Subject: How can I test and check if my Turbo is working?
Message:
I have a '95 Suburban 6.5TD, The truck has never really had any power to speak of, The turbo impeller spins while running (I peeked). I have never heard the high pitched whine from my truck either, should I? How do I know or can tell if my turbo is working properly? I know on ford and dodge diesels I can easily hear them whistling. Will the waste gate actuator open by revving the engine in park? I'm at a loss, and I don't want to replace a bunch of expensive parts that are working fine.
Thanks for your time and advice!
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How to Inspect Your Turbo
RE: How can I tell if my Turbo is working?
Message:
I do suggest you install a boost gage, no self respecting turbo owner is without one. 😉
You can have a shop hook up a scanner to verify boost, too but a cheap gage is probably less and you'll have it.
The waste-gate actuator will move if revved in park, but you will need to rev it up to at least 2500 rpm or more probably to notice it move.
The boost on the 6.5 is not all to high, there is a very good aftermarket boost/fuel control that adds a ton of power and can help mpg too so with fuel savings can pay for itself eventually.
Before adding power mods, I do advise the PDC remote kit to prevent PMD failures, (and advise it even without any mods) as dependability should be #1.
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Happy Motoring-David
Administrator at Yahoo Autos Groups 'ChevyGmcDiesels"
Colin
RE: How can I tell if my Turbo is working?
Message:
What color is the exhaust? white, black? The waste gate is normally closed to allow all exhaust gas through the turbo fins and only activates when boost gets above the factory spec'd tolerance for correct emissions, economy and power.you cannot get the waste gate to open without loading the engine...needs to be dyno'd to test. Have the complete intake system pressure tested to check for pressure loss.
RE: How can I tell if my Turbo is working?
Message:
Colin, I beg to differ, if you have a 6.5TD and have a boost gage, normally working boost system, and rev as I mentioned i guarantee you will definitely see it build boost...
Also, If losing boost between turbo and intake you will note blackish oil residue where leaks are...
Ty, I forgot to add to hear the turbo more a Hi-Flow Air Filter and Hi-Perf exhaust will help breathing and you WILL hear turbo more.
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Happy Motoring-David
Moderator at Diesel Doctor
Phil
RE: How can I tell if my Turbo is working?
Message:
What is the blackish residue you are talking about. I am assuming it is oil weeping from the turbo bearings. I have this problem and need to fix it. I'm assuming a new turbo would be the only fix.
RE: How can I tell if my Turbo is working?
Message:
NO! It is normal, it is from the CDR (crankcase depression regulation) system, like a PCV (positive crankcase ventilation) system on a gas engine. It is oil vapor being sent via that gold-ish color tin can (CDR valve) on the passenger side valve cover and tube that goes in to the rubber turbo elbow which is intake air and the oil vapor is to be burned with combustion.
When a turbo goes bad you will usually either hear impeller grinding on housing or have oil leaking in to engine and the will show up as excessive oil consumption and bluish exhaust smoke.
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Happy Motoring-David
Moderator at Diesel Doctor
Ty Nuottila
RE: How can I tell if my Turbo is working?
Message:
Well folks I replaced the Vacuum Solenoid and the Waste gate actuator. She's running better than ever! I probably only needed to replace the WG actuator, but for an extra $35 I thought I should be thorough! It seems the actuator had corrosion on the inside and would not perform at 100%. There is now no smoke what so ever, and she has more power than I can remember.
I also heard that GM put's something in these turbo's to keep them quiet, some California noise pollution law or something, and we cannot expect to hear the tell-tale turbo whistling. I cannot confirm this to be 100% true however?
RE: How can I tell if my Turbo is working?
Message:
Maybe that's what all the dents in the exhaust pipe off the turbo are for, noise suppression...
I know they add restriction and increase EGT (exhaust gas temps).
To hear the turbo and for a more efficient engine adding a hi-flow air filter and hi-per exhaust is the way to go...
Glad to hear you got it working good now, you may want to add some boost and get some power and mpg out of the 6.5 with the boost/fuel controller...
Always inspect your diesel turbo for any signs of wear, use a detergent cleaner and make sure the fan is tight and the blades are not damaged.
Guest
RE: How can I tell if my Turbo is working?
Message:
Fuel filter hoses tend to crack and leak.
Check for vacuum at the hose going to the waste-gate actuator on the turbo, you want to see at least 20 inches of vac, if less trace back to find problem.