Important info on all diesel air intake

[tom chelbana]

Surprised this hasn't come up before now but for the last couple weeks the most active post has been the New Aire owner whose engine was full of water that came in from the air intake on the outside of the coach. Almost 14K reads and 111 responses should indicate the awareness of the this problem. Here is what we found today when we were looking to see if our 18 London Aire could have this problem with the air cleaner filling up with water from the outside intake. The answer is Yes. The reason this is happening is because the bottom of the drain tube was covered with foam insulation as shown in the photo. With this problem all Newmar coach owners should check to see if their drain line is open. Again all owner's should check this drain line so they don't have this major problem.

Newmar Man

[JMcG]

Thanks Tom, will check it immediately.
JMcG
2016 VTDP 3725

[zzotte]

Thanks Tom

Zzotte

[dp7]

Originally Posted by tom chelbana

Surprised this hasn't come up before now but for the last couple weeks the most active post has been the New Aire owner whose engine was full of water that came in from the air intake on the outside of the coach. Almost 14K reads and 111 responses should indicate the awareness of the this problem. Here is what we found today when we were looking to see if our 18 London Aire could have this problem with the air cleaner filling up with water from the outside intake. The answer is Yes. The reason this is happening is because the bottom of the drain tube was covered with foam insulation as shown in the photo. With this problem all Newmar coach owners should check to see if their drain line is open. Again all owner's should check this drain line so they don't have this major problem.

Newmar Man

Isn't there supposed to be a duckbill on the end of the drain line?

[kdnash]

I posted the same question (#57 in the rainwater in crankcase thread). On our 2019 DSDP you cannot see or inspect the drain line for the air intake. From the looks of Tom's picture it was taken looking up from the engine bay. The drain line disappears into the foam/bulkhead going up to the upper air intake at the rear DS cap. When you look into the upper intake from the top the screen prevents you from seeing anything. I'm am going to try inspecting it with a borescope from the top. I spoke to the service manager at our dealer after reading about the issue (he is familiar with the New Aire owners water issue) He stated that the way the drain is constructed at the intake that there is no way possible for water to enter. I'm going to try to see for myself.

[Kountry 2SUM]

Is this a model and year specific problem?

[Dav L]

Having removed / replaced my 2002 MA rear cap and thoroughly inspecting the drain system, it would be difficult even with a bore scope to look at the drain from the top. The drain is about 6 feet down from the top. Better would be to find the drain exit, and you can put the bore scope up that tube. Even better (but more work) would be to remove the air intake ducting (about 5" diameter) and look through there to undisturb the drain as is condition.

kdnash: I think the later models have both the air intake drain (which on mine is at the very bottom of the intake plenum as water goes "downhill"). And there are also roof drains (not a factor, unless by small chance there is a puncture and all that roof water is falling into the air intake - very unlikely). I suspect the tube you are seeing at the top of the intake might be the roof drains and not the plenum drain.

For the other post, this is what should have been done by the repair dealership. But they so far from the OP's posts have been clueless and non caring to properly diagnose the issue. And I believe they are now trying to get that OP to pay for a complete engine replacement due to their crappy service. I feel sorry for the OP who doesn't have the technical background to realize he is being taken for an expensive ride.

I don't know the specifics of his RV, but if it's anything like mine (very likely) then it's not a design issue (what others are suggesting) but more than likely malicious damage (an insurance claim) OR exactly the type of situation that you have found on yours (Tom's) - poor workmanship from whoever sprayed all that spray foam and clogged up the drain tube.

It's a very simple drain system...if water enters the plenum via the intake (at the top rear of the cap, it runs to the bottom of the plenum and exits out the drain who's opening is at the very bottom of the plenum. The air exits the 5 inch hose that is mounted above the drain. So the plenum would have to fill with gallons of water before entering the turbocharger / engine. Possible if the plenum drain was clogged and much rain occurred. OR that someone put a garden hose into the intake and poured more water than the drain can relieve.

Too bad because I don't think the other OP has the background to protect his wallet.

If it were me and the servicing dealership said "I can't get to your RV to drain the water out for a few weeks", it would have been towed to another place to immediately address the issue to prevent additional rust damage. Which usually means my shop But any ole parking lot will usually suffice

All of my opinions are only based on silly ole forum posts which are always incomplete and inaccurate...the true story is another thing...

