D045k281

Can someone please help me diagnose the issue on my 2014 GL 450 showing engine light with P0299. It shows vacuum leak on solenoid in the engine reader. I got it fixed from the european mechanic, he told me it was SOLENOID PRESSURE VALVE and changed it but the issue still exists. Did someone else have the same issue?

silvergl

I do not have direct experience, but if the code is a vacuum leak, I would get a smoke test done. A cheap way to rule out a leak, which can manifest in many adverse ways and lead you on a parts replacement journey.

black06c230

Could be the pressure valve under the cover $50 or could be the check valve $10 each. Similar issues here so replacing them all tho coming week.

D045k281

Let me know the part number if that solves the issue please.

bwaldmer

Can you list the parts please. My 2015 GL550 just started showing the same P0299 code.

black06c230

2 of these $25
https://www.ebay.com/itm/31451404790...mis&media=COPY

1 of these $50 but seems to be hard to find
https://www.autohausaz.com/pn/PB-0001531800


still waiting on parts but also read to check air filters. I checked and both sides had tons of stuff in there, more than usual. So cleaned out will order some AFE Pro dry filters I use my G and E AMG models. Why I never put butter filters in there 🤷🏻‍♂️. Anyway cleared code and drove much better today. Time will tell and I will have the parts on standby, as I want to see now if it really was the filters restoring air flow.

bwaldmer

Thanks for the info on the air filters. I pulled mine and they were dirty. I put new ones in and the error code cleared soon after.

D045k281

i have changed my air filters but still code came after driving for 50 miles

mcoady1

Any updates on this?

Historic code on mine after checking with iCarsoft, no CEL. Think I need to change my air filter but otherwise no power loss.

black06c230

I went to replace the boost solenoid under the engine cover but she I was removing one of the rubber lines it easily tore. Replaced solenoid and temp super glued the rubber line were torn. Issues resolved but I suspect it was really just a small tear in the rubber connector that when warm would often cause the code.

Hope that helps as those are easy cheap options to check if the turbos seem to not be leaking.

D045k281

Are you able to share the image of the rubber line you are talking about? I got the boost solenoid replaced but that didn’t fix the issue. I was told my the dealer it needs whole new turbo but at this point it is not worth it to change the turbo on this car. Any help to resolve this issue without changing turbo will be appreciated.

mcoady1

My code never triggered CEL and actually went away, but I ordered the vacuum pump check valve and hose and will replace at some point.