Mercedes GLS EGR delete
Seven seats, a horsebox on the back and a school run in between. The mix of towing and short trips that fouls a GLS's EGR is the mix we come out to.
Mobile software delete at your location, £220.
For off-road and track use only.
How the GLS gets used
The GLS is the largest Mercedes SUV and it gets bought for one of two lives. The first is family and towing: a caravan or horsebox at the weekend, the school run and the supermarket in the week. The second is the executive-hire and chauffeur trade, where the car waits outside a hotel or an airport terminal with the engine idling, does a motorway leg, then idles again. Farms and rural estates run them too, on the yard, the field gate and the track before the road proper begins.
Both lives are hard on the EGR, for opposite reasons. Idling and short trips never get the intake hot enough to burn deposits off the valve, so carbon builds up and the valve sticks. Towing at full load pushes more exhaust gas through the cooler at higher temperature, and on the OM642 V6 that is what cracks it. Either way the engine management light comes on and the car drops into limp mode, usually on the motorway with a trailer behind you.
What changes after the delete
The ECU stops commanding the EGR valve, so a sticking valve can no longer put the GLS into limp mode. Exhaust gas no longer passes through the cooler, so the coolant-loss route through a cracked OM642 cooler closes. No EGR fault codes, no repeat valve bill, no second cooler at dealer rates. The valve and cooler stay in place; nothing is removed and nothing is ordered. The car stays where it is parked for the visit and is back in use the same hour. The delete targets the EGR maps only. Fuelling, power and everything else in the ECU are left as Mercedes set them.
GLS engines we cover
GLS 350d: OM642 3.0 V6, 2015 to 2019
The X166 GLS arrived in 2015 with the 350d and the OM642 V6, the same engine as the GLE 350d, the E350 CDI and the Sprinter 319 CDI. EGR cooler leaks and oil-cooler leaks are the OM642's known weak points, with valve faults alongside. The delete covers the valve and takes the cooler out of use.
GL 320 CDI and 350 CDI: OM642, 2006 to 2015
The GL X164 and the first X166 GL carried the same V6 before the GLS badge arrived. Same engine, same fault, same fix.
GLS 350d and 400d: OM656 2.9 six-cylinder, 2019 onward
The X167, launched in 2019, moved to the OM656 straight six. It is a newer engine with a shorter fault record, so we confirm coverage from your reg before we set off.
Anything not listed, call 0161 694 7331 and we will confirm. Every Mercedes we cover is on the Mercedes EGR delete page.
More than one GLS
Chauffeur and executive-hire operators often run two or three GLSs alongside S-Classes and V-Classes. We can work through them in one visit at your yard or depot and fit the appointments around bookings and shift patterns, so each car is off the job for about an hour and no longer. It is £220 per vehicle. Send us the reg of each one before the visit and we will confirm the engine and ECU type in advance.
Questions from GLS operators
Can you come to a site, depot or farm to do a GLS?
I run more than one GLS. Can you do them in a single visit?
How long is the GLS off the road for?
Can you do the DPF and the EGR on the GLS in the same visit?
Other Mercedes models we cover
Arrange a visit for your GLS: call 0161 694 7331, tell us where the vehicle is and when it is off the job.
It is £220 per vehicle, we come to you anywhere within a 40-mile radius of Eccles, and same-day and next-day slots are common. No call-out charge, no strip-down, nothing removed from the car.
For off-road and track use only.