Low Boost

[wideoval007]

I have a 2002 Monaco Diplomat diesel. I am experiencing low boost, about 10....it used to be over 20. Cummins dealer says that #3 exhaust gasket is blown out. They only told me this after spending $800 on a fix that didn't work. They say to repair will cost $5300(they'll probably have to replace the cylinder head after they break off exhaust manifold bolts) not too re-assuring! Any suggestions? This problem just accured on last road trip(a very bumpy road trip)

[DMTTRANSPORT]

Originally Posted by wideoval007

I have a 2002 Monaco Diplomat diesel. I am experiencing low boost, about 10....it used to be over 20. Cummins dealer says that #3 exhaust gasket is blown out. They only told me this after spending $800 on a fix that didn't work. They say to repair will cost $5300(they'll probably have to replace the cylinder head after they break off exhaust manifold bolts) not too re-assuring! Any suggestions? This problem just accured on last road trip(a very bumpy road trip)

If they break anything...what your supposed to pay for their incompetence, I wouldn't let them touch my Coach, they are out to get something for nothing...go elsewhere! Run! I would let everyone know on here the name of the shop....

[gemert]

Originally Posted by DMTTRANSPORT

If they break anything...what your supposed to pay for their incompetence, I wouldn't let them touch my Coach, they are out to get something for nothing...go elsewhere! Run! I would let everyone know on here the name of the shop....

Xs 2

[1bigmess]

A leaking exhaust gasket is easy to hear. You can get a length of hose and stick one end in your ear and move the other end around the engine until you hear it. You can even get an "official" mechanics stethoscope that will direct sound towards both ears. If you have an exhaust leak, you can find it and identify almost exactly where it's coming from this way. This is what I'd do before I spent another dime on chasing a problem.

I'd also change my fuel filters and inspect the entire intake system. A hole in the charge air cooler or somewhere else can also reduce boost.

[dennis45]

Let's put this into perspective.
An exhaust leak before the Turbo will result in low manifold pressure. Could be a cracked manifold (very common on the ISC), blown gasket on the manifold. Could also be a Turbo problem.
During the disassembly, it is possible to have siezed, or broken bolts but this can be minimized by applying a penatrant oil to all exhaust bolts prior to disassembly. Overnight would be ideal.
Now, if there is an issue with broken bolts, the labor costs go up because these things are time consuming to deal with. In severe cases, the cylinder head might have to be removed but IMO, this would be a rare exception.

If this were mine, I would get an estimate before they begin and make it clear that you must be notified if there are ANY complications beyond the estimate and you require all the old parts.

From your description, it doesn't sound like the shop you are dealing with are very knowledgable. Are they an actual Cummins Shop or just a truck shop. Not knocking truck shops but there are ones that know what their doing with trained people and ones that just work on stuff.....if you know what I mean.
If they cannot answer your questions to your satisfaction and provide you with a detailed estimate, I would go looking elsewhere.

Just a guess, but I think to R&R the manifold will run about 6-8 hours for two people (for a side rad rig, rear rad would be more) plus parts. Labor $1200 - 1800.

Good Luck

[twinboat]

It's sounds like they are being up front with you. They have done enough gaskets to know that the studs are going to break off.


You could take it to another shop but be prepared for the same quote or a call, halfway thru the job, that the price will be higher.


I have broken some exhaust studs off in my day, even after using every trick in the book not to. Once broke, there is the time consuming drilling or welding thru nuts, if equipped, to get them out.


Spraying penetrating oil on 13 year old, unprotected studs, that are rusted to about half the diameter of new, is not going to help. I have put a wrench on studs that simply fall away, with hardly any torque at all.


It's not the mechanics fault the gaskets failed or the nuts seized on the studs, making them imposable to unscrew. Blame Cummins for using the hardware that they did.

[courtjester]

man that quote is outrageous. First of all, I'd be suspicious that the cause of the boost issue is the exhaust. Its just as likely to be the CAC or one of the connections.

Not sure about your unit, but on our old Monaco, there was a hard steel line that ran to the waste gate. If that line cracks, its hard to see and will allow the boost to go away.

