Here are some details on the used 4.0L engine for my daughter's TJ. As Jess mentioned via an email, there are several different versions of 4.0l engines. I'm somewhat familiar with the different versions because of the research that I did when I swapped the 1997 TJ engine into my 95 YJ. My daughter's 99 TJ is almost identical. I think her intake manifold is different - some people like the 99 intake because they think it flows better and will retrofit it onto earlier TJs or YJs.
Her new (used) block is a 53020569, and the cylinder head is a 0630. Both date to 1997-98. I don't have a picture, but her 99 TJ has a distributor - I replaced the cap/rotor back in 2020. (I think the 2000 engine with the weak 0331 head that Jess mentioned had a separate coil per cylinder.)
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| Block Casting Number |
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| Cylinder Head Casting Number |
I had my initial doubts, but I'm beginning to trust this engine. There's no ridge at all on any of the cylinders, and you can see how clean the cylinder head is in the image above. The oil pan was also very clean - no chunks, sludge or sparkles that would give me any concern. So, it does seem like a low-mileage engine.
The new engine had some very light corrosion on #6. I saw this problem with the borescope a few months ago and asked about it back then. Best guess: it looks like some water leaked into the intake manifold and found it's way into #6 because of the way it was sitting. The corrosion looked horrible, but cleaned up very easily with a brass brush.
I also lapped that valve, and it cleaned up great too.
The #6 cylinder wall was a little stained, but not really corroded. But the #6 top piston ring was somewhat corroded and locked in the groove. I cleaned up the piston and replaced those #6 rings.
New head gasket and head installed after chasing all the threads. In case anyone notices the head bolts...yes, I reused the head bolts - per the factory manual they can be re-used once:
Rocker arms torqued properly and new valve cover installed:
Old Harmonic Balancer removed (and scrapped), and new front crankshaft seal installed. (Because of the lack of noticeable wear, I did not change the timing chain) or remove the timing cover.)
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| Scrapped! |
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| New Seal on the left |
New thermostat and thermostat housing installed:
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| New housing and thermostat installed |
New water pump installed:
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| Old Water Pump |
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New Water Pump and new Heater Tube
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I'm a big fan of the factory service manual - it's worth the extra cost to have all the details and torque settings.
As it sits today. No pictures, but I also replaced the PCV valve and grommets.
I still need to replace the rear main seal and oil pan.
Most of the missing parts will be swapped over from her 99 engine (Intake manifold, exhaust manifold, accessory drives, alternator, dipstick, etc.).
