Hello. I’m a newly registered member of this site, but I have read various posts over the years. I purchased my GL450 new in 2007. It had been one of the best driving and most reliable vehicles we have ever owned during the first eight years. The only item addressed during the extended warranty to six years was the rear door latching mechanism. After the warranty expired I installed the much discussed and typical front air strut replacements using Arnott stuts (based on the recommendations on this site). I also had an oil cooler replaced in 2015. Other than those items and regular oil/transmission fluid maintenance/tires/brakes, it has been a joy to drive. A year and a half ago we moved to Texas from the northeast, and I towed a small trailer. I think I pushed the car a little too hard while driving in the Tennessee mountains on the way down. While climbing a mountain going about 75mph I saw an engine warning light come on for a few seconds. I slowed down and the light went away. I pulled over at the next exit and checked the fluids and overall engine and it seemed fine, and I made it to Texas without a problem. Then two weeks later I got the check engine light followed by the car going into “limp” mode. I took it to the dealer where they told me the right cylinder head needed to be replaced (#2 cylinder was showing low compression). The estimate was $6,500. I got a second opinion from an independent shop and they said the same thing with a $4,800 quote. I opted not to do the repair because I thought if the right cylinder was bad, I might have damaged the left one as well. So I parked it in the garage to deal with it later. I debated whether to replace the one cylinder head, or both, rebuild the engine or replace the engine with a low mileage one, based on the car having 154,000 miles on it and that engine light that came on in the TN mountains. New cylinder heads were about $1,750, and a low mileage engine was about $4,500-$5,500 - and about $2,000-$2,500 to install it. My wife got a new van and I had a pickup, so it became one of those projects that “I’ll just do later.”

Well, almost a year and a half later I found a 2007 GL450 engine on Ebay with 64,000 miles located in Houston and bought it for $2,200. I didn’t intend to wait that long, but I just didn’t want to put in a high mileage engine without knowing its maintenance history. I found a reputable transmission shop to install it for $1,900 and everything went well with the install. It’s got new oil, coolant and PS fluids as well as new engine air filter and cabin air filters. It’s running awesome. I also got a new battery and a new aux. battery because it had been sitting so long. The only thing that didn’t survive the engine change was the A/C system. After getting an estimate of over $1,600 to replace the A/C compressor, receiver drier and expansion valve at a local independent shop, I decided to tackle the job myself. A huge thanks to the members of this site, and especially member Mefferso (X164 forum), I got the confidence to do it. I spent about $680 on the best parts and some tools I didn’t have. I rented the A/C gauges/hoses and vacuum compressor from Autozone. My wife and kids were skeptical, especially after they saw the car torn apart getting ready to replace the A/C items. But I did my research, learned everything I could and got it done correctly. The A/C is working awesome. If you’re a handy DIY type of person, trust me, you too can do the A/C job. I’m either going to add to Mefferso’s original post or post a new thread with a link to Mefferso’s original post and add my experiences and lessons learned to it and hopefully help others to do the job too.

Anyway, it’s been about 800 miles since the A/C repair and a little over 1,100 miles since the engine replacement and so far all is working properly. Thanks again to all the members who add their experiences to this forum. It’s given me the confidence and knowledge to properly do repair work on my car. Now the GL has become my daily driver, and I’ve fallen in love with it all over again. The ride quality, quiet cabin and overall smooth handling is luxury defined. I know there may be some hiccups along the way, and I’m prepared for that. I believe that with Mercedes ownership comes a certain level of responsibility as far as knowledge and maintenance is concerned. In hindsight I should have just paid the extra for a low milage engine and did the engine change a year and a half ago. And I should have purchased an OBDII scanner years ago as well. I got an Autel MD802 OBDII scanner that has really given me much more confidence in the systems in the car. I was able to clear a check engine light and clear a fault that was not allowing the Keyless Go to work as well as clear the battery light fault. Now every system in the car is working correctly.

Future work I plan on doing is replacing the front upper and lower control arms to address the slight creaking over speed bumps (which really isn’t that bothersome), changing the transmission fluid/filter and differential/transfer case fluids, and adding a Bovee WMA3000a bluetooth adapter to the iPod cable to get Pandora. If there are any “must do now” items I need to tend to now, please let me know. I’ll report back on how the engine and A/C is running as time goes by.

 

Welcome to the forum. Quite the introduction.

 

Hey OP, awesome story.

Do you do your own oil changes?

 

Hi there am new to this forum and had a question regarding your iPod adapter setup. You see I also own a 07 gl450 and bought it 4 years ago. I wanted to have my phone connected via Bluetooth as well. I bought the carpro coolstream plugin to the iPod cable but the sound quality is rough to say the least. There's a lot of road noise & static. Do you get the same thing?