petehall12 Posted May 22 Share Posted May 22 While driving the motor popped back through the exhaust with a poof sound and a puff of black smoke. After that turbo will only build to 25 pounds and it has roaring noise over around the turbo area. And still pops back through the exhaust but it is random. No check engine light. The motor runs good still pulls loads fine. Changed the fuel filters on it and found silicone chunks in the top of the primary filter. But it is still doing the same thing Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 Can you cut the filter open and remove some if the element to see whats going in the filter? Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 I assume you have a powerleash engine brake. You may want to replace the orings for the celenoids. Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 I will when I get home tonight. Still trying to figure out were the silicone came from Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 2 minutes ago, Joey Mack said: I assume you have a powerleash engine brake. You may want to replace the orings for the celenoids. It is a Jacob’s Jake brake Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 So it truly is silicone and not fuel worms? Thats really odd. Do you have a Davco filter as well Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 Jacobs, ? Ok, somehow i dont recall Jacobs on an ASET. Well, can you check the valve adjustment to see if its in spec and look for a sticking rocker arm,? Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 5 minutes ago, Joey Mack said: So it truly is silicone and not fuel worms? Thats really odd. Do you have a Davco filter as well Not sure what are fuel worms? It has two filters side by side on the left side. It doesn’t have a water separator Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 And the motor seems to run great as long as you keep in under 20 pounds of boost no miss or hesitation in the take off but going from 20-25 pounds of boost you hear a roaring noise coming from under the hood and it won’t go to 30 pounds it stays right at 25. Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 15 minutes ago, Joey Mack said: Jacobs, ? Ok, somehow i dont recall Jacobs on an ASET. Well, can you check the valve adjustment to see if it’s in spec and look for a sticking rocker arm,? Yeah I can check that this weekend if the truck doesn’t get any worse and it makes it till then Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 Hows the exhaust manifold and gaskets look? Any cracks under the turbo in the center section? Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 41 minutes ago, Joey Mack said: Hows the exhaust manifold and gaskets look? Any cracks under the turbo in the center section? It looks ok I don’t see any black soot marks around 1 Quote Link to comment Share on other sites More sharing options...
JoeH Posted May 22 Share Posted May 22 I'm wondering if there's a fuel delivery/ignition issue? Loading up fuel in one cylinder from poor atomization in a failing nozzle, or there's a hot spot on one piston that occasionally causes an untimely detonation. Our 1979 endt676 had a slight miss when my dad bought it, wound up being a piece of silicone stuck in the piston cooling nozzle. But that was before I was born, so just anecdotal on my part... Just throwing out dumb ideas... Quote Link to comment Share on other sites More sharing options...
JoeH Posted May 22 Share Posted May 22 How are your oil seals on your turbo? Do you have oily soot in your exhaust or oil in your intake pipes? Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 1 hour ago, JoeH said: How are your oil seals on your turbo? Do you have oily soot in your exhaust or oil in your intake pipes? The intake pipe is clean I am going to pull the exhaust side tonight and look at the fins. I had an old mechanic tell me the same thing he thinks that with the turbo not building enough boost fuel might be accumulating in the exhaust and detonating especially it being so intermittent. I have been running the truck for 8 hours so far today and it has only happened 4 times Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 22 Author Share Posted May 22 Especially since it is just a straight turbo no vgt or watergate the only 2 reasons it won’t build boost is either the fins are bad on the exhaust side of the turbo or it has leak somewhere. I hooked a smoke machine to it last night and didn’t see any leaks. Quote Link to comment Share on other sites More sharing options...
JoeH Posted May 22 Share Posted May 22 What chassis is this? Probably not an RD600, but the charge air coolers on RD's do tend to crack along the seams where the core mates to the tank. But this shouldn't yield the popping sound in your exhaust, just the low boost. My '95 RD688 went down to 21 psi max til I noticed it had cracked. Quote Link to comment Share on other sites More sharing options...
JoeH Posted May 22 Share Posted May 22 You'd need to pressure test it, not just smoke test. Quote Link to comment Share on other sites More sharing options...
Joey Mack Posted May 22 Share Posted May 22 (edited) if its not a trash truck I suspect and RD 688S or a CV 713 Edited May 22 by Joey Mack I made a Boo Boo Quote Link to comment Share on other sites More sharing options...
fjh Posted May 22 Share Posted May 22 Also if it’s an mr check the hat on the inlet of the air cleaner if it collapses on the intake it will momentarily shut down till the turbo stops sucking! 1 Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 23 Author Share Posted May 23 (edited) 4 hours ago, JoeH said: You'd need to pressure test it, not just smoke test. It is cv 713 yeah I am going to figure out how to pressure test it with the smoke. But what ever happened yesterday happened all at one time I heard the pop and after that I had the boost problem.also when it pops you get puff of black smoke out the exhaust. But also the primary filter is only half full of fuel isn’t that supposed to completely full all the time? I also have replaced the fuel lines from the tank to the filter and the filter to the pump. Edited May 23 by petehall12 Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 23 Author Share Posted May 23 9 hours ago, JoeH said: How are your oil seals on your turbo? Do you have oily soot in your exhaust or oil in your intake pipes? Checked the exhaust side and rechecked the inlet side of the turbo tonight the fins look good and there is no oil around it Quote Link to comment Share on other sites More sharing options...
JoeH Posted May 23 Share Posted May 23 36 minutes ago, petehall12 said: It is cv 713 yeah I am going to figure out how to pressure test it with the smoke. But what ever happened yesterday happened all at one time I heard the pop and after that I had the boost problem.also when it pops you get puff of black smoke out the exhaust. But also the primary filter is only half full of fuel isn’t that supposed to completely full all the time? I also have replaced the fuel lines from the tank to the filter and the filter to the pump. Measure inside of the CAC rubber boots, if it's same as my '95 RD then two 4 inch pvc pipe caps should fit in there, one on inlet, one on outlet. Mount a tire valve stem on one and pressurize it. Should hold up to 35psi with no leaks, but if there's a leak you'll hear it quick. Does this turbo have a waste gate? Your waste gate could be faulty, which would explain sudden black smoke and low boost. Quote Link to comment Share on other sites More sharing options...
petehall12 Posted May 23 Author Share Posted May 23 7 minutes ago, JoeH said: Measure inside of the CAC rubber boots, if it's same as my '95 RD then two 4 inch pvc pipe caps should fit in there, one on inlet, one on outlet. Mount a tire valve stem on one and pressurize it. Should hold up to 35psi with no leaks, but if there's a leak you'll hear it quick. Does this turbo have a waste gate? Your waste gate could be faulty, which would explain sudden black smoke and low boost. No I don’t have a wastegate Quote Link to comment Share on other sites More sharing options...
fjh Posted May 23 Share Posted May 23 9 hours ago, petehall12 said: Checked the exhaust side and rechecked the inlet side of the turbo tonight the fins look good and there is no oil around it So check all the turbo boots and charge air boots for splits . also the air compressor hoses to and from the inlet on the lower manifold and at the compressor! 1 Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.