Skip to main content ↑ ↓
Topic: C8.3 turbo (exhaust manifold) problem (Read 1072 times) previous topic - next topic

C8.3 turbo (exhaust manifold) problem

I'm getting blow by around the turbo. It appears to be coming from main turbo housing on the downstream side or exhaust side, not the intake or compressed charge outlet. There is more blow buy toward the back (transmission) side of the engine, but it apparently is also reaching the top of the engine compartment top where the insulation had come down.  I had thought it was simply the old original insulation deteriorating to the final degree. I also see some melting of the wire loom going to the remote start, stop buttons at back of engine compartment. No visible blow by at idle as viewed from engine cover.

The turbo is a Holset HX40W 3537568 which is still listed on the Holset website and there is no superseding part number according to their site.

I'm in Albuquerque visiting my son and parked in his driveway.

1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: C8.3 turbo problem

Reply #1 –
Have you checked the head to exhaust manifold, manifold itself and gasket between exhaust manifold and turbo.

As sooty as it is right now, you may need to clean it to even find the source (unless you find a blown gasket, broken exhaust manifold, broken exhaust manifold studs, etc.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: C8.3 turbo problem

Reply #2 –
Sometimes I can't see the forest for the trees. Definite gasket leak at manifold. This is the number six cylinder. Now what? Could it be both?
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: C8.3 turbo problem

Reply #3 –
Well, most likely a warped manifold. Most likely you will experience some broken bolts getting it off, start spraying them often with penetrating oil of your choice, along with the 4 turbo bolts/ studs. If you have a small propane torch a little heat and spray and light tap with a hammer over a couple of days will help. Some folks have the old manifold re surfaced at a machine shop IF you can get all the bolts back in it. You will need all new bolts and gaskets. If you want a new manifold try Vanderhagges truck parts. Cummins will hurt your feelings. Search Exhaust manifold here on the forums lots of posts.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: C8.3 turbo problem

Reply #4 –
Looks as if the gasket is totally gone. Big reason for low or no boost. Fix right away as the exhaust in a bad case, can eat into the cylinder head at the port making head removal necessary so it can be machined.  Your is probably OK now.

Because the exhaust manifold design, always give #6 exhaust port a frequent loo

Couple of good videos on YouTube on how to get a manifold off without breaking studs.

Pierce
Pierce and Gaylie Stewart
'93 U300/36 WTBI
Detroit 6V-92TA Jake
1140 watts on the roof
SBFD (ret)

Re: C8.3 turbo problem

Reply #5 –
Unless you are in a real hurry, start by soaking all the exhaust manifold bolts/nuts with penetrating oil for a couple of days.

An excellent homemade one is 50/50 ATF/Acetone.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: C8.3 turbo problem

Reply #6 –
Looks like a bad manifold gasket which cost very little .Most times removing manifold bolts is a pain and can take time. Wish you were still in Oklahoma and you could come down to Arkansas to my shop and we would do it. You have the skills but may not have the tools, I don't know. A battery or air powered impact plus a drill to drill out the one or more that break. Like Pierce said, start now with penetrating oil and repeat several times.
Dub McBride 1996 270

Re: C8.3 turbo problem

Reply #7 –
How does an amateur check out exhaust manifold for warpage? Is it better to just replace it at this age with one like Barry bought? I've already started soaking the bolts with PB Blaster. I've got 109,000 miles on this engine that is 25 years old.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: C8.3 turbo problem

Reply #8 –
Quote from: Realmccoy –
How does an amateur check out exhaust manifold for warpage?

Long, absolutely straight surface.  Even a large L square should be enough to see if it is warped.

