New 6.5 Owner - Engine Misfiring

[6.6/6.5]

John,

Thank you for the response to my posting. Yes, the p/u was purchased on eBay from a Utah auction firm. The body, chassis and drive train seem to be in very good condition, but the engine is problematic. I need a work truck and it will serve my purposes very well once the engine issues are resolved. I ordered a compression gage and adapter last night and I will report the compression data as soon as they are measured.

Some additional symptoms: The engine smokes heavily (blue smoke) on starting. The smoke clears approximately 2 to 3 minutes after starting. There is oil in the induction hose between the filter housing and the turbocharger. I will replace the CDR as soon as one can be purchased. The engine produces a "clicking" sound at idle. This noise either stops or is masked with higher engine speeds. Probing with a stethoscope didn't provide any definitive information, but there does seem to be a slight increase in the volume of the metallic clicking sound in the proximity of the No. 6 cylinder.

Besides servicing the fluids and filters, I've replaced the glow plugs which has made the starting much better.

Jim

[BobND]

As for the CDR, there's a 90+ % chance the oil in the hose is simply from oil mist condensing out of the engine blowby simply passing through the CDR, as it is supposed to.

The CDR is basically an open, empty chamber with a spring-loaded diaphragm that begins to close off the crankcase ventilation flow if the crankcase pressure begins to go negative.

Realistically, the only time that would happen is with a restricted air filter, or POSSIBLY on an engine in very good condition, with very little blowby, at high RPM's (LOTS of air being drawn in by the turbo.

The CDR's that I have replaced were replaced because the diapragm developed a leak, and oil leaked EXTERNALLY through the tiny weekhole in the side of the CDR.

[moondoggie]

Good Day!

When does it miss? All the time? cruising? Heavy footfeed?

Blessings!

[6.6/6.5]

The engine misses most noticeably at idle. However, I am quite certain that it continues to miss at higher engine speeds. The clicking noise can be readily heard at idle, but is still detectable up to 1500 rpm when the exhaust and combustion noises tend to be more apparent.

[JohnC]

Could be a piece of detritis in one of the injectors. At higher power levels it has less effect. Loosening the fuel lines one cylinder at a time will isolate the offending cylinder, then you may want to have that injector tested.

[gvig]

I purchased a warranty pull out (6.5) that had this very problem, finally found a broken valve spring. When you isolate the cylinder and find no compression at idle speeds, check the valve springs, a valve will float open without enough spring pressure, but the compression pressure at high rpms will blow it shut.

Good luck!

[6.6/6.5]

The following is a report on the compression test. The Matco compression gage and adapter arrived today and the following data were measured:

No. 1 = 330 psi No. 2 = 340 psi
No. 3 = 290 No. 4 = 340
No. 5 = 300 No. 6 = 320
No. 7 = 310 N0. 8 = 220

No. 8 was the first cylinder tested so it had the advantage of a more warm engine than the remaining cylinders (No. 1 was the last tested).

So, tomorrow the intake manifold and rocker arm covers will be removed in an attempt to determine what ails cylinder #8. Given the relatively low compression readings, I suppose that I should be contemplating a "drop-in" remanufactured engine or pulling and overhauling the existing engine. The truck's condition warrants a decent engine. I'll do some trouble shooting first.

[JohnC]

Hey, guys, this really cheap compression tester is probably a bargain if it gets through all 8 cylinders! It's even less ($16.99) in the latest sale flyer!