ALH Intake Cleaning

[Ovrhill]

Doing a timing belt and intake cleaning on an '01 Golf. EGR and intake were about two thirds, or more, blocked with carbon build up.

I have those items cleaned and ready to re-install. There is some buildup around the intake ports on the head. I'm a little bit unsure whether it is worth the risk to try and scape some of that off.

Is it ok to leave the intake ports as they are and out the intake manifold back on?

 

[braddies]

From Myturbodiesel.com Intake cleaning article

The cylinder head is best cleaned while off the car. If you want to clean the cylinder head while on the engine, I suggest removing the camshaft (follow timing belt removal as spec. in your factory service manual or see 1000q: timing belt removal ALH engine) so that all the valves are closed. You can then use a brush to clean. I would avoid using liquid cleaner just incase it were to leak into the engine and cause hydrolock (engine damage). Make sure to follow up with compressed air to blow out all loose carbon particles.

 

[Vince Waldon]

Unfortunately a restriction is a restriction, regardless of being in the inside of the intake manifold or at the ports themselves.

Your call if the restriction you're seeing needs to come off... but if so, the safe way is to either pull the cam OR rotate the engine as you go, so that the port you're working on has a closed valve.

 

[Ovrhill]

The ports on the head are restricted much less than the manifold. As in most cases, the largest part of the buildup was in the neck of the manifold.

I was just wondering if there is a risk of ingesting some of the buildup left in the ports due to increased airflow.

I really dont want to mess with the ports on the head unless it's nessessary.

 

[J_dude]

I was just wondering if there is a risk of ingesting some of the buildup left in the ports due to increased airflow.

From what I’ve heard, yes, that is a concern.
I, however, cleaned my intake before I knew this (there actually wasn’t much buildup in mine, but I had it off anyway), and I did not clean the ports in the head, and I haven’t had any catastrophic failures... yet lol.
Although I suppose that could potentially be the cause of the “tick” I’m currently procrastinating about...

 

[Ovrhill]

Thanks J_dude. I'll probably take my chances as well unless someone else can convince me otherwise.

 

[jokila]

Don't mess with the ports.

 

[Ovrhill]

Don't mess with the ports.

That's my plan

 

[gforce1108]

You can do it safely with some preparation and caution. Rotate the engine until both valves are closed on that port - clean, vacuum and make sure no debris is left behind. Rotate until the next is closed and so on.

 

[Ovrhill]

This seems to be a risk vs. reward situation to me. The intake ports do have carbon deposits around the edges of the openings. However, they are not blocked or do not appear to be causing any substantial airflow restriction. The biggest restrictions were in the EGR and the neck of the intake manifold.

I am inclined to leave the intake ports as they are unless increased airflow from the intake could cause what is left to flake off and be ingested. I am just unsure how much of a concern that should be.

 

[KrashDH]

Can you post a picture to give us a better idea of how much you're talking about?

 

[Ovrhill]

This is what I am looking at on all four ports. All opinions appreciated!

 

[KrashDH]

Man if that was my situation, I'd probably go the route @gforce1108 mentioned above and get that crap out of the way...

 

[Ovrhill]

I do understand your thinking Krash.

 

[oilhammer]

Don't really do much of these anymore, but we made a shop vac the "special tool" for this.... good thing it is still around, because it has become the tool for cleaning the DI gasser intake ports, which I DO do a lot of now.

I just stick that vacuum tube down near the ports, and use my 90 degree hose removal tool and dig it out, shop vac pulls anything loose right out.

FYI: don't use a shop vac you care about, because it will be filthy black inside forever.

 

[Lug_Nut]

The accumulation is relatively soft, much softer than the valves and seats. I wouldn't worry about ingesting the head tract restriction during combustion. Note the soot chunks in the image below.

idle soot

smoke / soot at idle

forums.tdiclub.com

 

[Ovrhill]

Thanks Guys. I might give this a go.

Are the intake valves assumed closed if the associated cam lobes are pionted up in the "V" position?

That question might expose my ignorance. However, I'm not sure how to know for sure otherwise.

 

[Lug_Nut]

"points" on the cam are up, then they aren't pushing on the hydraulic followers down below.

 

[Ovrhill]

"points" on the cam are up, then they aren't pushing on the hydraulic followers down below.

So, when points are up, intake air is blocked or open?

 

[J_dude]

So, when points are up, intake air is blocked or open?

Blocked.

 

[Ovrhill]

Hopefully my embarrassment will save someone else save someone else some pain.

Is this the best or easiest way to know that the port is blocked?

 

[Vince Waldon]

Probably best and easiest, other than removing the cam entirely so that all bets are off.

Not quite the same engine, but here's cylinder 1 with both cam lobs "up", so no pressure on the hydraulic lifters and hence both valves are closed:

 

[Ovrhill]

Got it. Think that I'll go for it. I'll let everyone know how it turns out. Thanks!

 

[Vince Waldon]

You've come this far and are right there... go for it!

 

[gforce1108]

FYI: don't use a shop vac you care about, because it will be filthy black inside forever.

you aren't kidding there!!!

Most of the ones I've done intake cleaning on have had little to no buildup in the head. One was driven in limp mode/bad MAF/whoknowswhatelse for ages and I couldn't even get air to blow through to torch it out. Every tube in the cooler was clogged and all 4 intake ports were full of gunk (90k mile 98 Beetle).

 

[Ovrhill]

Here's the pic after the scraping and vacuming. Looks a lot better. And, I feel better about it. Hope that it runs.

 

[Ovrhill]

All four are done. As @Lug_Nut stated, build up in the ports was a little bit softer than what was in the EGR and manifold.

 

[oilhammer]

You can start the engine and run it like that.... noisy as all heck... and be careful nothing loose is nearby (paper towels, rags, hair, clothes, low hanging scrotums,) because it'll suck it right in!

 

[Ovrhill]

I've got the valve cover and the vacum pump off. Started in on a timing belt job that somehow got sidetracked. I'll get through the TB job and see what happens.
It's more likely that something off on the timing belt job would keep it from running than anything that I have done so far.

 

[Gothmolly]

Man this really makes me want to do mine. Still getting 48mpg with plenty of pep, it's hard to bother. But I imagine its gross in there.