Rising Coolant Level--Head Gasket?

[guest]

I think I am getting fuel into my coolant, which I think means I probably have a head gasket leak. How quickly does this problem progress? In other words, how long can I drive it like this before I am sitting on the side of the road? The leak seems to be slow, based upon the rate at which my coolant level is rising. I'm not having any coolant temperature problems, and my mileage has not suffered.

If it is a head gasket, what does a repair like that on a CAT 3126 cost?

 

[rode2rouen]

I would recommend that you get the truck to a dealer/repair shop for diagnosis ASAP!


Rex

 

[RichM]

If you can stop at a SpeedCo and get an oil analysis. I don't think fuel can get into your coolant but oil could. If your head gasket is blown it's usually the other way,coolant leaks into your oil. If possible try smelling your coolant,if you smell diesel fuel I think you have big problems.

 

[guest]

Rich, I understand what "big problems" can mean, I've had them before, but what exactly do you mean by "big problems"?

If there is no performance problem, no weird smells or sounds and there is not a mileage loss, what are you thinking when you write "big problems"?

I don't need a coolant analysis to know, however, that there is SOMETHING in my coolant that shouldn't be there, because I am running CAT extended life coolant, which is red, and the window on my coolant reservoir is showing a clear to light green substance. I suppose it could be some kind of residue from the green coolant that used to be in the system. When the truck is running, the coolant reservoir window shows red, indicating that whatever is in there is mixed with the red coolant, but when the truck has been sitting a while whatever is in there is rising to the top of the red coolant and that is why I see it in the reservoir window.

I recently had a coolant hose bust and have been paying closer attention to the coolant level and the other hoses since then, which is what has caused me to notice this issue.

As I see it, what I am seeing could be:

- water
- diesel, or
- leftover green coolant

I agree that a Speedco coolant analysis should probably be the next step.

 

[davekc]

You are not going to like my answer but I will give it to you anyways. When your truck blew its hose it likely got a hot spot in the engine.
What does this mean? It means you have a cracked injector sleeve. It does need to be addressed asap as your whole engine is being contaminated by the fuel/mixture. Since you have a return fuel line, you are pumping antifreeze into your fuel tank. Your tanks will have to be drained as well. Along with the contamination issue, you will likely damage the injectors. The are roughly $250 to $275 a piece and you have six of them.
Just to fix the injector sleeve I would project 1700 to 2000. If you replace injectors, add another 1600 to 1700. No real labor as they are already out replacing the sleeves.
Downtime is going to be two to three days from the time they start.
Take it somewhere decent.....not a job for a backyard mechanic.

Let us know how it goes.





Davekc
owner
21 years
PantherII
EO moderator

 

[davekc]

I should add, as you are cycling the fuel through your heater system, the cleanout has to be very thorough as that mixture is running through your heat system as well.
Your radiator will maintain the same quantity, but will pump the excess to your fuel tanks.
Since fuel is lighter, the antifreeze will settle on the bottom of your tanks. If you have a drain valve, you can open it and drain out the anti-freeze. Just drain until you hit fuel. Truck has to sit for several hours to seperate.

If you are unsure, take off the radiator cap and see if it smells like deisel fuel. Since you mentioned you changed anti-freeze, it may be just that. The green from the original.
Keep in mind, a small leak will not effect the performance or change sounds. It does give the engine a quick death if left alone.


Davekc
owner
21 years
PantherII
EO moderator

 

[RichM]

I think it's left over coolant. When you are running pressure build up in the system so the red mixture shows up.When the engine cools down ,the red coolant drains down into the block and the green shows up. I don't think you can mix the red and green,perhaps a radiator and cooling system flush is all that is needed.

 

[davekc]

That would be my quess as well if he smells no deisel after taking the cap off. If he does, then my other post would apply.
It would still be a good idea to check it out just to make sure.
A quick test is to take off the hose to your resevoir and pour it in a bucket. That will tell you if there is deisel mixed in. The fuel will float on the top of the anti-freeze.




Davekc
owner
21 years
PantherII
EO moderator

 

[guest]

A little more information:

The rising coolant issue predates the burst hose. When I say the coolant level is rising, I mean it is rising very slowly. The only way I know for sure that it is rising is that it seems like the overflow hose on the coolant reservoir spits a little coolant out periodically (I notice a small amount of coolant on the ground under the reservoir from time to time, typically when I stop the truck after driving a while), plus the issue of the green stuff in the reservoir.

