6.0 swap complete, have problems w/questions
 

1) The truck is really struggling to start. We reused the 2000 4.8L starter (143k miles). The starter started the 4.8 okay but I did think it was not starting it crisply. Does the 6.0 require a stronger starter or do I just need a new one?

2) SES light - 1 code was thrown relating to EGR. I don't remember the specifics. The EGR setup from my 2000 was used on the 2002 LQ9. Are the EGR systems different? Basically we used all the accessories and intake off my 4.8L. I was told just to have my tuner (Wheatley) turn off the EGR.


3) It seems I have an exhaust leak around my lower driver side fenderwell. I think it could be at the flange area where the mainfold connects to the rest of the exhaust. Could this cause a loss of low end power?


Thanks :judge:

1) As far as I know, the starter should be the same. What do you mean by struggling to start, is it cranking slowly? Maybe low battery voltage or the tune is off?

2) Did you just swap long blocks or did you swap the sensors over also? Not all 02's have EGR...I'd check for something unplugged or missing. You could tune out EGR if necessary.

3) An exhaust leak can cause power issues since the O2 sensor will get a false reading. Also, has the PCM been tuned for the 6.0?

1) The 6.0L actually has a different starter than the 4.8/5.3. My starter is 8 years old and I could tell it was having weaker starts on the 4.8. And I think it's just too weak to turn over the 6.0

2) We swapped the 6.0 long block and put everything from my 4.8 on it. The 6.0 did have EGR originally

3) The PCM was tuned by Wheatley for the 6.0. We used the exhaust mainfold from the 6.0. The truck it came out of was wrecked but I'm thinking maybe the area around the flange was bent slightly not making a tight seal with the flange on the rest of the exhaust piping? The leak sounds like it's around the driver's footwell, not in the engine bay.

Didn't know about the starter difference, learn something new every day ;) You might want to double check the exhaust manifold to y-pipe connection, I know that one of the two 6.0 manifolds are different from the 4.8 to 5.3 manifolds, just can't remember which one (left or right). Trucks equipped with 6.0's have dual pipes back to the muffler while the 5.3/4.8 uses a y-pipe. I wouldn't be too concerned with the EGR code since it can be tuned out with no problems...sounds like the only possible difference is the exhaust manifold since you used the ones from the 6.0. Aside from that, since you swapped the 4.8 stuff over, there shouldn't be any conflict, maybe a leak, busted wire to the EGR valve, etc.

One more question in relation to the starter...did you use the 4.8 flywheel?

Yes we did re-use the 4.8 flywheel. Is the 4.8 flywheel the same as the 6.0 flywheel? I just bought a 6.0 starter off ebay so I hope it works.

I *think* that the flywheels are different, not sure how though. I know that everyone swaps their trucks original flywheels on to the 6.0 when they do the swap...

I think the 6.0 behind a 4L80e had a different flywheel, but I think the one for a 4L60e is the same as a 4.8/5.3. We swapped it over just to make sure.

As far as the starters go, the 4.8/5.3 starter is 1.5kW and the 6.0 starter is 1.7kW. I don't know how much of a difference that makes but I already ordered it and I hope it works with the setup I have now. The truck will barely crank over if it's cooled down but if it's hot the starter can't turn over. Battery voltage appears to be good.

Hope it works for you...the LQ9 has slightly higher compression than the other motors, which will make it harder to crank. The way you're describing the no start condition sounds like the starter is weak.

That's what I'm hoping. I mean everything was straight swapped over from the 4.8 so I think that brings the problem to the starter. I picked up a new 6.0L starter off ebay for $61 shipped.