Grill block / WAI side effect?
 

I installed a partial grill block on the Little Green Car. Now I notice that there is pinging. I don't know why, but I didn't think that a grillblock would cause a Warm Air Intake effect and require a timing adjustment.

Is this in line with your experience with grill blocks?

In a year I don't think I have heard this described once. I think you probably are observing a coincidence, not a cause and effect relationship.

The 96+ Hondas should all have knock sensors and automatically retard timing, if I'm not mistaken. Something funny is going on.

Only the V-TEC models (EX and HX) had knock sensors in the early sixth gen, though maybe they all had them by 99-00. Mine is a 98 DX. No knock sensor. But the car does adjust ignition timing electronically, just not valve timing.

I've watched intake temps on my Paseo with a FULL grill block. It might get warm air while sitting at a red light, but without a bellypan and more sealing the intake temps drop right down to ambient as you get moving. I should also mention my Paseo sucks intake air from the engine bay.

Grill block
 

Did you make a hole for air intake flow?
I made a grill block for my turbodiesel car, but aldo made one opening on it, to allow cold air to get into admission.

Oldbeaver

Intake air is taken from the engine compartment. I did not do a full block. I blocked the section that is in the bumper below the license plate mount; the opening above the bumper is completely open.

I suspect that LittleGreenCar needs a timing adjustment or a knock sensor.

These Civics can also get a hard carbon buildup on the cylinder tops that the valves hit against when they open. It sounds a heck of a lot like "knock" or ping.

My wife and my carpool buddy both insisted my Civic was pinging. I tried retarding the timing to various degrees with no success. At one point I had it retarded so much that it ran poorly and gave a check engine light due to lousy combustion; I promptly set it back to a more normal amount of advance. Still made the noise but ran stronger.

Mine finally had enough valve trouble that it needed a head rebuild, and when my buddy got the head off I found a huge buildup of hardened carbon on all the cylinder tops. Easily a 1/16 inch thick of HARD stuff, which I removed with considerable effort. After the head rebuild the persistent "knock" was gone.

How do these deposits build up? Are there means to prevent or correct it without physically disassembling the head and/or rebuilding it? Is the problem unique (or uniquely worse) in Hondas?

From what I have read, it seems it is a large side effect of idling too often. For how most people drive on ecomodder, it might be a fair idea to loose mpg once every 2-3 months and drive a bit harder on the car (freeway for example) to help clear out the engine.

Seafoam helps a TON with carbon build up.

Back on the main topic, I gained a WAI effect with my grill block, but prior to the last part of the block (lower) I sealed the hood and installed an upper grill block. I have no belly pan yet. Engine temps went from 202 to about 213-220 and intake temps went from about +5F over outside temp to around +50, not quite as hot as some WAIs, but still it is warmer. I notice no ping or timing changes via scan gauge, just a MPG increase and lower engine loads :).

A few times per tank I really open it up, a nice WOT scream up to 7500rpm on a highway on-ramp. Last time I had my engine open it was spotless, at ~75,000 miles.

EDIT: I'm not recommending you redline your engine at WOT, but rev it up a little occasionally, push some air through it.

More info - LittleGreenCar has 350,000+ miles. A lot of this was stop and go rush hour traffic.

So, I'll go after the idea of hard carbon first, and attack that with Seafoam.

After the seafoam treatment, I would also pull off the EGR and check for blockage. I don't think seafoam can get to the EGR circut and clean it and with 350k miles, it might need a cleaning. Not long ago I was in O'Reilly's and they had seafoam on sale for ~$6.66/ can (buy 2 get one free).

Make sure you perform the treatment late at night, and/or well away from the city and any other groups of people. It causes a HUGE cloud behind the car, and it is not good for your health!

Of how my dad described the treatment, you will need some vaccume hoses and a "T" adapter. Hook up a vaccume hose to one of the ports on the throttal body to the T adapter, then from the T adapter to the can. Start the car (check if warm/cold start is ideal in the manual), and let it idle. Every so often, plug off the T adapter to make it suck in extra seafoam. When the can is nearly empty, plug off the T adapter and flood the engine (make it die). Let it sit for atleast 30 mins. Make sure you could change the spark plugs since this treatment does not do any good on them. Plug wires never hurt to change, but that depends how old yours are.

