Engine losing power
 

I drive a 2006 Volvo, with a 475hp ISX Cummins, and 18-speed gear shift. A few days ago, when I started out in the morning, the engine sounded a bit different, a bit ragged at times, and the usual high-pitched whistling sound of the turbo, was missing.

I started out with an empty trailer, ran for about 60 km, switched to a loaded trailer at the customer's site, and after running for about 25km, when I started to go up a grade, I had to downshift drastically. On prior occasions, I've negotiated that same grade by dropping a gear, from 8.5 to 7.5....but this time I had to drop to 4, and when I looked at the turbo pressure, there was barely any, even going up the grade. I reached the conclusion that there was something definitely wrong, most likely with the turbo, and managed to limp it to a nearby Petro Canada truck stop. From there, I got in touch with my shop, who sent out a tow truck, along with a replacement truck for me to complete the trip.

Since my truck is under warranty, it was taken to Volvo, where, after 2 days, they said that they could find nothing wrong with the truck, much to my astonishment. Currently, it's back at the yard, and I've been asked to switch back to it from the replacement truck.

Could any of you surmise on what could possibly be the problem, and why Volvo gave a clean chit to the truck ? Thanks in advance.

If the boost pressure is just about nonexistent and it has low power there is obviously a problem with the turbo, or a major leak in the piping or charge air cooler.

When the ECM does not see sufficient intake manifold pressure, it will not allow the engine to get full fuel when you push the throttle to the floor.

Why the dealer would say there is nothing wrong with it, given the low boost condition is a mystery to me.

EGR valve

What exactly does the EGR valve do, and in what way, in your opinion, could it be causing the problem ? Thanks

The EGR valve opens and closes, controlling how much exhaust flows from the turbo manifold(before the turbo), into the engine inlet.

Very common problem on the ISX engines. Usually you'll see a huge puff of black smoke when you shift, the engine wont make boost, and it will be GUTLESS.

Because it's open, the turbo cannot do its job.

Thanks for that, Allan. What really surprises me, is that the guys at Volvo said that there was no problem with it, even though it's still covered under it's original warranty.

Take it to Cummins.

The Volvo guys may not be familiar with that engine, at least not as familiar as the Cummins mechanics who work on them exclusively.

You still need to take it back to the dealer and not another shop. If you don't get a response then ask to speak to the owner. Then make a call to Volvo if that doesn't work. It's there problem, not yours. Make them fix it.

Exactly, besides, your engine warranty is with cummins not volvo.

He can take it to a any Cummins actory store and they will do the warranty work on the engine. :roll: Why take it to Vulva, where the mechanics have marginal training on all brands of engines when you can take it to the place that exclusively works on Cummins.

I'm pretty sure the warrenty states that you bring the truck back to Volvo. If the radio in my Ford Mustang goes south I don't pull up to Bose.

Cummins warranty their engines, not Volvo. You can take it to any truck dealer that is Cummins authorized, and they will bill Cummins for the work. Same with Eaton, any Eaton authorized dealer can do warranty work on Eaton products and then bill Eaton.

Trucks are different than cars for warranty, the vendors warranty the major components, if your Volvo break down in BFE where there is only a Pete dealer, you can get your Cummins, Cat or Detroit fixed there instead of driving/towing 400 miles to the Volvo dealer.

That is one reason Mack wasn't a good choice for OTR years ago, because with all Mack components, you had to take it to a Mack dealer, which were few and far between.

the isx senses the positon of the egr poppet valve. if the ecm commands the valve closed, yet the valve doesn't actually close, it will set a fault code. in the case of a 'stuck' egr valve, the engine light should remain on

Actually, Steve has a valid point, since it's Volvo, that's should be your first step under warranty!
I've had a Volvo with the CAT. While still under warranty, my CC quit!
I was in Syracuse NY, went to Volvo dealer, and they send me to CAT dealer, w/o even looking! :x
CAT guys(same town) real nice folks took me in, and spend 2 hours, before they find the problem.
It was a faulted brake sensor, not CAT, so, they charged me for 2 hours labor.

The only reason, that i got my money back from Volvo, was that i went to the Volvo first, and they did send me to CAT! :wink:

Solo, an power problem, like an EGR valve would be a Cummins problem. CC problems are different, as there are Volvo components involved in that system.

I agree, but what i wanted to say,that if you are not 100% sure, of what's the cause, it would be the safe bet, to start with the Volvo.