[wildcat]

I'm passing this along because I seem to have rather unusual things happen...  The black rubber seal in the throttle body got pinched or something during re-installation.  This lead to emergence of anti-freeze into the intake manifold which caused the valves to stick and produced the described noise.  I thought "oh damn" its not like I can spray carburetor cleaner through the intake to the individual valves... what to do?  The first thing I tried was squirting water into one of the tubes that carries water through the throttle body... thinking that would atomize into the engine, which it did like water injection, but it wasn't quieting the valves at all.  Then I go the bright idea to pull the spark plug on each piston while it was running.  That did the trick... it "flooded" the cylinder with fuel which broke up the glycol and after several attempts I got all the valves quietly humming along.   You can't drive the car with that racket and it would probably burn the valves or ??? I didn't want to have to take the head apart, so anyway, pulling the plugs on each one and a little patience cleared the problem.  Really had me going though.

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[banditsc]

If you are not concerned about your throttle body icing up you can connect the two coolant hoses into the TB together and be done with that. Will also have the benefit of not heating your TB up.

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[wildcat]

I tried that and the problem there is you have to cap off the throttle body, otherwise you get vacuum from the air-intake.  If you've got a good seal to begin with that may not be a problem, but then the seal will dry out, which could be a problem. 

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[banditsc]

I just put rubber caps on my ports. Been running that way for a probably 5 years now. Alot of people have gone that route now.

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[wildcat]

Thanks for the tip. Worth considering.

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[flash]

been about 10 years for me

 

once you replace those o-rings, there should be no air getting in the outer two.  that is a sealed system, connected to the cooling system.  i capped them, just because, and never thought about running them open, but it shouldn't make any difference.

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[kwikt]

Disconnected as well..... no need to worry about throttle body icing in Florida

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[wildcat]

Right, unless I go skiing up at Big Bear in a blizzard.  B)

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[flash]

for a street car, there is no need to disconnect it.  on the other hand, in california, unless you go up to the snow, there is no reason to have it connected either.

 

i have it connected on the white car, and disconnected on the blue car.

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[wildcat]

Did you also plug the short pipe to the reservoir, and that curiously routed left side that goes under the manifold to what looks like a pump which then goes around the back side along the engine through a metal tube and then the short vacuum valve to the large radiator hose?  Is that a small pump on the engine next to the fuel rail?  

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[flash]

not sure what you are looking at.

 

i didn't change anything else.  i just capped the 2 ports on top of the throttle body, and couple the hoses that came off of them.

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[wildcat]

Don't know if you're interested but I followed those two tubes, one around the engine.  The first just goes to the reservoir or overflow.  The second goes around the backside of the engine etc.

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[flash]

yeah - it just grabs some of the coolant and runs it through the throttle body to warm it up.  connecting them together just bypasses that path.  as long as the o-rings in the throttle body are intact and sealing, there should be no leaks.  i've had those caps erode before (i have to change them every couple of years), and there have never been any vacuum leaks (i have a vacuum gauge in my dash)

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[wildcat]

Wanted to write a follow up on the cylinder flushing procedure.  Before the glycol incident, one or two of the valves of cylinder 4 would tick tick initially on startup.  This has been going on for 5 or 6 months. It was annoying but would go away when the engine warmed up.  Its gone. I start it up and it purrs. The performance is better too. I think that procedure re-programs the computer.

 

BTW, and I know this is counter to most people's custom, I use regular gas all the time.  I've tried premium with no noticeable difference. The guy that sold me the car said it ran fine on regular, so that's what I started using. Later I discovered most people didn't.  So I thought I'd pass that along as well. 

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[flash]

ACCCKKK!!!!!

 

it says right on the gas cap door, and in the owner's manual, to not use anything lower than 93 (the way we measure it here in california), which you can't even get here.  if you use lower octane, the knock sensors will pick up the knock, the ECU will retard the timing, and you lose performance.  i've actually tested this as a part of the programming for the supercharger.  even with 91, the sensors come into play when you are really on it, especially on a hot day.  engine output goes down a measurable amount, though you may not "feel" it with the seat of your pants.  if you have a performance chip, it will only make things worse.  if it gets really bad, and exceeds the ability of the ECU to pull back (which is limited to 6 degrees) the knock can result in detonation, and do serious damage to your engine.

 

that's a really bad idea.  gas is cheap.  pistons aren't.  use the right stuff.

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[94SilverCab]

Maybe I'm an idiot, but I only use Premium in both the 968 and the Infiniti...the 968 fund is "Entertainment" (not "Transportation"), and the cost for the Infiniti is about $100/year different.

 

Jay

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[flash]

not an idiot.  i've seen the results of detonation.  it's not pretty, nor is it inexpensive to fix.  you would have to stack up the cost difference on the fuel for 80 years to equal the cost of the repair of the engine (10000 miles per year - 25mpg - 3.50/gal vs 3.75/gal - engine build $8k)

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[Bulti]

Make that 100 years if your country doesn't produce any oil and has thieves for politicians. Tax-wise I mean...

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[wildcat]

I realize what the literature says et al but I'm telling you it runs great, over the last 3 years a tweek here and there, I'm really happy with its performance.  I was up in the UTC area and came down La Jolla Village drive and onto to 5 and boom I was gone before I realized it.  I'm familiar with my car, I shouldn't be surprised, but I was.

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[flash]

i'm willing to bet a tank of gas that it isn't "running great".  i am dead certain that the ECU is pulling back timing, and reducing your power.  at a full 6 degree pull, it's about 15hp over 4.4k rpm.

 

the other issue with any form of detonation is that it hammers the head gasket.  i posted some pics here of what it looks like.  every one of those little explosions puts a strain on it.  with the head gaskets already being known to be deteriorated due entirely to age, that is asking for a failure.

 

it's not good on the valves either.  it chips away little bits every time.  eventually you lose the sealing of the valves, and again more power loss.

 

again, i don't get the idea of taking on the risk.  you can't buy enough of the difference in the price of gas to equal the cost of the repair of the motor.  but then, i also see guys running around on 10 year old tires too, which makes about as much sense.

 

but, do what you want.  it's your engine.  just don't come crying here when you decide to go out and hammer it on a hot day and blow your motor.  we're here to help, but you have to actually heed the advice to benefit from it.

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