Assuming the problem is in the manifold, if you're careful, those studs will come out. It can take a combination of heat, penetrating oil and patience, but you can usually get them if you're careful and not in a hurry. One trick is to use very liberal amounts of penetrating oil and move the nut only a small amount at a time. Each time it moves, squirt it again and turn the nut both ways. If all else fails and you break a couple off, go ahead and pull the manifold and see how much stud you have sticking out. You can weld a nut onto the stud and the combination of the heat and a new surface to attach your wrench to will allow you to back the stud out. I've dealt with bunches of broken studs and have never found one I couldn't get out sooner or later. Even if the stud is broken even with the head, you can hold a nut over the stud with a pair of pliers and still weld the nut to the remnants of the stud.

Once the manifold is pulled, you can have it surfaced and in most cases will not have to replace it.

Have fun

[dennis45]

Originally Posted by twinboat

It's sounds like they are being up front with you. They have done enough gaskets to know that the studs are going to break off.


You could take it to another shop but be prepared for the same quote or a call, halfway thru the job, that the price will be higher.


I have broken some exhaust studs off in my day, even after using every trick in the book not to. Once broke, there is the time consuming drilling or welding thru nuts, if equipped, to get them out.


It's not the mechanics fault the gaskets failed or the nuts seized on the studs, making them imposable to unscrew. Blame Cummins for using the hardware that they did.

Having been there done that, you are right on the mark. The engine compartment in these things is a magnet for rust and corrosion. I replaced my manifold myself. It came off without any problems but the potential for problems is pretty high. Then it's up to the mechanic to do the best he can to get it done. At $100+ per hour, it adds up. Nobody works for free.

[Mr_D]

Originally Posted by dennis45

Let's put this into perspective.
An exhaust leak before the Turbo will result in low manifold pressure. Could be a cracked manifold (very common on the ISC), blown gasket on the manifold. Could also be a Turbo problem.
During the disassembly, it is possible to have siezed, or broken bolts but this can be minimized by applying a penatrant oil to all exhaust bolts prior to disassembly. Overnight would be ideal.
Now, if there is an issue with broken bolts, the labor costs go up because these things are time consuming to deal with. In severe cases, the cylinder head might have to be removed but IMO, this would be a rare exception.

If this were mine, I would get an estimate before they begin and make it clear that you must be notified if there are ANY complications beyond the estimate and you require all the old parts.

From your description, it doesn't sound like the shop you are dealing with are very knowledgable. Are they an actual Cummins Shop or just a truck shop. Not knocking truck shops but there are ones that know what their doing with trained people and ones that just work on stuff.....if you know what I mean.
If they cannot answer your questions to your satisfaction and provide you with a detailed estimate, I would go looking elsewhere.

Just a guess, but I think to R&R the manifold will run about 6-8 hours for two people (for a side rad rig, rear rad would be more) plus parts. Labor $1200 - 1800.

Good Luck

And going to an actual Cummins shop doesn't guarantee anything either! At Cummins NW they broke one shock (bent it enough that it wouldn't move at all) and ruined the one on the other side (leaking) on the drive axle, broke a very expensive inside sliding door and left scratches on the bedroom woodwork. Plus lost two engine belts that I requested them to save. They haven't come forward to pay for any of it.
On a CC Magna in AZ a non running one was brought to the Cummins shop, owner spent $20,000 getting it running and 20 miles from the shop it threw a rod through the crankcase. Cummins wouldn't pay a penny of the $44,000 to repair the engine after it blew.
The old Cummins that treated people right seems to be gone.

[dennis45]

Originally Posted by Mr_D

And going to an actual Cummins shop doesn't guarantee anything either! At Cummins NW they broke one shock (bent it enough that it wouldn't move at all) and ruined the one on the other side (leaking) on the drive axle, broke a very expensive inside sliding door and left scratches on the bedroom woodwork. Plus lost two engine belts that I requested them to save. They haven't come forward to pay for any of it.
On a CC Magna in AZ a non running one was brought to the Cummins shop, owner spent $20,000 getting it running and 20 miles from the shop it threw a rod through the crankcase. Cummins wouldn't pay a penny of the $44,000 to repair the engine after it blew.
The old Cummins that treated people right seems to be gone.

Mr. D, I hear what you are saying and have followed your dilemma with your Magna. Between that and your health issues I sincerely hope things begin to change in your favor.

[Jake74]

I would first check all the intercooler connections for a split, if that's good I would move to intercooler itself and have it checked for a split seam or crack in the core.

[DD788Snipe]

Originally Posted by Jake74

I would first check all the intercooler connections for a split, if that's good I would move to intercooler itself and have it checked for a split seam or crack in the core.

Have the intercooler pressure tested.