And, any place that surfaces manifolds should be able to resurface it for much less than a new one.  And, a resurfaced "already seasoned one" that has been milled is a better choice than brand new ASSUMING it is not cracked or too warped to mill satisfactorily.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: C8.3 turbo problem

Reply #9 –
Once you get the manifold off lay any straight edge across the gasket surfaces any gaps indicate warping. Also more than likely you will not be able to start all the bolts back. Check that before you have it machined, you can also have the holes slightly enlarged if that is the case. Where it me I'd just replace it. When you reassemble it be sure to use some high temp nickel anti-seize on the threads. Makes life easier if you ever need to remove it again.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: C8.3 turbo problem

Reply #10 –
Similar mileage as yours Patrick,  I had the same issue with my 8.3 exhaust manifold had shrunk and busted stud/bolt on number 6.
I supplied the exhaust manifold and farmed it out to a local truck shop for R&R. I sprayed all the bolts many times over a month with heat cycles and they still broke 6 or 7 bolts removing, I could have done that!
Wish I would have asked to see the broken bolts, I'll always wonder...
Those threaded bolt holes in the head go all the way through so you can spray both sides.
New manifold has reinforcement between exhaust ports should help with the shrinking. There is no 2 or 3 part manifold available for this model 8.3

3929779 | Cummins C8.3 Engine Exhaust Manifold for Sale
Doug W.
96 36' U270 CSGI #4946
04 Toyota Tacoma 4x4
PNW

Re: C8.3 turbo problem

Reply #11 –
If you need a shop, MC Diesel is good.  M.C. Diesel | Albuquerque Diesel Mechanic | 
We were stranded in the U240 in Socorro last year with a bad injector.  Mark drove down to fix it.  He seemed very honest and was more than willing to work under the bed.
Dave and Kelli
1997 U295 40' Build #5188 CSGI
1995 U240 36' Build #4621 SBID-SOLD
2006 Jeep Wrangler Rubicon

Re: C8.3 turbo problem

Reply #12 –
If you want to hire it out, Cummins in Albuquerque is a coach care location. I had them do work on a Cummins 8.3 coach when I lived there. 
Dan - Full timing since 2009
2003 U320 40' Tag 2 slide

Re: C8.3 turbo problem

Reply #13 –
The parts quote I got from Cummins for the manifold, fasteners, and gaskets was over 1200.00 just for the parts!!! But that was for a 1999 ISC 8.3.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: C8.3 turbo problem

Reply #14 –
Quote from: bbeane –
The parts quote I got from Cummins for the manifold, fasteners, and gaskets was over 1200.00 just for the parts!!! But that was for a 1999 ISC 8.3.
I don't think the C8.3 would be any cheaper. Just to put a little icing on the cake, someone broke into my pickup and got $4,000 of fishing and kayak equipment. They also hit my neighbor's car and my son's car last night.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: C8.3 turbo problem

Reply #15 –
Keep in mind that a new cummins manifold is going to do exactly what the old one did....shrink.  As Brett suggested, provided the old manifold is not cracked, having it resurfaced and reinstall with new studs and gaskets, drilling the holes oversize so it'll line up with new studs will save you some $ and give best service.  Preshrunk....like new jeans. 
"Not so  long ago we were a nation of risk takers, riding five million pounds of  thrust straight into space."  Joe Gresh
Chuck Pearson
1996 U295
2018 Can Am X3 TurboRS

Re: C8.3 turbo problem

Reply #16 –
Quote from: Chuck Pearson –
Keep in mind that a new cummins manifold is going to do exactly what the old one did....shrink.  As Brett suggested, provided the old manifold is not cracked, having it resurfaced and reinstall with new studs and gaskets, drilling the holes oversize so it'll line up with new studs will save you some $ and give best service.  Preshrunk....like new jeans. 
I agree plus if you should have to end up replacing the old manifold later on it will be much easier next time because of new bolts and the anti seize Bruce mentions. I sent you a pm about the thieves.
Dub McBride 1996 270

Re: C8.3 turbo (exhaust manifold) problem

Reply #17 –
FYI: You cannot buy at this moment a new exhaust manifold from Cummins, out of stock. The original manifold 3929778 has been superseded by 3931441 and both are out of stock. I called a number of online truck part companies, a few advertise the manifold as in stock, but when you call they say it's out of stock. There is an aftermarket. A diesel parts store in Louisiana has found me an original manifold and is supplying me gaskets, bolts, lock plates. A RV engine shop, Statkus Engines, has agreed to R&R the manifold, but no opening until mid July. They won't start the repair unless a new manifold is on hand based on their experience with this manifold. A highly recommended mobile mechanic said "no thanks," take it to a shop in case of complications.  I seriously considered doing it myself, but if it goes south it will be a mess here in my son's drive way. I do not know how to weld, so any broken bolt removal technic requiring a welder is not an option at this point. A wrecker would have to drag me into the street and then block all traffic while hooking me up.

