Exhaust sputter

[mattdenryter]

Hello all,
I am posting this for a friend of mine. He owns a 2003 fleetwood pace arrow 37A. Chevy workhorse 8.1 L. He recently noticed a sputtering noise from the exhaust tailpipe at idle. No noises from engine compartment. Engine starts right up every time with no issue. Any ideas what could be the cause of the exhaust sputter?
Thanks all.

[MustangGT]

I started my F-53 Ford once after it sat idle for several months. There was a loud FOOOOMMMMMMM!!! from the tail-pipes while cranking. Our dog just happened to be walking my wife past the pipes at that moment. The wife said the dog almost got its head blown off by the volume of water that shot out of the pipes. At LEAST a gallon!
Cool steel pipes at night + very humid weather = a lot of inside exhaust condensation. That explains why the exhaust components rust-out so fast.
Everything ran fine though. No problems after warm-up. Exhaust sputtering while engine is warming-up seems normal.

[justlou]

darsben wrote:
If sputter persists then do tune up. Plugs for sure but Rotor cap, rotor and wires if it has been over 2 years for these parts.

The 8.1 does not have a cap and rotor or distributor. It uses a modified COP (coil on plug) system that receives its spark command through the computer via a crankshaft trigger.
The short plug wires used have a relatively short life due to engine heat and when replaced you should buy the best silicone wires possible.
When we owned a gas MH that had the 8.1 engine it almost always had some water coming out of the exhaust when warming up. This would go away after the engine reached proper operating temperature. To achieve proper operating temperature you need to drive the MH not let it sit and idle. A good 10-15 mile drive will properly warm up the entire engine and exhaust system.

[ArchHoagland]

bsinmich wrote:
It won't get hot enough until it is driven. Get out on the road for a 30 mile trip and I bet it will have disappeared. For Arch Hoagland, we only have a possibility of a little wet snow on Mon. and then all Tulips after that.

Hit 96 here at our house yesterday.

[Daveinet]

Water is one of the byproducts of your cat. I'm not sure why some systems produce more water than others, but all of them do produce a small amount of water. I had a Jeep that produced massive amounts of water. With the old Jeep, there was a return tube on the cat that fed back into the intake. There was so much water dumping back into the intake, it actually would ice up the carb. I finally disconnected the tube, and ran it that way in the winter. Usually every fall, I would forget and get pulled over to the side of the road when it quite running. Just a matter of pulling the tube, and then knocking the ice down into the engine where it would melt, so I could start it up and drive it. Strangest thing. I never did figure out why it did that, but just dealt with it. I don't think it was a head gasket, as it never used water.

[bsinmich]

It won't get hot enough until it is driven. Get out on the road for a 30 mile trip and I bet it will have disappeared. For Arch Hoagland, we only have a possibility of a little wet snow on Mon. and then all Tulips after that.

[ArchHoagland]

I see you are in Michigan...that water is probably ice still melting......

I'd pull the doghouse cover off and listen for noise near the exhaust manifolds. Very common problem on gas engines.

[chuckftboy]

sounds like he may have a bad exhaust manifold gasket or even a cracked exhaust manifold. I think thats where I would look first.

[mattdenryter]

Just found out that all recalls were completed on the coach, including the catalytic converters.

[mattdenryter]

There are 47000 miles on the MH. He said he has never had the exhaust manifolds worked on. Everything on the dash works correctly. Tires are from Nov of 2012. He went back to the coach today, and let it run for about an hour (didn't drive it just let it run for an hour) Still made a sputter noise with water dripping from pipe. No excessive smoke or anything coming out of pipe just water dripping. He also looked under the coach and there was water dripping from the exhaust pipe were it begins to bend up.

[rgatijnet1]

On 2003 Workhorse chassis there was a recall(60401-C) on the catalytic converters for coaches with the 8.1L engine. If the recall was not done, perhaps the original incorrect catalytic converters are starting to fail.
Also moisture build up in the exhaust system can cause a sputter as it warms and starts to boil. If you see a little water coming out of the exhaust pipes, the vehicle needs to be driven for an hour or so to burn off all moisture.

[Daveinet]

Depends on the type of sputter. First thing I would do is make sure all the spark plug wires are pushed on all the way. The 8.1 was notorious for spark plug wires coming off. The problem was that because of the short length of wire, it was very easy to not install the wire all the way. As a result, they would come unplugged. Its not a persistent problem, once they are plugged in correctly, they do not fall off. Its just a matter of difficulty getting them plugged in all the way. If someone is just the least bit lazy, they will miss one or two. You need to make sure you feel the snap down into place, rather than just pushed on.

[ArchHoagland]

How many miles?

Has he ever had the exhaust manifolds worked on?

Do the Actia dash gauges work ok?....All characters on the digital display readable?

How old are the tires?

[mattdenryter]

Thanks, will tell him to run it for a bit and see if that helps. I want to make sure nothing is major with it cause I am considering buying it from him.

[darsben]

Could be condensation in exhaust.
Start engine and run for at least an one half hour to rid exhaust of moisture.
Does sputter go away? If so it was moisture.
If sputter persists then do tune up. Plugs for sure but Rotor cap, rotor and wires if it has been over 2 years for these parts.
Have timing checked.
My guess is the warm engine will cure the problem