kenavt
SILVER Star
Hey folks, I'm working to adjust the valves on my 1HD-FT, and was wondering a few things. Hoping to get some advice from folks who have done this before. The backstory here is that I went to replace my valve cover gasket, and thought I'd adjust the valves while I was in there - but I'm quickly learning that's easier said then done on one of these diesel 24-valve motors. Most folks online I've seen doing this have done it as part of a larger job like a timing belt swap, or pulling the intake manifolds to clean and delete EGR. I really wish I had left it for a bigger job, but here we are!
The first thing is how to put the engine at TDC exhaust (not TDC compression) to adjust the second set of valves. I put the engine at TDC compression by popping off the timing belt cover and checking the mark there on the camshaft pulley, as the crankshaft pulley mark is near-invisible with all the front-of-engine accessories on. The FSM says that you should just turn the crankshaft a full 360deg... so I've been doing a full 360deg to hit the TDC mark on the camshaft pulley a second time, which means I end up back at TDC on compression... is the rotational relationship not 1-1 there? Are there any other easy ways to figure out when I'm at the "right" TDC?
The second thing is that I measured my first few valves before adjusting them (stone cold), and I was measuring that the valves were dramatically out of spec (intake is supposed to be ~0.008", I was measuring 0.028" and above). The engine seemed to be running fine before, maybe a bit rattly and loud (I'm not used to being near diesels), so... are these readings valid? Could these be right? I feel like if the valves were this out of spec, there would have to be some sort of issue. I did leave the valve cover off for a long time (weeks) as life got in the way of me finishing this job.
FSM snippets below from RM-437E, the 1HD-FT Engine Repair Manual (but RM-617E for the 1HZ, 1HD-T, 1HD-FTE looks similar)
The first thing is how to put the engine at TDC exhaust (not TDC compression) to adjust the second set of valves. I put the engine at TDC compression by popping off the timing belt cover and checking the mark there on the camshaft pulley, as the crankshaft pulley mark is near-invisible with all the front-of-engine accessories on. The FSM says that you should just turn the crankshaft a full 360deg... so I've been doing a full 360deg to hit the TDC mark on the camshaft pulley a second time, which means I end up back at TDC on compression... is the rotational relationship not 1-1 there? Are there any other easy ways to figure out when I'm at the "right" TDC?
The second thing is that I measured my first few valves before adjusting them (stone cold), and I was measuring that the valves were dramatically out of spec (intake is supposed to be ~0.008", I was measuring 0.028" and above). The engine seemed to be running fine before, maybe a bit rattly and loud (I'm not used to being near diesels), so... are these readings valid? Could these be right? I feel like if the valves were this out of spec, there would have to be some sort of issue. I did leave the valve cover off for a long time (weeks) as life got in the way of me finishing this job.
FSM snippets below from RM-437E, the 1HD-FT Engine Repair Manual (but RM-617E for the 1HZ, 1HD-T, 1HD-FTE looks similar)