Lately the car (02' 996tt) has been having a misfire at WOT. It's similar to what others report where it's above 4K RPM, doesn't happen in 1st gear, but all others. My car has a UMW tune (1 bar).

I drove around with the Durametric and it shows misfires on 2,5, and 6.

I'd been planning to change coils and plugs and 90,000 miles; currently have 85,900. I could just go ahead and change them out now to see if that's the issue, but is there anything else I should be looking at well? Can i look at some other things via the Durametric that might be helpful?

Just one other tidbit, the car is using about 1 qt oil approx every 1500 miles. Depending on who you ask this ranges from normal to too much. Not sure if there's any relation.

Thanks.

 

same with me tonight

 

Coils are such a common issue with these cars, I have changed them as early as 12,000 miles in some cases. You will probably find cracks in the coils indicating that they are bad. If you can see cracks by quickly glancing at the coils then they are extremely bad, if you look very hard and spot hairline cracks they should be changed as well.

I am sure you will find your car runs very differently with some new coils.

 

I changed plugs every year... coils every 2 years...
do it and it will go away

 

Mr Ski what do you think about the aftermarket coils offered by BBI and Evoms. IMHO the BBI ones are a great improvement in quality over stock which does not happen much with aftermarket components.

 

Since I won't do this myself the yearly/bi-yearly change is a bit overkill unless there's an issue. The plugs/coils were last changed at 60K, so their due anyway.

What brand parts are you using?

 

Ya but also the MAF when they get a little dirty they start acting crazy clean your MAF.

 

^^^^ +1. Use 997 coils. You oil consumption is normal too.

 

Recommend you change the variocam solenoid bracket when you do the plugs. They are $15-$20/each (2 total required), and can cause some very peculiar issues. Cheap insurance because they are known to fail.

I do agree with your assessment, sounds like coils and/or plugs.

 

Plugs are probably due (past due) given the tune.

Some advise replacing coils along with the plugs. Me I don't replace the coils until the tech who does the plugs tells me the coils need doing. So far, after 2 maybe 3 plug changes (car currently at 108K+ miles) he has not told me the coils need changing. No misfires.

But it is up to you when the coils get done.

Oil consumption varies from engine to engine and how it is driven. Given the engine has a tune and is probably driven harder than most or driven harder than most more often, my WAG is the oil consumption is where it ought to be.

 

HAHA just cleaned my MAF wow what a difference also no more misfiring. I run the EVOM intake.

 

What is the estimated cost to replace plugs?

Tks
J

 

600 to 800 dollars about 4 to 6 hours

 

Hour and a half if you have tools and a jack.

 

If you could do this in anything close to that time I would be nothing short of amazed. You saying that tells me you have not done them before or you are better then all the good wrenches on here and that I know personally!

Without removing the bumper and IC's the job is so tight you almost have to be a contortionist (And willing to bleed). And to remove the bumper and IC's and do the plugs and coils in that time would require two people with a lift that were really focused and hustling.