ISL 9 Engine Intermittent Whistle

[earlstar]

My ISL 9 450 Cummins engine (2015 Dutch Star) recently developed an intermittent engine whistle. When Idling it whistles for about 7 to 8 minutes then stops. It will remain off until I depress accelerator, increase engine revs to 12 to 15k, release and it goes to idle then starts up again for another 7 to 8 minutes. Could this be related to EGR cycling on and off? No increase in sound when accelerating.

[theroc]

It's not uncommon to hear whistling sounds from an ISL or any Cummins. Some will say it's "normal" turbo noise but it also could be a small leak in the turbo/manifold area. Leaking gaskets are sometimes a problem, etc. I'm not an expert so while you're waiting for more knowledgeable responses, take a look at some of the comments in this thread:

Cummins 400hp high pitch whistle

[earlstar]

After trying everything I knew, I took coach to Orlando Branch of Cummins. After a two week wait they finally diagnosed the problem as a busted exhaust manifold gasket. The gasket and an clamp cost $133. The labor to make repair was initially quoted at 10 hours at $175 per hour with stipulation that if a bolt was broken it would have to be re quoted. The tech did not use an oil penetrant and broke 1 bolt. I visited the shop, was shown the broken bolt and noted that the manifold had been fully removed. Apparently, they could not get enough hours extracting 1 bolt, so the next morning I was told that the tech had broken two more bolts trying to get manifold off and that it would take a full 10 hour day to get all 3 bolts out before the gasket could be installed.Consequently, the quote was revised to add ten hours labor. After realizing what was going on, I did not even press them on how two additional bolts were broken after the manifold had been completely removed the prior day. No complaint yet on the quality of the work, after a "goodwill" discount of 10%, the total cost was $3,701. I do not recommend this Cummins location. In my estimate, they spent more time trying to pad the bill than making the repair.

[Ray,IN]

Originally Posted by earlstar

After trying everything I knew, I took coach to Orlando Branch of Cummins. After a two week wait they finally diagnosed the problem as a busted exhaust manifold gasket. The gasket and an clamp cost $133. The labor to make repair was initially quoted at 10 hours at $175 per hour with stipulation that if a bolt was broken it would have to be re quoted. The tech did not use an oil penetrant and broke 1 bolt. I visited the shop, was shown the broken bolt and noted that the manifold had been fully removed. Apparently, they could not get enough hours extracting 1 bolt, so the next morning I was told that the tech had broken two more bolts trying to get manifold off and that it would take a full 10 hour day to get all 3 bolts out before the gasket could be installed.Consequently, the quote was revised to add ten hours labor. After realizing what was going on, I did not even press them on how two additional bolts were broken after the manifold had been completely removed the prior day. No complaint yet on the quality of the work, after a "goodwill" discount of 10%, the total cost was $3,701. I do not recommend this Cummins location. In my estimate, they spent more time trying to pad the bill than making the repair.

We have the same block and manifold.
That $3K was about equal to what I paid to have my broken manifold replaced at a local HDT repair shop. Even after days of soaking the bolts with PB Blaster 3 bolts broke in the block.
I felt for the poor mechanic who had to remove those bolts and replace the exhaust manifold while working upside-down.