I've been dreading an event like this. The joy of living full time in a motorhome with no home base. A friend is loaning me a pop up trailer so we can keep a couple of camping trips with our son alive. To add a little spice to the situation  my transmission control pad button for D is not responding consistently. I push it and nothing happens and then after several attempts it responds. Sent it off to Transmission Instrument in Flower Mound yesterday.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.

Re: C8.3 turbo (exhaust manifold) problem

Reply #18 –
Quote from: Realmccoy –
I don't think the C8.3 would be any cheaper. Just to put a little icing on the cake, someone broke into my pickup and got $4,000 of fishing and kayak equipment. They also hit my neighbor's car and my son's car last night.
Curses upon the thieving swine!
Regarding the shift pad, I'd love to hear what the problem is once Transmission Instruments figure it out.
I've heard they can sometimes respond to a little contact cleaner.
1998 U295 36'
Build# 5358

SMILE!....it makes people wonder what you have been doing.

Re: C8.3 turbo (exhaust manifold) problem

Reply #19 –
They rebuild the pad,contact cleaner may work temperarilly but it won't fix it.
96 U270 BUILD 4810
85 380SL
Drummonds TN.

Re: C8.3 turbo (exhaust manifold) problem

Reply #20 –
My manifold will need to be done at some point. This is concerning that the stock is not available. Hopefully they are making some more. I feel pretty lucky to have all the tools and skills to pull it off when the time comes. Wishing you the best of luck in the meantime.

Re: C8.3 turbo (exhaust manifold) problem

Reply #21 –
Noah, the under $200.00 aftermarket works just fine. I have over 10K on one I installed last year. Not even rusted yet.
Bruce, Linda, and Macy
Zoey RIP 1/20/19
1999 U295 40' build #5400
2017 silver Jeep Wrangler, 1260 watts of solar on top
Moving around the country

Re: C8.3 turbo (exhaust manifold) problem

Reply #22 –
Several aftermarket ones on Ebay for around $200.
Keith
2003 U320 38' #6197

Re: C8.3 turbo (exhaust manifold) problem

Reply #23 –
Resolution: STATKUS Engines in Albuquerque replaced my exhaust manifold with the new OEM and the aftermarket gaskets, bolts, lock washers I provided from Diesel Direct in Louisiana. I can definitely recommend Diesel Direct for fair prices and a quick response with good shipping. The only thing missing was the gasket for the turbo to manifold.

I sprayed the bolts with PB Blaster off and on for a couple weeks while waiting for my appointment. I did not get under the engine to spray the bottom bolts but I guess my blind spray efforts worked as no bolts broke in the removal of the manifold on my 25 year old engine with 109,000 miles. Labor was $1280 which included servicing the air dryer and engine air filter.

Rebuilt WT3 transmission pad working great. Ended up replacing engine compartment insulation as the exhaust leak took a heavy toll on my original tired insulation. Back on the road again.

Shipping prices for engine air filter have gone through the roof - $200! Cheaper to buy at NAPA or O'Reilly than order online. Prices are almost double from 15 months ago. STATKUS charged me less than NAPA for a new filter.
1998 36 foot U270 Build No. 5328 WTFE, 900 watts solar, Victron controller, B2B, bat monitor, 600 AMPH lithium with 2018 Chevy Colorado toad, SKP #110239, Motorcade #17781, 2021 Escape 17B for when Coach is broken down and campsites are too small, retired and full-timer since Dec. 2020. Part of RV family since 1963.