Ezrider Posted March 23, 2018 Share Posted March 23, 2018 (edited) so starting out i went to change a eup that i had been getting codes on. found a broken eup roller guide pin. (i had one other broken guide pin when my truck ate a camshaft last year and they only replaced that guide pin) roller and cam ha no unusual marks looked ok. pulled all the eup's out changed the remaining 5 guide pins that had not been changed. also noticed a exhaust leak on the #6 exhaust manifold gasket. so i pulled the manifold new gaskets and studs. on the manifold and turbo. seems how i was already going to have all the eup's out i went ahead and put 4 new eup's in to make all my eup's new within the last year. got it all back together and started up everything seemed good, engine runs smooth everything seems just fine other than a strange chirping noise sounds kinda like crickets that is only present if i am over 25lbs of boost. it is directly related to boost psi not engine rpms. this sound was not present before the work? its a high pitched metallic sounding chirping noise. not a squeal but a rapid chirp only present when over 25lbs of boost and gets louder with more boost but lift off the throttle and it goes away even if rpm remains the same. engine seems to be running good other than this strange sound that i hope i am describing well enough. i had set a appointment at Mack for first thing in the morning tomorrow to have the eup trim codes updated. i may see if one of the techs can go for a ride and give me there thoughts. not that i have a lot of faith in there mechanics. i hate to start pulling eup's back out because the fuel lines are supposed to be one time use only. and not sure why anything there would be directly related to boost psi? pulled the intake and exhaust off the turbo there is a little more side to side play than id like but seals don't appear to be leaking and no in and out play turbo's tend to make more of a high pitched squeal than a high pitched chirp. checked the air to air boots that i had apart an re clamped them although if it was a boost leak it would be the strangest sounding boost leak iv ever heard. i don't see any signs of leaks around the manifold or turbo gaskets but i only drove it a few miles. you guys have any thoughts or guidance? Edited March 23, 2018 by Ezrider Quote Link to comment Share on other sites More sharing options...
fjh Posted March 23, 2018 Share Posted March 23, 2018 I hate to tell ya this but by what your describing sounds like a failing roller on a lifter!! Hopefully I'm wrong and I will be happy for ya! Quote Link to comment Share on other sites More sharing options...
Ezrider Posted March 23, 2018 Author Share Posted March 23, 2018 (edited) but would a lifter noise be directly related to boost? only make noise at 25+ psi of boost. that is what has me scratching my head. plus all lifters and rollers are about 3/4 of a year old. everything seemed fine with all the eup rollers and lobes. no skid marks everything seemed normal. sound was not present prior. Edited March 23, 2018 by Ezrider Quote Link to comment Share on other sites More sharing options...
fjh Posted March 23, 2018 Share Posted March 23, 2018 Just saying !!! True however most times you can pick the lifter sound out at idle can't explain the boost issue other than a boost leak ! Quote Link to comment Share on other sites More sharing options...
turckster Posted March 23, 2018 Share Posted March 23, 2018 To me it sounds like a possible exh leak or intake leak. With a cold engine you can use soapy water to find exhaust leaks. The Mack MP7 exh manifold gaskets do the exact same thing when they are leaking. 1 Quote Link to comment Share on other sites More sharing options...
carlotpilot Posted March 23, 2018 Share Posted March 23, 2018 kinda sounds like an old 335 with a broke head bolt Quote Link to comment Share on other sites More sharing options...
h67st Posted March 23, 2018 Share Posted March 23, 2018 8 hours ago, turckster said: To me it sounds like a possible exh leak or intake leak. With a cold engine you can use soapy water to find exhaust leaks. The Mack MP7 exh manifold gaskets do the exact same thing when they are leaking. Since it's only at boost, I would bet money on an exhaust leak. One trick I've used (if you don't see a smoke trail anywhere on manifold or gaskets) is to use a mechanic's stethoscope that has a hose to the working end. Pull the hose off and nose around the exhaust gaskets, manifold, etc. If there's a miniscule leak you'll pick it up with the stethoscope...just be careful because if you go jabbing that hose into a leak too fast you could damage your ear drums! Quote Link to comment Share on other sites More sharing options...
stuie56 Posted March 23, 2018 Share Posted March 23, 2018 had the same thing happen a few years back sounded like it was coming from tip turbin. ended up being a bad intake gasket.it only chirped under boost. Quote Link to comment Share on other sites More sharing options...
fjh Posted March 23, 2018 Share Posted March 23, 2018 (edited) Guess the metallic chirp is whats throwing me off ! Under boost is likly cause as stated could be any of the above mentioned things turbo base gasket is another thought! being as you have been changing eup rollers possibly the compressor inlet hose has split! its in that general area! Like I said I hope Im wrong about the cam follower thing Not a cheap fix! Edited March 23, 2018 by fjh Quote Link to comment Share on other sites More sharing options...