I siphoned a little out of the reservoir tonight (hand pump, not mouth) and it did not smell at all like diesel, it just smelled like coolant. Also, what I pumped out looked like dirty red coolant, the green tint was barely visible.

The hose that burst (I say it burst, it leaked a LOT) was the one going to the air compressor and I never ran out of coolant, I just added as it leaked out until I got to a place where I could replace the hose. Dave, as you probably know, there is a sensor in the reservoir that shuts the engine down when the reservoir nears the empty point. Each time the reservoir got low I topped it off. Therefore, there may have been a part of the cooling system that had lower pressure because of the leak, but there was coolant moving through the system at all times. Dave, does this make the doomsday scenario you describe less likely?

When I switched over to the extended life coolant a few months back, there were a few drops of oil on the surface in the pan with the drained coolant. Probably less than a tablespoon total. I had recently had the oil cooler gasket replaced because it was leaking and I thought possibly this could have had something to do with the oil in the coolant, though it was a very small amount of oil.

It still sounds like the next step should be to have the coolant tested. If there is fuel in the coolant, what might it be other than the scenario Dave describes? If there is no fuel in the coolant, do you think I should just try a radiator flush and fill and see if the green tint goes away?

Dave, I will drain the reservoir into a bucket and see if anything floats to the top. I think I have a rabbit's foot somewhere I can hold while I am waiting.

What about my original idea about a leaking head gasket?

 

[davekc]

That information is more helpful. The doomsday scenerio doesn't apply if there is not the presence of deisel in the coolant. A small leak in a hose will not cause hot spots within the engine. A burst with alot of rapid coolant loss will cause that.
If you are filling the resevoir on a regular basis, some leakage from the overflow hose is ok.
It is possible it could be a blown head gasket but a few tests will determine that. That is essentially the same cost short of not needing the sleeves.
If the coolant checks out, I would flush the system if the new anti-freeze is dirty in a short period.
Then you should be good to go.
As far as the head gasket, is there any other indicators that make you think that is a consideration?





Davekc
owner
21 years
PantherII
EO moderator

 

[Broompilot]

This is a great Post for using a great local mechanic. Speedco does a great job while we need oil and pm away from home but depending on them to service a truck all the time is asking for trouble.

My local mechanic would or better detect these kind of problems, second Speedco cannot adjust brakes from my expierence my brakes need to be adjusted at least every 25K. I pointed this out to my other truck and all the savings at Speedco dissipeared when we got the brakes adjusted elsewhere, at home I pay 0 for this service.

Now when I say every 25 they are not off by much but I want them right on. Find a great local mechanic and treat them well it will only save you $, time, and tons of frustration.

 

[guest]

Okay Dave, it is fuel in the coolant, but I am not following how coolant is going to get into my fuel tank. I don't understand what you mean when you talk about any excess coolant being pumped into the fuel tank. I'm sure I'm just not understanding what you mean.

I also don't understand why any fuel injector problem would cause fuel to get into the coolant. It seems like an injector problem would cause fuel to get in the oil, but not the coolant.

I am only leaning toward a head gasket problem because it seems to me that the coolant and fuel passages are separate and only a leaking head gasket or a cracked block would cause the fuel passages to leak into the coolant passages. There may be other ways of the fluids mixing, but, as I note above, I don't follow how an injector problem would permit fuel to get into the coolant (but I readily concede that you know A LOT more about these things than I do). I don't want to think about a cracked block, which leaves the head gasket.

I'm going to a CAT authorized shop after my delivery this morning. I'll probably be there a while.

 

[davekc]

I wish I could draw a picture. It would be easier to explain.
There are sleeves that go down in the head for the injectors. If a crack develops in the injector sleeve, it is putting fuel into your cooling system.
I should mention, that the injector sleeves are the specific issue rather than the injectors themself.
As mentioned a cracked head could do that but usually that is oil in the coolant or coolant mixing with your oil. A cracked block will do this but leak on the ground unless internal. Really two different issues.
As to how coolant is in the fuel tank? When it is mixing in the head, unburned fuel is sent through the return line back to your fuel tank. In your case, that fuel is mixed with coolant and settling on the bottom of your tanks.
Cat should be able to find the problem pretty quickly.
If you have a generator, I would bleed that and change the filter as it could be drawing that mixture into it.
Hopefully that explained it alittle better.





