Well the time has come to either replace or rebuild the engine, I have read and read and with slipping liners and other wear items I am hesitant to buy a used engine. I am also hesitant to rebuild mine because of the eventual issue of a liner coming undone. Of course I could spend 5k-7k and have a great engine in it but thats probably not happening. So firstly, how bad is this slipped liner business? Its seems to be an issue but how likely is mine to start slipping at 160k miles if I rebuild? Is it wise to purchase a used 4.0? My local mechanic quoted $1000 to swap the engine I purchase, has anyone swapped these and if so any advice would be appreciated to save that money. Thanks for your input! John

 

i don't think the slipped liners are really an issue with the GEMS 4.0's.

but any used engine you purchase will be a roll of the dice.

 

do a search.....it's pretty easy to "pin" the liners .....especially when the engine is out to be refurbished......

 

as stated above slipped liners in D1's, are a lot less common that a D2.
of course if anything abused can have issues.

if you know your block and it has not been severely over heated or neglected,
i would go with the one i know. jmho.

if you want to get fancy you can throw a 4.6 crank and rods in it

 

Iirc the liner issues are 03/04 mostly

I rebuilt mine no problem and threw in 4.6 crank and rods runs great wheels great, wish I did the stock 4.6 cam but either way its fine

Hell my rebuild was under 2 k iirc because I did the labor and built the engine , just had machine shop do work on components

What's wrong with the engine?

 

It runs beautifully until she's really good and warmed up. Then when any load is placed via acceleration/rev up or trailer it has a very loud and distinct "clack" coming from the drivers side of the engine. I replaced the exhaust manifold gaskets but a no go. I had a mechanic verify the left manifold is cracked but they say that's not the noise for sure and it sounds not good to them. I think it makes the noise once per revolution.

 

Just curious if you can tell/know does the noise sound like it is coming from the upper half of the engine or the lower half? To me just from what I have read so far could either be valves need some tending to/replaced or perhaps bad rod bearings. But that's just my thoughts from what I know so far of your issue.

As far as rebuild/replace/used replace. I would go with rebuild, as it looks like the slipping liners are not a huge issue in this year, and personally I always go with fix what ya got and ya know is good. Course also some valuable experience is gained in doing so. I learned a lot and have better respect for these motors after just rebuilding the top half of mine.

 

It does sound like the upper half to me, I thought it was an exhaust leak at the manifold because the sound is so close where they mate. , there is no noticeable loss of power or anything else when it is under load, just very noisy. I like the idea of just rebuilding the top

 

What's your budget?

 

Left manifold replacement may be wise prior to declaring DOA.
......