bigmackattack Posted January 20, 2010 Share Posted January 20, 2010 I work in a shop where we pretty much work on everything that drives or gets towed in. My Mack experience is limited, I mostly handle medium duty trucks,buses . We have an 01 RD triaxle ,E7 300HP.Towed in with engine noise. The engine is quiet until it reaches operating temp, then it begins to generate this heavy chirping sound from the center of the right side of the block.Using a "sonic ear" we determined the noise to be coming from cyl 3 unit pump.When we torn it down we found cyl 1, 3 , and 6 that the unit pumps lost their spring keepers. We replaced all the unit pumps at customers request. Noise Still There.This chirp resonates through everything. You can hear it in the Air compressor, the turbo and center of the block!Has anyone come across something like this?I thought it could be an intermediate shaft bearing, my gut feeling is that perhaps the cam shaft bearings are failing(spinning in the block)Any suggestions would be welcomed. Thankyou, Russ Quote May the Peace that excels all thought be with you Link to comment Share on other sites More sharing options...
bobo Posted January 20, 2010 Share Posted January 20, 2010 Hey In my experence the cam would make a "popping" sound not a "chirp". You might wanna check air comp. or (sounds silly) head gasket or head bolts, I have herd them do it under load. GOOD LUCK! Quote Link to comment Share on other sites More sharing options...
bigmackattack Posted January 20, 2010 Author Share Posted January 20, 2010 Hey In my experence the cam would make a "popping" sound not a "chirp". You might wanna check air comp. or (sounds silly) head gasket or head bolts, I have herd them do it under load. GOOD LUCK!Replaced the air compressor today. Noise is still there.What about the oil pump? That's about between cyl 3 and 4.......noise is very resonated and hard to pin point Quote May the Peace that excels all thought be with you Link to comment Share on other sites More sharing options...
Mackpro Posted January 20, 2010 Share Posted January 20, 2010 Replaced the air compressor today. Noise is still there.What about the oil pump? That's about between cyl 3 and 4.......noise is very resonated and hard to pin pointProbably a cam roller locking up and dragging on the cam lobe. We called it the "E-TECH Squeak". We could here the truck pull up to the shop and before the customer walked in the door the parts guys would be looking to see if we had a cam kit. Usually does it when hot and sometime only when you rev it up. Drop the pan and carefully look over the cam and reach up and feel the rollers. 1 Quote Link to comment Share on other sites More sharing options...
hatcity Posted January 20, 2010 Share Posted January 20, 2010 Cracked exhaust manifold? Once hot, crack will expand.2001 E-7 427 is what I have and found it there. Quote Success is only a stones throw away.................................................................for a Palestinian Link to comment Share on other sites More sharing options...
fjh Posted January 20, 2010 Share Posted January 20, 2010 Probably a cam roller locking up and dragging on the cam lobe. We called it the "E-TECH Squeak". We could here the truck pull up to the shop and before the customer walked in the door the parts guys would be looking to see if we had a cam kit. Usually does it when hot and sometime only when you rev it up. Drop the pan and carefully look over the cam and reach up and feel the rollers.CAM ROLLER! You have a cam job to do my friend! you changed the compressor ? then it sounds like you thought the sound was near that area,Likly one of #no 3or4 cam rollers has failed. pull the pan and look as 68 has said! Quote Link to comment Share on other sites More sharing options...
Mackpro Posted January 20, 2010 Share Posted January 20, 2010 CAM ROLLER! You have a cam job to do my friend! you changed the compressor ? then it sounds like you thought the sound was near that area,Likly one of #no 3or4 cam rollers has failed. pull the pan and look as 68 has said!If I had all the money our shop made off me doing cam jobs on ETECH's I would retire today! Quote Link to comment Share on other sites More sharing options...
fjh Posted January 20, 2010 Share Posted January 20, 2010 If I had all the money our shop made off me doing cam jobs on ETECH's I would retire today!Yup me to! maybe not that bad but almost! Quote Link to comment Share on other sites More sharing options...
Mackpro Posted January 20, 2010 Share Posted January 20, 2010 Yup me to! maybe not that bad but almost!I think I could do those cam jobs in my sleep. The first round of cam jobs sucked because Mack wanted us to also change the cam bearings, then changed it to only if you can hang your fingernail on #2 and #5 bearing. Then the round of cam jobs where the locating pin on the EUP's rollers broke off in the block and the roller spun around and took out the cam. Thoses days are behind us I hope. Now its just when the rocker arm hold down bolts break and the driver keeps driving and bust the ceramic roller lifter and messes up the cam. I'm running the overhead on an CV with an AI in it as we speak and I'm replacing the bolts as per Mack service bulletin so I dont have to put a cam in this one later. Quote Link to comment Share on other sites More sharing options...
