I was driving to work today, and my odometer ticked over 200k! it is a 2000 4.0sohc that I bought back in october with 196k. Now lets talk longevity. The engine ticks often, and there is an oil leak, but I baby it a lot. I check the oil almost every day, I change it every 3k with penzoil high mileage full synthetic, and try to not rev the engine above 3k rpm. What else can I do to make sure the engine stays in tip top shape? I want to try and get it to last as long as possible without replacing/ rebuilding it.

 

Exactly what you're doing. Timing chains will be the deciding factor.

 

You are doing about as much as you can do as long as you keep all the fluids at the proper level. With the 4.0 SOHC engine, it is good to replace the cam timing chain tensioners periodically. I replaced mine at 100K miles and at 250K miles I pulled the engine and did a rebuild of the cam timing chain system. The cam timing chain guides were still in good condition. They and the tensioners are the weak link in that system. What I did find was a broken crank to jackshaft tensioner which is not known to break.

I had no indication anything was wrong but just wanted to make sure everything is in good work condition and would continue to work for me for a long time. The work was not in vain because I did find some thing that needed repair. Now, it should be good for another 250K miles.

BTW, I don't baby that engine. I don't hesitate to take it to redline if I feel frisky. I certainly don't do that all the time but 3K to 4K rpm is pretty common. I tow a lot and do a lot of off-road trips. I think the 4.0 SOHC engine is a very durable one if maintained properly. The timing chain system is the weak link but not as bad as many people would make you think. Again, maintenance is key!