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Okrver · 11-29-2012, 10:21 PM

I have a 2002 Ambassador with a 300 HP cummins ISB 5.9.
I tow a Dodge Dakota with an ATV total weight about 5000 its.
I have notice a lack of power going over Raton pass on my way to Colorado.

I wanted to investigate my turbo, but don't have any information on it.
Does anyone know the model and where I can find more information on my turbo?

Thanks
Pat

adehaan86 · 11-30-2012, 06:20 AM

I am unsure about the turbo, you can look on it and usually say. I am guessing it's a holset.

However going over large elevations you will lose power. The air is thinner.

Steve Ownby · 11-30-2012, 07:11 AM

Hey Pat,

How long have you owned your Ambassador? Have you made this trip previously and you notice a difference this time? If you are sure there is a drop in performance, I would start by replacing the fuel filters and checking the air restriction gauge for the air filter. If you have a turbo boost gauge watch it carefully to see if you are not getting max boost anymore. It could be a leak in the CAC plumbing not allowing you to get full boost pressure.

If you don't have a lot of experience with this coach yet, it may be an expectations problem. The Cummins ISB is a very successful engine but I suspect you are up against the top end of its capacity. You are towing the max weight at 5k and if you have a fair amount of cargo, you may be asking a lot of your ISB.

topdownman · 11-30-2012, 07:25 AM

If you had some sort of turbo issue, I'd assuming you'd get some sort of warning. Are you seeing boost pressure?

slickest1 · 11-30-2012, 10:30 PM

Like Steve said above, fuel filters, air filters. Also check for broken or loose clamps or hoses on piping from turbo to air to air rad. Also check your exhaust manifold for cracks, as that is a common problem on these engines. Good luck.

Mr_D · 11-30-2012, 10:49 PM

Quote:

Originally Posted by adehaan86

I am unsure about the turbo, you can look on it and usually say. I am guessing it's a holset.

However going over large elevations you will lose power. The air is thinner.

Yes, it should be a Holset, or at least the one on our ISC is.
Cummins rates their turboed engines for full power up to 10,000 ft. Engines without turbo's will lose power much lower either diesel or gas.

Okrver · 12-02-2012, 08:47 AM

Thanks for the advise. I have owned since 2002, so it seems to be losing some performance. I normally do all the maintenance myself. Last year I brought it in for dash ac. I also had them do all the filters and oil changes.
I will do it myself this year and check all the suggestions.
I was trying to find more information on the turbo, as the cummins owners manual doesn't really break it down.

Pat