Hey guys. I just want to start off by saying I am NOT car savvy at all. Basically I have a 2000 Lexus LS400 and the ignition coil on cylinder 6 went dead and the cylinder is misfiring (code PO306). The mechanics told me it'll cost $650 to replace the one coil because they have to take off the "manifold". My question is, can this be done by myself and can anyone give me a step by step guide at how to go about fixing this problem? I appreciate any help I can get. Thanks.

 

you do not need to take off the manifold to replace the coil. Tops 1 hour of labour and the cost of the parts.

You can pick up a new aftermarket coil from RockAuto or similar for ~$100

 

That's not too bad. How do I go about replacing the coil then? And several mechanics are suggesting I replace all the rear coils while I'm at it because it's an old car. Do you think this is necessary or should I just replace them as they die?

 

do not pay $650 to do it. parts alone is about $100 and it is located on top of the motor.

how do you know it's the coil? a misfire could also mean it's the spark plugs which is more likely. how many miles does the car have? plugs are also about $60 and can be done on the driveway, though a long socket is necessary.

link below is for a 90-94 model, which will have difference but the general process is the same, where on you car the coils would be directly above the spark plugs themselves:
http://www.lexls.com/tutorials/ignition/sparkplugs.html

 

unless you have verified that coil to be faulty, I would suggest not replacing anything, except for maybe the plugs.
These cars are pretty robust and you don't have to replace parts just for the the sake of replacing parts like with domestics.

Do a search for how to test the coils on your car, and replace what is needed or find a competent shop to do the work for you. Unless that last shop took the coil out to test it on the bench, they are just guessing and spending your money for you.

Seeing as they said you need to remove the manifold, they probably didn't even pop the hood!

 

I took it to Sear's and they told me it was the coil that needs to be replaced but they didn't have the part to replace it. So it has been verified that it's a coil problem and not just my intuition. And I was calling around asking for quotes which is when Toyota told me about needing to take off the manifold...so they never actually looked at the car. But even if they didn't need to they were going to charge me $350 which seems excessive.

 

Sears..nope.There is a plastic cover with 3 or 4 bolts holding it down. Then access the coil. I think one or two bolts holding it down. Should only take about fifteen minutes for one coil and plug. But while your in there change all the plugs. Dont do this on a hot engine. The heads are aluminum and you could damage them.

 

I wasn't suggesting YOU were throwing darts at it, but unless Sears removed the coil and tested it on the bench, they are guessing. And if they did do that, then that should also be a tip off that what Toyota told you was wrong.... Or vice versa.

 

I don't trust the mechanic who say "Needing to take off the manifold". He must be a novice.

Before replacing the coil (I would say it the ignition module) I would swap it with the next one and check the code is shifted.

 

Like has been said make sure the coil was tested before replacing and if it is bad order one from rockauto.

1. Remove the 2 bolts and 2 nuts to take of top engine cover with 10mm socket.
2. Number 6 coil is the 3rd one from the front on the passenger side. Remove 1 10mm bolt pull out coil and disconnect it from the harness.
3. Connect new coil to harness.
4. Plug coil back onto spark plug.
5. Put 10mm bolt back in but don't over tighten it, just snug it up.
6. Put top engine cover on with 2 bolts and 2 nuts.

This is literally a 15 minute job if that's all that's wrong with the car. Changing the sparks plugs is a little more difficult since you have to remove the air tubing and use angles to get at some of the plugs.

 

The mechanic is probably basing the "manifold removal" on the the LS's more common FWD V6 counterparts, which do require that for the rear ignition coils to be removed

 

The diagnosis that was written down for me by the mechanic says to replace the spark plug as well as the coil.

 

sha4000 has good instructions on the ignition/coil pack procedure. Follow what Yamae mentions about swapping the module from an adjacent cylinder and checking. On a properly running car, plugs tend to last a long spell beyond the factory change intervals. Stuff happens so replacing the plugs may also be a consideration and would be suggested. If the plug is severely fouled or damaged, it is better to replace it. If doing one, I would replace all of them. If the plugs were recently changed buy a fresh one to replace that one only.

 

Yes switch the coil with another one.

 

So I'm looking at rock auto and they have three selections for ignition coils. http://www.rockauto.com/catalog/raca...?parttype=7072
Which do I choose? Also is it necessary that I change all 8 spark plugs while I'm replacing the ignition coil? I don't know when the last time they were changed was but at $.99 a pop I don't see any issue with replacing them while I'm working on the car.