Diesel Pusher losing power

[Wjohns02]

Just curious as to other have had similar experience.

Have a 2006 Tiffin Phaeton, currently on a road trip in WY and motorhome seems to loose power on even small inclines. Had the air filter changed in Odessa Mo. which seemed to correct the problem for a while. Currently we go from the ability to travel at highway speeds to literally having to climb the entrance to the rv park we are staying at for a couple of days at 5 mph because the unit wouldn't go any faster.

Am trying to find a diesel shop in Cody, WY to check the coach out but just wondered if other members have experienced anything similar.

Appreciate any feedback.

[Cummins12V98]

"But what I don’t understand is when someone asks for help online and then really isn’t interested in answering pertinent questions that could help them diagnose the issue."

No SHITE!!!

Or how about actually telling us what engine it has. Stating "Diesel"" is not quite enough.

[LouLawrence]

Thanks for the correction. I was thinking of the Sea Foam spray which is gas only.
I don't really think the air filter change did anything but rather than this is an intermittent issue that appears and disappears with the engine on/off cycles. OP needs to get a good read of the engine error code(s).

[Grit_dog]

LouLawrence wrote:
Last I looked you cannot use Sea Foam on a diesel engine (and why would you want to?).
I am guessing this is a turbo issue and the OP should be pursuing that avenue. Boost sensor possibly, cracked manifold or something similar.

No, it’s recommended for diesels as well. Although personally I feel it’s better suited for gas engines and there’s better stuff for diesels.
Namely, depending on the engine engine and age of it, a good dose of non-synthetic ATF is about the best injector cleaner you can use on diesel fuel systems.

But if not after witches brew stuff, there’s a cacophony of dedicated diesel fuel system cleaners and conditioners.
Hard for me to say how well they work as I’ve never actually needed them. Save for once on this old 6.5TD I bought. A couple quarts of atf did the trick in it. Only other time I use anything other than fuel is if there’s a chance it could gel. Which is also very infrequent.

[Grit_dog]

I really do feel for folks who don’t understand much about vehicles. Even the basics.
Would seem that since houses and vehicles /power toys like RVs are about the most expensive single items we most all own it would make sense to learn just a bit…maybe there’s more folks that have so much money they don’t need to be concerned with getting over charged…
But what I don’t understand is when someone asks for help online and then really isn’t interested in answering pertinent questions that could help them diagnose the issue.
Very common theme here. Not so much on other sites I’m on. (Admittedly mostly auto/power sports forums or pages.)

[jimh406]

LouLawrence wrote:
Last I looked you cannot use Sea Foam on a diesel engine (and why would you want to?).
I am guessing this is a turbo issue and the OP should be pursuing that avenue. Boost sensor possibly, cracked manifold or something similar.

Maybe you looked a long time ago. https://seafoamworks.com/uploads/2018/12/HOW2_Adding-Sea-Foam-to-Gas-and-Diesel-Fuel.pdf

I don't know if he should pursue your guess or not given your guess about Sea Foam. Joking ... kind of.

In any case, why do you think the air filter change helped?

[LouLawrence]

Last I looked you cannot use Sea Foam on a diesel engine (and why would you want to?).
I am guessing this is a turbo issue and the OP should be pursuing that avenue. Boost sensor possibly, cracked manifold or something similar.

[jimh406]

Wjohns02 wrote:
Thought I would come back with an update. So we were able to find a mechanic to check out the motorhome. Recommended changing the air filter (again). Explained that we had just done that two weeks earlier but followed his advice and changed it again. Seemed to correct the problem but really seems odd it could need to be changed so soon.

I'd have to guess the shop "said" they changed it, but either forgot, or didn't try to change it. Sorry, if the "shop" was you. If so, my comment doesn't make any sense. However, not all air filters are equal. Some engines put a lot of pressure on the filter and can collapse lessor filters. I only run the OEM types on my diesels. If the filter is not an OEM one, you might try that as well.

I'm also a big believer in additives like Sea Foam and Diesel Kleen. I find they help make my diesels run better although some say it is snake oil. YMMV.

[Grit_dog]

Sounds like it’s still not running right.
Have to provide more data. I presume a fancy coach like that has a full complement of gauges? Are you making full boost, what are egts, is the trans downshifting properly?
Could be rail pressure, weak FPR blowing off too early as well.

It’s wholly improbable that you plugged up 2 air filters in a week unless you drove thru the great dust storm of 1929 or a swarm of locusts, lol. What did the filter minder say? What did the filter look like? Did the mechanic actually ever look at it or did you just have a quick free phone call w him?

Sounds like this is a new purchase and no previous history with the unit?

[Wjohns02]

Thought I would come back with an update. So we were able to find a mechanic to check out the motorhome. Recommended changing the air filter (again). Explained that we had just done that two weeks earlier but followed his advice and changed it again. Seemed to correct the problem but really seems odd it could need to be changed so soon.

Has been an interesting 5 weeks on the road. Had one slide stop working altogether so now have to override it by using power directly from the battery. Had a pin break on another slide but was able to repair it. Replaced the onboard surge protector with a external one.

Still it has been a great trip, but expensive trip. We have done fine towing the Jeep on the interstate and relatively level ground but the motor home really struggled in higher elevations which was not what I expected with a DP. Often we did well to hold 25 mph when climbing hills out west.

Have several things to get checked out when we get home on Saturday as we continue the motorhome journey.

[Wjohns02]

Thanks for the quick feedback. Attempting to connect with a diesel mechanic in Cody today.

Recently had air filter and fuel filter changed. Not sure if unit has two filters but will find out.

Unit is not blowing black smoke even when we are crawling from a speed standpoint.

Will provide update once we can figure out the issue.

[Tyler0215]

If you got a bad tank of fuel you may have to change fuel filters 2 or 3 times to get back to normal.

[Wjohns02]

Thanks for the quick feedback. Attempting to connect with a diesel mechanic in Cody today.

Recently had air filter and fuel filter changed. Not sure if unit has two filters but will find out.

Unit is not blowing black smoke even when we are crawling from a speed standpoint.

Will provide update once we can figure out the issue.

[wolfe10]

Tyler0215 wrote:
Change the fuel filter

Yup, always the first thing to do with a diesel with performance loss.

Replace the fuel filter or if two be sure to replace both of them.

Cut open the old primary fuel filter to see if there is a contaminated fuel issue.

[Reisender]

Wjohns02 wrote:
Just curious as to other have had similar experience.

Have a 2006 Tiffin Phaeton, currently on a road trip in WY and motorhome seems to loose power on even small inclines. Had the air filter changed in Odessa Mo. which seemed to correct the problem for a while. Currently we go from the ability to travel at highway speeds to literally having to climb the entrance to the rv park we are staying at for a couple of days at 5 mph because the unit wouldn't go any faster.

Am trying to find a diesel shop in Cody, WY to check the coach out but just wondered if other members have experienced anything similar.

Appreciate any feedback.

We had those symptoms when we got a cracked exhaust manifold which apparently reduced turbo boost. (I’m not a mechanic so don’t understand this). Have your mechanic check the exhaust manifold. Ours was a Cummins ISC. 2003.