Somehow the cap of my second coolant reservoir popped off while driving and I lost a bunch of coolant. I think there is air in the system now because it will only allow me to add a little bit at a time. I'll fill it up, then start the car and it sucks the small reservoir empty again. Can I just keep repeating this process until it no longer drains from the reservoir, or do I need to take the car to the shop to have the system bled? Thanks in advance.
No smell since initially losing the coolant from the cap coming off. I've been able to add a good quart or so just filling up that reservoir and then starting the car until it drains, and I'm not seeing any coolant on the garage floor or burning smell again.
For me (some LONG threads about this....)...I was losing coolant from behind the engine into oblivion. It turned out to be a hose behind the engine next to my temp sensor....(5.5ltr)
I would just have the dealer do a coolant flush for you. They also can check for any leaks. I did mine for about 350$ and didn't have to deal with the mess. You can also ask them if they can give you some type of discount (I got 15% just for asking). They make vacuum coolant bleeders for this job. Worst case scenario>coolant leak>bad water pump>or thermostat. I think you just have air in the system and needs a good purge and fill. When is the last time you changed your coolant? Also, you can test coolant to see if it's time to replace or not.
what do you mean second coolant reservoir? The big one or the small one located near the turbos?
Yes, I mean the small one near the turbos. According to the Carfax report it says that the coolant reservoir was replaced and the coolant was flushed / changed about 2 years ago or 6k miles ago.
After filling the reservoir and starting the car about 10 times it seems to have gotten the air out of the system and filled up completely as it is no longer draining after driving the car.
Keep an eye on the coolant level but from my understanding it gets cycled from main reservoir. Use OE coolant IMO and thinking the turbos may have cause pressure under boost or something. Regardless, replace the cap to rule that out even though it’s probably not the cap. Did the service say it was done at a MB dealer? I think you’re ok as long as coolant in main reservoir is at level. Also, do more heat cycles and don’t drive the car hard until things normalize. After coolant flush air pockets can be trapped. How’s the level looking on both reservoirs?
The service was done at a place called Eurofed out of Atlanta. The coolant in the main reservoir has remained full during this process of refilling the secondary reservoir. After driving the car last night, and checking both reservoirs afterwards they are both at normal levels. So I think it's all good now, but I'll continue to monitor it.
I never worked on that engine before though have seen it is best to vacuum fill the coolant system for intercooler. If you think you have all the air out then great. But an inexpensive solution is use the Steelman vacuum tool. That is if you already have an air compressor. Can get the tool for $21 and the cap for $15 with free shipping on the Steelman website. Its less expensive than buying the large kits that have a bunch of caps you probably wont ever use. Only thing I had to do to the tool is swap out the fitting at the bottom for the coolant fill hose with just a regular nipple. That cap fits the regular coolant reservoirs, not sure if the intercooler cap is different?
