Exhaust manifold diy followup-tools, tips, technique

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Exhaust manifold diy followup-tools, tips, technique

December 04, 2015, 10:18:28 am

Like many others, I was bitten with shrunken exhaust manifold syndrome. My original intent was to pull the manifold, have it resurfaced and replace but it turned out to be shrunken too much to reuse. This turned out to be a significant job, but relatively inexpensive. Here's what I found.

The parts from Cummins Southern Plains, including new manifold, bolts, gaskets and bolt locks came to a bit under $600. Be sure to register for the Power Club and save 10%-you have to ensure the discount is applied when you purchase. Be aware that the turbo gasket part shown on quickserve, and Cummins parts fiche is wrong and will not work. (C8.3with dual port manifold) A proper new gasket is unobtanium so save the old one. Don't throw it away because you know you have a shiny new one on hand until you compare.

Ah the bolts. These are metric M10X1.5 with a 16mm head. On my engine, one bolt was pre sheared off, the one below it was hanging by a thread and light wrench pressure finished it off. These were the two closest to flywheel end of course, that require lyiing horizontally alongside the engine to access. All bolts were doused for weeks prior with penetrating oil, repeated heat cycles with torch, hammer blows to shock, other than the two which were pre-broken, and one which I didn't have impact access to and I managed to snap through stupidity, all others came out. What seemed to work best....penetrating oil pre soak, heat on bolt , whack the dickens out of bolt with as much hammer blow as possible,air impact wrench turned waaaay down, forward and reverse, withdraw bolt while still relatively hot. None of the bolts showed any indication of penetrating oil on embedded threads.

Zero luck in removing snapped off bolts. Drilled, heated, cursed, oiled, super German easy outs, maybe I just didn't cowboy enough on the easy outs but I was in terror of snapping one off. Ended up drilling them out and installing heli coils. Semi miserable job given the difficult access but bolts drill readily. Heli coils a snap to install. If I was doing it again I'd make every effort to kidnap an ex millwright like, ah, John Haygarth and get him to have a go at extraction. Maybe a bottle of single malt set just out of reach in engine compartment.....

Though only one port appeared to be leaking, pretty much all the exhaust ports in head showed significant pitting around them, given the age of engine was more disappointed than surprised. This was more than could be cleaned up with a file or stone so started looking at alternatives. I knew I didn't want to pull the head, but I sure didn't want the new manifold to leak either. What I came across was a Caterpillar product with rave reviews and priced like cocaine. CAT Manifold Sealer 2P-2333 picked it up in Houston. Applying some of this magic goo, letting it harden, then torch testing it indicates its some pretty impressive stuff. I ended up applying a thin coat to head surfaces only, that is between head and new gasket.

Anyhow, about a pint of blood or so later, buttoned it up, heat cycled, retorqued bolts and locked them. Just back from a 1500 mile test run and all is well. If anyone else is doing this job,and find a similar situation, along with my sympathies I'd like to offer:

Helicoil kit and odd sized drill bit necessary for installation.
Enough Cat 2p-2333 to smooth out pitted surfaces.

No charge, but limited to one who knows they need the stuff rather than pre emptive.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #1 – December 04, 2015, 10:45:44 am

Chuck,

Excellent write-up and generous offer! What is the mileage on your engine? Hoping to avoid this particular project (knock on wood).

Chuck

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #2 – December 04, 2015, 11:08:10 am

@Chuck nice work and write up. Glad you got'her done! Now go have some fun.

see ya
ken

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #3 – December 04, 2015, 06:37:43 pm

Quote from: Chuck & Jeannie – December 04, 2015, 10:45:44 am

Chuck,
Excellent write-up and generous offer! What is the mileage on your engine?
Chuck

135K miles at this point and climbing in inverse proportion to diesel prices!

BTW, used nickel based never seize (not the common aluminum stuff) on the new bolts just in case.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #4 – December 04, 2015, 07:17:53 pm

Beware!! 5.9 and 8.3 manifolds shrink. If you inspect the bolts regularly you can catch the problem before bolts start breaking. The bolt holes in the manifold are slots. You can watch the bolts move toward the inside of the slots as shrinkage proceeds. Replace the manifold before any bolt reaches the end of its slot. Check once a year. If a bolt hasn't started bending(which precedes breaking, it should come out without difficulty.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #5 – December 04, 2015, 07:58:03 pm

Wondering why some manifolds seem to shrink sooner than others.

Higher operating temperatures? (lots of trips in the desert)

More frequent heating-cooling cycles? (lots of short trips)

Engine out of tune? (running excessively lean or rich)

Occasional poor quality control in manifold manufacture? (faulty metallurgy)

Any other ideas?

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #6 – December 04, 2015, 09:50:48 pm

I don't know why the manifolds shrink, but I know ours shortened by about 3/4". Bernd said four bolts broke as they removed the old manifold. We have a shiny (?) new (!) manifold. Miles on the C8.3 is around 130K. The price for the manifold was about the same as Chuck quoted. I paid sometime else to do the work.

Most of the trips involved several hours each day. Temperatures were mixed, as we have travel at all times of the year. We don't "warm" the engine before rolling, but we do try to drive gently to start, and shut down gently as well.

