LOUD Turbo Noises - What am I hearing?

BKH · **Posted:** Wed Apr 25, 2007 9:40 pm

On my way home tonight, I thought I heard something strange above the stereo. I turned off the stereo and didn't hear anything unusual - at first anyway. Then, I stepped on the accelerator and heard much more than the usual turbo 'whoosh'. Now it sounded like the must ungodly amount of air was being pushed out somewhere just on the other side of the driver's side firewall. I backed off the accelerator and the noise went away. As I got off the highway and turned onto my local street, I rolled down the window. The sound is truly deafening. Little kids on the street were turning to see what in the world was making this air noise.

So tomorrow I have to call my service adviser and explain this. Any idea what this is? It literally sounds as though the turbo's air pressure is being pushed out, rather than pushed into the engine. But I still feel as though I have full turbo thrust. There's no change in power.

Oh and to top off my afternoon, the cable on the 4wd apparently broke. When it rains, it pours!

huxrules · **Posted:** Wed Apr 25, 2007 10:11 pm

possibly the exhaust pipe fell off the turbo.

BlackLibertyCRD · **Posted:** Wed Apr 25, 2007 10:25 pm

I was thinking the same thing.

BKH · **Posted:** Wed Apr 25, 2007 11:20 pm

Thanks for the suggestion - I like to be "armed" when I call for an appointment.

As soon as I have the official answer, I'll post it.

onthehunt · **Posted:** Thu Apr 26, 2007 12:35 am

Boost leak. Check your cac hoses.

Endurance · **Posted:** Thu Apr 26, 2007 1:24 am

CAC hose more than likely.

BVCRD · **Posted:** Thu Apr 26, 2007 8:25 am

CAC hose x3.

vtdog · **Joined:** Fri Sep 30, 2005 11:27 am **Posts:** 640

I believe the noise is from a bearing failure on the hamster wheel. It is covered under the 7/70 lubricated engine parts warranty

BlackLibertyCRD · **Posted:** Thu Apr 26, 2007 10:37 am

BVCRD wrote:

CAC hose x3.

He said he has no lost of power, I would think a broken CAC hose would have a big lost of power. I have a free flow muffler and hear a big rush of air when stepping on it from the tailpipe. I would think a loose or cracked exhaust pipe would make a very loud rush of air noise with no lost of power.

BVCRD · **Posted:** Thu Apr 26, 2007 10:51 am

BlackLibertyCRD wrote:

BVCRD wrote:

CAC hose x3.

He said he has no lost of power, I would think a broken CAC hose would have a big lost of power. I have a free flow muffler and hear a big rush of air when stepping on it from the tailpipe. I would think a loose or cracked exhaust pipe would make a very loud rush of air noise with no lost of power.

I would think that sound would be more of a rumble noise. I was thinking the CAC hose was loose but not completely off.

BKH · **Posted:** Thu Apr 26, 2007 10:55 am

I take it in tomorrow. If I take the plastic engine cover off, is the cac hose something that will be in plain sight?

Definitely no loss of power. Definitely huge increase in air noise. It sounds like a strange jumbo jet taking off!

BVCRD · **Posted:** Thu Apr 26, 2007 12:35 pm

BKH wrote:

I take it in tomorrow. If I take the plastic engine cover off, is the cac hose something that will be in plain sight?

Definitely no loss of power. Definitely huge increase in air noise. It sounds like a strange jumbo jet taking off!

No need to take the cover off. As you stand in front of the Jeep, one of the 2 CAC hoses goes just along side the air filter box and turns down to the turbo. It looks like a radiator hose. The other is lower on the drivers side.

chadhargis · **Posted:** Thu Apr 26, 2007 12:56 pm

What exactly does "CAC" stand for. ______ after cooler??

BVCRD · **Posted:** Thu Apr 26, 2007 1:00 pm

chadhargis wrote:

What exactly does "CAC" stand for. ______ after cooler??

Charged Air Cooler

chadhargis · **Posted:** Thu Apr 26, 2007 1:21 pm

Makes sense to me.

Kellog13 · **Joined:** Sat Jan 27, 2007 9:21 pm **Posts:** 74

On mine the dealer did not tighten the band clamp (turbo to exhaust) properly and it was loud and smelly when you pop the hood with the engine idling.
My turbo problems continue with the CRD in the dealer twice last week, once this week and scheduled for 3 days next week. They are leaning towards the Cat Converter being faulty, its not that. I'm staying the coarse and letting them change whatever they want as I see this as the only means to an end, come to think of it, there's not much else to change.

BKH · **Posted:** Tue May 01, 2007 12:05 pm

Well I got it back on Saturday. They tightened the intake and cooling hoses. The minute I drove out of there, I knew it wasn't fixed. The service manager at my dealership is really great - very un-service manager, in my opinion. I called him and told him what was going on. Today I took it back in and showed him that I had noticed the following over the weekend:

Air-leak noise is coming from the driver's side of the engine;
There is oil leaking onto or from the top hose on the driver's side (routed towards the front of the car - sorry I don't know the technical name for this hose);
When I press the accelerator, it appears that small sprays of oil are coming from somewhere on that side of the engine bay.

On the lot was a new Grand Cherokee 3.0 diesel, with the Mercedes Bluetec engine. I'm very, very, very tempted.

skywarn · **Posted:** Tue May 01, 2007 6:00 pm

are you running an EHM?

BKH · **Posted:** Tue May 01, 2007 7:06 pm

Got it back. All is well. All would've been well on Saturday if the mechanic who worked on it the first time had tightened up the CAC hose as I suggested (based on everyone's recommendation). Thanks for all the advice.

Jeger · **Posted:** Wed May 02, 2007 5:21 am

It still concerns me that oil is coming out of the output side of the intercooler. In order to get there it would have to travel from the CCV or past leaking turbo seals, through the turbo side CAC hose, and all the way through the intercooler. An intercooler coated with oil probably doesnt work real well. It may be worthwhile to try and get them to clean or replace the intercooler and then install a provent or do the EHM afterwards.

LOUD Turbo Noises - What am I hearing?

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