sageuvagony

Ok, 2 days ago I decided I wanted to combat my fuel/sluggish power problem. I knew it wasn't the engine since I had it swapped out after my last one died, and gas mileage didn't change a single bit. I had pretty much cleaned everything out EXCEPT the intake manifold (Still the original one from my old D15B7) and am using it on a low mileage D16Y7.

When I removed the intake manifold, it was NOTHING but horror looking into the runners. There was LITERALY 1/2" thick layer of carbon on the bottom of ALL the runners. The plenum was it's own horror as well. Once I took off all sensors, throttlebody, etc, I sprayed the manifold with carb cleaner and let it sit for a while. I repeated this process about 12 times. I went through 6 cans of carb cleaner. I sprayed every port and everything. After the carbon was loose, I used my 3500PSI pressure washer for the inside of the intake manifold. EVERY SINGLE SPEC OF DIRT CAME OUT OF THERE. NOT A SINGLE DUST PARTICLE WAS LEFT INSIDE! IT LOOKED BRAND SPANKING NEW! It was so clean that I used the manifold as a beer bong that night (not really, but I could have)

Ok so cleaning it out was the easiest part. When I removed the throttlebody for some reason 1/4 of the gasket was missing.. anyways.. getting that gasket off was a bitch! The WORST of it all was removing the dreadful paper gasket that was BAKED on my engine! I bought gasket remover which helped ALOT. Boy, they aren't kidding when they say that this stuff will burn your skin if it touches you. IT WILL! I was wearing 2 pairs of latex gloves and all of the sudden I thought I felt something cold on the back of my fingers, when in fact I realized that the gasket remover burned a hole through the 2 gloves and was slowly burning into my skin!!! I ran to the sink and washed for 5 min in severe pain!


After HOURS of work removing the gasket off the engine, I was finally done. I go to reinstall everything and all goes well. (I regret not buying the hondata gasket at this point but I'll get it soon in the future) When I started the car and test drove it, WOW.... JUST.... WOW!!!! Here is a list of things it fixed/changed

1. Cold starting - No longer bogs/sputters for the first 10 seconds when cold starting the engine.
2. Throttle Response is INSTANT now. No horrible lag/delay like before.
3. Torque has improved ALOT!!!!!! I break traction easilly in 1st gear now while doing a slight turn and slightly giving it gas. I used to only be able to do this in rain!
4. Car starts up STRONG! No sissy engine start anymore.
5. My brakes have become much more sensitive than before and less pedal pressure is required to apply the brakes. (I've been fighting this brake problem since I got the car and NEVER thought it would be a vacuum problem!)
6. Car used to have some power when engine was cold but would lose that power once engine reached operating temp. Very annoying. That is NO LONGER A PROBLEM, and has more power than ever!
7. The IACV used to have about a 1 second delay for it to react to me turning on the AC. Now, the INSTANT I hit the AC button, the IACV works instantly.
8. Idle is SUPER SUPER SUPER SMOOTH! Never once since I've owned this car have I ever had smooth idle. My steering wheel always shook and was embarrasing. I'd push up on the steering wheel with my knee when ever any of my friends were in the car with me to keep it from shaking as much.
9. The intake is now noticably louder/deeper. Sound more vtec-ish (Although I don't have vtec) I would assume it sounds more like a deeper growl now due to the hollowing effect of the intake manifold. Sound BEAUTIFUL!!
10. Gas mileage I'm not sure of yet, but I'm sure I'll have around 380 miles to the tank as once before.

Now you guys might be thinking I'm exaggerating a little, but I am not exaggerating ONE BIT. That's how bad my car was running since I've owned it (2002) and I thought it was normal! I doubt this intake manifold has EVER been cleaned. It's probably been there since 1992 un touched.

All of this brought a tears to my eyes (don't think I'm a wuss please) because I never knew this car had all this goodness hiding because of a clogged intake manifold! I was SO jumpy and happy after all of this. I really wish I had a before and after picture of the intake manifold inside. The layer of carbon/soot was SERIOUSLY about a 1/2"

If you guys have never cleaned out your intake manifold and is old, it wouldn't hurt to do so. In my case, it was the cause of ALL of my problems I have been trying to deal with since I first got the car! I am so HAPPY!!!!!