Lastly, let us know the results!

I don't recommend flooding the engine, that's one of the few ways (only way?) Seafoam can cause any damage to an engine. Suck up too much at once and you risk hydrolock.

My reading suggests the following method:

Add half a can to the gas tank, slowly suck up the other half using a vacuum line (being careful not to kill the engine), and then shut off the car and let it sit 10-20 minutes. Start the car again and rev it up for a few minutes, and then take it for a drive, being generous with the throttle. Some say to put Seafoam in your oil at the start too, but I don't trust it. An oil change is recommended after Seafoaming.

Looking at your mileage log, I think you have a bit of tune-up work to do. Driving the car easy should get you much more than 30 mpg.

I concur on checking the EGR system and cleaning that. Also take a look at PCV valve and the ignition system, along with simple things like the air filter and fuel filter. And can you tell if the cat has ever been changed?

The method I said (from memory) was the instructions of a "kit" with seafoam. As for hydro-locking the engine, the kit used a flow limiter on the line from the can, so I'm pretty sure they designed it so you couldn't have too much go in to hydro-lock the engine, but enough to foul out the plugs.

Right on the product it says it can be used in the gas to clean the injectors, oil to clean the inner part of the engine, and of couse the vaccume system to clean the intake and cylenders.

Some good images: Seafoam - Mechanical Database

According to the site above, doing the same with water should work well too.

With 350k miles, I would be really careful with anything that cleans the engine oil areas, mainly since 350k miles worth of junk is built up, it could block oil pathways and kill the engine if they are cleaned and therefore put into the oil. On the flip side, if it has been treated within 100-150k miles ago, or the engine has always had high quality oil in it, go for the cleaning. This might be a really good thing for engines with sludging problems (newer toyota engines).

Seafoam is fun but the neighbors tend to complain or call the fire department..... So i have heard. ;)

Ok, picked up a can of Seafoam today and mixed a dose into the gas tank at manufacturer's recommended 1 oz per gallon, sort of. I figure I have about 4 gallons left, so I put in about 4 oz (1/4 of a container) by eye ball measure.

According to the label, I can "drive the engine clean." Hmmm, we'll have to see about that! I've got the remaining 12 oz stowed in the trunk and will dump the rest in with the next fill (approx 12 gallons).

I will keep the forum informed as to the result. I'll also get after some of the other ideas recommended. She had new plugs, gapped at 1 mm (spec), about a week ago. (pinging was before plug change).

Air filter is recent and still 'clean.' The LGC probably does need a fuel filter because I don't recall when I last did that, same with PCV and EGR system. An oil change is due in a few hundred miles, so I may delay that pending seafoam in the tank result. That way if I decide to use the vacuum method, I won't be dumping a fresh oil change.

Regarding carbon deposit building I wanted to share a story with you. My friend used to drive Opel Astra 1.4L 16V, and he used to be a very genttle on the throttle. After about 6 months of driving he started to have trouble with the dying engine. Mostly when it was idling at the stops it just suddenly died. Since car was still under warranty he went to the dealer shop and they checked whole engine. There was an old mechanic who said to my friend "You're driving too gentle, and probably most of the time it's a city driving". My friend confirmed. After that mechanic took apart the engine and showed to my friend all valves covered with a carbon. Then everything was cleaned and put back together, mechanic just drilled a bit valve guides, to loosen valves a bit. Because that was the reason for engine to die, carbon was blocking valves within guides and valves just ocasionally stayed opened a bit. No compression, no power.
As you can see carbon can cause very strange engine behavior.

Pinging
 

Sorry Andrew63,

Who are you aiming yr question?

Oldbeaver

FYI- Seafoam now comes in a spray can with a plastic hose that will go in front of your throttle plate and allow you to put the intake back over it. That way you cam be sure to not get too much or too little in your engine.