My FIL just acquired a 2002 Frontier with the 2.4L engine. It has 290k miles and doesn't want to start.

Pulled codes, saved codes. random misfire and egr valve stuck P1402 I think.

Check fire. it's good, checked fuel, it's good to go. here's where it gets interesting. Check compression. 0psi across the board. Pulled valve cover to see if timing chain broke. Nope it's still good, but the oil looks slightly milky.

I didn't get to do a leak down yet, but it seems like it may be a head gasket causing the issue. I forgot to add, the oil i slightly milky. That' what's is steering me towards a head gasket also.

Cam timing probably jumped. Pull the cam cover, set the crank to TDC and look at the position of the cams.

Thanks, that's on the agenda. I'll probably have to end up doing a head gasket due to the water intrusion.

well found the culprit, the main timing chain guide that the tensioner presses on was broken. So, that explains why it was so out of time. We picked up a new timing set and will throw her on and then see how bad the damage to the valves are. Hopefully, not all of the valves are bent. If so, not that big of a deal, pull the head and lap new valves in. The water intrusion doesn't seem to be bad that we drained some oil. So, HG may be good to go.

The saga continues......

installed a new timing set and confirming my suspicion still no compression. Time to pull the head. So, after a few hours taking out time we were able to get the head off and sure enough, you can see where the valves kissed the pistons. All 16 valves are toast, but the intakes are way worse than the exhaust valves but I am changing them all out and inspecting the valve seats when I remove the old valves to see if they are ok. The pistons crowns are in good shape and the cylinder walls still have the factory cross hatches despite having 270k hard miles on the engine.

So, head disassembly time and I will post as I go. Hopefully it's like the few K series hondas I did in the past, lap the new valves in and GTG.

well I was able to put the head back on the engine today along with all of the valve train components and front timing cover. I have to say while this engine isn't was easy to work on as the honda engines are, it still wasn't too bad. I lapped the new valves in and checked for proper sealing. Looked good, the exhaust seats could have used a new cut but they weren't that bad.

That degree wheel I bought, was extremely easy to use to install the torque to yield head bolts.

There is one thing that I don't understand why the nissan engineers designed the long timing chain tensioner the way they did. The tension is driven by oil pressure along with a spring, which is fine, but there is no mechanism to stop the tension from going slack besides the oil pressure. Seems to me like that could cause a timing jump if there ever was a misfire with the engine.

its alive!!!!