EGR and Manifold Cleaning? Want MPG increased!

A friend of mine had a Golf tdi and said he cleaned alot of oil gunk buildup out of his egr and intake manifold. Afterwards his car ran better. Do our Passats have the same problem wth gunk buildup? Not getting the mileage like I did when the car was new. I used to get 39 mpg all hwy. Now I only get 35 mpg. I had the ceramic glow plugs and ecm flashed which improved the mpg over the stainless glow plugs (stainless gp I got 33 mpg hwy) but still not like when car was new.

EGR is easy enough to clean, not many have done the intake.

MY1STVW said:

A friend of mine had a Golf tdi and said he cleaned alot of oil gunk buildup out of his egr and intake manifold. Afterwards his car ran better. Do our Passats have the same problem wth gunk buildup? Not getting the mileage like I did when the car was new. I used to get 39 mpg all hwy. Now I only get 35 mpg. I had the ceramic glow plugs and ecm flashed which improved the mpg over the stainless glow plugs (stainless gp I got 33 mpg hwy) but still not like when car was new.

Click to expand...

From my reading and actual inspection of my intake after 190k, the BHW is nothing like the ALH and earlier TDIs for coking. Have you put the car on VAG lately? All sorts of things will decrease your mpg over time: vacuum lines deteriorating, turbo wear, N75 wear, dirty MAF, fuel tank algae,lift pump wear, cam wear, injector and/or nozzle wear, just to name a few. Make sure you always have clean air and fuel filters and check the fresh air inlet into the air cleaner box. Lastly, don't forget frequent "Italian" tuneups and occasional diesel purge treatments. Don't baby it too much. No diesel likes that!

I have cleaned mine. Like 50harley mentioned, they are not nearly as bad as the alh's which could nearly clog completely in their day. What I found was the intake manifold had about 1/4 inch of build-up throughout which is a big enough deal when it comes to the runners of the intake which are pretty small to begin with. The even bigger deal in my case was the amount of build-up in the intake runners of the cylinder head. At its thickest point it measured 3/8th of an inch thick in cylinder 1-3 with cylinder no.4 intake runner being completely clear!?! Before I cleaned it, the car was a bit on the sluggish side and it produced a lot of black smoke. After I cleaned it there was a very noticeable crisp to its performance and the exhaust burned clean since it was no longer choking. I used a power washer on the cylinder head which it was off of the motor. The intake can be soaked and then power washed or burned out. Be prepared to make a mess as the stuff is nasty!!!

I didn't notice a huge difference in mpg's but ill tell you it sure ran better. Another thing to consider is to clean your charge pipes and intercooler. They tend to collect oil over time which makes the intercooler less efficient. For me, this made a huge difference for some reason. Car felt great after performing both of these free but very messy services.

Have fun!!!