blown99

I performed a cylinder leakage test and found the air going right into the crankcase, past the rings. I removed the heads and pushed out the pistons and found my answer. All of the ring gaps were lined up! except on two pistons (the two being the ones with 375psi compression). The carbon tracks blew right past the rings and trough the oil control ring. Also decided to check the heads for warpage as I have no info on the previous running condition. Found both heads to be warped pretty good. Cylinder walls look good. So as part of Navistar up-time program this engine will be getting a new EGR cooler, oil cooler, turbo (pulled apart no good)water filter bracket and hoses, coolant expansion tank, new rocker arms, two cyl. heads, 8 psitons, rod bearings, just about every gasket and a branch tube update. Everything but the injectors (which I am sure I will find are bad once this is running) block and crank will be new.

The rods don't apear to bent ( from looking up past the crank) Also didn't notice any scoring on the camshaft indicating broken cam followers. Supposedly they were driving it, started running very bad, nursed it back to the yard, shut it off, then there techs went out to look at it, and killed the batteries trying to start it. I didn't get a chance to tear the heads of today as us international guys are 3-4 deep in the 6.0 work too.

I removed the pan. Not a spec of anything. I had white smoke vapor coming up past the hpo manifold/rockers while cranking for extended periods.

20 - 30 thousand miles is all I am seeing out of these turbos before they need maintaince, (in international chassis). Its been about a 50/50 chance of reconditioning them once I open them up and inspect.

Ok, tested the high pressure oil system today, pressurized the system and found no leaks/air leaking. Dissabled the glow plug system and gave it a little starting fluid - nothing. removed valve covers and checked rockers and puch rods- ok. Performed a compression test. Cylinder 1, 3 have 375psi,5, 7, 8, 6, have 140- 150 psi, 2 has 275 psi, and 4 has 175psi. I remove the high pressrue oil manfolds and bar the engine over to verify that the valves are opening and closing. Did not appear to have any bent valves as the vavle heights visually looked the same. Tech line wants me to drop the pan and look. All looks good, no scores, no metal on the drain plug magnet. I still think that the cam timing has changed as the cam gear is only sweated and keyed to the shaft. Engine group said that it wasn't possible because I would get a cam and crank sensor codes saying that the signals are not matching/synching. There is no popping back through the intake or exhaust while cranking and I did notice white smoke (smelled like fuel) coming up past the push rods while cranking for extended periods. The injectors are buzzing while it is cranking, IPR is about 21%. Also removed the fuel lines at the back of the fitler housing and put balloons on them and cranked to check for compression blowing back through an injector, nothing found. So basically the rear 4 cylinders have low compression with the exception of #2. Spec is 375 - 400 psi.

Had a school bus (international bus) towed in today for a no start condition. Batteries were low so I charged them, checked for codes, no active codes. Performed hard start no start diag. with MDII. Have 1200 psi for the icp, 45 pis fuel pressure, 13.5v showing for ECM volatge. While cranking it sounds very uneven, low compression, so I do a relative compression test. Cylinder 2, 4 read 0 rpm and 3 and 5 are around 6-8 rpm, the rest about 10 or 11 rpm. Cranking rpm was 175 rpm. No sounds of it even attempting to start skip smoke etc. Sounds kind of like a car with a slipped timing belt. Tech line wants me test the high pressure oil manifold/system and check for a broken branch tube. Doesn't sound like the right rode to go down. I'm leaning towards a valve train issue. Wondering what others have run into. I can't see a bad rocker arm on one cylinder keeping an engine from running. (tsb's on rocker arm failures). Thanks for any info.

Since ford doesn't allow their techs to recondition them, do they replace every one that has codes for excessive exhaust back pressure and or low boost? I have found that marking the exhaust housing for the actuator linkage makes reassembly of the unison ring much easier as you won't have to keep lifting hte ring and repositioning it.

\\ I agree with you. I almost always see a star pattern when I do a tear down whether it be a navistar, cummins or cat engine. They can range from dots on the piston in a star pattern to lines ranging out from the tip of the semitorital cone on the piston to the dish. Did the customer burn a hole in a piston? Do you have any pictures to put up?

What about an EGR valve? Does the ford diagnostics have the ability to graph the EGRP and the EGRD? Was the EGR cooler leaking internally also, causing the muck to build up in the intake and possibly plugging the EBP sensor and tube. I've been finding a lot of the VT 365 EGRP not matching the desired and they don't throw codes for this, (at least in the internationals).

A MAP sensor with a partially plugged line/orifice will cause this condition. I have run into this after an EGR cooler was leaking and there was plenty of muck floating around the intake.

If any parts show pitting then a new turbo should be ordered. They (international is concerned with the scratches left by the 3m scotch brite pad and wants us to polish the surface to eliminate them. I have attempted to recondition many of these turbos and have only had two that were salvagable. Typically I am finding the turbine wheel is damaged requiring turbo replacement.