Any idea on this very non-technical description

[LDRider]

All

Admittedly my knowledge of my Cummins engine is turn the key and it works. With that in mind I would appreciate any insight or comments into this issue:

The 2017 Thor Tuscany 45 AT fires right up. Yesterday while airing up and generally running the engine I got a high pitched sound. If I put my foot on the gas it goes away. After the engine has been running for a while, it goes away.

Important Note: No leaks, drips, engine warning lights - all seems to be fine but it is a new sound.

Any ideas or things I should check before driving to Freightliner? Thanks in advance for any thoughts on the subject.

[Bill Johnson]

Could it be the belt or a pulley

[Greybear]

Originally Posted by LDRider

All

Admittedly my knowledge of my Cummins engine is turn the key and it works. With that in mind I would appreciate any insight or comments into this issue:

The 2017 Thor Tuscany 45 AT fires right up. Yesterday while airing up and generally running the engine I got a high pitched sound. If I put my foot on the gas it goes away. After the engine has been running for a while, it goes away.

Important Note: No leaks, drips, engine warning lights - all seems to be fine but it is a new sound.

Any ideas or things I should check before driving to Freightliner? Thanks in advance for any thoughts on the subject.

Admittedly that's not a lot if information to go on, but my first thought was belt noise. When the fan or alternator belt is cold, sometimes it will slip slightly causing a squeal. Sometimes, hitting the gas makes it go away, and sometimes it actually makes it worse.

As the belts heat up from friction, a lot of the time the squeal goes away unless it's really worn. You might want to visually inspect the belts looking for checking or cracking. Some belt dressing might help diagnose and treat the problem.

[lwmcguire]

Go back by the engine and have someone else start it

The Turbo can make a squeal but usually at higher RPM's

Belt old or tensioner bearing going out would be my first places to check

[LDRider]

It does sound like a belt or bearing. I will poke around and see if I can visually see what is going on.

Thanks all. Ill post if I find something.

[EA37TS]

Have you had a full blown scheduled service performed or just LOF since new?

The full blown service costs about 1200.00 and checks tensioners, idlers etc. That stuff is not included in an LOF service.

[Bill Johnson]

Originally Posted by LDRider

All

Admittedly my knowledge of my Cummins engine is turn the key and it works. With that in mind I would appreciate any insight or comments into this issue:

The 2017 Thor Tuscany 45 AT fires right up. Yesterday while airing up and generally running the engine I got a high pitched sound. If I put my foot on the gas it goes away. After the engine has been running for a while, it goes away.

Important Note: No leaks, drips, engine warning lights - all seems to be fine but it is a new sound.

Any ideas or things I should check before driving to Freightliner? Thanks in advance for any thoughts on the subject.

5 years old you might want to just put a new belt and tensioner on just to be safe. If the tensioner is loose the belts may squeak or squeal, especially when the engine is first started.

[Laco]

My guess is the turbo. I had a 41 foot bus with the Cummins 400, and it would often make a sound similar to what you describe, not a squealing like a slipping belt, but just a high pitched sound. Did that for the thirteen years I had it, never got worse or caused any problems.

[LDRider]

Originally Posted by Laco

My guess is the turbo. I had a 41 foot bus with the Cummins 400, and it would often make a sound similar to what you describe, not a squealing like a slipping belt, but just a high pitched sound. Did that for the thirteen years I had it, never got worse or caused any problems.

LACO wins. The issue is a lost bolt on the turbo that is causing the air to be sucked in and making the noise. Off to Cummins to have a new bolt and gasket installed.

Thanks everyone for helping me through this issue.

[JIM SNYDER]

Originally Posted by LDRider

All

Admittedly my knowledge of my Cummins engine is turn the key and it works. With that in mind I would appreciate any insight or comments into this issue:

The 2017 Thor Tuscany 45 AT fires right up. Yesterday while airing up and generally running the engine I got a high pitched sound. If I put my foot on the gas it goes away. After the engine has been running for a while, it goes away.

Important Note: No leaks, drips, engine warning lights - all seems to be fine but it is a new sound.

Any ideas or things I should check before driving to Freightliner? Thanks in advance for any thoughts on the subject.

A simple guess...maybe a loose drive belt..

[71_340]

Replace the serpentine belt, idler pulley (if present) and tensioner (you can usually buy a kit). Those parts are considered maintenance or wear items.

[MJC62]

Post 9. OP has a bolt missing on his Turbo...

[DogLovers]

I also drive a Thor Tuscany. I hope it is just a bolt missing on the turbo as that is a fairly cheap fix compared to a lot of other potential issues.

[Bill Johnson]

Originally Posted by LDRider

LACO wins. The issue is a lost bolt on the turbo that is causing the air to be sucked in and making the noise. Off to Cummins to have a new bolt and gasket installed.

Thanks everyone for helping me through this issue.

They make a thread locker for turbos might be a good idea when replacing the gasket and bolt

[simidrm]

That’s not uncommon to see those turbos use 2 studs from the manifold down in the back and 2 studs from the turbo up on the other side and people think you can just finger tighten the studs but that’s why they come loose the studs have to be torqued as well as the nuts, and the gasket is a metal gasket so chances are it would be ok to reuse, I personally wouldn’t do that but to replace that gasket means removing the turbo and since it’s cooled by engine coolant that has to be drained and new sealing washers and new oil drain tube gaskets.

[simidrm]

Hey that almost identical to my mh what year is that