JediJD

Having lurked for years, feasted on the knowledge of my betters and made one small comment...I find myself with an oddity and would appreciate some feedback.


2008 GL450, roughly 80k miles. Had driver front airmatic problems at 60k, took it to an indy and spent about $1900 including some services. Got smarter when the rears went out at about 70k, ordered Arnott's delivered to an undercar specialist who made short work of the process. Then a few weeks ago, the passenger front went out...I ordered Arnott spring replacement and (here is where I overthought it) from another parts source, an OEM compressor. The compressor arrived in an Arnott box, btw. I took it back to the same undercar specialist, who replaced the passenger side (bag only) and compressor...charged me about $300 labor. Now everything works great, and the car rides like a champ, but when the compressor comes on it sounds like a lawnmower engine...good grief...ridiculously loud. Took it back to the installer who said everything was installed perfectly, and he has done good work for me for years.


So much for background, now for question. Is anyone aware of an installation error that would cause the compressor to be noisier or less noisy...eg, isolation bushing or something? If so, I may be able to direct the installer and if not, since I can't take it off, send it back to the parts people, and leave the car on the rack for a week, I'll just eat the difference and order one directly from Arnott. Thanks in advance.

alx

it is a reman compressor that most likely didnt turn out as expected. it happens.

if it is an arnott reman call them. they have an excellent service and most likely will replace it for you without much hassle.

a noisy compressor is just that- a noisy compressor (most likely bearing gone bad). to answer your question- i am not aware of any way to install it the wrong way or hurt it during installation...

TylerAdams

Hi I was just wondering how your noisy compressor is going? I had a very similar issue as you, my front bags went out, which I replaced on my own. Then a couple weeks later my rear bags went out, which i replaced on my own. When the rear one went out, i happened to be getting out of my car and immediately heard the hissing sound and a lour rattling lawnmower noise in the front. Since replaceing the bags, the car seems to drive and ride just fine, but i do get the occasional compressor sound which is rather annoying and I dont recall having that noise before the bags went out, so i'm hoping the motor isn't burnt out, or if it's a simple fix like a rubber bushing or something.

JediJD

Still pretty noisy. I've communicated with Arnott, and a representative tells me that as long as the insulation bushings are installed, that's all that can be done. The mechanic tells me some are noisier than others, it was installed properly, and it is just louder than the last one. I've learned to live with it. However, I'm reminded every time I drive my wife's 2010 GL550 (which is silent) that it could be better. Generally, I have lots of ambient noise in the GL450 and I think I'm going to try new door seals, and the tires aren't far from time to replace, so perhaps that combination will cocoon the experience a bit. I'll keep the thread posted.

JediJD

Solved. While under the car on another issue, I was looking at the compressor and thought I'd try tightening the mounting bolts again...but, they were already really tight...which struck me as odd given that there are insulators on the bolts...so I loosened them a little. Started her up...no noisy airmatic compressor. So...if your airmatic compressor is too noisy, double check that you have mounting insulators and that they aren't overtighted. YRMV.