Turbo Gauge dropped to the bottom and lost power when pulling into campground

[stonetm]

My wife and I are in Groveland, CA outside of Yosemite for a much needed r&r. Unfortunately, on the final climb to the campground my 8V92 lost power and the turbo gauge dropped to the basement. Does anyone know of a good roadside mechanic? or a limp fix to get us back to Sacramento/Stockton?? Called French Camp Detroit Diesel and they were no help. "Haven't seen one of those things in years" gives me great confidence with that one. **sigh**

[ajducote]

Have you checked the clamps and connections on all the pipes that go from the turbo to the charge air cooler, and from the charge air cooler to the engine? It could be a simple as a hose clamp that broke or a connection that blew off. It is easy to check and may be easy to fix if that is al that happened.

good luck

[truk4u]

Stonetm,

I'm not familiar with anything on the west coast, but Valley Power appears to be 2 cycle friendly.

855 Stillwater Road
WEST SACRAMENTO, CA 95078
Phone: 916 372 5078
Fax: 916 372 2721


We have lots of members in CA, hopefully someone will try to help. Have you called the Prevost Hotline?

[stonetm]

Thanks for the advice, it appears everything is hooked up.

[stonetm]

Good information. Thank you

[jj628]

Last year my American Eagle sat at two different repair centers for over 6 months. When I finally got it back on a trip halfway to Albuquerque from Missouri I started losing power on hills. Barely could make the hills at 20 mph. Put some Lucas fuel treatment in at Alq and it was ok until Phoenix. A month later I was on my way to Flagstaff same problem. Got it to the Freightliner shop--they pulled the fuel filters( two months old now) and they were full of algae. Fuel in the tank for a long period in a humid climate is the culprit I guess. A little more Lucas and new filters solved the problem.

[Jon Wehrenberg]

Stone,

You do not post your year coach (which will tell DDEC level) so take this advice with a grain of salt.

On a DDEC equipped 8V92 there is a turbo boost sensor on the RH side (facing the engine) and if it fails you may not get any turbo boost. It can be as simple as a failed rubber hose connected to the sensor or the sensor.

Add your coach info in the signature line and please post the results of your repairs.

[Bill Dator]

I have a 8V92 and had a similar problem. Changed the fuel filter to a 30 micron one and it solved the problem'

[Will Garner]

Stoney,

KISS (Keep It Simple .. ) well you know the rest. Start with the fuel filters. They are available through NAPA and other parts houses as well as DD and Prevost. I had the same problem going to and from OKC last October. Spent a night on the way home in Goodlettsville, TN at Prevost watching mechanics play with turbo pipes and etc. When I pulled the on ramp to I-65, same old lack of power (lost boost) and several hundred dollars down. I limped on home, changed the fuel filters myself, and the problem was solved. So I suggest you get a can of diesel fuel (needed to pre-fill the new filters), new fuel filters (2), and then get your hands greasy changing out the filters. When you are done and the power is back you should feel a warm glow of achievement in what you have accomplished.

IF that does not work, and you will know on the first hill you pull, then go for the more complicated "solutions."

Oh yeah, welcome to the wild and wacky world of POG!

[jj628]

Will,
Yesterday, just as we were leaving New York and paying nearly $60 in tolls to drive part way across the state, I stopped at the last turnpike station to top off fuel before going into Vermont. Within a half an hour we were going up hills at 20MPH at 1/2 power. Something similar had happened before, as I wrote on this thread. I read your post last night and hoped we had the same problem as you--we did. We bailed out of VT and headed to as Freightliner shop about 70 miles south. They had the secondary filter but not the cartridge for the water seperator. God does take care of drunken sailors and Irishmen. I left the shop with the same problem I had arrived with but I had to stop for fuel----in the next stall over was a Detroit Deisel service van. The guy was on the phone and a little surprised when I knocked on his window and told him not to leave. I asked him if he knew anything about 8v92's --some he said. I told him my sad tale and he said " I have one of those filters with me I think" He did--changed it for me in about two minutes---and wouldn't take any money! Problem solved and we are back in business and on our trip.l would send a letter to DD but they might fire the guy for giving stuff away.
Again, thanks for the great advice. jjf

[sticks]

I apologize in advance for my stupid question BUT, where are the fuel filters located? how easy are they to get to? Is there an old thread describing this fix? I figure if I bone up on this it won't happen to me the next time I try to pull UP into Las Vegas .

[Jon Wehrenberg]

Fuel filter types and locations vary depending on the type coach and converter. On my XL the primary Racor is on the RH side inside the RH side door next to the AC compressor and the secondary filter is low, same side behind the chassis batteries.

