When my car is not 100% HOT, I get a very strange thing happening I'm driving with my foot on the gas @ ZERO load. When HOT, the exhaust snaps, crackles and pops beautifully. Prior to full temp (driving with foot on throttle @ zero load), the care sounds like it has the "blown diffuser" that the Formula One cars had last year. Kind of a blow through, sick, farty burble sound.

If I do not remove my foot 100% from the throttle OR put some load on the engine, I get a flashing CEL, which eventually goes solid and goes away a couple of days later if the situation is not induced again. I don't have the codes handy, but remember it to be a missfire code on multiple cylinders.

Despite this, the car is running very strong, idles smooth and has no WOT issues typically seen with previous missfire codes I've had.

I'm taaking the car into the dealer this coming Wednesday and any help getting the boys going in the right direction would be appreciated!

Regards, Mike

 

Have you pulled the code?

 

Sounds like a missfire and could be various things. Most likely plugs/coils. Try to see if there are codes stored.
How many miles?

 

Yes. I did pull the codes with the Durametric, and lost them. lol I share a Durametric with a buddy and it's currently at his house. They were definately Missfire codes. But unlike other times I needed to replace: Plugs, Coils and Injectors, there are zero WOT issues. Only issue is when driving when engine is cold with foot on throttle at zero load.

 

replace, assuming the DTC's are misfires. Definitely do plugs, if the coils have never been replaced, I would do those as well.

 

I will replacce the plugs. I do this every year anyways. Defo not typical plug ssymptoms this time imo. I have also changed coils in the past due to missfires. Completely different symptoms this time. Same with injectors. Did them before also, but this is diffferent. . . very strange indeed . . .

 

any different .. Simple to do, would rule out a MAF issue.

 

Just replaced my Hitachi MAF. Car's running great. Just STRANGE pre-fully hot situation.

 

cold.

Have you been able to isolate the misfires to a specific cylinder ?

If all else fails, start with a pressure test, always a good place to start ...

Good luck.

 

Yes. I did a pressure test and was 100% This was surprising as I hadn't done a pressure test in 3(?) years and figured there must have been some leaks. I then determined the MAF needed replacing (it was full of water - another story all together! lol). Car is in the shop now and getting new plugs. Hopefully that solves the issue. If I remember corectly, the missfires were in cylinders 4, 5 and 6.

 

Mine seems to have thrown those codes when my alternator was going out, car would throw a CEL on cold starts multiple cylinder misfires. This is before the car threw any Generator failure warning. At first, clear them and they didn't come back, after a while car started acting funny though.

How is your battery voltage?

 

Thank Heavy. Cars in the shop. Getting the plugs changed. If the condition persists, I'll deffinately look into the generator.

 

Maybe check valves or the solenoid from the air pump across to the diverter side?
Also one under the diverters.

 

Thanks Sam ;-) I'll definately put that on my 'next to check' list also.

Mike

 

Check your tappet solenoid bracket for a crack/broken. Also, the solenoid itself could be bad - I had a flashing CEL that only occurred at steady, easy part throttle at highway speeds and as soon as I gave it any gas, it would disappear. The car ran perfectly at all times, but this did register as a misfire on that bank. Nobody could find it, I replaced plugs, coils, injectors, even tried my original throttle body...finally, someone mentioned this solenoid bracket issue to me. Oddly, it was broken on the side that was not throwing a code, so I just tried a new solenoid on the mis-fire side. Sure enough, it never happened again. About $125, I think.