So I just got my v12 running after it had been sitting idle for several years. Took it out for a run today and it was not idling after warming up. I’m suspecting a bad coil for that. Also lots of blue smoke coming from the A bank. The engine only has about 27k miles so not thinking it’s bad rings. Anywhere I should start? I’m no mechanic so forgive me for lack of knowledge on this engine. Engine is a pre HE 5.3l with EFI.
Not idling ? What do you mean ?
With 27k miles, unless the engine was heavily abused, or run out of oil, it’s indeed practically new.
Stuck piston rings is one possibility and an Italian tune up could possibly fix it.
If the engine got seriously overheated head gasket is an other possibility.
Remove the spark plugs of the A bank to see how they look like and do a compression test.
Well I found the culprit for the blow by. The crankcase breather was totally fouled up.
I’m still trying to determine why my idle was so low after the engine warmed up. I was stalling out at stop signs unless I popped it into neutral.
Sorry, but I can’t see the connection. Did it stop now?
My logic says that a fouled breather will make the engine leak from everywhere but not make it burn oil. And why this would effect only the A bank?
The idle is adjusted with a screw that’s located at the Auxiliary Air Valve.
Did you fix any vacuum leaks? This would lower your idle.
Do you detect any misfire?
There was no misfire. I ordered a compression tester to test the cylinders on the A bank. There were some cracked vac line from the car sitting for years. I ordered replacement line.
The breather is clean now and I saw no smoke coming from the A bank when I started the car yesterday, but I didn’t warm the car to operating temp. I will know for sure the verdict when my compression tester tool arrives.
More than anything I suspect a ring that’s stuck due to the engine sitting for several years.
Check compression, but if the results are not good drive it some more and check again before you jump to conclusions.
Do you know the history of the car?
My parents owned the car. They had no issues with it. They rarely drove it. When I got the car and started working on it I found a lot of goofy home repairs like spliced wires going to the o2 sensor. Mismatched plugs. I think these might have been done by the owner prior to my folks.
There were also serious problems with the injectors on this engine when I got the car. A few injectors stuck wide open in the A bank. I have fixed the injectors at great cost, but my fear is that raw fuel had thinned out the oil causing damage to the cylinders. I never drove the car with the injector problem obviously, but like you said, until the compression tester arrives I won’t know for sure.
Yes, compression test is the wisest thing to do at this point.its possible the ring/ bore damage could have occurred due to bore wash. But don’t beat yourself up about it until you have the compression read outs!
Check your transmission vacuum modulator. Vacuum is connected to A bank and if diaphragm is shot then transmission fluid might be sucked into A bank manifold and you get blue smoke from A bank pipe.