Davekc
owner
21 years
PantherII
EO moderator

 

[guest]

Okay, I have one or more cracked injector sleeves. I could not get the mechanic interested in the idea that I may have gotten coolant in the fuel tanks. He said he did a pressure test and the fuel pressure was greater than the coolant pressure, which, according to him, would cause fuel to get in the coolant, but not vice versa. He did not seem at all concerned about coolant in the fuel tanks.

I explained to him that davekc thinks there might be coolant in the fuel. He looked at me and said "Who's davekc?"

What do you think Dave? Press the issue of coolant in the fuel or trust the mechanic? He's a CAT certified guy and he went over his conclusions with the area CAT shop and he said they "concurred" with his findings. I was impressed that he used the word concurred.

I lucked out with this shop. It's in Janesville, Wisconsin and I found it by using the service facility locator on the CAT website. I delivered my load this morning at 6:00, I was at the shop at 6:30, they pulled my truck in at 7:30, they had the problem diagnosed and parts ordered at 9:30, at 3:00 all of the parts were in, and they tell me I will be out of here before noon tomorrow. I'm pleased with the shop. It's an Chevrolet in Janesville, WI. Shop rate is $89/hour. This repair--replacing all six injector sleeves and some O rings and doing a coolant system flush and fill--will be $1444. It's a lot, but it's fair for the work they are doing.

Dave, very nice diagnosis. Thanks.

 

[davekc]

Glad I could help. It looks like they gave you a good price and getting you out in short order. I had a extra hour of labor factored for checking both your tanks. If the pressure is high enough he may be correct with regards to the fuel tank.
Depends alittle on the severity of the crack in the sleeves.
It would be my opinion to have it checked. Popping the drain plug and draining a little off the bottom of your fuel tank is cheap insurance. If.....understand if......there is any coolant in the fuel tank, when that gets up to the engine, you could possibly drop an injector. It goes without saying, check and replace the fuel filters. Again, very cheap insurance.



Davekc
owner
21 years
PantherII
EO moderator

 

[guest]

The crack is very small. They don't have all of the sleeves out yet, but he said he couldn't feel the crack, so I assume it is not large.

I will replace the fuel filters, as you suggest.

There was no oil in the coolant when he drained it, not even a little bit, which made me happy.

 

[davekc]

When he removes the fuel filters, have him dump the fuel out of them and see if it is free of coolant. I have seen more than one drop a injector after this type of repair when this wasn't checked.
I usually go with "never assume anything"




Davekc
owner
21 years
PantherII
EO moderator

 

[rode2rouen]

A little background on HUEI type fuel systems that may clear up things a bit.

These engines (Cat 3126 and International DT/HT) use VERY high fuel pressure when running....over 50psi is required just to get them started, and it will be higher when running.

Cooling systems will usually have about 8 to 12psi when running at operating temp.

Looking at the pressure differential between the 2 systems, it's pretty easy to see how fuel could end up in the coolant and not vice-versa. 50+psi will find it's way through a very tiny fracture that 10psi may never penetrate.

Another problem that occurs with these engines is injector o-ring failure. The high pressure oil system on these engine generates 500+psi when cranking and can easily run over 1000psi when under load.
Defective injector o-rings can cause an apparent oil consumption complaint and the give away is black tinted fuel in the tanks.


Rex

 

[bryan]

HI
I'm with Davekc on this one.What he is recommending is just cheap preventive maintanance.A gallon of lost fuel and a new filter are cheap.Peace of mind is priceless.We use to check the tanks on the KW every month and we would change the fuel filter when ever we did anything under the hood.Deisel fuel systems are very sensitive and very big bucks to fix.

 

[guest]

Actually, none of the injector sleeves were cracked, it was just some degraded O rings on the injector sleeves. Seeing this made me feel better, because degraded O rings are understandable based upon the age of my engine.

Since my attempt last year to assassinate my engine by running pure fuel treatment in it, I have now replaced almost the entire fuel system--I have replaced the HUEI pump, all six injectors, all six injector sleeves and more O rings than I can count (these O rings are everywhere in the fuel system).