Valve timing

[nykolos]

I have a 2000 Rodeo 3.2 DOHC, I'm trying to set the camshaft sprockets to the right position and I'm really confused as where the drivers side cam should be. For the passenger side, the Haynes manual says to rotate the sprocket until it springs into place lining up the mark to the valve cover, got that one, but the driver side they describe it different, they say the DS side wont spring into place on the mark and you'll have to rotate it and additional 90 degrees, which is not whats happening here, the DS springs into place on the mark just like the PS does. If I rotate the sprocket further, there is a position where the mark on the sprocket is 90 degrees counter clockwise the valve cover mark and the groove in the sprocket is lined up to the valve cover mark, is this the position where I should rotate it an additonal 90 degreess? or should the cam be set to the position where the sprocket springs into place?

Any help would be appreciated

Thanks!

[rodeo02]

Off hand I dunno the exact settings, but if you rotate the cam drive sprockets at all with the T-belt off, you will throw the valve timing off. It will be mess (lots of work) to re-establish valve time at that point. You'd have to remove valve covers to set the cams per specs, locate TDC of cyl#1, etc.. again, I don't know the exact procedure. IMHO- haynes and chiltons always seem to be riddled with errors. Helms is the only way to go for isuzu. Download that trooper manual that's floating around. The 3.5L has the same specs.

G/luck
Joel

[nykolos]

Originally Posted by rodeo02

Off hand I dunno the exact settings, but if you rotate the cam drive sprockets at all with the T-belt off, you will throw the valve timing off. It will be mess (lots of work) to re-establish valve time at that point. You'd have to remove valve covers to set the cams per specs, locate TDC of cyl#1, etc.. again, I don't know the exact procedure. IMHO- haynes and chiltons always seem to be riddled with errors. Helms is the only way to go for isuzu. Download that trooper manual that's floating around. The 3.5L has the same specs.

G/luck
Joel

Thanks Joel, TDC on the engine is actually the #2 cylinder, I just removed the DS valve cover to see where the cam is positioning, the lobes on the cam should be pointing up or away from the lifters, correct? this would be the closed position. I lost the timing because I removed the heads, I did a lower engine rebuild on the motor because of a spun rod bearing, changed out the crank, rod and main bearings, rings, seals etc, and reinstalled the heads, I didnt do any head work though, the Haynes manual was great, just wish they would of elaborated more on the cam positioning......Nick

[rodeo02]

Wow! you've done a lot of work. Did she run low on oil to spin the bearing? Was it bearing #1? I've seen conflicting info on the actual cause of the bearing failure. Some say low oil, some say it's a design flaw. #1 is closest to the oil pump, so you'd think it would be the last to starve. Yep, since the cams are direct acting, lobe up = valve closed.
G/luck
Joel

[nykolos]

Originally Posted by rodeo02

Wow! you've done a lot of work. Did she run low on oil to spin the bearing? Was it bearing #1? I've seen conflicting info on the actual cause of the bearing failure. Some say low oil, some say it's a design flaw. #1 is closest to the oil pump, so you'd think it would be the last to starve. Yep, since the cams are direct acting, lobe up = valve closed.
G/luck
Joel

I've been working on it for a couple weeks now, waiting for the parts takes the longest. My wife ran it low on oil, and YES, it was the #1 rod bearing, a mechanic told me it's because most of the torque is in on the front of the crank, I dont know if thats true or not, I thought it was a oil flow problem myself, after inspecting the other bearings, a few others were well on there way.


It's our fault for not checking the oil regularly, but Isuzu is to blame for the rapid oil consumption, it burned over 4 quarts within 3000 miles, and the Rodeo has about 70K on it.....Thanks for the help!

Nick

[rodeo02]

Originally Posted by nykolos

.... a mechanic told me it's because most of the torque is in on the front of the crank...

Nick

Interesting. That does make sense! I guess our only preventative measure is MAKE SURE the oil lvl is topped up.

Thanks
Joel