Has anybody had any issues with the turbo making a screeching noise? It sounds like a belt slipping. It is definitely the turbo as I have taken off the boost pipe and it has stopped making the noise. Any help would be greatly appreciated. TIA
Turbo making screeching noise?
- Thread starter glynny82
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jonney
Member
if your sure its the turbo at fault i would take it off and check it out before more damage happens.
The turbo's easy to check. Try turning the impeller - it should be smooth, not gritty, and there should be no play in the shaft.
The outlet hose from the turbocharger should have a slightly oily film on its inner surface. Wipe some of this with a clean cloth - do any metallic particles come away? If so, the impeller is rubbing the housing, the bearings are in need of replacement - you could put a bearing+seal kit through it and it will be ok, but if it has been rubbing, some of the fan tolerances may be out - you'd be better replacing the turbocharger.
If there's no metallic flakes/powder in the pipe and the shaft is good, then a more common (quite common) cause for shrieking is a boost leak. Boost leaks are usually easy to spot - that aforementioned oil causes hard black spray deposits around them. Key places to look are the hose joins.
Another place to look is the EGR tube. On the intake side, the EGR tube undergoes boost pressures while being fed exhaust pressures from the other end (which is right near the turbocharger). Sooty deposits will reveal where there are cracks. Cracks in the EGR tube can cause that noise - blocking both ends of the tube is an acceptable solution (unless you work for EPA).
Finally, check the bolts holding the turbocharger to the exhaust manifold. The exhaust gasket can act like a reed in a woodwind instrument (mine did). Look for sooty emissions from around the flange.
The outlet hose from the turbocharger should have a slightly oily film on its inner surface. Wipe some of this with a clean cloth - do any metallic particles come away? If so, the impeller is rubbing the housing, the bearings are in need of replacement - you could put a bearing+seal kit through it and it will be ok, but if it has been rubbing, some of the fan tolerances may be out - you'd be better replacing the turbocharger.
If there's no metallic flakes/powder in the pipe and the shaft is good, then a more common (quite common) cause for shrieking is a boost leak. Boost leaks are usually easy to spot - that aforementioned oil causes hard black spray deposits around them. Key places to look are the hose joins.
Another place to look is the EGR tube. On the intake side, the EGR tube undergoes boost pressures while being fed exhaust pressures from the other end (which is right near the turbocharger). Sooty deposits will reveal where there are cracks. Cracks in the EGR tube can cause that noise - blocking both ends of the tube is an acceptable solution (unless you work for EPA).
Finally, check the bolts holding the turbocharger to the exhaust manifold. The exhaust gasket can act like a reed in a woodwind instrument (mine did). Look for sooty emissions from around the flange.
So I managed to fix it. I went through the steps as mentioned above and it ended up being the bolts holding the turbocharger to the manifold. All 4 of them were loose. Tell tale sign was soot around it as you mentioned. Maybe it was the trip to the snow last weekend (hot & cold) that loosened them up. Saved me a bit of $ going to the mechanic and the time of my truck being off the road. I owe you a beer or 3! Thanks a lot Tony.
jonney
Member
that was an easy fix. i must say there is some need for either Lock-Tite or Spring Washers on most engine bolts etc. when i did my egr mod i was suprised how easy the bolts were to undo and turn out by hand , just that dab of lock tite or spring washer would be a safe bet for reliability. yes i will fit lock washers one by one to most easy to access bolts around the engine area, whats a few bucks and some time when it comes to this assurance. [ lose turbo bolts ]
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