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kuhar69

E-7 350 No Pulling Power

22 posts in this topic

Guys I run a 2003 Mack RB688s dump truck with a E-7 350. I'm a owner operator.

Last month I had a loss of power problem I got on the site here and you guys all pitched in and fixed my problem. Rhasler had given me the exact problem and how to fix it I am gratefull for the help. Now that the truck is back on the road with a new speedo sensor and a new fuel transfer pump I didnt get the power that I thought I would gain.

Now the only thing I didnt do as was suggested was to bring the truck to a Mack dealer and have them turn off the parameter thats detects the tampering with the spedo sensor to prevent the derate power.

My friend has the same motor in a RD688 and he pulls a trailer with his machines on it.

My truck wont even entertain that idea!.

I just seem to have the RPM's to shift her to get her ass in gear.

Now when the truck is not loaded it runs like a bat out of hell.

Mark

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Guys I run a 2003 Mack RB688s dump truck with a E-7 350. I'm a owner operator.

Last month I had a loss of power problem I got on the site here and you guys all pitched in and fixed my problem. Rhasler had given me the exact problem and how to fix it I am gratefull for the help. Now that the truck is back on the road with a new speedo sensor and a new fuel transfer pump I didnt get the power that I thought I would gain.

Now the only thing I didnt do as was suggested was to bring the truck to a Mack dealer and have them turn off the parameter thats detects the tampering with the spedo sensor to prevent the derate power.

My friend has the same motor in a RD688 and he pulls a trailer with his machines on it.

My truck wont even entertain that idea!.

I just seem to have the RPM's to shift her to get her ass in gear.

Now when the truck is not loaded it runs like a bat out of hell.

Mark

Give me your trucks serial number and I'll check some things out for you. Probably the easiest (and cheapest) thing you could do is give the engine a good visual inspection. Look over the exhaust manifold and turbo closely for signs of exhaust leakage and cracks (particularly at the center manifold section towards the cylinder head and at the turbo mounting flange). Make sure you dont have any loose charge air cooler hoses, and check the intake manifold elbow. The original clamp holding the elbow to the manifold was a worm type clamp that would loosen in service causing the elbow to wear against the manifold resulting in loss of boost pressure.

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Hey man thanks again!. Do you mean the VIN number??? where do i find the serial number

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Hey man thanks again!. Do you mean the VIN number??? where do i find the serial number

Yes. It should be on the metal tag on the driver's door. If that tag is missing it should also be stamped on the right frame rail somewhere around the area of the shock absorber.

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Yes. It should be on the metal tag on the driver's door. If that tag is missing it should also be stamped on the right frame rail somewhere around the area of the shock absorber.

I sent you the vin number check your mailbox hopefully you got it.

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I sent you the vin number check your mailbox hopefully you got it.

I got it. You have an E-Tech CCRS engine (as opposed to an ASET AI engine). You can disregard the earkier remark about the intake manifold and elbow as thid was not used until the ASET AI engines were introduced. Another possible leak point in the boost system is in the air inlet for the air compressor. It is a metal tube that comes off of the rear of the intake manifold and wraps around the rear of the engine. These tubes sometimes develop a hole. It is really hard to get at on your chassis. The floor board has to be removed and usually several curses have to be uttered at high decibel levels before it can be removed, so check the easy to get at stuff first. I see now that you have a post related to the cab air ride. A sagging cab will cause the cab to push into the tube and rub a hole in it so you may need to check it anyway. This was also a common occurence in our area with the mechanical engines. The cab would actually bend and restrict the throttle linkage at the rear of the cab. Do you have a pyrometer or a boost pressure guage installed on the truck?

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My Pyrometer reads somewhere nere ???? PSI looking at the gauge the needle is always towards the left???

My Mechnic said to keep an eye on that make sure it does not read a lot of presure cause then we may have to service the aire filter which is brandnew.

I"m still wet behind the ears with this stuff its the first time i have ever owned a truck on my own.

So I might say something sooner or later that guys are gonna laugh!!

Mark

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I have one of those 4 foot long cameras that are flexible and have a light on the camera end. Would this help me find a air leak under the cab maybe spray water on the line with a squirt bottle and with the camera look for bubbles.

If i have to take up the floor that sounds like my friend the torch has to come out and play??

Mark

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I have one of those 4 foot long cameras that are flexible and have a light on the camera end. Would this help me find a air leak under the cab maybe spray water on the line with a squirt bottle and with the camera look for bubbles.

If i have to take up the floor that sounds like my friend the torch has to come out and play??

Mark

No to both questions. The Cab floor board has a section that is bolted in that is removable. You need to remove the floor mat, guards, throttle pedal (fold the pedal back toward the seat and remove the two bolts holding it down, be careful reinstalling as the bracket is aluminum and the bolt threads easily strip out). After removing the floor board bolts the plate has to be lifted and turned slightly to get the clearance needed to remove it from the cab. It takes some practice but isn't too hard. The pipe will not show bubbles with the engine running if there is a hole in it because the engine and compressor will both be pulling air in through the hole.

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No to both questions. The Cab floor board has a section that is bolted in that is removable. You need to remove the floor mat, guards, throttle pedal (fold the pedal back toward the seat and remove the two bolts holding it down, be careful reinstalling as the bracket is aluminum and the bolt threads easily strip out). After removing the floor board bolts the plate has to be lifted and turned slightly to get the clearance needed to remove it from the cab. It takes some practice but isn't too hard. The pipe will not show bubbles with the engine running if there is a hole in it because the engine and compressor will both be pulling air in through the hole.