I'll post back later this week on status of my gas mileage. Back then when I adjusted my FITV screw out all the way, I had a horrible bouncy idle BUT I was getting about 380 miles to the tank vs 230 miles to the tank that I normally get. When I fixed the idle by screwing in the FITV, gas mileage went back down. I knew at this point that the car was always running rich and not with enough air. The black soot all over my bumper always explained the richness as well.

Thank you guys who helped me in identifying parts/hoses when I really needed the help. Honda-tech rules!

eg2jr

iTrader: (7)

bump

sageuvagony

hmm?

BlitzSix

congrats on the results. Did you use any guide/howto on how to do this ?

sageuvagony

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by BlitzSix &raquo;</TD></TR><TR><TD CLASS="quote">congrats on the results. Did you use any guide/howto on how to do this ?</TD></TR></TABLE>

Nah I just remembered how to remove the intake manifold because I had to change my headgasket on my old engine once. Taking it off isn't really hard at all. You just have to make sure you remember where all the hoses go. I labled them and took plenty of pictures before I pulled it off so I know where everything goes. I didn't think of cleaning the manifold back then since my main goal was to only replace the head gasket.

To remove the manifold you just unbolt the stuff you see such as the fuel rail, all the nuts holding the manifold to the engine, and the 2 bolts on the BOTTOM of the manifold that are attached to a support bracket. I wish I would have taken pictures of ALLLLLL of the crap/gunk that came out of that manifold.

Right now I feel like a little kid who for the first time am celebrating Christmas with tons of presents for the first time ever

sageuvagony

I just realized that I didn't bolt the bracket on the bottom to the manifold. Is it alright to leave it like that? or should I just put in the 2 bolts?

civicjoe

You talking about that intake mani brace? On my old D16 I took it off and the same on my B16. So far.. no problems at all.

Mr.Quang

iTrader: (2)

I always left my bracket off if I ever had to remove it. zero problems over many years being like that

slvrcvc93

me 2 I never keep it on after a swap makes it easier to take on and off also I clean mine about once a year I had the same problems a long time ago.

redef90si

iTrader: (3)

props to the OP and i agree 100% with what he says i took a buddys d15b2 gas sipper apart and couldn't beleive how bad it was.As stated above the was so much carbon and build up i'm surprised it ran.I will be doin this with my d16a6.

alphalanos

So to clarify you just take it off and spray it down with the carb cleaner/pressure wash? I havent done much around the engine. Im assuming its a good idea to change the gasket at the same time. I kind of hope mine is like yours was lol . Maybe ill get an improvement too.

sageuvagony

You're gonna want to replace both the throttle body gasket and intake manifold gasket. Remember that you should remove the throttle body off of the intake manifold so that way you don't spray any sensors. I stripped the intake manifold of all hoses and sensors to where it was just metal. Tons of carb cleaner, a brush, and a pressure washer is what I used.

The gaskets will most likely tear when you take the stuff off. MAKE SURE to FULLY remove the old gasket completely or you may have air leaks. The new gasket I used was a metal gasket so next time it won't be a problem removing it. Again, make sure you remember where all the plugs and hoses go.

I just filled up my tank so I'll let you guys know in a few days what my gas mileage is.


Modified by sageuvagony at 9:14 AM 8/15/2008

sde780

how many miles are on your car? I only have 50k but I'm getting some of the things you described, mainly less power, horrible gas mileage, and the shakes

sageuvagony

156,500 miles is what it had when I took off the manifold a few days ago. The condition of my old D15B7 wasn't so great at all. It would burn oil, the valves had a thick layer carbon baked onto it, and blew 3 headgaskets before I decided to swap the engine for a D16Y7 with only 36,500 miles on it. I'm guessing the old engine puked on my intake manifold. I replaced only the bare engine and left ALL of the D15B7 components. The times I took the manifold off the engine I never bothered to look at the condition of the intake manifold.

mizzoEG

Wow, I'm impressed with your results man. I still got the ole' bastard B7 in my EH2 as well with about 180k, it runs decent for its mileage but could definately be better. I noticed that it has a bad headgasket because I've noticed traces of oil in the coolent reservoir and my radiator keeps bubbling when I idle the engine with the rad cap off.

