Rsc1717 Posted May 29, 2022 Share Posted May 29, 2022 Have a noise coming from the engine can not really hear where it’s coming from . Seems like a belt squeak or something like that but only does it in higher gears and while in gear does not do nothing on idle . Also have to be on the pedal halfway or all the way down kind of noticed when boost goes over 20psi. I’m thinking it might be something turbo related have noticed my boost did not go past 30psi when I noticed this issue . It used to easily go 34 paso to 36 while loaded . Just trying too see if anybody has encountered something similar. Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/ Share on other sites More sharing options...
Popular Post upsman Posted May 29, 2022 Popular Post Share Posted May 29, 2022 Boost leak in charge air system. 3 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498816 Share on other sites More sharing options...
Rsc1717 Posted May 30, 2022 Author Share Posted May 30, 2022 Ok that would be in front of turbo correct . Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498844 Share on other sites More sharing options...
mechohaulic Posted May 30, 2022 Share Posted May 30, 2022 broken clamp, cracked hose air system. higher gears possibly due to engine under load. idle- pressures aren't high enough. Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498847 Share on other sites More sharing options...
Rsc1717 Posted May 31, 2022 Author Share Posted May 31, 2022 Ok yes I gave it a look today dint see anything found one small leak but dint fix the problem . I still don’t get past 30 psi and have that squeaky whining noise while in high gears and over 20 psi . I’m a keep on checking just ordered a turbo boost leak tester . Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498906 Share on other sites More sharing options...
Popular Post D-Day Posted May 31, 2022 Popular Post Share Posted May 31, 2022 Charge air cooler is built like a radiator with tubes out of aluminum its common for them to split a tube especially on the side by the radiator dropping boost and making whistling noise easier to find when you remove the cooler and look for dark stained areas or pressure test 3 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498910 Share on other sites More sharing options...
Popular Post fjh Posted May 31, 2022 Popular Post Share Posted May 31, 2022 (edited) 9 hours ago, D-Day said: Charge air cooler is built like a radiator with tubes out of aluminum its common for them to split a tube especially on the side by the radiator dropping boost and making whistling noise easier to find when you remove the cooler and look for dark stained areas or pressure test Exhaust gaskets ? turbo gasket ?Utube gasket (the tube that attaches the egr cooler to the exhaust side egr valve )this little devil is a pain to nail down AND a horses ass to repair! ! If you can catch the truck when its ready to regen this noise will show up during a regen if it is indeed the you tube gasket ! During regen ! while the noise is present pour hot water all over the pipe and joints if the sound changes you have found your issue! Just something to try! Edited May 31, 2022 by fjh 2 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498922 Share on other sites More sharing options...
Joey Mack Posted May 31, 2022 Share Posted May 31, 2022 'F' is onto something!! the orings at the tube he is talking about are a pain in the a$$.. all it takes is for the oring to split, and the leak starts.. iit is a squealing sound under a load. you wont see it til you take it apart.. jojo Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-498925 Share on other sites More sharing options...
Rsc1717 Posted June 2, 2022 Author Share Posted June 2, 2022 Ok found the issue cracked intake manifold . How should I go about removing it dint want to break any bolts . 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499130 Share on other sites More sharing options...
Popular Post Joey Mack Posted June 3, 2022 Popular Post Share Posted June 3, 2022 if you come across a bolt that feels like it wont turn,,, use a pointed punch and a hammer, and hit directly on the head of the bolt a few dozen times.. then try to turn it.. not a guaranty, but it has worked for me many times.. another thing I have done is drill 1/8" holes into the bolt bore, (Since its junk anyway) and fill it with PB Blaster.. I just did this a few months ago on a C-15, to get the valve spacer off to replace the wire harness.. just be creative and patient.. the cost of parts is higher than the cost of 'time'.... jojo 2 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499131 Share on other sites More sharing options...
fjh Posted June 3, 2022 Share Posted June 3, 2022 1 hour ago, Rsc1717 said: Ok found the issue cracked intake manifold . How should I go about removing it dint want to break any bolts . if you found a cracked intake you likly already have a broken bolt! is the crack at the front just below were the egr tube enters ? if so look for a missing bolt at the bottom 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499136 Share on other sites More sharing options...
Rsc1717 Posted June 3, 2022 Author Share Posted June 3, 2022 32 minutes ago, fjh said: if you found a cracked intake you likly already have a broken bolt! is the crack at the front just below were the egr tube enters ? if so look for a missing bolt at the bottom It’s on the driver side of motor intake manifold don’t know if theirs a egr tube by their . And yes crack is like 5 inches from beginning of intake started at the bottom and worked it’s way up pretty long crack . Trying to find the torque specs for intake manifold. Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499140 Share on other sites More sharing options...
Rsc1717 Posted June 3, 2022 Author Share Posted June 3, 2022 Yes it looks like their is the first 2 missing bolts at the bottom . I guess somebody broke them before . 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499141 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 There is a service bulletin on the intake manifold bolts . They came out with some new longer bolts with spacers on the ends . The broken bolts and intake manifolds we’re common more on the MP7 than the MP8. But seen plenty of both . The broken bolts usually come out easily sometimes with just using a pick to spin them out. If you do have to drill them they are very soft and drill easy. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499162 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 Mack service bulletin SB214061 shows the new design intake manifold for MP8 and MP7’s that use the longer bolts but no spacer. If your intake manifold is not broken and your just replacing the broken bolts the service bulletin SB214057 shows using the longer bolts with a spacer , I will try to attach links to the bulletins 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499163 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 https://www.scribd.com/document/514541769/sb214061 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499164 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 (edited) Edited June 3, 2022 by Mackpro 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499165 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 The SB215057 only applies if your using an original old style intake manifold 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499166 Share on other sites More sharing options...
Popular Post fjh Posted June 3, 2022 Popular Post Share Posted June 3, 2022 (edited) 10 hours ago, Rsc1717 said: Yes it looks like their is the first 2 missing bolts at the bottom . I guess somebody broke them before . Nope they break for some reason likley heat related from the EGR coming into the top! Pro mentions a bulletin check into it I was not aware of the bulletin! The new manifold comes with a new gasket but not the bolts ! in my mind it SHOULD come with new bolts TOO ( A Kit) how ever This is a Volvo owned company they nickel and dime for everything!!😡 I was heavy into vehicle inspection just before my retirement this last Feb I would look for these bolts being missing while checking over all the other functions! Found a fare few! I always looked it was fairly common! So when you buy your new manifold Ask the part guy for bolts cause they likely wont offer them! Edited June 3, 2022 by fjh 3 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499169 Share on other sites More sharing options...
Mackpro Posted June 3, 2022 Share Posted June 3, 2022 Good reminder FJH, ask for new bolts because with the new thicker manifold the old bolts will be to short, 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499176 Share on other sites More sharing options...
fjh Posted June 3, 2022 Share Posted June 3, 2022 4 minutes ago, Mackpro said: Good reminder FJH, ask for new bolts because with the new thicker manifold the old bolts will be to short, A good parts guy would know to offer the bolts However ......................! 1 Quote Link to comment https://www.bigmacktrucks.com/topic/69861-mack-mp8-squeaky-noise-from-engine/#findComment-499177 Share on other sites More sharing options...
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