Maintenance questions for a 4.0 with 200k miles

MangoTango

MangoTango

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First of all, Merry Christmas! I hope everyone is doing well today.

So my 4.0 is at 200k and I've been experiencing some lifter noise. Since I've already got most of the front end out of the way (replacing lifters, cleaning and painting the engine), I was wondering if there are other things I should be considering at this point? Other than the lifter noise the engine runs great so I'm unsure if I should be considering things like a timing chain replacement, rocker and pushrods, valve springs, high flow water pump, thermostat?

I have an opportunist but also "if it aint broke dont fix it" conflicting mindset. Thanks for the input!
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With that many miles I always install a new Melling oil pump. Your choice whether to go the standard or high volume. Some have experienced clearance issues with a high volume pump, but I've installed 3 with no clearance issues. In all cases, standard or high volume, oil pressure increased significantly and valve train noise decreased.

Edit: Also, if it hasn't been replaced, I'd do the entire cooling system. I've done timing chains at that mileage, but, unless there's a failure problem, I typically haven't noticed any appreciable wear. Of course if the timing cover is leaking and you need to do the gasket, you might as well do the chain while your in there. If the engine is running fine and compression is good, I wouldn't rebuild the engine. 200k really isn't bad on the 4.0l.
 
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I had my 225K all original motor out for a frame swap. I just had new seals / gaskets put in (IE RMS, exhaust, intake, etc... but no head gasket),. If it runs strong, I don't see the point in yanking it and doing a rebuild. I'd personally just replace what is original or old and go from there.
 
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High flow water pumps are a complete scam, at least as far as the 4.0 is concerned.

What problem is a supposed "high flow water pump" attempting to solve anyways? A problem that doesn’t exist 😉
 
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If it was me and I was already to that level of taking the engine apart, I would just rebuild the entire thing. It would be cheap, straight forward, and you'd get 600k plus out of it pretty easily.

At the bare minimum though, I'd probably at least rebuild the head and do the timing chain I suppose.
 
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Do a compression test. How's the oil pressure? These will tell you what you should be doing. Good compression? No reason to mess with rings. Good oil pressure? No need to mess with bearings. Get any leaky gaskets now. A new water pump isn't a bad idea. They are wear items that need replacement weather they leak or not. The vanes in the pump wear back with use resulting in less and less coolant flow.
 
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Goatman said:
Do a compression test. How's the oil pressure? These will tell you what you should be doing. Good compression? No reason to mess with rings. Good oil pressure? No need to mess with bearings. Get any leaky gaskets now. A new water pump isn't a bad idea. They are wear items that need replacement weather they leak or not. The vanes in the pump wear back with use resulting in less and less coolant flow.
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X2. Test to see if repairs are warranted.
 
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Irun said:
With that many miles I always install a new Melling oil pump. Your choice whether to go the standard or high volume. Some have experienced clearance issues with a high volume pump, but I've installed 3 with no clearance issues. In all cases, standard or high volume, oil pressure increased significantly and valve train noise decreased.

Edit: Also, if it hasn't been replaced, I'd do the entire cooling system. I've done timing chains at that mileage, but, unless there's a failure problem, I typically haven't noticed any appreciable wear. Of course if the timing cover is leaking and you need to do the gasket, you might as well do the chain while your in there. If the engine is running fine and compression is good, I wouldn't rebuild the engine. 200k really isn't bad on the 4.0l.
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That's not a bad idea. Last time I drove it the oil pressure seemed fine to me, but there's no telling how old the pump is and I have to replace the rear main seal and oil pan gasket so might as well do a pump.

The radiator was installed new in 2013 when I bought it and Ive put less than 5k miles on it since, but I do notice the heater only puts out luke warm air so I might flush that while I have the lines off. I'll do a replace if the flush does not fix it.
 
Goatman said:
Do a compression test. How's the oil pressure? These will tell you what you should be doing. Good compression? No reason to mess with rings. Good oil pressure? No need to mess with bearings. Get any leaky gaskets now. A new water pump isn't a bad idea. They are wear items that need replacement weather they leak or not. The vanes in the pump wear back with use resulting in less and less coolant flow.
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You just reminded me that I bought a compression tester a while back. Might as well put it to use and go from there. The oil pressure looked good to me but I'm relying on my faulty memory. Since I'm already replacing the rear main seal I'm going to just get a new oil pump regardless.

Ordered up Fel Pro Gaskets for the head, oil pan, intake/exhaust, and I will get a new water pump (non high flow) and replace that as well. Oh and a thermostat.

This should be good enough for now as long as the compression test comes good.
 
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Chris said:
High flow water pumps are a complete scam, at least as far as the 4.0 is concerned.

What problem is a supposed "high flow water pump" attempting to solve anyways? A problem that doesn’t exist 😉
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Thanks for the input of this. I saw a few but the reviews were terrible. I haven't overheated but I could probably just get a 180 degree thermostat, new water pump, flush radiator and be done with it. I live in the North and it's not like we get really hot days here unless you consider 90 hot lol.
 
The 180 degree stat its another scam. I just read a post by Jerry explaining how it would just open up sooner on cold temperatures. I live on a Island in the caribbean where is 80-100f all year round with humidity between 70-100 and have no problem with the 195 stat. A cooler running engine is not necessary a good thing. Its best to keep it within the range it was design
 
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MangoTango said:
Thanks for the input of this. I saw a few but the reviews were terrible. I haven't overheated but I could probably just get a 180 degree thermostat, new water pump, flush radiator and be done with it. I live in the North and it's not like we get really hot days here unless you consider 90 hot lol.
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The 180 degree thermostat is also a scam. You want the factory 195 degree thermostat. It's just fine, even if you're in super hot climates like Arizona. @Jramos013 is right about that.
 
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Chris said:
The 180 degree thermostat is also a scam. You want the factory 195 degree thermostat. It's just fine, even if you're in super hot climates like Arizona. @Jramos013 is right about that.
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I fell for that BS years ago with my XJ. Replaced the factory thermostat with a 180 degree one along with a high flow water pump. Waste of time and money as there was no gained benefit from either.
 
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chino1969 said:
I fell for that BS years ago with my XJ. Replaced the factory thermostat with a 180 degree one along with a high flow water pump. Waste of time and money as there was no gained benefit from either.
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Yep, nor would there ever be unless you were running 16 psi of boost and some serious engine work, at which point then you might actually need to lower temps.
 
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