[Ricci]

Hi - Checked our drain today. It was completely closed and buried in foam. Not possible for water to exit via the duck bill. Other than driving through a hurricane I doubt this would be a problem, however one overzealous worker at a Blue Beacon with a power washer wand could have filled the box to the point that water would make it to the filter. The issue than is does the filter decompose from the water and take out a turbo or does the engine suck in water and the possible damage that would result. It's a quick fix to peal off the foam insulation and exercise the duck bill. But that is some high class QA at the factory to not check that.


Tom

[Akdare]

Could someone post a picture of what this area should look like?

[tom chelbana]

A couple of additional points. The problem on the our 18 London Aire is the foam that is sprayed in the drain area is covering and sealing the duckbill on the end of drain hose. When checking you are looking for the end of the hose to see if the duckbill is on and can open to drain. Keep digging the foam out around the blue drain line hose till you find the end.
One test you could do to check your drain line from the air intake is to spray water into the air intake and see if water drains out the bottom hose. When you do this you will want to remove the air line leading into air filter so if line is plugged you won't soak your air filter.
For the last couple years both Cummins and Spartan have been recommending replacing your paper air filter once a year because when water gets into air filter it damages the glue that holds the filter together. Then the paper from the air filter stats coming apart and gets into the turbo which can damage the turbo. Even with drain open there will be water getting onto air filter when.
This problem would be effecting all coaches with diesel engines for at least the last 10 years.
Newmar Man

[Spikester]

I would think the drain line would originate from a low point in the ducting between the air intake screen and air filter housing to be effective. Is this a bad assumption? I have not looked at mine yet, as on a rear radiator model it is a bit of a chore to get to the air intake piping to locate where the drain line starts and ends.

If the start end of the tubing is easily accessible, I would think removing it from the duct piping fitting and using water or air to see if the line is open and functioning would be a quick way to evaluate in functionality.

[Dutch Star Don]

On my 2005 Monaco Diplomat, the air pickup was in the same spot as Newmar and most other DP's. On the Diplomat, they installed a 2" duckbill in the lower bend of the 8" airline. I expected to find something similar on my Newmar, but it's a different design. Newmar is colleting water near the air intake at the top and draining via a blue hose (haven't seen any other color yet) that runs down the inside corner on the driver's side. It was pointed out by Stuart W that the passenger side has two blue hoses running down the inside corner. Those are the two rear roof drains. Now I know what all three hoses do.

With that said, I've been reading threads on two different RV Forums for 14 years. I think I've read maybe two reports about water ingestion. Those reports describe the air cleaner material getting wet and falling apart. I've NEVER read a report about water intrusion, especially on a modern coach, that filled the cylinders with water. I personally find it hard to believe that a coach can ingest that much water while driving down the road.

So...... check your drain hose, but I don't think I would lose sleep worrying about water ingestion.

[Ricci]

Hi Spikester - I think it would be more prudent to not get water into the air intake line rather than drain it at it's low spot. Once water is in there you have the risk of things growing in any corrugations in the pipe or at any elbows. If that "growth" were to let loose, as slimy stuff will do, it will make its way to the filter to become a problem. So it's best to not allow water in. You are right that the use of air to test the drain makes more sense. Using air avoids the possible contamination of the airway and if done with pressure, air will compress but water doesn't like to compress. It lessens the likelihood that a joint will be forced open.

Hi Don - Agree that you are extremely unlikely to ever see an engine that has filled it's cylinders with water through the air intake system unless it is at the bottom of the sea. The issue with water is that it doesn't compress well and the engine can not take that extra strain. It will cause piston failure or a bent rod due to extreme high pressures. (or blow the head off the block, but less likely in a diesel). A bent rod will stop the engine but a hole in a piston leads to other issues such as a run away engine as it feeds off the crankcase oil until it self destructs.

Tom

["007"]

Tom I see the blue drain line and foam at bottom of picture is the foam covering the grill pictured in second picture on ground near your foot?
Why would they be placing all this foam in that area to plug the drain up?