So a little update on my truck. I replaced the injectors and IP and the problem is still there. Under load, like going up a hill or rapid acceleration the engine starts knocking, blowing tons of smoke, and tries to runaway. Sometimes the smoke is white sometime black. If I get on the brakes and get the engine slowed down the knock will fade away and it runs perfectly again. Any idea on what this could be? The only thing I can think of is headgasket because of the smoke but neither the oil or coolant is contaminated. Any help would be great before I yank the heads.
Knocking, blowing smoke, general dismay
- Thread starter Hyde
- Start date
david85
Full Access Member
What sort of blowby do you have?
Have you serviced your CDR lately or modified your crank case ventilation system?
Are you keeping track of oil consumption?
Did you disturb the injector pump drive hear housing at all? (wondering the timing gear may be off)
Are you running an auxiliary fuel pump?
Have you serviced your CDR lately or modified your crank case ventilation system?
Are you keeping track of oil consumption?
Did you disturb the injector pump drive hear housing at all? (wondering the timing gear may be off)
Are you running an auxiliary fuel pump?
david85
Full Access Member
Some things to try is to clean the CDR out and see if any return lines are blocked.
To clean the CDR valve you take it off the engine and soak it in gasoline. Also check the intake for pieces of dried up rubber.
Does it cold start, and idle easily?
To clean the CDR valve you take it off the engine and soak it in gasoline. Also check the intake for pieces of dried up rubber.
Does it cold start, and idle easily?
david85
Full Access Member
I had a problem similar to that on a mitsubishi diesel once. There was a oil drainback problem that caused oil to fill the valve cover until it would go out the crank case vent hose and get sucked in by the turbo inlet.
When driving the feeling was of a runaway engine. It would start to crackle louder and spool up on its own accord until enough oil was sucked out that it would come back down again. Threw tones of smoke too....and not all blue either.
This is why I asked if the engine is using large amounts of oil that can be observed on the dipstick after a drive involving a runaway event like this.
To prove things once and for all to myself with that particular engine, I routed the hose to an oil jug under the hood. Sure enough, under the same conditions, the engine ran fine this time, but when I pulled over there was over a liter of oil in the jug that would have otherwise been ingested by the engine.
I would check your CDR valve or even rig a temporary RDT into a jug like what I did to see if oil injestion is causing your problem because if it starts and idles easily, I don't see this being caused by something in the fuel system unless you have a major air leak (but that would likely cause hard starting).
When driving the feeling was of a runaway engine. It would start to crackle louder and spool up on its own accord until enough oil was sucked out that it would come back down again. Threw tones of smoke too....and not all blue either.
This is why I asked if the engine is using large amounts of oil that can be observed on the dipstick after a drive involving a runaway event like this.
To prove things once and for all to myself with that particular engine, I routed the hose to an oil jug under the hood. Sure enough, under the same conditions, the engine ran fine this time, but when I pulled over there was over a liter of oil in the jug that would have otherwise been ingested by the engine.
I would check your CDR valve or even rig a temporary RDT into a jug like what I did to see if oil injestion is causing your problem because if it starts and idles easily, I don't see this being caused by something in the fuel system unless you have a major air leak (but that would likely cause hard starting).
Trying to run away.... that has to be oil. It's either being fed through the CDR, or by a serious head gasket or cooling jet/cracked piston weirdo thing. I'd ditch the CDR and switch to a road draft tube pronto, at least until you figure it out. The knocking is comeing from predetination, since the oil is being sucked in on the intake stroke. If there is enough of it, you could hydrolock. 
Thanks a bunch guys, I read the RDT article today and it said a sign of a failing CDR was oil on the air filter bolt. Well there was a good bit on there. I pulled the CDR but it must be a Ford only part or something as no one within 40 miles even knows what it is. Looks like I wall to an RDT and see if that helps does the trick. Thanks again guys
E3TZ-6A665-A"Adapter assembly for Crankcase Ventilation" That will get you a new one at the ford dealer
I see that thing has an automatic tranny. do not try to drive that thing till you either get a new cdr or remove the thing and get that oil pumping action eliminated. You have no way to kill that thing if it starts to run away short of removing the air cleaner and throwing a heavy blanket etc over the intake, not something I want to do with the fan spinning at overspeed inches away
Hey thanks a ton guys! Got the RDT done today and that cured the problem. I cut the CDR apart to make a blockoff for the intake and the thing was full of oil, I dont think thats supposed to happen. Thats a huge relief that I dont have to pull the heads. And that I have my truck back!
david85
Full Access Member
It was probably a badly deteriorated CDR. they are supposed to close off as the engine powers up to prevent too much oil consumption, but I never heard of a runaway problem like this before. First time for everything I guess.
Keep an eye on that draft tube to make sure you aren't unloading a ton of oil through it. That would indicate an internal oil drainback issue. Some oil in the CDR is to be expected, but if you dumped half a cup or more, then thats not normal. I still prefer to use the CDR but thats just me.
Keep an eye on that draft tube to make sure you aren't unloading a ton of oil through it. That would indicate an internal oil drainback issue. Some oil in the CDR is to be expected, but if you dumped half a cup or more, then thats not normal. I still prefer to use the CDR but thats just me.