I'm planning on taking the time, effort and money to just fix the problem because of motivation from stories like this, its just so inspiring.

I recently pulled off my FITV and cleaned it up with oven cleaner and screwed it all the way in. This corrected my cold start idle drastically. My car used to idle over 2000RPM at a cold start , but now it never jumps past 1500RPM and decreases from there as it warms. I also completely cleaned out my IACV with Non-Chlorinated Brake Cleaner and noticed better idle from that as well.

I'm planning on replacing my headgasket soon and along with that I plan on changing the waterpump/timing belt and along with that now, I plan on stealing your intake manifold cleaning method , seeing as it will be easier to do when the head is off. I'm also thinking about working on the head but I'm not sure yet, dont want to get too ahead of myself. Congratulations on your results.

IndySporty

Props to you man this story is truly inspiring to me as well! I have a 92 VX hatch (275,000 original miles and doesn't even burn oil) that only gets 27-30 MPG. After I get the new wideband O2 and do this intake manifold cleaning, I'm looking forward to getting 45+ with the AC on! lol....

TheJGB3

Instead of using carb cleaner, use either Mopar Combustion Chamber Cleaner (MCCC) (available at a Dodge dealer) or Cleens (available at any GM dealer part# 992872). These top end cleaners will MELT the carbon INSTANTLY!

bmoua

looks like i'll be doing this when i have the time...

Endo-land

This seems very interesting, especially with an intake that has the crank case breather piped to it. Any suggestions of milage on the odometer that this would be recommended.

ESmoothSTi

Im about to hit 200K on my 98EX and am getting about 27-30MPG as well. I pulled my intake opened the throttle body and shined a flashlight in the intake mani to see if it was dirty but it looked pretty good, evenhad some metallic reflection. Was most of your grime in the main body of the mani or more in the runners near the ports? Id hate to pull everything apart to find out it wasnt bad at all. I am systematically replacing the MPG related parts to try to get the most out of it.

95delsolz6

I had the same reaction to my IM this past winter. I pulled it off, 186k miles, and could see there was carbon throughout. I only used one can of carb cleaner.

sageuvagony

^^This is after I semi-cleaned it ^^^That hose which is the crank case breather was FILTHY! If you only knew the dirty things that just kept coming out of there. I thought it was never going to end. I'm telling you, the old engine which was in blah blah condition did a number on that intake manifold.



^^ That's my old engine with the same manifold. That pic was taken about 5 years ago so the manifold was in worse condition than in the pic. This cleaning was the best thing ever. At the moment I'm so obsessed with the smooth idle! I can't get over it!

95delsolz6

I don't think I cleaned those lines. How did you clean them out? air pressure?

sageuvagony

When I was spraying the manifold I didn't have the pcv valve or pcv hose on the manifold, but I did keep that line on the bottom circled in red. When I was spraying the manifold, I mistakingly sprayed in the PCV hole and that's when I noticed the carb cleaner running out of that bottom line. It came out extremely thick and gunky. I would spray carb cleaner, immediately rinse with water, and just repeated the process till water came out clear. I wouldn't leave the carb cleaner in the line too long since I'm not too sure if carb cleaner is too friendly with hoses. My valve on the bottom was most likely stuck as well.

I also took off the injector seals and washed them by hand with water and soap, then lubricated them. With the seals off, I used carb cleaner on the holes on the manifold where the seals sit. There was PLENTY of carbon on there as well. I didn't use carb cleaner on the seals themselves. Ohh and wipe off the tips of the injectors as well. If you see my pic up there, you'll see that the injector tips are BLACK. They are supposed to be a BRIGHT BROWN color. After I wiped them off I was amazed that they weren't supposed to be black


Modified by sageuvagony at 7:00 PM 8/18/2008

00civiccali

doesnt an oil catch can keep your intake manifold clean?