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Gary, Australia Car Mechanic
Category: Australia Car
Satisfied Customers: 999
Experience:  Senior Technician
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Just going through the configuration of the ignition system

Customer Question

just going through the configuration of the ignition system on my 2002 Terracan
JA: Have you checked the battery lately?
Customer: the battery is fine it is one of those that the butterfly screw went down into #5 cyclinder
JA: What is the model of your '02 Hyundai?
Customer: Terracan 3.5 v6
JA: Are you fixing your vehicle yourself? What have you tried so far?
Customer: replaced ignition leads,coil packs,air filter replaced butterfly chamber
JA: Anything else you want the mechanic to know before I connect you?
Customer: All the forums I've read have had no luck with the problem misfire and backfire
Submitted: 8 months ago.
Category: Australia Car
Expert:  discostew replied 8 months ago.

Hi Frank im stew ,a mechanic here in australia,can yo be a bit more specific 'what' exactly fell into cyl 5 please,debris of any sort,in an engine cylinder,particularly a multi valve head like yours,usually means valve damage at the very least,would have zero compression on 5 to prove it,thanks,stew,i will follow up question a couple of times i ask for a rating, thanks stew

Customer: replied 8 months ago.
What I'm not happy about is you've already taken the full fee for services and you haven't even got all the details. The intake of this vehicle has a bank of 6 vacuum controlled butterflies which have a nasty design flaw, the screws that fix the butterfly to the shaft have a habit of unscrewing and getting sucked into the engine!
Expert:  discostew replied 8 months ago.

Frank,i havent been paid at all,justanswer may have taken a fee,but i dont get anything if the answer is not accepted/rated,the butterflys you talk about are part of a two speed intake manifold,many engines use a similar system,check your compression..this will prove the head/engine is damaged,if you want a free forum to argue theory over fact, just answer is not the place,i'm a busy mechanic trying to help people for a fee,not a you tuber with too much spare time,p.s.check your compression before replying

Customer: replied 8 months ago.
Sorry for upsetting you that was not my intention! I don't have a compression gauge but will make an adapter out of an old spark plug and hit it with compressed air that should give me a pretty good indication!
Expert:  Gary replied 8 months ago.

Hello Frank,

With your No.5 at TDC compression, and some air pressure, you may here the source of the leak, through the intake manifold, or out the tailpipe.

Some small loss through the oil cap.

Generally, any solid object bends a valve or two.


Expert:  Gary replied 8 months ago.

Hello Frank,

Do you need any further help?

I hope my advice has been of assistance to you.

Kind regards


Customer: replied 8 months ago.
what I found was that number 6 piston has some scarring but should clean up ok but when I go to put the head back on I have a question is the firing order really 1,2,3,4,5,6 because that is what it says in the manual?
Expert:  Gary replied 8 months ago.

Hi Frank,

That is the correct firing for your engine, common for many v6 engines.

1 and 4 as pair is a sign..

Sounds like you are getting there.


Customer: replied 7 months ago.
ignition coil piston 2 also connects to piston 5 plug and 4 to 1 and 6 to 3 then they should all be right!
Expert:  Gary replied 7 months ago.

Yes, that is the pairing.

1 and 4, 2 and 5, 3 and 6.

Are you together now nearly ready to start her up now?