Vball7

Sorry in advance for the long story, but here goes...
I've got a 2002 with the 4.6. A few days ago the truck suddenly lost power and the check engine light came on. Power came back but it was running pretty rough. Took it down the the dealership and they said the thermostat was stuck. Replaced it and did a coolant flush and two miles after leaving the dealership the temp gauge spikes, coolant starts running all over the place, and engine starts running rough again. Let it cool off for an hour, then limped the mile and a half back home. Temp spiked on the way, but just before I got home temp suddenly fell back to normal. Now dealer says I have a leak in a head gasket and wants $2,500 to tear apart the motor just to look for other damage. Does this make any sense to anybody????

obusnizzle

is white smoke coming out the tail pipe? Why didnt you take it back to the dealership? Its quite difficult to kill the head gaskets on a mod motor, you most likely had a pressure bubble in the coolant system creating a high point in the system. Your first mistake was not taking it back to the dealership immediately after it started spewing.

Vball7

No white smoke at all. It was bad timing. Picked it up from the dealership as they were closing, couldn't get it back in until morning and that's where it's at now.

NGM

Won't always have white smoke when a head gasket blows. IF the Combustion is going into the coolant no coolant in the exhaust. An air bubble can and will cause it to overheat then suddenly go normal. Don't rule out a blown head gasket, but on something that big get a second opinion.

Bryce_James

Try calling diffrent dealers, I got told the same thing and it ended up being a vac. leak.

sysman_rick

Ask the service writer how they determined it was a head gasket. Did the dealer do a pressure/leak test or a flourescent dye test? Don't guess on these motors.

bigredford

Any coolant in the tank? Start there, then when they do go out they usually go out in the back so you need to crawl under the truck and look if it's leaking off the bell housing. That's how we found the one I had to replace when I was a mechanic. If it's the problem, I hate to tell you but it's a bitch to put them in and when you do it's recommended to put the timing chains and gears in as well since it's apart. I would put pressure to the coolant tank first and check if any antifreeze is dripping out anywhere.

wde3477

What is the dealer's basis for diagnosing a head gasket?

What's the difference between the estimated repair costs and a crate long-block?

When the truck lost power, did the coolant temperature spike then?

What was the fault causing the 'check engine light'?

Just sounds to me like the dealer is fishing for dollars. Definitely investigate further.