Blown head gasket?

So, truck ran fine last night with the exception of the small shuddering at cold start that started happening. Went to work this morning and it is shaking like mad at all speeds, pretty much, especially when given throttle. Recently had a high temp situation where it was wanting to overheat while idling at a red light. Came home, topped off coolant and changed my oil, which was planned already. I was about a quart low. Temperature issue resolved (for now) but I have noticed I've needed to top off the coolant fairly often up until the overheating issue. Like mentioned previously, I have in the past had an issue where it would want to idle low and shudder, I thought I may be having a misfire. so I did the usual: clean the MAF, seafoam, clean throttle body, changed plugs and coils. That resolved the issue for some time but it recently came back. I.e., rough at start but issue goes away after I start moving and works the rest of the day- might occasionally get a little sputter when I leave work if I don't run the truck at lunch time. Anyway, was doing some other trouble shooting for a non-related issue and pulled all of the interior fuses to check them. The problem started this morning after having pulled those fuses, may not be related. I cleaned the MAF today and reset the ECU, but to no avail. Does all of this sound like a blown head gasket? 2005 4.0 v6 ~219,000 on OD

 

1. You need to test to see if you have exhaust gases in your radiator coolant there a tester for that

 

2. You need to perform a leakdown test

 

Yes I think Im going to try to find a tester here in town tomorrow. I saw a video earlier of someone using one and thought that might be a good thing to try.

 

Harbor Freight sells the test kit for the coolant.
They also sell the leak down kits too.

They aren’t the best of quality, but should do for the avg DIYer that might only use it once every few years.

Be warned……..Do NOT over tighten the hose that threads into the spark plug.
If you over tighten it, it can come loose at the crimp for the hose and then it is “game over”.
Now you have hose fitting stuck in the plug hole……

 

Ill run by there tomorrow. Got a OBD tool coming as well. Was just going to grab one from HF but wanted some additional features and my local store didn't have the model I wanted.

 

One more thing, I can hear what sounds like fluid moving behind my dash/firewall at times. Not sure if its related. Seems I looked it up a while back, too.

 

That would be a symptom of a bad head gasket. Do all the tests, look for symptoms. Start thinking about "what if". Have a Plan B and Plan C.

 

I had a bad head gasket on my 4.0.

I was losing coolant over time with no visible leaks or overheating. This was going on for about 6 months.

I tried an exhaust gas tester but that yielded a negative result. I was able to confirm that the head gasket was leaking on cylinders 4 and 6 using an inspection camera. It would only leak into the cylinders when the cooling system was pressurized. When pressurized, I would see a drop of coolant seep out from the head gasket and run down the cylinder wall. This would occur once every minute or so.

 

I had marbles rattling around the dash with bubbling coolant. I did the combustion / exhaust test in the coolant and it turned yellow quickly … HG getting replaced as we speak. 2005 195k miles. My bet is HG.

 

Have a 06 Taco with 165K and have the same issue with the exact same cylinders. Debating on blue devil, head job or used engine swap from Engine world (eng from Japan with under 50k).

 

I sent you a PM.

 

Sounds like a headgasket

The rough running on cold start is the engine choking for a few secs on the liquid coolant that oozes into the cylinders with the engine off

The sloshing sound behind the dashboard is air pockets in the cooling system (from the low coolant level) moving through the heater core

The steady loss of coolant is a sure sign too. It's leaking into the cylinders. I'm assuming you've looked it over thoroughly for any external coolant leaks right? If it's not leaking externally it has to be leaking internally..

Chemical block tests don't seem to work on these engines for some reason. Try pulling the plugs on the back 2 cylinders after sitting and see if you can see liquid on top of the pistons. If you can get your hands on a leakdown test kit even better

 

All signs point to yes. Just finishing head gasket on my truck, seems to be very common with high mileage. Easy to get an inspection camera. You will see coolant on the piston. If not, pull the spark plug after truck has cooled, hold a piece of white paper near the spark plug hole and bump the ignition. If coolant is on top of the piston, will be all over the paper. You can probably also smell coolant in the exhaust.

 

Thanks everyone for all the replies, Im 99% sure its a HG leak. I have other issues too so have been tracking them down. had a misfire on cyl 5, tested and replaced the coil on that one, Ran great for a while but then started the shuddering, hesitation, surging again and threw codes for cats and o2 sensors on both banks. Trying to figure out that now. Haven't found any vac leaks yet using the carb spray method. could all still be related to a possible HG leak, given how both banks coded at once. P0430, P0420,P0174, P0171 also got a misfire on cyl 2 and a random misfire when this happened. Cleared them out and the bank errors returned but not the misfires. In my limited experience, tells me theres something in front of the cats and o2sensors causing a lean condition. (?)

 

All of that makes so much sense, thank you. I have one spot that looks like its probably a leak, looks more like oil than coolant though. Ill need to give it a better look, to be honest. The way its running you'd think it'd be pretty obvious. After I swapped out the Coil yesterday, it ran like a charm and idled in the driveway for some time, I took it for a loop around town and it did fine until i went to power up a hill, then the troubles came back and threw the codes mentioned above.

 

You mean like this....?


Sigh...

 

Ugh, I cant find a vacuum leak anywhere. Seems fine at idle since replacing the one bad coil. Ran really well until It got on the highway and then it started shuddering/surging again. I pulled the power on the MAF sensor with the engine running and it shut right off. I've checked every hose I can find and sprayed around everything with no change in idle that I could detect. I recently ran some Berrymans through the system, because my fuel gauge was sticking, to see if it'd help break the float free. Maybe i loosened some crap up and clogged up an injector or two? Starting to suspect fuel injectors. Id test them but Hell, by the time I pull everything off to get to them I may as well just replace them.

 

What @b_r_o said makes perfect sense.
You could have a coil that becomes an open circuit when it gets to hot.

I'll just leave this here...