Keeps blowing head gaskets

[asasial]

new to forum. i have a 2002 4.7 4x4 ram.
it has been a total POS!!! had it a little over a year and a half.
10,000 miles after buying it, around 95,000 miles on the truck it blows the head gaskets. tore it down. had heads shaved. felpro gaskets, new head bolts,
8,000 miles after that it starts loosing water literally about 2 gallons per 100 miles. tore top end back down changed the gaskets again. as well as a set of heads.
now 4,100 miles and it's loosing water again at about the same rate.
i have been a diesel mechanic for years so yes i know how to change a head gasket.
Can anyone tell me why these engines keep blowing head gaskets.

not to mention the oil pressure drop and the dash was fine on it when purchased now there are literally about 20 HUGE cracks in it.
i don't trust that truck to drive to town. much less go on a trip.

 

[ramhunter9]

first off welcome to RF .

second 4.7's have been known for head problems . I wish i could help but i have never worked on a 4.7 . but allot of guys on here have , so stay tuned they will pop up

 

[asasial]

thanks... i hope so... i'm under the hood more than i'm behind the wheel...

and that's a good lookin truck... mine's looks good... for a yard ornament... but not that good

 

[ramhunter9]

thank you

 

[Silverbullet08]

like rh, the 4.7 are known to have that problem.

have u considered an engine swap? prob cheaper then having to keep replacing heads...

 

[Bigtman07]

Just as an extra thought there is some light reading material in the DIY section for the third gens. The Shop manual is there for download. That may be a place to help you look. As far as why it's loosing water that is a good question. Are you sure it is ending up in the head and isn't just leaking out the water pump or one of the coolant hoses? With new heads it shouldn't be blowing gaskets that fast. Unless it is for sure showing up in the oil I would think that it is comming from some where else. Maybe the intake has a crack letting the water leak out.

Is there any evidence that it is hitting the ground?? Just thinking out loud.

 

[asasial]

yes i have considered a swap but would prefer to get away from the 4.7 all together.
i have a really good manual. it's like 700 pages i downloaded but i'll take a look. the last time i changed them when it started loosing water you could see in the gasket where it was leaking between a water jacket and the number 8 and 1 cylinders. the black portion of the gasket was gone. the engine is dry as a bone as far as leaks go. no signs of leakage and it started loosing water just before it blew the gaskets all the other times. the first gasket completely blew full steam coming out of exhaulst, and had been loosing water for a few weeks.

 

[Silverbullet08]

yes i have considered a swap but would prefer to get away from the 4.7 all together.
i have a really good manual. it's like 700 pages i downloaded but i'll take a look. the last time i changed them when it started loosing water you could see in the gasket where it was leaking between a water jacket and the number 8 and 1 cylinders. the black portion of the gasket was gone. the engine is dry as a bone as far as leaks go. no signs of leakage and it started loosing water just before it blew the gaskets all the other times. the first gasket completely blew full steam coming out of exhaulst, and had been loosing water for a few weeks.

thats what i meant. putting in a hemi...

 

[asasial]

i would love to acutally missed out on one not to long ago complete with harness. ecm, everything for $800. is there any info out there on doing one? i tried a while back to look it up but couldn't find much.

 

[ramhunter9]

We might have something we can find

 

[asasial]

that would be great. i love the truck it's self. just hate that damn engine. have been wanting to do other things to it... lift, rims, etc. but can't the engine keeps eating my budget!!!!

 

[Bigtman07]

Just thought I would throw that out there.

I would like to say warped heads but you had them replaced so I doubt that.

I know it sounds dumb but did you re tourqe the heads aftera few heatcycles?? And did you use copper coat on the bolts and gaskets? Just stupid little things that can go wrong.

 

[asasial]

i re-torqued the heads after about 3 days. (probably about 200 miles)
i didn't use copper coat but i did use indian head.

 

[asasial]

speaking of torque does anyone have a final torque for the head bolts. i hate that 90 degree torque turn crap

 

[Bigtman07]

It should be in the service manual I would think. Let me see what I can find.

Found this with a quick search.

•Step 1: Tighten bolts 1-10, 20 N·m (15 ft. lbs.).
•Step 2: Tighten bolts 1-10, 47 N·m (35 ft. lbs.). Tighten bolts 11-14, 25 N·m (18 ft. lbs.).
•Step 3: Tighten bolts 1-10, 90 degrees. Tighten bolts 11-14, 30 N·m (22 ft. lbs.).

Maybe it will help?

 

[asasial]

all i ever found was i 3 step torque i think it was ( don't quote me) 25 lbs then 65 lbs then a 90 degree torque turn for final torque... like i said my numbers may be off but it was something like that.

 

[KGBIGCOUNTRY]

The 90 degree isnt hard to do just make sure you pick the same starting point for each bolt, I cant remember the finial on my 5.7 off the top of my head but the snap on dig wrench was giving us the finial on a few of them.

 

[asasial]

the torque turn isn't the problem. it's just hard to check the torque after it's been ran. was wanting a final torque so i could check them later on.

 

[Bigtman07]

Ahh ok I got ya. I'll see what I can dig up for you. But that's on a side note. We still need to figure out why it's blowing the gaskets to start. I know the 4.7 has sealing problems cause the aluminum heads and iron block. Hmmmmm that is a very interesting problem.

 

[KGBIGCOUNTRY]

Did you knock the locator pins down some after you got your heades milled?