Do I need to clean my intake manifold?

I just recalibrated my EGR per the FAQ on my '97 Passat. The engine burned dinodiesel its first 50 kmiles then mostly B100 the last 11 kmiles. At 61 kmiles total prior to the recal, do I need to clean the intake manifold or does it take more miles to clog the intake significantly with stock calibration? I have no indication of reduced performance.

Any opinions?

As far as I know, the B100 should be CLEANING your intake slowly. You should be getting some black smoke at WOT if this is the case. From what I understand, the B100 has a solvent effect on the soot buildup and will loosen the particles.

Best thing is to do a quick check to see if there is a soot buildup. To be honest, I am trying to figure out how to clean mine, so I am not much help to you there, but if you search the treads, you can find plenty of info on how to see if your intake is clogging.

d

It's easy to check. Undo the hose clamp at the inlet to the manifold (just before the EGR). Move the intake/intercooler piping out of the way, take a flashlight and look into the manifold. You should be able to see any build-up.

Pay close attention to the top of the intake, by the EGR diaphram. The build-up seems to be heaviest there.

I just cleaned (actually still cleaning) the intake on my "spare" engine. I'll get back to you w/more details on the allen head sizes, etc.

Hey Dieseldad, How ya been? I've been too busy lately to work on my Passat so haven't been on the forum much. Now I have several repairs and upgrades to do: Cat. converter noise (I think), rear hatch lock problem and addressing this intake cloging issue. I'll take your suggestion and tear things down to the point I can see inside for an inspection. At that point, if I need to clean the intake, I'll want a list special tools, etc. Wants no gas, I've heard also that biodiesel has a cleansing effect on the intake. Having done the EGR recalibration along with the effect of using biodiesel, I should be in good shape for the future.

Dosma-
I'm wondering about your rear hatch problem. My 98 NB TDI rear hatch lock is loose (actually can be pulled out) and won't open either w/key or electrically. Dealer wants to order new tumbler/etc for about $300. Any light you can shed? Thanks in advance.

As far as I know, the B100 should be CLEANING your intake slowly.

Click to expand...

That's some black magic if I ever heard of one. At best, running bio will slow down or prevent FURTHER buildup in the intake than what has already accumulated there.

I'd be interested to hear the rationalization as to how BD will actually CLEAN the intake since there is no fuel introduced anywhere in the intake.

As far as I know, the B100 should be CLEANING your intake slowly.

Click to expand...

That's some black magic if I ever heard of one. At best, running bio will slow down or prevent FURTHER buildup in the intake than what has already accumulated there.

I'd be interested to hear the rationalization as to how BD will actually CLEAN the intake since there is no fuel introduced anywhere in the intake.

Click to expand...

Just a guess on my part, but could it be the result of the same factors that cause the buildup - i.e. EGR and CCV? Combustion ain't perfect - could it be that enough BD to provide the cleaning effect survives the combustion process and is routed thru the manifold by these two systems?

Patrick

As far as I know, the B100 should be CLEANING your intake slowly.

Click to expand...

That's some black magic if I ever heard of one. At best, running bio will slow down or prevent FURTHER buildup in the intake than what has already accumulated there.

I'd be interested to hear the rationalization as to how BD will actually CLEAN the intake since there is no fuel introduced anywhere in the intake.

Click to expand...

There was a discussion about this in the Bio-D forum. Apparently people had some buildup in their intake, and after driving with the biodiesel for a while, things cleaned up. A little bit of a different driving style has to be used, though. Have to drive hard in third and fourth gears in order to get the proper cleaning. One down side of this method of cleaning is the black smoke you will produce. Apparently, some soot will be blowing out your tail end for 1-2 months.

I recently did a high speed run on a deserted road in the desert and that seemed to dislodge some gunk because I got plumes of smoke for a few WOT take offs after that.

High speed runs: good for what ails ya!

Re: BD cleansing.
Not sure exactly how it works, just that it does.
My '98 TDI cleaned itself out after 3-4 tankfulls of B100 and a daily full throttle blast. But my TDI is stock.
Disabling the EGR will probably prevent unburned bd from entering the intake and cleaning it. I would return it to stock while you're burning B70 - B100. And yes, expect huge clouds of soot to be blown out the tailpipe at full turbo boost.