Popular Post Mack Technician Posted March 23, 2018 Popular Post Share Posted March 23, 2018 Mack Engine Crickets begin to chirp when they are celebrating the death of a roller lifter. Cruel Little Bastards! Turbo boost leak is usually constant whistle, hiss. Hope that could be what your hearing if it is an air pulsation + leak= chirp? Under boost intake valves become easier for the lifter to open / Under boost'n'power exhaust valves become harder for the lifter to open. Stress on lifters becomes easier at an idle than at high RPM. Grab your wife and start shaking her toward and away from you. The faster you shake the more stress you feel in your arms........that's how momentum + directional shift can bend pushtubes at engine overspeed. Engine Speed = increase valve train stress. Increased speed = stress = more pressure on roller = more chirp. Shaking = divorce and jail. Has echoing of what happened to you last year. 3 1 Quote Link to comment Share on other sites More sharing options...
Ezrider Posted March 23, 2018 Author Share Posted March 23, 2018 i really do not want to go threw another cam job. i hope that's not the case. seems how the sound is present now and not before it seems most likely its related to something i touched. im really leaning towards exhaust manifold now. this morning when i ran it over to mack to get the eup trim codes updated i couldn't get it to do it. but roads are shit today and i was bobtail could not really get it up on boost without spinning the tires in any gear. its running nice and smooth. when i got back to my shop i started digging in to trying to find the source of the noise. one thought was maybe i installed the exhaust studs too deep. the bottom exhaust stud holes to break into the push rod tubes. although not sure how that would relate to boost and i measured the depth the old studs were installed at and installed to the same depth. figured id check anyway pulled the valve covers looked down the push rod tubes studs do not protrude. checked lash on a few cyl and were in spec. ran it with the valve covers off thinking it might be easier to hear a chirp from the lifters if one was present. everything seemed normal. pulled 4 of the eup's back out i reused the fuel tubes and bolts that were installed yesterday. ill probably have to keep a eye on that. but after 4 of them including the one that had the broken guide pin everything looks ok there still. i did find a couple very small soot trails on #1 exhaust gasket. re torqued the exhaust manifold and did get a bit of movement on the nuts when i re torqued it. i didn't start it back up yet. left the air cleaner off ill run the torque wrench over the manifold one more time tomorrow. going to dump the sump again. pulled the eup bore drain plugs this time but got oil out of them when i first pulled them but didn't notice any fuel when i pulled up the eups's so id rather just dump and refill the sump than take a chance of fuel contamination. didn't have enough oil on hand to re-fill so ill have to pick some more up in the am. hopefully the roads are better tomorrow and i can see if re-torquing the manifold fixed the sound or changed it. if not i may have to hook up to one of my trailers. i hate to head out to haul a load if somethings not right. really kinda hard to pinpoint as there is no sound unless your over 25 lbs of boost or so. Quote Link to comment Share on other sites More sharing options...
br549 Posted March 23, 2018 Share Posted March 23, 2018 Pull the turbo hose off at the turbo and install a plug, you can buy them or make one with 2 spuds one for air gauge and one for air pressure and pressure the whole system, air cooler, manifold gaskets and air compressor tube and get the system up to 25 or 30lbs and see if you hear it. I had one that was making a noise only under boost and it was where we had pull the hose off of the charge cooler and the cooler had a rough seam in it and it leak and made noise. We buffed the seam back smooth and it took care of it, that way you should eliminate the boost pressure system. you should be able to see signs of the exhaust manifold leaking exhaust, as one said on mp engine we have spray water around exhaust while idling but the water don't seem to work good on E7 engine. To me if it appears and disappears with 25lbs and quits when letting off you will probably fine a small leak on pressure side of the system. Quote Link to comment Share on other sites More sharing options...
