Turbo replacement

[eugeneb]

Hi

I have finally bitten the bullet and decided to fit a new turbo, mines got a mild ‘siren’ noise when cold. As the truck is secondhand I have no service records but suspect its not been particularly well maintained. I am going to put some engine flush through the motor and change the oil before doing anything else. I will clean all the pipes and also the intercooler etc. once the turbo is fitted I want to prime it. Whats the best way to crank the a yd25 on a 2007 Pathfinder without starting?

 

[Old.Tony]

If you mean prime the turbo with oil, the installer should do that for you. If it's fuel, there's a primer bulb near the filter.

Before replacing the turbocharger, I'd have a look at the exhaust joints - pay particular connection to the exhaust manifold -> turbocharger join. In my car, I had a sound like a really poorly played clarinet happening, louder under load. Examination revealed black sooty emissions around the join between the exhaust manifold and the turbo, where the gasket had been worn/eaten to the point where it operated like a reed in a woodwind instrument.

You should check the EGR tube as well (gold tube that runs from the exhaust manifold around to the EGR valve on the inlet side). Look for the sooty emissions.

 

[Tappet]

Whats the best way to crank the a yd25 on a 2007 Pathfinder without starting?

Not 100% sure but I would guess, disconnect the injector plugs. It shouldn't deny cranking but as sure as hell it won't start.

 

[joe2006]

pay particular connection to the exhaust manifold -> turbocharger join. In my car, I had a sound like a really poorly played clarinet happening, louder under load. Examination revealed black sooty emissions around the join between the exhaust manifold and the turbo, where the gasket had been worn/eaten to the point where it operated like a reed in a woodwind instrument.

Sometimes I too had that sound under load and because of Tony's much earlier post about the issue, asked my mechanic to check that exact gasket before a trip away.
As he couldn't replicate the sound on a test drive, told me, "She will be right. Just keep an eye on it". On the way home from our trip, the gasket completely failed, as did the DPF and the car ended up on a flat top with the caravan towed behind. The engine bay covered in soot. Not sure whether it was the gasket that caused the DPF to fail or visa versa but after he replaced the gasket and handed me the car back still throwing codes because of the DPF, I never used that mechanic again.

 

[eugeneb]

If you mean prime the turbo with oil, the installer should do that for you. If it's fuel, there's a primer bulb near the filter.

Before replacing the turbocharger, I'd have a look at the exhaust joints - pay particular connection to the exhaust manifold -> turbocharger join. In my car, I had a sound like a really poorly played clarinet happening, louder under load. Examination revealed black sooty emissions around the join between the exhaust manifold and the turbo, where the gasket had been worn/eaten to the point where it operated like a reed in a woodwind instrument.

You should check the EGR tube as well (gold tube that runs from the exhaust manifold around to the EGR valve on the inlet side). Look for the sooty emissions.

yeah they included a small tube of oil, but I thought it would be good to make sure I had oil coming out the return before starting it, basically giving it the best starting life!

 

[eugeneb]

I was thinking the same, unplug the injectors…