The Racor filter is easy to access, the secondary I access from the pit, but it could be reached by crawling under from the RH rear side.

[jj628]

Have you found out what the problem was? jjf

[Kenneth Brewer]

Fuel filter types and locations vary depending on the type coach and converter. On my XL the primary Racor is on the RH side inside the RH side door next to the AC compressor and the secondary filter is low, same side behind the chassis batteries.

The Racor filter is easy to access, the secondary I access from the pit, but it could be reached by crawling under from the RH rear side.

Same here on our H3, I think the secondary is where Jon has his, as well, my memory is perfect, but short, and I am not able to check the secondary today.

[stonetm]

Update-Bus is in the shop. Fuel filters did not correct and they are pulling codes this week to see what they come up with. The fuel is old but looks decent for the age. I keep hoping for something simple!!

Will pass along when I get the details.

[Jon Wehrenberg]

Troy,

Your original description sounded like it relates to the Turbo Boost sensor.

It is a small black plastic case slightly smaller than a pack of cigarettes. It attaches to the engine via a small length of tubing around 1/4" in diameter. If the sensor fails or the tubing gets a crack and leaks air it renders the turbo inop.

Its an $89 part (it was back in the 90's anyway) and when mine puked the DD shop wanted to spend hours pulling codes and analyzing it. I heard everything from a bad ground to all sorts of other obscure causes. I risked the $89, replaced it and the problem went away. I remeber pulling the code without a reader by jumping between two pins on my coach (the old fashioned way) so all I had was a code number that suggested a problem in that area.

It would have cost me more than $89 in fuel to get to the DD folks anyway so the risk was minimal.

This is purely a guess and it is being offered without any knowledge of what may really be going on.

[stonetm]

Update to the problem-Cracked Exhaust Manifold...Actually more of a big crack and piece fell out. As I have the blankets on the Manifolds, it was not visible until they were removed. Have no ideal why yet..as we get deeper in we will see. So shop is looking for best deal on manifold, will replace and hopefully that's all.

Thanks for all the posts and assistance and will drop update when back on the road.

[jj628]

Sorry it wasn't fuel filters but glad you found out. jjf

[Jon Wehrenberg]

Troy,

FWIW do a truck salvage yard search.

Detroit Diesel is proud of the manifolds for the 8V92 so if you can scour the junk yards. A broken of cracked exhaust manifold on an 8V92 is not uncommon. If the manifold does not crack the gasket between the manifold and the head also has a tendency to blow out. Your exhaust shielding masked the problem which would have been evident due to the excessive sooting which occurs when the manifold or gasket fails.

Replacing the manifold is not hard, but unless you or the mechanic are extremely lucky the studs tend to come out in stead of the nuts coming from the studs and the result is a loss of coolant. I suggest the coolant be drained and retained before the replacement starts. The correct torque on the manifold nuts is critical. While you have it apart take a real good look at the tubes going from the end of the manifolds to the turbo. They tend to fail right at the joint near the ends. When they crack the same thing happens with loss of boost.

[stonetm]

Thanks Jon..This time I have to depend upon the shop to do as I no longer have my storage unit. They have experience with the 8V92's so I will touch base with your comments to ensure it's done correctly.

Any reason to replace both while in engine or is that a little crazy?

I will be curious to see if I get any power gain? I had noticed the coach ran much better when cool then when hot..makes sense with the expansion of the manifold...and my wife said it was sounding like we had a hole in the muffler....go figure!!

Thanks again to all!

[Jon Wehrenberg]

I ended up replacing 2 manifolds on my first coach on two separate occasions. The failure on both was at the back of the engine where both had cracked. If you choose to replace both hang on to the good one you removed. If the good one has a good gasket and no cracks I wouldn't replace it or even touch it.

[stevet903]

Here's one on Ebay for $75:

http://cgi.ebay.com/ebaymotors/8V-92T-8V-71T-Detroit-Diesel-R-B-Exhaust-Manifold-/380254761795?pt=Boat_Parts_Accessories_Gear


Steve

[Jon Wehrenberg]

It has to be the correct side and that one does not have the hole for the pyrometer probe. The price is good.

[stonetm]

As a final post, I wanted to provide a photo of the broken part. Based off the way my midrange power has increased I am betting this was going bad for over a year! Thanks to all for your ideas.

[gmcbuffalo]

Troy call around to diesel repair shops they may have what you are looking for locally. I found mine doing that.
Greg