Bad headgasket without overheating?

[Andrew]

Recently got a 2005 Dodge Dakota 4.7l/6speed 4wd.

It drove home fine, ran cool the entire way home approx 45 minutes of twisry turns and hills/mountains. It was low on coolant when I got it, prior owner claimed he just did the water pump and it had air still.

He fired it up, I watched the tailpipe, nothing seen. Test drove, ect nothing obvious.
Oil looked approx 1k miles or so dirty....but clean. Overflow was empty, but no oil stains, oil cap was clean.

Topped off the antifreeze after getting it home, let it cycle until the level stayed level...didnt see any issues.

Drove to work, checked, and the level was down again. Drove home, topped off (while it wasnt running)

Today, after getting to work, the overflow was 99% full, and lots of movement coming up. Doesnt necessarily look like bubbles though, more like streams of coolant flowing through but when I opened the cap of the radiator while it was running from the 7min trip home...no coolant showing? The cap was maybe room temp. No steam from the tailpipe.

Im guessing a head gasket failure? Its the only thing that makes sense to me.

 

[94toytruck]

They are pretty common for head gaskets and cracked blocks/heads. Use a HC tester to see if exhaust gas is coming through the coolant. You may need to out a throttle block in it and let it get nice and hot, I liek to use a spill free funnel in the rad neck so it spit coolant all over.

 

[Elwenil]

I'd buy a radiator cap first. Sounds exactly like a cap that won't hold pressure.

 

[Andrew]

I figured a couple/ten bucks for a cap couldnt hurt I guess. Would have grabbed one today, but no local auto parts places open in my neck of the woods on Sun.

 

[Andrew]

Will see today. Im really hoping that its just a bad cap, but kinda doubtful. Then again, it doesnt check off usual head gasket symtoms either....

Last time I had a bad radiator cap, it was still hot to the touch to take off. With this truck, it is easilly just warm. No gloves needed, at all.... Even after the trip over the mountains home.

When I pulled the dipstick while looking it over at the owners house, the oil looked, maybe dark maple syrup colored. Not black, still see through. Yesterday it looked about the same after putting maybe 50 miles on it. Honestly, though Im not sure how long it takes to turn to milkshake if there is a head gasket issue.

 

[Andrew]

Well, got a new radiator cap. Builds pressure, still have constant bubbles in the overflow.

Oil looks clear when warm, maple syrup color. Temp never goes within 1/16" of the halfway mark, can grab the upper radiator hose, and the cap is cool/warm (outside temp is 33° currently)

Guessing cracked head or gasket....sadly, there is seemingly steam coming from the tailpipe. There was none noticible when I had the prior owner start it and we let it idle for maybe 10 minutes while looking it over.

 

[Andrew]

Gasket set showed up today (Fel Pro) just waiting on head bolts (Fel Pro) and see if I can not somehow screw up the timing in the process