boost guage?

Have diagnostics been completed to verify the turbo's are defective?

 

What kind of diagnostics are available .. can you suggest any process I may undertake .. or lead me to ..
I am a bit green to say the least.

I would hate to undertake something of this nature to find there is another answer?

Thanks East coastZed.
Steve

 

Remove the dump pipes and see if they are seized.

Remove the intake pipes, start the motor (if it will without going through the AFM, my old NA did enough to run) and you should get some flow out of the turbo outlet pipes.

 

you canremove the intake pipes and see if they turn, the engine will also run without the intake hooked up not very well but it will idle. as I suggested earlier you can also manually turn the turbine to ensure it is free, I have also started the engine with the turbo inlet off for long enough to see it turn as well - this is not an option I would recommend.

 

It would be most unusual for both turbo's to seize, one might, but not both unless there was an oil pump failure, in which case your engine would be compromised.
Do you have access to a pressure gauge or boost gauge?
You could install one on a temporary basis to determine if there is in fact any boost available.
Perhaps you could ask someone you know that has a TT to confirm whether or not you do have a performance problem.

 

I agree it would be unusual for both to go however IMO it would still be better to eliminate the idea of both turbos having failed than to assume they are both still functional on a vehicle that appears to have no boost. It is always possible one was dead already and the 2nd has now seized. not probable but anything is possible and with a Z I would never rule out the most annoying of potential issues, in fact I would never assume anything is not possible when it comes to things going wrong.

 

So if it was only one turbo failed there still should be some boost? or if one fails the boost is lost completely , as is now symtomatic.

does this sound like both turbos are dead / siezed.

I would have thought one turbo on the way out would have been noticable at some point and to have two go with no real warning and niether blowing smoke or oil leak / problem being more evident is even less likely.

please don't get me wong here I do not have any experiance with this so I'm trying to determine logically what could have happened and what are the usual symtoms of a single failure of one turbo.

I guess I need to get someone to assist with this and try to confirm the damn thing or things have failed before replacement procedure is undertaken.

Is it usually the case that when a turbo dies that there is smoke or oil or thelike .. or if one has siezed then it just 'blocks' everything and boot is completely stifled.

A big thanks for every comment .. Its all about learning and getting the stuff down for the next bloke too.

 

The VG balances itself by feeding one turbo's air to the opposite bank and same on the other side. If air is restricted to one bank (i.e. dead turbo) then there will be a lot less exhaust to spin up the other turbo and on it continues.

 

Last month I had an issue with turbos not producing any boost, like zero!. No smoke, no noises. With the forums help I found that one turbo had seized from lack of oil supply, hence no smoke and reason for seizing.
If you have flexible oil supply hoses this could be the culprit or maybe a blockage in oil supply line, most likely at restrictor.
Anyway drop off the intakes to turbos and check for seizure or excessive wear that would allow rotor to touch housings

 

2nd Hand SPARE PARTS dealers? Aussie

Assuming one or more turbos are dead and I need to get 2 to fit can anyone put me onto an importer who may have some available in good condition (I can't think why someone would want to import rubbish - got enough here already).

The wanted section and a search in the for sale has not netted any responses

 

what about a faulty recirc or blow off valve?

have they been looked at?

 

before you shoot off getting replacement turbos confirm they are the issue, I have been vocal in saying check them but as Jinxed pointed out there are other factors to cause boost issues. Also I would stay clear of 2nd hand turbos unless you intend to get them serviced. Always a headache installing a turbo only to have to pull the enmgine again because its not as good as initially thought. IIRC Coz sells a new core for close to the price of the cheap chinese turbos. Consider that as an option for your turbos.

 

Thanks for your great input.

I will have a look at the suggestions as soon as I can and see if any problems other than Turbos (death of) can be found before I take the this (replacement) course.

Much appreciated all these comments ..
Steve