97 Esprit V8 misfiring???

[Jati]

Hi All,

Here's a question for the engine experts....
My 97 Esprit engine was partially rebuilt under warranty due to a timing belt mishap....New head, some pistons, rod, etc.. This was performed about 500 miles ago. The odometer is at 23,000
The engine runs great but I have a sound emitting from the left side exhaust outlet (car has straight pipes coming off of the cats going into silencer tips).
The sound is only present at idle. It sounds like a pist, pift, etc... almost like a valve is not seating or a slight misfiring. My guess is perhaps, a partially clogged injector or two, or maybe an exhaust leak???? The sound is coming from the side with the new head. I checked for water in the spark plug wells, but that area is bone dry. The plugs are new. Also, the engine is not skipping or misfiring under load. Also, the check engine light is not on.
Any advise on what to check?
TIA, Jati
PS. Unfortunately the nearest Lotus shop is about 175 miles away, in Atlanta.

[ErnestM]

Plugs may be new, but how about plug wires?

ErnestM

[kmaier]

Not sure what the cause of the sound you hear could be, possibly check for an exhaust leak either at mounting points, welds and piping as well as the exhaust manifold. Might be helpful to raise the rear hatch and remove the engine cover to see if you can hear it there as well.

A rough idle could be anything from bad gas, sticky injectors, sloppy ignition timing, basic ignition problems, rattling cambelts, idle solenoid and associated plumbing or even an ECM that has learned idle from before the engine was rebuilt (hence reset ECM).

If you think you have a valve issue then do a compression test. The fact that you appear to have good performance would tend to indicate no valve train related problems and that the injectors appear to deliver adequate fuel. I would also say the ignition appears to be okay as (ignition) problems usually show up at higher RPMs and higher loads.

Hope this helps.....

Regards, KM
2000 V8

[rob.e]

I just replaced an exhaust manifold gasket. I didn't get any noises at idle.. only tell tale noise was a little 'fluttering' noise on acceleration when the engine was cold. Don't know if that helps at all?

[Jati]

Success!!
Pulled the plugs on the left bank and found that the #1 cylinder plug must have been dropped when it was installed....One of the two tabs was bent into the electrode. I regapped and now the noise is gone
Runs smooth!
Now if I can just find the new coolant leak that is dripping ever so slowly onto the left side/middle engine craddle.
L.O.T.U.S. Lots Of Trouble Unless Serviced

PS. This car is going to force me to purchase & install a lift.

[az88turbo]

Jati said:

Success!! L.O.T.U.S. Lots Of Trouble Unless Serviced

L.O.T.U.S. "Lots Of Trouble Usually Serious" I thought???

Mark - 88 Turbo