Engine Swap 98 grand into my 2000 XJ?

The engine (4.0) in my '00 XJ has been loud since I've owned it, but last week it suddenly went up to a whole new level. People turn to look when they hear me coming down the street. SO, bought an engine from a '98 grand that has about 50k fewer miles and runs.

I've started taking things apart on both and am starting to see some differences, some I expected, some I didn't. Is there anything tricky or terrible about this swap? Looks like I just take all the accessories, manifolds, mounts from my bad motor and swap them onto the "new" and fabricate a bracket for the coil pack.

The exhaust and intake openings on the head look to be a little different shape. Is that going to be a problem?

Thanks in advance. Steve in Colorado Springs

The exhaust manifold will bolt up and work, it's not ideal. I know someone who is running a 98 engine on their 2001 ... no mounts for the coil rail it's just sitting on the spark plugs, and nothing special for the different exhaust ports.

Engine brackets from the XJ will work. Engine brackets from the Grand will not work.

Any 1990-2001 XJ or 1993-98 ZJ 4.0L engine block will interchange.

Reuse as needed or required: Intake/exhaust manifold, cylinder head, distributor less ignition or distributor, sensors, belt drive accessories, flex plate.

Thanks all. Made a lot of progress today. Yes, I did have to swap out water pumps. Slight issue with the oil filter. Put the angled attachment off my old engine on, but can't tilt it down. Going to wait to see what, if anything is in the way when I put it back in the vehicle. may take the attachment off and screw filter straight on. Otherwise looks like the filter will have to be upside down.

The oil pressure sender is in a different place, but should be ok with old sensor.

Any hints on how to be sure the "distributor" goes on correctly? Looks like it can only go two ways, would like to pick the right way the first time.

Generally when installing the distributor you ensure No.1 cylinder is at TDC compression stroke with the timing mark a couple degrees before 0.
Then you will need to put a pin or tooth pick in the hole in the dist housing to align the base plate and housing for rough timing before inserting the dist to align the dowel pin on the block.

The smaller '00-01 cast exhaust manifolds won't properly cover the larger '91-99 7120&0630 heads' exhaust ports. To do it right, either buy a new&improved 0331 casting head(~$400), a used TUPY cast 0331 head from a newer TJ/LJ(~'02-06) or a bigger header. There is also an adapter plate that bottlenecks the older heads' ports down to the newer manifolds, but I am unfamiliar with the brand/details.

sjroocos said:

The engine (4.0) in my '00 XJ ... SO, bought an engine from a '98 grand that has about 50k fewer miles and runs.

I've started taking things apart on both and am starting to see some differences, some I expected, some I didn't. Is there anything tricky or terrible about this swap? Looks like I just take all the accessories, manifolds, mounts from my bad motor and swap them onto the "new" and fabricate a bracket for the coil pack.

The exhaust and intake openings on the head look to be a little different shape. Is that going to be a problem?

Thanks in advance. Steve in Colorado Springs

Click to expand...

When you get this done, can you provide an update? Everything kept from old vs brought over with donor vs .... so anyone else doing this knows exactly what they're getting into?

Success!! Completed the swap and it started right up! The engine was from a '98 ZJ and I put it in my 'XJ.

Brought over nearly everything from my old motor. Flex plate, motor mounts, brackets, accessories, water pump and manifolds. Did not use the oil filter 90 deg bend from my old motor as the angle of the oil filter mount on the '98 block is different. There's plenty of room for the filter without it though.

As mentioned above, the exhaust manifold openings are a bit smaller than the head's exhaust port. I'll likely just leave it that way unless I notice a problem. I kept the '98 exhaust manifold. If there is a problem I'm thinking might be cheapest just to install that and take to a shop to have the upper section of exhaust cut out and redone to fit.

Right now the coil pack is just sitting on the plugs, but I plan to make a could little brackets off the valve cover bolts to hold it in place.

It was a pretty straightforward swap for the most part. Thanks to everyone for the help.

sjroocos said:

As mentioned above, the exhaust manifold openings are a bit smaller than the head's exhaust port. I'll likely just leave it that way unless I notice a problem. I kept the '98 exhaust manifold.

Click to expand...

The exhaust manifold that came with the head doesn't match up?

The exhaust manifold that came from the '98 will fit the head, but won't match the exhaust pipes. The '98 manifold is one piece, steel tube and has only one outlet, whereas the '00 manifold is a two piece cast.

Was actually thinking of using a dremel to smooth out the bottom edge of the cast iron manifold, but not sure it's worth the trouble.

I know that. You said you kept the 98 exhaust manifold.

Sorry, Meant I kept it around just in case I decide it's worthwhile to use it at some point. I actually installed the '00 manifolds.

If the smaller outlets on the '00 manifold becomes a problem, I think the easiest fix is to install the '98 manifold and have the exhaust system modified to fit it.

Performance wise the mismatched ports aren't a good thing. Sealing wise there is only like 1/8" of manifold touching the head on the lower portion. Keep an eye out for leaks.