Lower Intake Manifold Gasket Replacement

[TheBackyardDIYer]

I have a question in regards to cleaning...I am changing the lower intake manifold gasket and when I got the lower intake manifold off, I found that the holes that lead to the pistons (?) are loaded with crud...now this is my first venture working within an engine, all my work to this point has been external...so I'm not sure what all the proper names are for everything.

This is what I'm looking at...this is where the manifold mounts...that way we are all on the same page
[IMG][/IMG]

And this is the crud I was talking about...
[IMG][/IMG]

Now, should I leave it or is there a safe way to clean them out without the risk of messing something up?

[Mustang_Driver]

if i were you i would get a jug of solvent a stiff bristle brush not a wire brush!!! and a bucket and let the manifold soak for a little while and use the brush to remove the CRUD..... but with that much crud this looks more like a lot of Blow-BY past the piston rings but that's another animal altogether..... but like i said soak the manifold in solvent try and clean as much of the crud as possible and re-install after you get it put back together i would get a compression test done ( Just because with that much build up it looks like oil is getting past the piston rings).

But like all mechanics say clean parts are nicer to handle...and gaskets will seal better

Hope i helped

[TheBackyardDIYer]

Mustang, maybe I wasn't clear enough, as I don't exactly know what all these parts are called.The pictures there aren't the lower intake manifold, but the engine (heads(?), I'm not sure) where the lower intake manifold mounts...I already have the lower intake manifold out in these pictures and what you see here is still in the car.

If it is from "blow-by" what exactly does that mean and what will I have to do to fix it?

Thanks for your

UPDATE: After searching and reading, the picture is of the heads, which I suppose to clean those would require removing the heads, and I don't think I really want to do that right now. I think I'm just going to clean the intake manifold really well and button it all back up.

[2002windstar]

That is the cylinder head that you have pictured.

I just replaced my manifold gaskets (upper and lower) and mine looked almost like yours.

pic of mine is attached.

Those ports go into your cylinders, I personally would be careful on making sure debris does not fall into the cylinders when cleaning the surface for the new gasket.

I had my kid hold a shop vac by where I was cleaning the surface and move it as I moved, I also used a plastic scrapper, don't use a metal scraper to clean the surface.

I did not try to clean the ports out for fear of getting crap into the cylinders.

Hopefully other can provide more info for you.

Good luck with your project.

[TheBackyardDIYer]

Yeah, I figured it was just best to let sleeping dogs lie...unfortunately it wasn't until AFTER I had cleaned the surface that I thought about using my shop-vac...but I was extremely cautious in not getting any debris down into the holes...it took quite a while of careful scraping. Thanks for your input.

[2002windstar]

If you have completed your project yet make sure you clean your EGR ports on the lower intake manifold, I did NOT do mine and it appears that I may be regretting it.

[TheBackyardDIYer]

I was just thinking...is there a set amount of time I have to wait (because of RTV and thread sealant) once I get everything put back together before adding fluids and starting up? The back of the Utra-Black bottle says sets in 24 hrs...do I need to wait that long?

[2002windstar]

You should be able to start re-filling your coolant without an issue, same if you changed your oil.

As for the actual starting, I did wait overnight till I started the engine and bring it up to temp, no leaks presented themselves and just had to top off the coolant once, Although it is not being driven for any distance until I get an idle/timing/backfire issue resolved.

Waiting can't hurt but may not be necessary, sorry I can't give a more definitive answer.

[TheBackyardDIYer]

My EGR ports were a mess...I took the whole lower intake manifold out and soaked it in purple power for about an hour then scrubbed it with a nylon brush (or whatever those things are made out of...not a wire one), let it soak for a little longer, and then rinsed it thoroughly and dried it with my air compressor and sun.

I ended up running out of daylight anyway, so I suppose it will set-up overnight. I need to replace both air-filters and fill-up with fluids, so I guess it will be set-up enough.

Hopefully you can get your problem solved and hopefully I don't run into a similar one.

[12Ounce]

That engine does look a bit of a mess. As Mustang Driver says, it looks like piston blow-by ... or it could be stopped up engine air filter, or too much EGR, or even a messed up PCV system. I would be inclined to rebuild the engine ... or, at least, remove the heads for a look at cylinder walls. But that's a different level of ball-game!

[TheBackyardDIYer]

Yeah, I've about reached my limit right now on money I can sink into it...I would love to dig in further, but just can't right now.

[Mustang_Driver]

I hope everything works out ok and goes back together easy

[12Ounce]

I'm about to replace all my gaskets and hold-down around the intake manifold and front cover ... been about 100k miles since I've had the engine open for service and it wants some more service! I'm expecting my passages and EGR jets to be fairly clean due to engineering changes I made in intake area. May change out the water pump this time.
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375K miles on car. I (lightly) rebuilt the engine @215K miles.

[TheBackyardDIYer]

Well so far it seems as though everything is working fine...No more of that jerking junk at red lights and stop signs. It seems to idle much smoother as well and I may be crazy, but it had a hard downshift from 2nd to 1st (?), when I was about to come to a stop, that seems to have stopped. I still have to change the transmission fluid in a couple days or so and hoping that will help my other transmission problem of not going into OD...I also ordered an OBDII scanner that can hopefully give me the stored transmission codes that I get (which AutoZone didn't give me).

I replaced that PCV line, cleaned the EGR ports extremely well, and changed the air filter, so hopefully that will help with the "blow-by" you guys mentioned, until I can afford to dig back in and go further. What exactly would I need to be looking for on the cylinder walls you mentioned?

[12Ounce]

You will find some information on the subject in various books such as Haynes, etc. ... but in general you look for "vertical scoring" , hopefully none .. or none too deep: a "ridge" that's not too pronounced ... a "ridge" is left at the top of the cylinder wall that is not worn by the top piston ring, the top ring can't reach quite all the way up the wall ... leaving the ridge (usually about 1/4" or so) that may see almost no wear: And not too much "smoothness" on the walls ... it seems a contradiction; we want the walls smooth, but not so slick that the rings make very little contact. This is easily corrected by a couple of passes with a special set of stones.
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A cylinder wall wears in a cone shape normally ... with the largest diameter at the top, just below the ridge. Its best to re-bore the block to a larger piston size if the wear is great. But if the engine oil has been well maintained ... an engine can be "rebuilt" quite successfully by removing the lower corner of the ridge (so a new ring won't bump into it), using a tool made for that purpose .... honing the cylinder walls, cleaning the piston ring grooves and piston tops of build-up and replacing the rings. The rings can sometimes be reused, but they should be replaced in their exact location. (I have never reused rings.) My '99 Winny will likely reach 500K miles on its original pistons.