fjh Posted January 20, 2010 Share Posted January 20, 2010 I think I could do those cam jobs in my sleep. The first round of cam jobs sucked because Mack wanted us to also change the cam bearings, then changed it to only if you can hang your fingernail on #2 and #5 bearing. Then the round of cam jobs where the locating pin on the EUP's rollers broke off in the block and the roller spun around and took out the cam. Thoses days are behind us I hope. Now its just when the rocker arm hold down bolts break and the driver keeps driving and bust the ceramic roller lifter and messes up the cam. I'm running the overhead on an CV with an AI in it as we speak and I'm replacing the bolts as per Mack service bulletin so I dont have to put a cam in this one later.Thataboy!I don't pull the lids on one with out asking if they want to replace bolts as a precaution warrenty or not !It amazed me that we went from a 7/16 sized bolt that never had a problem to one that was smaller than 3/8 to create a problem made no sence.The ac don't seem as bad as AI less bumps I guess. Quote Link to comment Share on other sites More sharing options...
JerryB Posted January 22, 2010 Share Posted January 22, 2010 (edited) Hey In my experence the cam would make a "popping" sound not a "chirp". You might wanna check air comp. or (sounds silly) head gasket or head bolts, I have herd them do it under load. GOOD LUCK!That's my thought too. The only chirp I've ever had was either a broke head bolt or blown headgasket myself. Every time I couldn't find the chirp in that same area he mentions it was on #4 blown to the front and chirping between the heads. Edited January 22, 2010 by JerryB Quote Link to comment Share on other sites More sharing options...
bigmackattack Posted January 22, 2010 Author Share Posted January 22, 2010 We are pulling the pan down today to take a look. The shop manager says we won't see anything, but I believe what you guys are saying is on the money.Thanks for all the advice. Quote May the Peace that excels all thought be with you Link to comment Share on other sites More sharing options...
bigmackattack Posted January 22, 2010 Author Share Posted January 22, 2010 CAM ROLLER! You have a cam job to do my friend! you changed the compressor ? then it sounds like you thought the sound was near that area,Likly one of #no 3or4 cam rollers has failed. pull the pan and look as 68 has said!Pulled the compressor out to look at the aux shaft for end play or bearing noise, found that the compressor was leaking, customer asked for it to be replaced. The noise is in that area and we are going to drop the pan. Quote May the Peace that excels all thought be with you Link to comment Share on other sites More sharing options...
fjh Posted January 22, 2010 Share Posted January 22, 2010 That's my thought too. The only chirp I've ever had was either a broke head bolt or blown headgasket myself. Every time I couldn't find the chirp in that same area he mentions it was on #4 blown to the front and chirping between the heads.The noise he has is low on the block!To find a head gasket the best way to find it is to pour water over the area you suspect while the engine is runing the sound will change as the water passes over the area.The cam is more likly! Quote Link to comment Share on other sites More sharing options...
JerryB Posted January 22, 2010 Share Posted January 22, 2010 The noise he has is low on the block!To find a head gasket the best way to find it is to pour water over the area you suspect while the engine is runing the sound will change as the water passes over the area.The cam is more likly!You're right. I was just thinking out loud about the chirp. My head gasket experience is limited and I found that if it's blown it would only chirp when the engine is under load anyway. Quote Link to comment Share on other sites More sharing options...
fjh Posted January 29, 2010 Share Posted January 29, 2010 You're right. I was just thinking out loud about the chirp. My head gasket experience is limited and I found that if it's blown it would only chirp when the engine is under load anyway.Any word on the out come of this project ? Quote Link to comment Share on other sites More sharing options...
bigmackattack Posted January 30, 2010 Author Share Posted January 30, 2010 Found number four cam roller turned and broken. Now I'm doing my first Mack Cam Job. Yee Ha! Thanks for the advice guys! Quote May the Peace that excels all thought be with you Link to comment Share on other sites More sharing options...
Mackpro Posted January 31, 2010 Share Posted January 31, 2010 Found number four cam roller turned and broken. Now I'm doing my first Mack Cam Job. Yee Ha! Thanks for the advice guys!Make sure the H-ring is straight and not turned or to high. The H-ring is the sleeve that is drove down into the block, it holds the lifter straight. Alot of the time if the engine is run enough with a bad lifter it will beat the H-ring up to high in the block or turn sideways. You can check it by pulling all the push tubes out the put a straight edge on top of the heads and running a welding rod down to the H-ring, then mark the H-ring height on the welding rod to the straight edge. Compare the heights to the bad lifter H-ring. If it is high sometimes you can drive it down with a punch otherwise you have to pull the head and install a new one. good luck. Quote Link to comment Share on other sites More sharing options...
mack4ever Posted January 31, 2010 Share Posted January 31, 2010 hello all.we got one renault whit the sane chirp in the shop i work.we toke the oilpan out and chekt the rollers.the roller from the first lifter was bad but the camshaft is good.we just replace the roller.the engine has just run over one milion kilometers. mack 4 ever. Quote Link to comment Share on other sites More sharing options...
Jobenshain1994 Posted January 10, 2016 Share Posted January 10, 2016 Broken fire ring .. loosing compression. . Quote Link to comment Share on other sites More sharing options...
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