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dissappearing coolant

1364 Views 13 Replies 6 Participants Last post by  jake8886
I took the toy for a long ride this weekend (500+ miles) and before I left I topped off my coolant which was down again. I thought I had resolved this before. I noticed my drain plug was leaking at the bottom of the radiator, I tightened it up and thought that was the end of it. But a few weeks passed and it was low again. On the trip we were driving into 40mph sustained winds going up some grades too. It was a struggle to keep the truck at 55 (65mph road too) on the hills. I figured it was just the wind, but then I noticed my heat was surging. The temperature of the air coming out would fluctuate to the point where it was definitely cold and back to it was definitely way too hot and would make you sweat. The truck never overheated on the trip, but the surging heated air temp with the dissappearing coolant makes me think there might be a head problem. I really hope there is nothing majorily wrong with it, I just got the damn thing outfitted properly for work and I find myself thinking about upgrading.

What should I check first?
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To test for a leaking head gasket

check for combustion gasses (CO2) in the cooling system. There is a tool known as a block tester that can do this or if you are really careful you can use an exhaust gas analyzer. If you suck up coolant it can damage the analyzer.

Of course, first you could use an "old fashioned" cooling system pressure tester. Pump it up to about 15psi and see where it leaks. If no external leaks are apparent then look for coolant in the cylinders, or crankcase.
how much would a decent pressure tester run?

I just went through emissions about 2 weeks ago and the only number that was out of line was the HC's @ 122 PPM out of a limit of 160. The CO was .30 out of 5.4% and NOx was 675 PPM out of 7000.

Does that help any?
I'm sure a good one would be over a hundred bux. You may be able to rent one from a tool rental facility.

The emmisions would be off if you had a large enough leak, But it does not have to be that bad for combustion gasses to be pushing coolant out slowly like you have been experiencing.

you may have something else wrong but it sure is acting like a head gasket.
A decent repair or radiator shop should be able to do the coolant pressure and exhaust gas tests.

NAPA lists a block tester to check for HC gases at around $45; they might have to order it. The catalog calls it a "combustion leak tester kit.” They should also have the pressure tester.

The two tests should give a thumbs up or down on a head gasket problem.
Went to autozone to pickup a coolant system pressure tester since they have the free tool-rental thing. Well I was able to test the cap, but not the system since it didn't come with the correct adapter. Craftsman makes one with multiple adapters for $86+tax. I guess I will try that next.
I changed the oil and didn't find any signs of coolant (visibly). Also, I found my radiator low again (fins visible), however the resevoir was full. I took it out and dumped it into the radiator to bring it back to the top. The cap held pressure to 10lbs and then when I gave it another pump to it would release, its a 13lb cap btw.
I am going to ask the obvious because I've had a similar problem. Are you seeping/leaking at the water pump?
The same exact thing was happening to my truck.....long story short i replaced the waterpump and had no problems......didnt cost much and didnt take long.
Started the truck today to let it warm up (went down to 5F last night). Air temps were about 15F and the truck struggled to start, but it did on the second crank. As I was heading back inside I heard it start to idle-surge. I checked the coolant level and it was still OK, As I was shutting the hood I noticed some steam coming from the exhaust manifold. It looks like my lower radiator hose has a pin-hole in it. It was damn cold old still and it was smoking pretty good like it does in normal cold weather. I'm not sure if I was imagining it or not but I could have sworn I smelled coolant in the exhaust. :cursin:

I'm leaving for another weekend cruise today so I said f' it and parked it. I'll deal with it on Monday when the temps will be a little warmer (hopefully). I just hope this snowshower they're calling for on sunday isn't anything major, otherwise I'll be fixing the hose sooner than I want to.
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Well, I drained the system today. Opened up the radiator and then the block. Blew air through it, filled with water, air'ed it out again. I did that a few times and got a noticeable amount of sludge out. I decided to fill it up with just water and circulate the system a little and then drain it again. I couldn't get all the air out of the system though. It started getting hot so I shut it down and opened up the hose to the thermostat. I found the thermostat ripping hot and open. but there was no water in the hose.

Would this indicate a bad water pump like everyone was suspecting?

One of the bolts that holds the thermostat housing also snapped off in the block too. Just my damn luck. Hopefully the bolt extractor set I got for x-mas will work.
After getting the truck back on the road again it started loosing coolant again slowly. yesterday I dropped almost a gallon on a 180 mile trip, had a nice steam trail behind me in the early morning too when the truck was cold. I dropped it off yesterday to have them confirm that it was a head gasket and this morning they did just that.

They're working up a price to do the job, any ball park I should be looking at before they call me? also, if you had to do the head gasket what else would you do while you were in there? I know my valves need to be adjusted, but what else should they look for or change? I would like to add a different cam to get a little more torque, but I can live without it. I'm also considering doing the job myself since I have a lot of downtime in the winter. Just have to hope this snowstorm next week misses us like all the other ones this winter.
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Well. I'm about 1/3 of the way through the job so far. I've got the air intake chamber off, exhaust manifold off, valve cover, power steering belt. Still have to mark the timing before I take that apart.

I'm planning on going to the parts store soon to pick up some gaskets. Should I change the fuel injectors while I have the intake all apart? What else should I look at?
Im in the process of rebuilding my own engine, and i had that same bolt snap off on me... i got lucky and had about half inch sticking up. i had to file down the sides and soak it with lube then clamp and twist. i got that pos though!
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