The above video summarizes my day in 3 minutes, but doesn’t show a lot of detail. For that, read on…
My car has been a tad sluggish lately and I recognized within that the symptoms of a clogged intake manifold. Emissions regulations require an Exhaust Gas Recirculation system, which re-routes exhaust gasses back through the intake. This helps burn off stuff that is considered undesirable in the atmosphere. The downside of that is sometimes it doesn’t get burned off.. it lodges itself on the walls of the intake. Once this starts it can rapidly accumulate and clog up the intake almost completely.
My car has been running fine for months, years really. Around Thanksgiving (that’s late November for my non-US readers) the weather here took a turn for the colder and I have not been able to make any significant amounts of BioDiesel. So for the past two months I’ve been running on 100% pump-purchased petro-Diesel. I’m not certain this is the source of my problem, but I think it is a large contributor. The only other time this clogging happened to me was in 2005 when I ran my car for two months on fuel siphoned from the tank of a generator we decommissioned at my old office. I started using it in March, ran it through mid-May on this free source of fuel (which has a red dye in it as it is not road taxed… yes, I was breaking the law, but what was I supposed to do with it?!) and in late May my EGR clogged up. I didn’t realize the cause and had a mechanic fix it. He described to me what had to be done so that if it happened to me again I could do it myself.
Sure enough, the exact same symptoms returned last week.
The job is pretty straight forward, except the manifold is on the backside of the engine. This means a lot of time is spent bent over the car, or in my case, lying on top of it to save my back. The bolts are all invisible and had to be found with a mirror. It took me about an hour to get all the stuff around and above the manifold removed, and then I spent several hours scraping, soaking, and scouring the manifold and EGR valve.
Above you can see the worst of the clogging. That is thick, wet soot completely covering the inside walls of the Intake Manifold’s … well… intake, right where the EGR empties into it. Most of this stuff came out pretty easy with a screwdriver. Note how clean the outside of the manifold is right now.
Above is the output side of the intake manifold. The photo does not show it very well, but the ports are pretty clogged up. Not as bad as the main intake, but still pretty restricted. It is a wonder the car ran at all. I imagine another week or two of driving would have choked it to death. Again, note how clean the exterior of the manifold is!
I don’t have any fancy parts washer in my stable of tools. I just have a screwdriver, some paper towels, various items used to scrape things, and I started with a can of “Bra-Kleen”.. which did an “OK’ job (better on the EGR, which I did not photograph, sorry.) I gave up on the Bra-Kleen and drove to the parts store for 2 cans of Berryman’s Chem-Tool intake and carb cleaner. Holy shit that stuff is amazing. Smells awful (thankfully I was doing this work outside) but man it just blows this gunk away! The Chem-Tool cleaned out the areas near the openings right away, but the interiors areas were still pretty gunky. I let those soak for an hour or so. Eventually the manifold’s inside was pretty clean… but somehow the outside had gotten filthy. Mostly by me handling it as I cleaned the inside. I tried cleaning the outside halfheartedly, but realizing that it didn’t really matter gave up.
The important part to get clean was the part that was REALLY dirty to start with. Above you can see the startling difference in the main intake’s cleanliness. It is close to being godly… Worship the orifice! 😉
The manifold went back on pretty easy. In fact everything went on pretty easy… up until about the 3rd to last bit, the pipe from the exhaust up to the EGR itself. For some reason I could not get the cap nuts to “bite” into the threads, no matter how I tried. They fell out many times. They would seem to go, then fail. Thankfully my stepson Adam was here and he took a turn and was able to get them in. Whew. That done I installed the intake hose from the turbocharger, washed the engine off, and installed the engine cover and was done!
I drove the car “around the block” which in my neighborhood is a several mile run. The CEL came on as I went down the driveway, which bothered me. Shutting off the car, and restarting it put out the idiot light (the computer likely freaking at something to do with the job) and it stayed off for the rest of the drive. Out on SR530 I was able to get up to about 80 MPH and let it run on the redline for a bit to blow out any remaining gunk I could not get removed with the tools, metal and chemical! The car seems to have a new lease on life… running great!
I retuned home, and cleaned up the tools, put everything away, took a shower (did I mention that this was a filthy job?) and went out for dinner… ordering myself a Cadillac Margarita to celebrate: