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You are in the Hyundai Santa Fe
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Hyundai Santa Fe
#1 of 20 Very Weird and Wacky Problem
Oct 01, 2010 (9:25 am)
So I have been trying to help out a friend with her 2004 4-Cylinder Hyundai Santa Fe. About 4 weeks ago it was running very poor. I changed the spark plugs and discovered that the number 4 cylinder plug had a closed gap. I put some additive down the cylinder to break up any carbon build-up and replaced all the plugs and it was running great. About 3 days ago it started running poor again. I pulled the plugs and sure enough the number 4 had a closed gap. I opened it back up reinstalled the plugs and it is running fine again. This makes no noise at all.. no knocking or anything, and it takes several weeks and several hundered miles for this to act up. Any thoughs on what is pushing the gap closed. I dont know much about Hyundai's. any help would be outstanding.
#2 of 20 Re: Very Weird and Wacky Problem [followme21]
Oct 01, 2010 (2:12 pm)
is their something bridging the gap or is it actually closed? any other conditions exist on the plug? what brand/type plugs are you running? It could be a few things- mechanical failure, wrong type plug. also, try cleaning out carbon with a 3 step system instead of pouring directly into plug hole - i wouldn't keep reusing that same damaged plug. And what do the other plugs look like when you pull this one and find it bad?
#3 of 20 Re: Very Weird and Wacky Problem [somedai1]
Oct 01, 2010 (8:00 pm)
Thanks for the response and tips. I only reused this plug this one time so my friend could get home..a couple of miles away. I think the were "champion" plugs..and they are the ones the part house gave me for this application. The other three look great,good clean and a little white. This one was of course was black from incomplete combustion. And the gap is actually closed at the very tip of the electrode. What type of "mechanical failure" could cause this. And could you recommend a 3-step cleaning system? No other systems occur,... one minute is running great then all of a sudden a miss.
Thanks again any help would be great.
#4 of 20 Re: Very Weird and Wacky Problem [followme21]
Oct 02, 2010 (10:38 am)
is the plug black and oily? or black and caked with soot? did you say no other codes from scanner except misfire? i guess detonation could cause the plug to get like that... just need to find out what caused the detonation... try changing the plugs to NGK - champion was not meant for Hyundai's - sometimes it doesn't matter but certain cars are particular to the type of plug... the other plugs seem to be running too hot... so they are white... maybe the plugs are hot plugs and you need to run a colder plug. also - this car is distributor cap and rotor? or coil packs? it may be needing more than just plugs...
#5 of 20 Re: Very Weird and Wacky Problem [somedai1]
Oct 02, 2010 (11:30 am)
The plug was more sooty then oily, and it wasnt a complete miss, because I pulled the plug wire off with the engine running and it made a difference as the engine about died, so even when the gap is closed it is still firing a little, I assume because only the very tip of the plug is closed. I was getting the code P0430--"catalyst system below threshold bank two". The car has coil packs.. number 4 has the pack on it.
Thanks again for any input.
#6 of 20 Re: Very Weird and Wacky Problem [followme21]
Oct 02, 2010 (11:51 am)
hmmm. the catalyst below threshold could have been caused by the misfire... not the other way around... but one plug like that would seem like carbon build up or improper fuel mixture. either way - you should have more than one code... then again - it is a Hyundai... change the O2 sensor located after the cat and switch to NGK plugs...
#7 of 20 Re: Very Weird and Wacky Problem [somedai1]
Oct 02, 2010 (1:50 pm)
I will try switching plugs.. and I'm with you, I am thinkng I'm getting that code-P0430 due to the incomplete combustion in that cylinder with the bad plug. But I will try the plug switch and see what happends.. Any other ideas I will listen to as well. If it was the plugs I would think it would do it to more then consistently one-cylinder. But worth a shot as I have no other clue.
#8 of 20 Re: Very Weird and Wacky Problem [followme21]
Oct 04, 2010 (6:56 am)
it could be the coil pack... if it is working intermittently- it could allow fuel into the combustion chamber that does not get burned... then when it does fire... BOOM- detonation- damaged plug- if the packs are interchangeable - switch it to another cylinder- see if the problem occurs again at the new position... try this 1st so you don't waste on the new plugs...
#9 of 20 Re: Very Weird and Wacky Problem [somedai1]
Oct 12, 2010 (10:38 am)
So I have done a little work. I replaced the plugs with NGK plugs and even replaced the coil pack on the number 4 cylinder..the plug that kept having the closed gap. Gave the car back to the owner she drove it for about 100 miles or so then it goes to missing again and I pulled the number 4 plug it was fine.. Pulled number 3 and now it had the smashed shut gap. I replaced it, went for a drive and it worked great.....I am gonna try soaking some sea-foam or A.T.F. in the cylinder to maybe break up and carbon build up thats floating around. Other then that I am out of ideas.. Any thoughts?
#10 of 20 Re: Very Weird and Wacky Problem [followme21]
Oct 12, 2010 (11:02 am)
I don't think carbon build up would close the gap tho'. any new codes? Timing may be off. I think too much fuel in the chamber would cause the plug damage. So many things could cause that but you would most likely get codes... Is that a timing belt car? was that ever replaced? how many miles on that car? but still... without other codes - you may want to investigate further into the O2 sensor issue - may be bad cat or sensor or both... clogged cat possible too.... try Berryman 3 step fuel system cleaner. Runrite or Justice Brothers could work but only the pros can get that stuff...