VE II SV6 two cylinders 5 and 6 misfiring- running out of ideas??

[dtwestoz]

Hi all,

We have a VE II SV6 thats been off the road for a 3-4 months now and I'm running out of patience. Has done about 135,000 km, been regularly serviced for the last 50,000km any way. Originally was driving in suburbs and pulled up at some lights and the engine light came on and car started to run like a dog. Let it cool down and still the same. Had it towed to regular mechanic who said it was producing errors P0300 and P0315 and based on diagnostics it was most likely timing chains and quoted $3500 to fix. Thought this was extreme so after getting some recommendations found a local mechanic with decent experience doing the job who quoted about half the price!! He did the timing chain kit (and harmonic balancer) and still running like a dog up to about 2700rpm and then its OK. He has replaced plugs, coils, had injectors tested, ECU tested, leak down test, compression test, swapped injectors around, tried swapping some sensors from another VE and still cylinders 5 and 6 misfiring. Two auto sparkies have spent some time on it now as well.

Any ideas from the JC gurus?

Thanks

 

[Mitchy337]

Hi all,

We have a VE II SV6 thats been off the road for a 3-4 months now and I'm running out of patience. Has done about 135,000 km, been regularly serviced for the last 50,000km any way. Originally was driving in suburbs and pulled up at some lights and the engine light came on and car started to run like a dog. Let it cool down and still the same. Had it towed to regular mechanic who said it was producing errors P0300 and P0315 and based on diagnostics it was most likely timing chains and quoted $3500 to fix. Thought this was extreme so after getting some recommendations found a local mechanic with decent experience doing the job who quoted about half the price!! He did the timing chain kit (and harmonic balancer) and still running like a dog up to about 2700rpm and then its OK. He has replaced plugs, coils, had injectors tested, ECU tested, leak down test, compression test, swapped injectors around, tried swapping some sensors from another VE and still cylinders 5 and 6 misfiring. Two auto sparkies have spent some time on it now as well.

Any ideas from the JC gurus?

Thanks

have a look at the pistons bro, had the same sort of issue on my sv6 wagon and ended up getting a whole new engine altogether as it was cheaper than replacing the single piston. wish you the best!
Mitchy

 

[blackvxss]

what was compression on 5 and 6???

I'm guessing your mechanic knows the issue. ie no fuel or spark to 5/6????

Try a new engine harness sounds like a wiring issues

 

[grey_hawk]

Head gasket blown between 5+6 ?

 

[grey_hawk]

And forget that ,senior moment...

 

[lout]

thats quite a nice parts cannon
P0300 random misfire, no mention of 5 and 6
p0315 crank position sensor not learned, which is most likely what is causing your random misfire

https://www.engine-codes.com/p0315_cadillac.html

not that op has been back for 3 weeks to check for suggestions

 

[Scotty_HSV]

Hi all,

We have a VE II SV6 thats been off the road for a 3-4 months now and I'm running out of patience. Has done about 135,000 km, been regularly serviced for the last 50,000km any way. Originally was driving in suburbs and pulled up at some lights and the engine light came on and car started to run like a dog. Let it cool down and still the same. Had it towed to regular mechanic who said it was producing errors P0300 and P0315 and based on diagnostics it was most likely timing chains and quoted $3500 to fix. Thought this was extreme so after getting some recommendations found a local mechanic with decent experience doing the job who quoted about half the price!! He did the timing chain kit (and harmonic balancer) and still running like a dog up to about 2700rpm and then its OK. He has replaced plugs, coils, had injectors tested, ECU tested, leak down test, compression test, swapped injectors around, tried swapping some sensors from another VE and still cylinders 5 and 6 misfiring. Two auto sparkies have spent some time on it now as well.

Any ideas from the JC gurus?

Thanks

Low Battery voltage is a killer on the VE’s if my R8’s drops .5 of a volt she runs and sounds like a chook cooker misfiring on almost every cylinder

 

[NB66]

What sort of voltage with the engine off and rested for 30 minutes ? Mine is 12.7V which on a lead acid SOC chart comes in at 70% SOC. This means the battery is in good condition, and you wouldn't think it needs replacing..

 

[krusing]

thats quite a nice parts cannon
P0300 random misfire, no mention of 5 and 6
p0315 crank position sensor not learned, which is most likely what is causing your random misfire

https://www.engine-codes.com/p0315_cadillac.html

not that op has been back for 3 weeks to check for suggestions

Your on the case @lout

 

[krusing]

not that op has been back for 3 weeks to check for suggestions

Thats normal !