My 2015 Audi Q7 TDI gave me a massive headache last week when the low coolant warning flashed on my dashboard right as I was driving down the highway. After tearing down the engine bay over the weekend, I noticed a huge pool of coolant crusting up inside the valley, which turned out to be a cracked factory EGR cooler leaking all over the intake manifold and threatening to clog up my whole system with nasty carbon buildup.
Dealing with that exact coolant leak in the engine valley is practically a rite of passage for anyone running a Gen2 3.0 TDI platform, and it made me absolutely despise my car for a few weeks last year. It gets ridiculously frustrating when a failing emissions setup forces hot exhaust gases back into your intake, coating everything in heavy soot and eventually dumping coolant right onto your oil cooler housing. When my stock cooler finally gave out and started throwing check engine lights constantly, picking up the “Evo” EGR Cooler Delete Kit was what I used to completely clean up my engine bay, bypass the leaky cooler assembly, and make the whole setup run so much smoother and cooler on long drives. Upgrading to custom-engineered aftermarket hardware specifically made for these 3-litre diesels completely restored my trust in the car, plus working under the hood is ten times easier now without all that restrictive factory piping in the way. My biggest advice if you are tackling this job yourself is to make sure you have a set of triple square bits ready, drain the cooling system thoroughly beforehand, and take your time cleaning off all the old grime from the engine valley before installing the new block-off plates and bypass hoses.
Performing major mechanical modifications on a daily driver always brings a mix of excitement and underlying worry about getting everything torqued down correctly. Even when you follow every workshop manual step to the letter and double-check all your hose clamps, that initial turn of the key after reassembling the intake area always gets your heart racing a bit. Keeping extra fluids in the trunk for the first couple of test drives is always a smart precaution.
