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Can A Bad Valve Cover Gasket Take Out Coils?


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#1 Sonix

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Posted 19 August 2012 - 11:31 AM

One of my Rollas (98) is making a shuttering sound and a slight loss of power. I've done the plugs and wires and am looking to go further by seeing if the coils (btw how many are there) are OK. I don't think you can return them so the shotgun approach is out of the question, they cost ~50 bucks at Rock Auto. A little history, I had a bad valve cover gasket and the leaking oil has stopped, but could it of taken my coil(s)out?

What would be the procedure for checking them first?

#2 fishexpo101

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Posted 20 August 2012 - 06:33 AM

Coils that get heavily oil soaked "could" become damaged, but that is a pretty long shot. More likely not getting clean power, excessive heat/vibration, or a faulty replacement coil / plug wires are more likely to be the cause of a dead coil. Those coil on plug setups - those are more likely to be damaged if the plug wells fill with oil. Your setup uses two coil packs - one (No. 2 coil) for cylinders #1 and #4, the other (No. 1 coil) for cylinders #2 and #3.

When it make that shuttering/fluttering sound and power loss - does the CEL flash? Does this happen more often from a dead stop, accelerating from cruise, decelerating, certain RPMs, etc.? Depending on the mileage and what was already done on the car - could be a number of possibilities. I'd pull the plugs and see if there is anything that can be tied to a particular cylinder or pairs of cylinders.

#3 Sonix

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Posted 20 August 2012 - 06:58 AM

Coils that get heavily oil soaked "could" become damaged, but that is a pretty long shot. More likely not getting clean power, excessive heat/vibration, or a faulty replacement coil / plug wires are more likely to be the cause of a dead coil. Those coil on plug setups - those are more likely to be damaged if the plug wells fill with oil. Your setup uses two coil packs - one (No. 2 coil) for cylinders #1 and #4, the other (No. 1 coil) for cylinders #2 and #3.

When it make that shuttering/fluttering sound and power loss - does the CEL flash? Does this happen more often from a dead stop, accelerating from cruise, decelerating, certain RPMs, etc.? Depending on the mileage and what was already done on the car - could be a number of possibilities. I'd pull the plugs and see if there is anything that can be tied to a particular cylinder or pairs of cylinders.

Thanks for the reply! :P

1.I have new plugs and wires.
2. Before I installed the v/c gasket there was oil in the plug wells, clean as a whistle now though.
3. Only happens under load when going (uphill), like when accelerating from...say 40mph to 60(accelerating from cruise). Idles great. 33-34mpg too!
4. No CELL after I replaced the cat, about 5,000 miles ago. But I didn't think a 98's brain could give codes for my problem.
5.I may have gotten the coils wet though, after my high pressure motor clean debacle!
6. I'll pull the plugs again, maybe they did change in the last 3,000 miles. I don't know if this is where you are going, but if 2 plugs match a particular coil, it's a brilliant diagnose!

Only 2 coils is great to hear,Rock Auto has them at 50 bucks a piece.

#4 fishexpo101

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Posted 20 August 2012 - 09:04 AM

Correct, lots of times, only one of the coils gets "weak" compared to the other. You can readily see that when you pull the plugs - one set will looks different than the other. Could lead to alot of the issues you are seeing. Not 100% sure if the coils are identical - if they are, you can swap them around and see if the problems follow the plugs.

Doesn't take long to see a difference show up on plugs - could be a significant change from the last time you looked at them.

If everything looks OK - start looking at other systems: fuel injection, pre-cat O2 sensor, exhaust leaks, tired fuel pump, etc.

#5 Sonix

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Posted 02 September 2012 - 12:16 PM

Fish, finaly got over my fear of mechanicing :D I was afraid of finding more water on the plugs (remember my wire plug car wash fiasco!) that might indicate a gasket breach, but nope, all four are looking great. If you see beauty in a plug they are sexy! I'm also glad that you said 2 coils, I watched a Toyota video where there was coil over wires making them $250 for all of them!

Could an old battery be causing this, it starts the car fine but is 7 years old? Advanced auto says it's ok, but I don't trust them. If not it's back to the coils, but I'm getting 32-34 mpg, 32 with air 34 without it and always on highways doing 55-65.

#6 fishexpo101

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Posted 05 September 2012 - 11:32 AM

7 years is a pretty long time for a battery, even under ideal conditions. The 1ZZ-FE is stupidly sensitive to electrical noise and power quality - so it could be as simple and cleaning up/replacing the battery and especially the battery terminals. Also can't hurt to check chassis grounding points - there are several - pretty obvious as they are bolted directly to the chassis or the engine. Even one that is a little loose or has corrosion built underneath it can cause enough intermittent electrical gremlins to pop up and cause you a headache.

Since the car is still performing pretty well - I'd lean more toward electrical noise being your culprit. Coils can fail, either very slowly or quickly - can be tough to diagnose until they actually fail. But not really known as a trouble area for this engine. Intermittent electricals, clogged injectors, dirty throttlebody, intake and exhaust leaks are more likely to cause the driveablity issues you are seeing. Mileage is still excellent, so O2 sensor is still kicking. Start with the simple/easy to check stuff first - then go from there.

#7 Sonix

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Posted 05 September 2012 - 02:06 PM

Usually I don't like to throw money at a problem, but in this case all the things you mentioned are normal (for you, not me) fair. So, in this case the battery needs a bath in baking soda then engine cleaner, the baking soda again...might thrown in some brushing too! Then off to have the battery checked. I read somewhere that a battery can start and run your car, but you can still have problems. Might just replace it though,I feel like I'm playing on borrowed time.

I did buy a car stethoscope and all the injectors sound the same, on this car and another one I have. They are the same year so one of these weekends I'll switch the coils from one car to the other to see whats up.

Might help, might not, but I'll be satisfied with what I did.

#8 Sonix

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Posted 01 October 2012 - 11:26 AM

UPDATE:

I know it's been a while, but I've been buisy and slow, if you get my meaning!

Holy molly, the battery did the trick for 95% of the problem, but had to replace a CV joint. Now I'm back in buisness. I never knew that a battery that starts the car could effect the running of the car, but it dose. Smothe acceleration form 0 to 70mph even under the load a hill provides.

Smart xxx mechanic said that if I replaced a clamp on the power steering tank it would stop leaking!

Edited by Sonix, 01 October 2012 - 11:30 AM.