My clue regarding the problem was exhaust soot on the side of the engine. I could see that the bolts were bent when Bernd pointed out the problem while we looked at the engine from the viewpoint in the bedroom.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #7 – December 04, 2015, 10:16:58 pm

Chuck, the Cat stuff sounds like the Devcon filler I used to fix my CAC a few years ago. We used it on bad castings in England for the Deltic Diesel engine so I know it is good.
Next time you have a problem stud soak it with Prune Juice as that stuff will move anything!!
Good job on repair and I actually do know what it is like getting them out as I did a cummins engine manifold on a friends coach a few years ago and had to drill out 2 of the broken bolts. I was lucky as I got the old thread out.
JohnH

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #8 – December 05, 2015, 01:30:20 am

fix of ours at Cummins shop was $1300. No significant problems with bolts, no head problems. Caught it early because a salesman at MOT heard the leak when I was in the driveway there. Hard to hear, to detect. Am trained now, sorry to say.

I saw a leak on another coach where the heat was blowing up onto the turbo, not good. Even then after got it fixed but was not done correctly, incorrect part and had to be redone in a thousand miles.

Mike

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #9 – December 05, 2015, 08:07:51 am

Quote from: Chuck & Jeannie – December 04, 2015, 07:58:03 pm

Wondering why some manifolds seem to shrink sooner than others.

Higher operating temperatures? (lots of trips in the desert)

More frequent heating-cooling cycles? (lots of short trips)

Engine out of tune? (running excessively lean or rich)

Occasional poor quality control in manifold manufacture? (faulty metallurgy)

Any other ideas?

My impression was that the manifold shrunk significantly during our summer travels this year. Two things that were different, cheap diesel, which I guess encouraged a bit more of a lead foot, along with an abbreviated travel season this year, and a significantly heavier toad. As usual the travels consisted of an "escape from Alcatraz" style drive out of the S. Tx. heat, and every mountain range between Tx. and the PacNW. I wish I could say I had been monitoring the manifold but fact is I really didn't pay much attention to it until I spotted a soot trail from a leak. Like J.D. noted the original manifold had shrunken an amazing amount. One thing I did note, when shooting the original manifold ports with the IR gun, a significant difference in temp between them. Valves, fuel, air flow, who knows? Will look into this more.

I tried to grill Cummins on whether the "improved" manifold was going to be resistant to the same problem but no luck there. I do note some improvement in power with the new, at this point the ports line up well. They are not that large to start with, and the old manifold was probably blocking them a few percent due to shrinkage. I will be keeping an eye on this area for sure.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #10 – December 05, 2015, 09:12:41 am

For those who want to find out if they have an exhaust leak, it is very easy.

Both from above (raise bed) and from the back, with a strong flashlight look around where the manifold bolts to the head. Any sign of black (soot) indicates a leak.

Also look between the segments of the manifold itself if yours is multi-piece and from exhaust manifold to turbo.

The multi-piece manifolds allowed for more expansion/contraction than the one piece ones.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #11 – December 05, 2015, 06:28:21 pm

Here's what my 3116 looked like a couple of weeks ago and one showing how it looks now. I was surprised to even get the bolts to thread in by #6. I wouldn't bet much on this lasting for long. If it blows again, I'm going to see if a 3 piece manifold from a 3126 will bolt up.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #12 – December 05, 2015, 07:12:45 pm

Quote from: Dave Larsen – December 05, 2015, 06:28:21 pm

Here's what my 3116 looked like a couple of weeks ago and one showing how it looks now. I was surprised to even get the bolts to thread in by #6. I wouldn't bet much on this lasting for long. If it blows again, I'm going to see if a 3 piece manifold from a 3126 will bolt up.

I would have been tempted to weld on some more material if materially possible and machine the hole over to line up?

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #13 – December 05, 2015, 10:12:19 pm

Unless your 3116 exhaust manifold has shrunk a LOT, it can probably be resurfaced. And a resurfaced "seasoned" manifold will be a lot more stable than a new one. Most speed shops can recommend a shop that surfaces manifolds-- Not a big deal.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #14 – December 06, 2015, 02:04:08 pm

I had it resurfaced while it was off. It was definitely warped.

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #15 – December 06, 2015, 05:00:29 pm

Quote from: Dave Larsen – December 06, 2015, 02:04:08 pm

I had it resurfaced while it was off. It was definitely warped.

Common with any of the one piece manifolds, Cat or Cummins. Suspect with your resurfaced seasoned manifold, the problem will never resurface.

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Exhaust manifold diy followup-tools, tips, technique

December 04, 2015, 10:18:28 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #1 – December 04, 2015, 10:45:44 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #2 – December 04, 2015, 11:08:10 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #3 – December 04, 2015, 06:37:43 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #4 – December 04, 2015, 07:17:53 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #5 – December 04, 2015, 07:58:03 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #6 – December 04, 2015, 09:50:48 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #7 – December 04, 2015, 10:16:58 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #8 – December 05, 2015, 01:30:20 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #9 – December 05, 2015, 08:07:51 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #10 – December 05, 2015, 09:12:41 am

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #11 – December 05, 2015, 06:28:21 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #12 – December 05, 2015, 07:12:45 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #13 – December 05, 2015, 10:12:19 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #14 – December 06, 2015, 02:04:08 pm

Re: Exhaust manifold diy followup-tools, tips, technique

Reply #15 – December 06, 2015, 05:00:29 pm

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