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intake manifold gunk

1697 Views 9 Replies 6 Participants Last post by  kato258
i've read several posts about some kind of stuff clogging up the intake manifold in TDI's....i have around 43k on my TDI....is this something i should be worried about?? Thanks for the help.
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Re: intake manifold gunk (NJTDI)

Well, you should..
That gunk you refer to is related to a mixture from exhaust gasses, dumped by the EGR valve and oil vapors from the CCV, when both mix they make that nasty gunk that sticks all over the intake manifold and EGR mechanism.
I would recomend that you clean the intake manifold, that may already be quite dirty and disconnect both the EGR and/or the CCV, to prevent further messing..
I´m planning on doing this next week, i´ll keep you informed of any improvement.
Re: intake manifold gunk (NJTDI)

the problem tends to be less if you use premium diesel (less smoke, less gunk). at 25,000 miles, i disconnected the CCV and switched exclusively to amoco premier diesel (50 cetane). at 40,000 miles, the moderate amount of gunk i had has now dried up and been blown away.
it's simple to inspect your egr. undoing one hose clamp should do it. the gunk in the manifold will be somewhat worse than you see in the egr. if the gunk in egr looks bad, the intake should be cleaned before you choke off flow or, worse yet, you get crap stuck in the valves.
don't expect a dealer to do it or to understand. they don't have a maintenance procedure of intake cleaning.

[Modified by kato258, 8:58 AM 11-28-2001]
Re: intake manifold gunk (kato258)

How do I disconnect the ccv? I don't have much experience with this stuff so do you recommend I check/clean the "gunk" myself?
Re: intake manifold gunk (NJTDI)

i have a version of a CCV mod posted at http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic&f=17&t=001986. some guys prefer to run the gases thru a condenser, others thru a hose down to the belly pan. all will work. just keep the oil vapor away from the air intake.
i would suggest that you can easily inspect your EGR. if its heavily hard caked, it and the intake manifold both need cleaning. if it's soft and gooey, you should be able to dry it out to a point where it'll gradually erode from just the air flow, provided you get rid of the ccv. high sulphur fuel and smoke feed the gunk.
some suggest that a high quality synthetic oil like delvac 1 may vaporize less. dunno about that, but it IS good oil. i wouldn't use anything else.
disassembling and cleaning an intake manifold is a tough job. hondo had a gtg where at least a dozen people disassembled and cleaned. see http://forums.tdiclub.com/NonCGI/ultimatebb.php?ubb=get_topic&f=18&t=000344. come on out to chicago and drivbiwire will clean it for you for a modest charge. good luck.
btw, there's a NYTDI on Fred's that did a cleaning. you might contact him.

[Modified by kato258, 2:16 PM 11-28-2001]
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Re: intake manifold gunk (kato258)

how do u go about cleaning the intake manifold?
isnt that a REALLY difficult thing to do?
and a LOOOOOOTTTT of work?
and how hard is it to diconnect the CCV?
any walk throughs?
Re: intake manifold gunk (Zuber Speed)

i work on VWs i had one tdi that was soo cloged that you could not get a finger size instument into the egr and VW knows about the problem but wont admit to it publicly
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Re: intake manifold gunk (marsrocco)

To clean it, the only proper way to do it involves getting the intake manifold off the car. I have only done this on A3 and B4 engines, the A4 is a bit different, but the general idea will be the same.
1. Remove the engine cover and the various intake and intercooler pipes that are in the way.
2. Remove the outlet pipe from the turbo compressor. When you do this, the turbo will be somewhat exposed ... cover it with a clean rag to prevent anything from getting in there.
3. On the '96 B4, you have to remove the oil feed line to the turbo, it's in the way of one of the manifold bolts. Other models may or may not have this issue. The fitting at the turbo will probably be quite stiff. Be CAREFUL but persistent, once you get the threaded sleeve off, the line can be carefully but firmly popped loose if it's stuck. COVER THE OPENING in the oil feed to the turbo, and put the oil line in a clean place so that nothing will contaminate it.
4. Disconnect the EGR vacuum hose connection, and remove the EGR feed pipe. On models equipped with an EGR cooler, you can unbolt it from the back of the intake manifold (2 bolts) and swing it out of the way, no need to drain the coolant.
5. Remove the single bolt that holds the air intake pipe to the intake manifold. On A4-chassis cars, you might not have this, but you'll probably also have to disconnect the various things that connect to the anti-shudder valve.
6. If there's anything left in the way of the intake manifold, get it out of the way. If there's anything still attached to it, get it un-attached. Various models might have different minor issues here.
7. Remove the 6 bolts which secure the intake manifold to the engine. On some models the heat shield over the exhaust might partly block a couple of the bolts ... a careful tap with a screwdriver and hammer will solve it. Some of the bolts are tricky to get to, 6mm allen socket on some, 6mm ball-end allen wrench on others.
8. Clean out the manifold using suitable nasty solvents, glass-bead-blasting, high pressure water and detergent blast, or whatever works. Paint remover apparently works well, but don't get it near anything painted.
10. Re-assemble. Don't forget the oil line!
Check everything over before starting the engine, make sure that all fasteners are accounted for and properly tightened, make sure all electrical and vacuum connections are put right.
DO NOT attempt to clean the manifold while it is still attached to the engine. For one thing, you won't be able to get at the stuff further down. For another, if solid particles get into the engine, that's bad news.
This is a good half-day job for someone who knows which way to turn a wrench.
Brian P.
'96 Passat TDI mit UPsolute
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Re: intake manifold gunk (TDIracer)

I´m planning on doing this next week, i´ll keep you informed of any improvement.
Have you cleaned it yet?
Re: intake manifold gunk (NJTDI)

i won't expect a perfomance improvement unless it's really badly clogged. this is preventative maintenance. two bad things can happen: the gunk could seal off your intake or a piece of crud will break off and enter the engine.
the easiest thing to do to avoid this is to use 50 cetane low-sulphur fuel. or do like drivbiwire does and add a 1/2 a bottle of power service per tank.
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