the atty's to respond about my lemonade stand.

 

[EB]

Could the turbo share coolant on both sides hot and cold???... ... if yes then could the hot side have a small crack/leak into hot exhaust and if yes ... . then could it be small enough to not affect the sensors in the exh???? I know it is a stretch. But I'm hoping to trigger some out of the box thinking. Still waiting for the atty's to respond about my lemonade stand.

I don't know. Everyone I have talked with say no. I'm waiting for a new EGR cooler, which is supposed to arrive tomorrow. (I hope) As soon as it is put on, I'll be hooking on to my trailer and pulling it on about a 75 mile test run. I'll be going up and down the only hills around here to see if I can get it hot. If it does, I'll take straight back to the dealer.

At least they did say, when it is fixed, we will set down and talk about the bill.

 

[KIKER]

A friend of mine had an '02 CTD with about 100 miles on it that lost a freeze plug. It just fell out the second day on a job I was helping him with. It turned out the casting had been machined out too big and inserts were installed and then the freeze plugs. The dealer found this out when he tried to install a new plug and it wasn't even close to fitting. The friend got a new engine block from the dealer and was not a very happy camper. This probably doesn't apply to your problem, but might get you to look at possibilities not apparent.