97 Camry V6 misfiring

[AllanJames]

Hi,

Had an issue with check engine light coming on and off for a few days and experiencing minor problems, stalling, not starting. The morning I drove it up to the mechanics it started running really rough. The check engine light was apparently a coolant temperature sensor which they replaced at a cost of $150, looked this up and it made sense for what I was experiencing initially with the car when the light was on before it got worse. This didnt get rid of the rough running, seemed to make it slightly better though.

Mechanic has suggested plugs or ignition leads and quoted $400-$500 to replace as spark plugs in a really bad location and will need to take some stuff apart to do it, I looked this up on here and other sites and yeah looks like a real pain to do, tried replacing spark plugs that I could get to this morning, hoping that it was just one of the front ones that had fouled or something. No good. I managed to replace one of the back ones but cant reach the others (dont know how some of the people here have done it!)

In replacing the 1 back spark plug I noticed there was a small amount of oil around the hole and the plug socket was oily also, I believe from reading today that this could possibly cause the wire to fail/short?

The car seems like it's missing and shakes a bit when going slow, when reaches a cruising speed it is not as noticeable. Not having problems starting.

Does this sound like ignition leads/ spark plugs?

I dont want to & cant really afford to pay out $500 for the mechanic to take the inlet manifold etc off and replace sparks/leads and then find out that it's not the cause.

Thanks for any advice

Additional info - the car was recently overfilled with oil, maybe a couple of litres, was drained the next day after only a short drive, thought this may have fouled a plug or perhaps has caused some other damage.

[Yuko]

Motor oil in the spark plug holes mean that the seals for the spark plug tubes have failed. Easy to repair on the 4-cly, but a pain on the rear bank of the V6. $400-$500 sound too much to replace just plugs unless that includes doing the valve cover seals. It is still possible to replace the rear spark plugs without removing the intake but it's a pain. But since there's oil in the tubes, it can damage the coils and cause it to misfire. Fixing the leak is needed.

[AllanJames]

Thanks Yuko,

I think I will ring around tomorrow and try and find a Toyota repairer dealership/specialist and get some quotes to replace sparks/leads and valve cover seals, they would hopefully have more experience with this crazy spark plug placing and fixing issues.

The local mechanics quote was just for the sparks & leads and reckoned it would be at least a few hours labour. After reading a few other threads I don't think an experienced workshop should take that long to do it even if taking off the inlet manifold? dread what they are going to add for doing the valve seals.

"It is still possible to replace the rear spark plugs without removing the intake but it's a pain."

That's what I read when researching and thought I would give it a go but honestly even after following the advice - universal joints - extenders --- patience, I just couldn't really see how I was even going to pull the boots off let alone get a socket and extenders into the equation! was also worried I would break a wire or something as could hardly even get a grip on the boot.

[ajkalian]

It's not necessary to remove the plenum to change either the spark plugs or the wires. Put a universal socket on a spark plug wrench, and then a 3" extension on the universal. The extension will stick out about 1" from the valve cover. Unscrew the plug, blow out the tube with compressed air with the plug still screwed loosely in the head. Pull the plug/socket/universal/extension combo out until the universal protrudes from the valve cover. The universal will flop over at 90 degrees and you can remove the plug.

The two main things to remember is to remove the PCV valve *and* the hose from the Passenger side of the Valve cover, and to unloosen and move out of the way the bracket that connects to the plenum with one bolt on the drivers side.

Some more info is here:
http://www.toyotanation.com/forum/sh....php?p=3667445

This is the third page of the thread. You might want to read the whole thread, though.

Good luck mate.

.....always wanted to say that