Is a loud turbo a bad turbo?

[jaynes]

Hey guys.



I don't know if its just because my engine is a little quieter than most 1st gen. trucks (yeah I know, I hate the fact that its quiet!), but the fact is, my turbo is loud! I mean, even on easy acceleration, after the truck has shifted into 2nd or 3rd gear, there is a noticable turbo whine, and i'm not even pushing it hard. When I do push it hard, it screams like a big rig. Does this mean its getting worn out, or is this normal? If it is getting worn out, what can I do to help it (cause I would really like an excuse to get a 16cm2 housing!), or if its normal, thats cool. Thanks for any answers!



jaynes



PS - the truck now has almost 178,000 miles on it, I can't figure out how to edit my profile. And I also can't find any numbers showing the size of my turbo. Its a '91, w/o the intercooler

 

[CrewCabDiesel]

Mine use to make turbo noise, but when i installed a Banks intercooler it went away(kinda miss it now, great freaking out someone beside you, but I can now here the radio ) I also have a "early 91" Cummins & from what I have found out, its the best of both worlds. We have the 9mm injectors, higher compression & will make more power with an intercooler than the 91. 5 to 93 trucks will. Also installing a crossflow radaitor is much easier than a 89,90 truck.

Kyle



PS, My old turbo was a 18cm

 

[Power Wagon]

Louder-than-normal turbo whine is usually caused by a leak, either exahust or fresh-air...



Normally, it's exhaust that's leaking. You don't need a big one, especially if it's kinda close to the turbo.



Also, an intake air leak (i HOPE you don't) will result in a lot more turbo whine.



If your engine is quieter than most, then you are probably running injection timing a little on the retard side. It gets louder as you advance.

 

[Gary - K7GLD]

"LOUD" turbo *whine* without significant intake mods would seem somewhat unusual - and MIGHT indicate leakage somewhere - but whine doesn't indicate any mechanical turbo problems. Noises to worry about in the turbo itself usually are any grinding noises or vibration. Periodic impeller checks for play back-and-forth or sideways is recommended during normal aircleaner maintenance - as is visual check for dirt on impeller blades or inner tract surfaces...

 

[jaynes]

Checking for leaks

Thanks!



Thats alot of good info that I wasn't expecting, especially thanks CrewCab, I didn't know all that.



Now what about pump timing. Is it normal to have the pump a little on the retarded side? I don't know much about the VE pumps, or any of the pumps for that matter. Should I have the timing adjusted, advanced in this case? I know the KSB advances the timing in cold weather, but should my normal operation be advanced alittle? If it doesn't need to be advanced, can it be advanced without damage to the pump occuring? I'm sorry, its just the asthetic "loud growling Cummins" sound that I'm not getting out of it. Not nessecary though, but should my timing be adjusted? Thanks guys, you're great!



jaynes

 

[KEENO]

Sig....

Hey Jaynes!



To change your Signature go to "user CP" (upper RH corner of screen) and 'poke'. Select "edit profile" and then change the signature block.



'submit modifications' when complete... Done... K?



I hope this helps...



KEENO

 

[Phil May]

The exhaust gets louder as the timming is retarded not advanced. The cause is unburned fuel and the exhaust valve opening while there is still combustion. When the timming is advanced the engine will rev easier and will rattle at idle but won't be loud in the exhaust. If your truck won't rev above 2800 it probably needs the timming set.

 

[jaynes]

Loud exhaust is too loud.

My exhuast now is extremely loud. I've set off car alarms before just be driving by them. THe engine itself is not loud at all. Its even quiet at idle, cause the timing is retarded. You think I should get it advanced alittle? I mean the timing adjusted? I would rather have my engine be louder and rattle more than the exhaust be really loud. Thanks!



jaynes

 

[Jones]

Hello jaynes.

As far as the size of the turbo, Get a small wire brush and a hand mirror. Where you'll be looking is the firewall side of the exhaust scroll. Right by the mounting flange, between it and the head pipe will be a series of numbers cast on the surface of the scroll. Some are part or casting numbers and there will be two digits by themselves, 18 or 21 or 16... Something like that. they're are the size in centimeters and thats what everybody refers to when talking turbo size. Smaller the number the faster the spool-up and the sooner the turbo comes in.

Hope this helps, Jones