Ezrider Posted March 24, 2018 Author Share Posted March 24, 2018 good idea. i don't have a rig to do that but should be able to cobble something up quick i may try that tomorrow. as far as signs of exhaust leaks i did find a couple very very small soot trails coming from the #1 exhaust port. vary faint trails maybe a 1/8th of a inch long if that but i have only drove it maybe a total of 20 miles. so far. i wonder if i ran the engine with the down pipe removed and try restricting the exhaust flow out of the turbo with a board to simulate the back pressure of spinning the turbine at boost if i might be able to create the sound as well. first ill probably try to take it on a quick test drive first if the roads are better maybe re torquing the nuts will have fixed it. Quote Link to comment Share on other sites More sharing options...
fjh Posted March 24, 2018 Share Posted March 24, 2018 you could try that how ever its not always the exhaust roller that fails ! Hopefully mack tec and I are wrong! The chirp sound is usually heard At Idle and you can usually hear it down low near the unit pumps and pick it out almost down to the cylinder front back or center! Sometimes intermittent ! Just sayin ! your symptom is not perfect for it however At Idle would be a dead ringer! We will keep our fingers crossed At this point! Quote Link to comment Share on other sites More sharing options...
Ezrider Posted March 24, 2018 Author Share Posted March 24, 2018 i guess if it is a cam best case it eats itself alive before i hit the one year mark. so i should have some recourse. im sure the failed valve yoke guide and the shop leaving drill shavings in my top end probably reduced the life expectancy of my cam a bit. i really hope the cam is happy for a long time i really don't want to repeat that whole ordeal allover again. Quote Link to comment Share on other sites More sharing options...
fjh Posted March 24, 2018 Share Posted March 24, 2018 Yup good possibility I remember you posting that! What a feasco ! if you find that this does come to a head as a lifter failure and its on the same cyl look no further for a cause I would think! Quote Link to comment Share on other sites More sharing options...
Mack Technician Posted March 24, 2018 Share Posted March 24, 2018 Sometimes it’s not only the crickets raising Cain. Crickets mean metal roller just stopped turning and is becoming a flat tappet or is sideways on cam bump(also becoming a tappet). Camshaft can also progress to be the Ruffed Grouse in your air filter housing trying to call up a mate. Exhaust lifter failure (complete progressed failure) gives you an audible “thump thump thump thump thump” at the air inlet of your filter housing. Starts to drive a fueled, one-cylinder, jake brake pulse backward out your intake. Intake/compression/power/no exhaust/POP IMO- EZ, your EZily in the top 5% of operators I’ve met who know their machines as well. If it wasn’t under warranty.... and if it was a cam.... rather see you fixing the cam. That drill shavings story shocks the conscience. Think the MP series is causing Gray Engine Amnesia at some dealerships, how else can you explain some of the stories on this site? Pay a high schooler $10 hr to help you get the hood off, set lifters up bore, etc. 1 Quote Link to comment Share on other sites More sharing options...
Ezrider Posted March 24, 2018 Author Share Posted March 24, 2018 i should have done the first cam job myself. i think i would have avoided 98% of the issues iv had. and i would be a butt load of money ahead. iv had to work my butt off this last year to make up for all the money that was spent and time lost due to that whole cam job fiasco. i was not aware of the jake pin issues prior to the valve yoke guide pin failure. but i think if i was doing it at the point i was replacing rocker arms i probably would have been inspecting the bridges if not just replacing for the sake of your there and your hands are on it that's the time to do it. the whole reason i took it to mack is i figured they would know the ins and outs of the job and i may overlook something they would catch, boy was i wrong. when we had one broken eup guide pin at the time of the cam job i questioned them about the cause of the failure of the guide pin and asked if replacing the remaning guide pins would be advisable. they said not a wear item probably broke due to the cam failure. when i replaced the remaining ones this week due to another one being failed, comparing the broken one to non broken ones i believe the wear point on the side creates the start of the fracture that causes failure. had they not advised me it was completely un necessary to replace the remain guide pins at that time i would have replaced them all at that time. when the bridge yoke failed i certainly heard the jake break out the intake noise your are speaking of. im not ready to call it cam failure yet. i pressurized the intake system today no eureaka moments there but did find a few leaks a couple boots that needed adjusting and a snug up and i have a bit of a leak at the charge air cooler. intake gaskets are fine. even bumped up to 40 psi nothing that would be heard inside the cab under load. Windex on the exhaust manifold right after a cold startup works amazingly well. a couple very slight exhaust leaks and a big one on #1 really kind of a bummer but hopeful that is my noise. tried slight over torque on 1 and 2 hoping it would seal it up but it looks like i have to try again on the exhaust manifold. ether that or run it and it will ether pack with soot and seal up or mostly likely burn the gasket out. i think the air is squeezing threw a pretty small area causing more of a chirping sound than what i would expect from a exhaust gasket. any tips to help a problem exhaust manifold seal up? 1 Quote Link to comment Share on other sites More sharing options...