Mack made that simple providing the mechnic with that acess panel in the floor that was smart.

Ok I'll check that out tommrow.

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On my dashboard i have I think 3 mounting holes for gauges right now they have black mack logo caps over them. Can I pop one of those out and add a Boost gauge is this a good idea and is it hard to do??.

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On my dashboard i have I think 3 mounting holes for gauges right now they have black mack logo caps over them. Can I pop one of those out and add a Boost gauge is this a good idea and is it hard to do??.

The RB didn't have an electronic dash so even the factory installed guages were mechanical. You just need to remove one of the 1/8" pipe plugs from the intake manifold and install a 1/4" ferrule x 1/8" NPT fitting in the manifold, attach a length of 1/4" nylon air tubing, route it into the cab along side the oil pressure line, and hook it up to a new boost guage. This would help a lot in troubleshooting low power problems.

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The RB didn't have an electronic dash so even the factory installed guages were mechanical. You just need to remove one of the 1/8" pipe plugs from the intake manifold and install a 1/4" ferrule x 1/8" NPT fitting in the manifold, attach a length of 1/4" nylon air tubing, route it into the cab along side the oil pressure line, and hook it up to a new boost guage. This would help a lot in troubleshooting low power problems.

Ok so i will install one Im about spending a little money if it's gonna help preventing a problem down the road.

Hell is sure beats a New truck payment!!.

This truck works man no leaks no fuss love it nice truck so far.

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Hi Guys I was gonna go thru the motions today with all the information you guys gave me but the truck got hired for the day so that was that.Thurday and Friday i cant look at it so that leaves me into Monday I will keep everybody informed stay tuned.

Thanks again for the help.

Mark

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Pulling power could be a number od things: engine might be past it's best or could need spark plugs or service for example.

If there is a screeching noise when you turn the wheel this would indicate the power steering belt needs adjusting or is worn out.

If you depress the clutch and it makes a noise this will most likely be the clutch release bearing. Not such a big deal but it will knacker up eventually.

I'd get into a garage and see what they think, all garages should provide a free estimate for repairs but ask before you go just in case. Being honest if the car isn't in very good condition besides these faults it's probably not worth repairing one of that age sorry but certainly see what your local garage say first and good luck with it.

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Pulling power could be a number od things: engine might be past it's best or could need spark plugs or service for example.

If there is a screeching noise when you turn the wheel this would indicate the power steering belt needs adjusting or is worn out.

If you depress the clutch and it makes a noise this will most likely be the clutch release bearing. Not such a big deal but it will knacker up eventually.

I'd get into a garage and see what they think, all garages should provide a free estimate for repairs but ask before you go just in case. Being honest if the car isn't in very good condition besides these faults it's probably not worth repairing one of that age sorry but certainly see what your local garage say first and good luck with it.

Damn, I think we got us a genuine "Genius" here. I could be wrong, but I've never in seen an E7-350 Mack Diesel engine with "spark plugs". Maybe this is some sort of "new" technology Volvo has incorporated I'm not privvy to.

Maybe the prior poster is deriving his clues from a magic "8" ball.

Rob

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Damn, I think we got us a genuine "Genius" here. I could be wrong, but I've never in seen an E7-350 Mack Diesel engine with "spark plugs". Maybe this is some sort of "new" technology Volvo has incorporated I'm not privvy to.

Maybe the prior poster is deriving his clues from a magic "8" ball.

Rob

Sorry to tell you Rob, but he's a "Truck Engineer". See his introduction post: http://www.bigmacktrucks.com/index.php?showtopic=14898&pid=59915&st=0entry59915

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Sorry to tell you Rob, but he's a "Truck Engineer". See his introduction post: http://www.bigmacktr...t=0

I had seen that at the start also. First thought was "Looney Tunes" with the possibility of hitting the post tab too quickly. That was until follow up posts.........

Rob

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I had seen that at the start also. First thought was "Looney Tunes" with the possibility of hitting the post tab too quickly. That was until follow up posts.........

Rob

Rob maybee he is talking about the white giesel engine from the early sixties. :lol:

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Guys that are helping me with this power loss problem. Im still busy I have not had the Mechnic look at the problem so in the meantime Im moving like a snail. Stay tuned the NEW Mechanic is gonna start fishing around tommrow night.

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Well we have been trying to solve my no pulling power issuie with this truck and it was discovered that on the "hot side of the Turbo" there was regular band clamps holding on the hoses. We replaced the hoses and the clamps with the correct Mack style clamps and also found the plastic nuts on the air cleaner were stripped so the top is not air tight. We replaced the nuts on the air cleaner and with the new hoses and the right style clamps holding the hoses on the air cleaner and the turbo I have better power cause the truck aint losing air from air leaks. Much better!

Next the truck is going into the shop to disconnect the fault that derates engine power via the speedo sensor. The mechnic feels that the computer may show another area to gain some more power but we need the computer to take the next step.

Stay Tuned!

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sounds like a crank angle timing sensor, possibily a coil. im guessing you have changed the fuel filter? other thing to mind would be the catalytic converter.

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