Help us help you. By posting the year, make, model and engine near the beginning of your help request, followed by the symptoms (no start, high idle, misfire etc.) Along with any prevalent Diagnostic Trouble Codes, aka DTCs, other forum members will be able to help you get to a solution more quickly and easily!
Already checked valve adjustment and all intake and exhaust valves are in good spec
Have replaced three good coils on front cylinders. Cylinders 5, and 6 seem to always be the ones with the highest misfire counts.
Also already moved injector 6 to cylinder 4 and misfire didn’t change.
Coil ramps looks good on all
Seems to only misfire after cold soak. And if you drive it for a good period of time, the. Park if for 15 minutes on start up it will misfire and almost have a rough idle for about 15 seconds then it clears up and the misfire counters clear up after a. Few minutes
Otherwise runs with plenty of power.
I’m running on fumes here to figure this one out. I’m thinking about putting on some injectors on the front cylinders even though waveform looks good on all of them
How many miles on this TL? Not to be a downer, but it sure sounds like you're looking at the beginning stages of a head gasket failure.
There's a few different ways to find out, depending on what tools you have available. The easiest might be to go for a drive, get it good and hot, then park it and pull the spark plugs out. Wait the usual 15 or 20 minutes, longer if you want, then come back and use a borescope in the cylinders to check for coolant. Piston tops that look cleaner than others are suspect. If you don't have a borescope, you can also have a helper crank the engine while you watch for coolant to spray out of the plug tubes.
A variation of this would be to use a cooling system pressure tester on the radiator to pressurize the system, to speed up the leakage of coolant in to the cylinders.
Another way would be to use a leak down tester with compressed air. Put cylinder #5 or #6 at TDC, remove the radiator cap, install the tester and crank it all the way up. If you see bubbles in the radiator, game over.
Tyler you rock my man that was dead one. Solution found. Huge leak down on cylinder 6 and 5. Instant leak found once I pressurize those cylinders. We found a low mileage engine for customer. Great thinking on that one my friend
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