Odd engine noise when accelerating

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08-30-2018, 05:37 PM

Silvermelon19

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Odd engine noise when accelerating

07 fit with 233k on the engine. I just replaced plugs and coils about a month ago and now when iam accelerating the check engine light flashes and seems like the car doesn’t want to go and also a loud knock from the engine. What’s up? What could this be?

08-30-2018, 06:08 PM

GAFIT

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Spark plug is probably loose. Very common problem. Do not drive it until you check. If it ejects, it could potentially cost you a LOT!

08-30-2018, 08:42 PM

Silvermelon19

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Quote:

Originally Posted by GAFIT

Spark plug is probably loose. Very common problem. Do not drive it until you check. If it ejects, it could potentially cost you a LOT!

thanks I’ll have it looked at!

09-05-2018, 06:00 PM

Silvermelon19

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So basically it only does it when the ac is on for about ten minutes . Still might be the spark plugs?

09-05-2018, 07:08 PM

GAFIT

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That's scary! Sounds like maybe the secondary fan isn't coming on with the A/C and the car is overheating? Are you getting a temp light?

Check the fans to make sure both are on with the A/C and report back please.

Good luck!

09-06-2018, 09:27 AM

Silvermelon19

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May sound like a dumb question but how do I check if both fans are running. Also I don’t see any temp light coming in just the check engine light flashes and loud knocking from the engine.

09-06-2018, 10:45 AM

doctor J

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Check engine flash = misfire.Read the code, than pull the coils and look for the soot/ brown residue on them.
It can be done faster than spending time typing replies

Letting this go will pop the plug out
If coil is bought of E-bay or from Alibaba its a cheap imitation
A/C makes engine work harder but may not be related.
90% of the spark plugs installed with antiseize and without cleaning of the gasket sealing surface
Even the car on the junkyard I stripped during my last visit, had NEW OEM coils ruined by leaks past the spark plug gasket.
It looks to me that a) Fit is too delicate to withstand normal service practice (I bough my 87 Camry from curbside flipper with new spark plugs installed but not tightened [gasket not compressed] and they neither leaked nor got loose) or b) most Fit owners don't know how to turn the wrench (sorry!)

09-06-2018, 10:53 AM

doctor J

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Since the fans are controlled by 2 wire thermistor (not single wire bi-metal switch) at the bottom of the radiator the right way is to unplug the wire from the sensor and plug in a good used sensor preheated to 96 degrees C. (Ask engineers who wrote this procedure how to do it (mad) ). After turning ignition to on the both fans should spin.
PS Toyota publishes temperature-resistance chart for its sensors, so the test is made by sticking 1 Watt resistor of appropriate value (per chart) into the connector (to imitate trigger temperature)

09-06-2018, 11:11 AM

GAFIT

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doctor J, as usual, is dead on with all of this. Check those plugs and coils!

For the fans, can't you just let it get hot enough to turn on the main fan, turn on the A/C, and then look at both fans to see if they are running? Asking because I've not studied ours, but I can tell you that they move a ton of air and make a ton of noise when both are running.