Carbonized diesel intake manifold

Rch · Sep 18, 2005

My wife's 2001 VW Beattle with 50,000 miles on a TDI diesel started to lose power and the previous MPG of 51 on the highway decreased. She drives only 3 miles to work, so alot of short trips. Here are a series of photos that graphically depict NOT working a diesel hard and NOT letting it warm-up. This was a $476 fix. She buys fuel at a high turnover station
/forums/images/graemlins/mad.gif

HGM · Sep 18, 2005

Good points, some folks just dont understand it. Fortunatly, it should get better with the fuel quality next year. Some stations currently have the ULSD, you may want to investigate and see if a dealer in your area carries this fuel.

Rch · Sep 18, 2005

Here is what it should look like. /forums/images/graemlins/smile.gif

Rch · Sep 18, 2005

Another view of clogged intake.
HGM, btw, what is ULSD? Is there any additive to counteract this ?

California · Sep 18, 2005

Is there an EGR feeding exhaust into that intake?

I thought a diesel had nothing but unlimited air upstream from the intake valves.

HGM · Sep 18, 2005

That looks like the EGR valve assy.

ULSD is the acronym for Ultra Low Sulfer Diesel.The '07 emissions regulations are reducing the sulfer content to .005ppm sulfer alowd in diesel fuel for reduced soot and Nox emissions. It is currently selling in the "green states", and you may be able to find it in your area if you ask. Otherwise I would recomend a cetane booster to increase the efficiency of the fuel, may also help the fuel economy. Not that ist bad now, but any little bit helps. /forums/images/graemlins/grin.gif

HGM · Sep 18, 2005

BTW,

Some diesels including the '04 6.0L Ford have a throttle plate. Its sole purpose was to promote EGR flow, this was the only year Ford used it.

Charolais · Sep 18, 2005

I started using Lucas Fuel Treatment this year after I bought a 1987 Ford F250 6.9L. And just prior to that I had a cat. converter to get stopped up on a 1998 Dodge truck.($475) After I used the first quart I bought a 4 gal. case. Use it in everything now. After a couple of tanks with the fuel treatment it's no problem to see the difference in the exhaust pipe color. In that 6.9 there was no problem hearing the noise level go down too. Sure made the injector pump quieter.

I feed hay with my Long tractor. It's just like those short trips you wrote about. When I put that tractor to work I've seen the muffler and exhaust pipe catch fire. Haven't seen that since I started using the Lucas. Never been much on additives but this one works for me.

Anyway it's just a suggestion.

cup149 · Sep 18, 2005

Clogging of this nature is common on this model of VW engine. Supposedly it is the EGR gases combining with the PCV vapors. Some guys are using an oil trap on the pvc line, others reprogram the computer to limit the amount of EGR gases. Check out some of the TDI forums.

Highbeam · Sep 18, 2005

You beat me too it. Kill the EGR and get that PCV out of the intake. Just imagine what your intercooler looks like... a slobbery tarry mess.

ZJ_HR · Sep 19, 2005

People were usually blocking EGR valve on VW TDI or SDI engines here, by putting copper washer instead of gasket, as it caused problems with sulphorous fuel. This appeared 5-6 years ago, especially on gentle driven cars.

HGM · Sep 19, 2005

Sure guys, and we can dump our used motor oil in the front yard too..... /forums/images/graemlins/wink.gif

If you drive the vehicle and dont let it idle for extended periods(more than 2-3min) you'll have less troubles. They're having the same troubles with the 6.0L Fords, I would immagine anything with an EGR. On the ones that have to idle (rescue, tow trucks, etc) they must be equiped with an idle kicker to help build heat in the engine. Dont fall into the "truckers do it" mentality, these are passenger vehicles and have different systems on them to allow it.

The soloution is a good fuel additive and keep it hot, diesels are self cooling at low RPMs. At least until you can get ULSD. Things will get better soon.

SkyPup · Sep 19, 2005

Part of the problem, in additon to the low quality diesel fuel with high sulfur, is her short trips not allowing warm-up of the crankcase fully each day. The PCV valve actually has an electrical heater to help keep the water vapor from freezing up or clogging the PCV intake.

Remove the PCV valve hose from the intake tract after the MAF sensor and plug the hole in the manifold and allow it to drip into a small container.

Like another mentioned, your intercooler probably is gunked up too from all the PCV related crud.

Also, a high quality full synthetic Group IV motor oil like Amsoil's or Chevron's or Exxon's top of the line has very low NOACK volatility, thereby decreasing the amount of oil vaporized in the crankcase and sucked into the PCV. For instance, dino Shell Rotella 15W-40 has >13% volatility, while Amsoil is ~ 5%.....

Our two eight year old TDIs have never had this problem in > 380,000 miles since we disconnected the PCV when new, use BP Supreme Diesel fuel, and normal drive to work is about 15 miles @ 65 mph one way each day.

Rch · Sep 19, 2005

cup149, I'm aware of Fred's TDI Page, http://www.tdiclub.com/ . Are there any other good TDI/VW forums ? I recall a Canadien guy who had an excellent site but have lost the link with computer crashes, switch to Fedora/ Linux etc. Any info is appreciated. /forums/images/graemlins/tongue.gif

cup149 · Sep 19, 2005

http://forums.vwvortex.com/zeromain?id=1

I thought I knew of another one but can't find it.

ELMO67 · Sep 20, 2005

OK, this is one that I know "a little bit about". There are many misconceptions about why the manifold and EGR valve plug up. It has NOTHING to do with the fuel!!! The ONLY reason there is an issue with carbon build up is because oily vapors ( crankcase ventilation), are mixed with recirculated exhaust gas (EGR). That is it- nothing more. Eliminate one or the other and you're problem is solved. The easiest way to do this on the VW TDI engine is to shut down the EGR system electronically, through the ECM. Unless the car is new, the intake and EGR valve still need to be cleaned for like new performance. Anything else you may read or try just doesn't cure the root cause of this problem. Yes, the car will still pass an emmissions test- don't ask me how I know, after all, this is the Internet, the source of more mis- information that all others combined....

SkyPup · Sep 20, 2005

The only reason exhaust carbon builds up is because sulfur atoms are the center atom of the carbonaceous buildup. Once you get rid of the sulfur in the fuel, as in ULSD, you will no longer experience this problem to begin with.

HGM · Sep 20, 2005

What SkyPup said......

I would hessitate from recommending for someone to alter their emissions system. The regular driving and elimination of short drives will help dramaticly. Good fuel is comming soon.....

ELMO67 · Sep 20, 2005

Ooookay, then, keep believing what you are fed about fuel being the issue. Rch's Beetle does not care how it is driven- this problem did not start on the VW engine until the EGR valve was added.

HGM · Sep 20, 2005

Care to explain why they dont have this issue in Europe....You need to understand the cooling characteristics of the EGR system and what it does to the fuel and yes PCV that is being burnt. It is all related, I'm not discounting that if you disconnect the EGR you wont notice the problem, just stating that it is designed to be there for emission purposes and if you drive it correctly with good fuel you wont have these issues.