Replace the headgasket or change the whole motor?

[lbrowne]

From what I see under the hood, and what I hear from people, trying to replace the headgasket with the motor in the truck would be a nightmare.

Should I try to do the headgasket with it still in the truck or just source a lower mile replacement motor? (I'll try to land a 2v out of a 2003 f150)

Was anyone else in this situation before?

 

[Sporttees]

I'm interested to find out the answer too. I had a durango that needed a head gasket and I was told by every mechanic I took it to that I should just replace the motor.

 

[Thermo]

lbrowne, I have pulled the heads off of my motor to do some head work and to fix a blown out plug (I Timeserted all 8 plug holes and ported/polished the heads and intake). It isn't an impossible job, but not a "lets have a beer and get this done" job. It will take you about 16 hours to remove everything necessary to get the heads off of the truck. If you only do one head, you may be able to cut it down to about 14 hours. Also keep in mind that you will need new head bolts as the factory ones are stretch bolts. so, when you tighten them, you actually stretch the bolts to their yeild point, removing any elasticity that they have. So, the next time you go to put them in, you are either going to have them too loose (leading to a head gasket failure in the near future) or you are going to over tighten them and lead to their catastrophic failure. does it happen every time. By no means. But, if you have luck like me, you are going to be that one.

The hard parts of this job is:
1) re-establishing the timing. In short, keep track of which chain comes off of which side of the motor. Also note that the chain has colored links in it. These match up to marks on the cam and crankshaft gears. You need to get these matched back up or the motor will run like hell. TRUST ME!!!!!!
2) removing the bolts for the exhaust manifolds WILL!!!!! lead to a few broken bolts. Normally the bolts fail right at the nut, so, after pulling the head off of the truck, you can use a little bit of PB Blaster and a set of vice grips to pull out the remaining part of the bolt. I replaced all of my bolts with capscrews to make any future work that much easier and the fear of having broken manifold bolts does not exist with me any more.
3) when removing the head bolts, the back bolts (against the firewall), the lower bolt can not be removed if the motor is still in the truck. What you have to do is to lift up on the bolt and the also lift on the head at the same time. This will allow you to remove the head. Once the head is move a little towards the center of the truck, the head bolt can be completely removed. Remember to do this when putting the head on else it is a royal PITA to have to undo a lot of the bolts that you have put in finger tight just to be able to move the head a little bit to fit that one last bolt.

Any other questions, just ask.

 

[lbrowne]

Thanks a bunch. I was looking through procedures people have posted about this on various forums. The last headgasket job I did was when I swapped the heads on my 86 chevy half ton with a 350. (put on rebuilt heads)

I guess this motor doesn't have pushrods and require valve train lash to be set etc?

I would think to make this alot easier, I should get the alignment tools for the cam and crank.

I'm now leaning towards doing the gaskets because it'll be alot cheaper than a motor around here.

 

[tonydiv]

If you have ever seen a professional shop that specializes in motor work, they will usually remove the front clip to make access easier (especially with a lifted truck)

It seems like a lot of work, but in the end it saves time.

There is a "may as well" factor involved. If you're going to all that trouble.... you may as well rebuild the whole motor.

 

[lbrowne]

If you have ever seen a professional shop that specializes in motor work, they will usually remove the front clip to make access easier (especially with a lifted truck)

It seems like a lot of work, but in the end it saves time.

There is a "may as well" factor involved. If you're going to all that trouble.... you may as well rebuild the whole motor.

Front clip - are you talking grill, bumper, rad and rad support headlights etc? I would think if you take the fenders off the upper frame rails would be in the way regardless.

I won't be doing a full rebuild on this motor.