larso1
Gold Member
Howdy, just thought I'd give a followup on the problem I'd posted about a few months ago on my Iseki TS1610F that would gush oil out the valve cover breather. Maybe it'll help someone else with a similar problem. Obviously I had plenty of blowby that prevented the oil at the top (head) from flowing back down the pushrod tunnels. This Isuzu motor has no crankcase breather which seems unusual to me, and if it had, it probably would have masked (and alleviated) the problem. Anyway, I had checked the cylinders with a leakdown tester and found 22% in front cylinder (not bad) and 35% in rear (not too good, but the motor had started up OK). The oil pressure was between 62 and 65-psi, normal according to the manual. I now have the head off and the pistons and rods out (it was really nice that I didn't have to split the tractor to do this). Well, the head gasket looks good....no tracks on its surfaces that would indicate leakage. I checked the rear bore with an inside micrometer, two places 90-deg. apart on bottom, middle and top of bore. All the readings, including piston to bore clearance, were well within the proper specifications indicated in the manual....within .0015-in. bore specs. There wasn't even a ridge at the top of the cylinders. The rings look good, no cracks and they all were free in the lands. I checked the pistons for cracks, and none to be found. Verdict: Looks like the compression rings must have gotten weak from an overheat condition sometime in its life. (This motor is not a thermosyphon, and does have a pump.) A diesel mechanic friend of mine said the previous owner probably let it sit and idle at slow speed for too long a time, which he said can overheat the rings. ( I know there's been a lot of discussion here in the past about pros and cons of idling a diesel, and I'm no expert on the subject so I'm just reporting what he said). Anyway, I'm going to hone it out with a ball hone, put in new rings, rod bearings and head gasket, and button her up. I'm pretty happy that it appears to be nothing more. I'll let you know how she runs when the time comes. Later,
Bill in CO
Bill in CO
