EGR Problems??

[KentandJoyce]

We have a 2006 Windsor with ISL 400 side radiator. 58k miles.
I was replacing with a new air filter and noticed that the 5" aluminum tube between the filter housing and turbo had "damp" sediment throughout the tube
near the turbo. The sediment had "run-off" patterns in it as if antifreeze had been washed into the tube causing the sediment to run back towards the air filter. This is coming from the cold side of the turbo (I assume). The air filter is fine, it did not fail.
When we returned from our last trip, as I parked the MH and shut everything down I noticed some antifreeze on the air filter housing that had come from the plastic pressure tank mounted above it. Not much antifreeze, but it had never done that before. The pressure tank was about 1/2 to 3/4 gallon lower than normal on antifreeze. The fan did cycle on and off a few times while parking, which is unusual as the weather is cool here in Northern Ca.
Could this be from the EGR cooler failing?
Any insight would be appreciated. I'm taking the intake tube to a Cummins dealer and some independents to see what their thoughts are.
Thanks,
Kent

[Dutch Star Don]

Kent.....On your coach, you have two small hoses that attach at the top of that plastic overflow tank. One of them runs to the turbo and I think the other runs to the thermostat. I'm thinking that hose is leaking and dripping down into the air cleaner tubing and possibly penetrating at some seam.

It's time (9 years) to replace those hoses. I did mine on my Diplomat last year. I pulled up the rear most interior engine cover which gave me access to the hoses from the inside.

While you're doing this, there is also a large hose running out the bottom of that overflow tank. It's an odd diameter (I think 1 1/14", I'm not sure). It should also be replaced. Napa carries the hose.

It doesn't make sense that antifreeze would be on the intake side of the turbo, unless it's leaking from that hose or the turbo is leaking coolant internally.

[Steve Ownby]

Originally Posted by KentandJoyce

We have a 2006 Windsor with ISL 400 side radiator. 58k miles.

I was replacing with a new air filter and noticed that the 5" aluminum tube between the filter housing and turbo had "damp" sediment throughout the tube

near the turbo. The sediment had "run-off" patterns in it as if antifreeze had been washed into the tube causing the sediment to run back towards the air filter. This is coming from the cold side of the turbo (I assume). The air filter is fine, it did not fail.

When we returned from our last trip, as I parked the MH and shut everything down I noticed some antifreeze on the air filter housing that had come from the plastic pressure tank mounted above it. Not much antifreeze, but it had never done that before. The pressure tank was about 1/2 to 3/4 gallon lower than normal on antifreeze. The fan did cycle on and off a few times while parking, which is unusual as the weather is cool here in Northern Ca.

Could this be from the EGR cooler failing?

Any insight would be appreciated. I'm taking the intake tube to a Cummins dealer and some independents to see what their thoughts are.

Thanks,

Kent

When you say"throughout the tube", do you mean inside the tube?


Steve Ownby
Full time since '07

[KentandJoyce]

DS Don, Thanks for the reply. I did replace the lower hose a few years back and I'll change out the two smaller ones before I hit the road again. I bought a new radiator cap because the old one was the original and I don't think it was holding pressure. That may be my antifreeze issue.

Steve, thank you also for the reply. Yes it is the interior of the aluminum tube that has moist sediment in it.

I went to the Cummins dealer yesterday with my tube, turbo boot and old air filter to ask them if they had ever seen something like this before and what their opinion was.

Their answer was yes, they had seen dirt on the intake side before, what they didn't know was how it got there. I showed them my filter and there is no evidence of dirt bypassing the filter or of filter failure. It's really pretty clean. They agreed it most likely didn't pass through this filter.

They thought perhaps that the contamination was entering through the air compressor line that connects to the nipple on the 5" intake tube. Upon inspection the inside of the nipple was clean (no oil or dirt) and the hose that connects to the compressor was also very clean. How the sediment got into the tube is a mystery to me?

I went back to MH and cleaned up around the turbo and made sure there was no debris that could be pulled into the open turbo or compressor line and then started up the rig. I ran the engine for 30 minutes running the rpm's up to 1400 and getting the coolant up to 181 degrees. Everything ran like a charm.
No oil or soot anywhere, exhaust is clear and clean. No antifreeze issues, etc.

My next plan is to clean everything up and reassemble the filter, tube, etc. and then run the rig up and down the hills to get everything up to operating temp.
After that I'll then disassemble the filter and tube to see what I've got.

I'll post my findings after the test run. Thanks for the replies.

Kent