Strange noise Volvo

[Nac]

Yesterday while driving back from switching a container about 10 mins. into coming home I heard a loud noise come from the truck. The noise only happens when under load or heavy acceleration. It sounds like a high pitch suction sound. If driving normal it sounds fine. Also when just parked and flooring it there is no loud sound. I looked under the hood everything seems fine. Is there something I should check before bringing to the dealer?

 

[MitchSA]

Sounds like a boost leak. When stationary the turbo is not boosting, when under load it boosts. Check all the hoses and the intercooler for leaks. Sometimes the boost pipes are sealed with o'rings, check that it hasn't blown one out.

 

[WaterDoc]

As mentioned, sounds like a leak in your intake piping. Check each hump hose for leaks starting at the turbo and working towards in intake. Grab all of the pipes and give them a good pull.

Also check around the intercooler for signs of leakage (oil stains).

Your leak may be coming from a pipe or hose that has rubbed through on another hose or bracket. So make sure to take a look around the piping for abrasion marks.

Is there a loss of power aswell as the noise?

 

[Nac]

I will take a look in the morning. The power is fine just louder when under heavy load. Will try to chase all the pipeing

 

[WaterDoc]

If the power is still good, then that tends to rule out a boost leak, unless is was a very small boost leak. While your looking around, take a peak at the exhaust and band clamps. Could be a small hole that whistles when under load.


Edit: Also check the intake piping from the air cleaner(s) into the turbo. Put a hand on it, and give it a good tug. The piping that is

 

[Nac]

Got it fixed. Ended up being broken bolts holding the intake manifold

 

[RocksnRoses]

Nac, does your Volvo truck have a Volvo engine, we have one that is doing something a bit similar and we have just had the engine rebuilt. The reason it had to be rebuilt was, prior to us owning it, someone left a small seal ring out of the intake manifold on #6 and because we work in very dusty conditions, it sucked dirt in and chewed up #6 piston. Now that I think about it, maybe the manifold came loose at some stage and the small rubber seal ring was sucked out. I think I had better have a close look at the intake manifold, because our driver has been saying that it is making a strange squealing noise noise under load, we thought it was the turbo, but that seems fine. Thanks for telling us what the problem was.

RnR.

 

[Nac]

Yes it has a Volvo engine.