My 2004 F-150 XL 4.2L V6 (w/ 225K miles) developed a head gasket leak. Found a used engine w/ 77K miles on it in a wrecking yard and will be swapping it out this coming week (July 4-8, 2012).

This head gasket leak is the first real problem I have had with the engine but I have heard that the 4.2L engine is prone to have certain idiosyncrasies (lower intake manifold leaks, etc.) Does anyone have any suggestions re: what I should replace while the newer engine is still on the bench and can be accessed much easier before it is installed?

I think I will go ahead and put a new lower intake gasket on before putting the engine in. What else should I think about?

Thanks.

 

I have a follow-on question: Is it true that you can use a replacement engine only if the donor engine it is the exact same size (i.e. 4.2L V6) and the SAME YEAR as the receiving truck?

 

You can use any 4.2L, I reckon, but the later would be better. That may involve swapping some pieces over, but a salvage yard won't tell you that just to cover their backsides.

If the 4.2L you found still uses those isolator bolts and o-rings, change them out, too. Some will recommend fiddling with the IMRC setup, but mine hasn't bugged me, so I can't tell you what that is all about from memory.

 

I am swapping a 1997, 4.2L V6 to a 1998, 4.2L V8 engine. But before I began I searched asked about the vin# issue. And got so manny mis-information, it made my head spin. So I finally emailed Ford manifacturers. They told me that between 1997-2010, they used the same basic engine and other then it being a V6 or V8. The engines are the same. You'll just have to swapp out the intake manifold, sensors, and exhaust. Everything else is the same. If you have any questions try emailing this site:http://www.partsvoice.com/