losiglow

iTrader: (1)

I've been putting off doing a valve adjustment for a few months since I've been busy with various home improvement projects. And the motor hasn't been especially noisy. But I finally bit the bullet and did it last Saturday morning, along with a few other little maintenance items like cleaning out the throttle body, intake manifold, fuel injectors, EGR, PCV, etc. Anyways, all those other things were pretty clean. A slight bit of buildup on the TB and IM but that's it. Once I removed the valve covers I was pleasantly surprised to see that the valve train was shiny clean. That wasn't the case on my wife's '09 Pilot that had used conventional oil up to 200K miles (got a good synthetic in there now). Anyway, I was surprised to find that the valves were surprisingly loose. Even the exhaust valves were loose, which I found to be a little bizarre since I've always seen loose valves on the intake and tight on the exhaust. The spec for the intake is 0.008" - 0.009" and exhaust is 0.011" - 0.013". That's the same on every J I've worked on BTW (3G TL, Pilot, 2G RL, 4G TL). I was seeing the intake around 0.011 and the exhaust as far as 0.015. There were two that didn't need adjusting, but the other 22 all required at least a quarter turn on the adjusting screw to get in spec.

As far as safety of the engine goes, most mechanics say that when in doubt, going a bit looser than tighter on the exhaust valves is good since too tight can result in the valves not fully contacting the head and thus, overheating and cracking since they're not cooling down like they should. However, too loose results in the valves not opening as far as they otherwise could, resulting in more pumping losses. Still, I live dangerously so I decided to go on the tight side for both, 0.008" for intake and 0.011" for the exhaust, but made sure the gauge was still able to move relatively freely with only a moderate amount of resistance.

I've gotta say, I haven't really noticed a difference with a valve adjustment in the past but the difference was significant after this one. Maybe because both intake and exhaust was loose. If you really want to breath some new life into your motor consider a valve adjustment. It took me 5 hours total after all the other stuff and assembly/disassembly. Check out Eric the car guy's video for a tutorial if needed. It's the same on the 4G as the 3G in the video. Easier actually since you don't need to move the power steering hose, coolant reservoir or some of the sensors on the intake manifold that no longer exist on the 4G.

dregsfan

How many miles on the car?

TL4GX2

losiglow

iTrader: (1)

168K. However, I had to have an engine replacement at 122K, which I had done with an engine that had 66K on it. So the actual engine would have closer to 112K. That's a long story. I originally thought it was a oil control ring defect but it turned out to be my fault. I gutted a cat but didn't remove all the substrate, which was then sucked in to cylinder #5 which scored the living crap out of the liner. It was only discovered when I removed the head off the old engine. Yeah, don't ever do that. I learned the hard way that you can actually get material in the exhaust sucked back into the cylinders during startup.


I've done Seafoam in the past, both through the intake, in the oil and in the fuel. The only difference I've noticed is when running it in the oil for about a hundred miles or so prior to draining. I've done that in any car that I've purchased used (which is all of them) and noticed that the oil darkened up very quickly presumably because the Seafoam was cleaning out whatever gunk might be in the engine. However, once I've owned the car and changed the oil more frequently with a good synthetic, I've never seen the darker oil thing occur using Seafoam in the crankcase after that. Again, presumably because the engine is significantly cleaner and there's nothing for the Seafoam to flush out.

I've never noticed any difference when it's in the fuel. And it doesn't have PEA, which is the best carbon cleaner for engines as far as I'm aware. Yeah, you get the white cloud but that seems to happen either way. I don't believe that's carbon though. I think that's simply the pale oil and naptha burning off, which are the main ingredients in Seafoam, along with a bit of isopropyl alcohol I believe. Looking at the before and afters on YouTube, of which there is quite a few, is less than impressive. So yeah, I don't bother with it. I just use top tier fuel and occasionally pour in a bottle of Gumout "Multi-System Tuneup" in the tank. I'm not sure if it does much either but it's not expensive and has lots of PEA (which is proven to clean off carbon). I've looked at my exhaust valves with a boroscope and they are clean. So the proof is in the pudding I suppose.

dregsfan

Ouch!

losiglow

iTrader: (1)

Yeah, that was a hard $3500 lesson.

I think if I ever have to replace an engine in the future that I'll try doing it myself. It really doesn't seem so bad as long as you have a cherry picker. Obviously it would be a pretty big job but the shop that did it only charged me for 22 hours of labor. Looking at the service manual, it seems like it would be do-able. And the engine would be super easy to service when it's out of the car so you have everything done when it goes in. Valve adjustment, timing belt, water pump, tensioners, thermostat, oil, sensors, oil pump, etc., etc., etc.

thoiboi

I've always heard that COULD happen, didn't hear any instances of it ACTUALLY happening.. Wow, lesson learned

losiglow

iTrader: (1)

It's always possible that something like a bit of dust might get sucked into the cylinder when you've got the intake manifold off and you didn't put a towel on the intake runners. Or maybe few bits of dried grease when you installed some high flow cats or PCD's. That stuff would either get pushed out or burned up. Maybe even melted then passed through the piston rings over time. Ceramic substrate on the other hand. No Bueno. You might has well drop some pebbles (sharp pebbles mind you) into the cylinder which doesn't bode well.