hatcity Posted March 25, 2018 Share Posted March 25, 2018 did you happen to run a mall amount of hi-temp RTV on the studs before install? nothing to do with exhaust leak, but may prevent slight oil leak later did you inspect the manifold for soot...may have a slight crack in it Quote Success is only a stones throw away.................................................................for a Palestinian Link to comment Share on other sites More sharing options...
Ezrider Posted March 25, 2018 Author Share Posted March 25, 2018 lower studs that break into the push rod tubes got a little high temp rtv the upper studs witch are just a blind hole just got copper high temp anti seize. did not see any cracks in the manifold. the leak is bubbling from the gasket itself. gasket surfaces were a bit rough number 1 was not leaking previously #6 had a blowout in the gasket witch actually didn't make much noise at all. number 6 seems to have sealed perfectly this time but #1 is leaking pretty bad #2 has a very small leak 5 got a couple tiny bubbles as well. but #1 is certainly leaking enough to be a problem. Quote Link to comment Share on other sites More sharing options...
Dirtymilkman Posted March 25, 2018 Share Posted March 25, 2018 Use the gray Mack silicone on your exhaust manifold. That stuff works wonders. I use it in the joints on the manifold too. Quote Link to comment Share on other sites More sharing options...
fjh Posted March 25, 2018 Share Posted March 25, 2018 19 hours ago, Mack Technician said: That drill shavings story shocks the conscience. Think the MP series is causing Gray Engine Amnesia at some dealerships, how else can you explain some of the stories on this site? Pay a high schooler $10 hr to help you get the hood off, set lifters up bore, etc. Yup think that is a true statement ! How ever RIDER I would'nt be so quick to say you would do the cam yourself you got to have a bit of a shop and a decent size press or porta power to tackle the project with! Unfortunately Mack had started hiring VOLVO thinking type engineers by this time and started veering away from the keep it simple motto, like bolt on cam gears , O ring and tubes instead of good ole hose clamps and hose THE true Captivate era was in ramping up ! Good JOB GUYS! Make the easy jobs harder so the job takes longer (Creates employment RIGHT!) 2 Quote Link to comment Share on other sites More sharing options...
1965 Posted March 25, 2018 Share Posted March 25, 2018 Flat file and straight edge on the surfaces. Quote Link to comment Share on other sites More sharing options...
Popular Post Ezrider Posted March 26, 2018 Author Popular Post Share Posted March 26, 2018 (edited) 11 hours ago, 1965 said: Flat file and straight edge on the surfaces. that is more or less what i did today. pulled the manifold back off found that where my leak was on number 1 was out by .014 i had about a 6 foot peice of aprox 5 inch wide 1/4 inch mild steel found about a 2 foot section of it that was pretty close to flat cut that section out glued sand paper to it and after about 4 hours its all within .003 cyl head is all within about .002 except for between the front head and the rear head it seems the front of the rear head is set off to the drivers side by about .004 seems how im off on the manifold in the same direction by .002 should mate up pretty good. really kicking myself for not straight edging the whole manifold. i had a blowout on the gasket on number 6 i set a straight edge across 5 and 6 and didn't see day light assumed seems how none of the others were leaking prior to removal everything was good to go. need to grab another set of gaskets in the am and throw it back on hopefully it will all be happy after that. i may bolt the manifold up without gaskets feeler gauge it measure the amount of crush between the new gasket and the ones i just removed and make sure that i have at least a few thow more crush in the gaskets than what i have for gaps. someday when i build a bigger shop im going to be looking for a mill an a lathe had it been a week day i probably would have been trying to find a machine shop i could bribe into milling it quick for me. but seems how im stuck on gaskets till the morning anyway did it the home brew way....lol Edited March 26, 2018 by Ezrider 3 Quote Link to comment Share on other sites More sharing options...
fjh Posted March 26, 2018 Share Posted March 26, 2018 Good Job Bro ! Hope this cures the issue Bro Dam sight cheaper and easier than a cam job And does make some sense to the symptoms you talking about ! Quote Link to comment Share on other sites More sharing options...
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