Hi - I had my 300ZXTT for 2 years and never drove another.

Eventually it blew a head gasket and had to have new head gaskets and a head reco etc.

The car runs much better now and power is good - but there are two things I am unsure about:

1. The turbos now make a slight but clear whine starting about 3000rpm that was never there before - at least not audible. (I have boost jets)

2. I notice a slight amount of oil sludge in the radiator water - am I right to assume after the gasket replacement a trace of oil sludge might appear in the coolant. There is no sign of water in the oil. Its 500km since the head job.

 

The car runs much better than ever now. Somehow the exhaust note is louder too - much louder - the ppl that did the heads said the valves were not sealing properly before.

Any comments appreciated - esp. from someone who has driven a few Zs!

JaquesZX

the 300zx have on more than a few occasions been referred to as the whistling kettle (turbo versions) maybe your noise ?....mine whistles alot when flooring it...i expect those with BOV's uprated air intakes etc ect get different whooshing noises etc

Boost jets do make a whine, No idea about the other stuff though mate!

Any noise on boost signifies either damaged compressor/exhaust impellors, or a slight boost leak somewhere.... A turbo in good condition should not whine ;)

Everything should have got a good coating of oil when you had the recon and gaskets done.

It could be that oil getting into the water.

 

I would change the water/coolent and also flush it through. Leave it a while and then check the water again, also keep an eye on the oil level. Nothing to be worried about, personally, just yet.

 

As you probably know, its the exhaust gas leaving the engine which causes the turbos to spool up. If you valves where not making good contact, the fumes could leak out during combustion which means on the exhaust stroke there is less pressure to spool the turbos.

 

The main difference would probably be your turbos spool up quicker.

Any noise on boost signifies either damaged compressor/exhaust impellors, or a slight boost leak somewhere.... A turbo in good condition should not whine ;)

 

Surely with jets in place, forcing air through a 1mm hole will make a whistle???

Not that you would hear with the background noise from the engine ;) The stock system actually has bleed valves, thats how safety boost is controlled ;)

Thanks guys for the excellent and quick replies!

Do we have consensus on a slight whine with boost jets?

Sounds more like the turbos spooling up than air passing through a small boost jet.

Cheers

What air filters are you running? One area to check would be the turbo outlet pipes not being 100% tightly secured, not the easiest to get to but it is possible - seen quite a few of these with lose jubilee clips ;)

Not that you would hear with the background noise from the engine ;) The stock system actually has bleed valves, thats how safety boost is controlled ;)

 

Ive not come accross anyone with jets in that does not have a whistle/whooshing from them???

 

Not wanting to argue your case as you know a hell of a lot more about this stuff than me, but seems odd that everyone (that I have come across) after jets fitted has a noise as described by this man? :confused:

The guys at the shop were pretty good so any turbo whine that was unusual they would know about - it was there right from when I picked the the car up. The oil was an initial panic but is was very old looking (rusty sludge) an probably left over from the engine work as SRRAE has pointed out - I'll keep a close eye on it.

I programmed my own chip after getting various maps from around the place - the particular one I use is some sort of Stillen race chip I am told - I never got hold of the proper JWT one, but I did get several from Japan. With the chip it pings on premium so with each tank I have to give it a good dose of octane boost to settle it - probably meant to run on race fuel. The guys at the repair shop only do 300ZXs - some quite hot and they wanted to know just what I have done to mine to make it run well. Programming chips is a pain in the butt and also you have to know what you are doing - I felt that unless you really know a lot about it its better left to the experts.

Time consuming as well! There are no bucks to be saved if you want to keep your engine intact!

Looking at boost controllers - a few guys are importing ones stripped off cars in Japan.

Probably not necessary but being able to adjust the boost is a good feature. That way I can check out whther or not I get a turbo whine on stock boost.

Cheers and thanks

I was worried about this as well, as I have a whiney whhistley noise on boost. Mr Duff kindly suggested checking the hoses, but I have found no loose jubilee clips as yet. It doesn't seem to affect performance, but I've only driven mine for any length of time. Mine could be slow as shite and I wouldn't know the difference! lol

 

I would love to meet up and get one of you guys to have a go in it so I'd know if it's performing anywhere near original specs or (dreaming) above :D . 0-60 and quarter times all seem fairly spot on, but I'm not exactly using Datron timing equipement here ;)

Thanks Kay I think we have a consensus view here - unless we all have leaking/ damaged turbos.

I'd love to go for a drive in your ZX but it's a bit difficult from here. There is a lot to be learnt from driving other ppl's ZXs and getting a feel for the beast.

May I suggest the local Nissan/Z/Datsun Club.

Cheers Jaques

I had whistle from boost jets - took them out, no more whistle, so I know it was them.

 

I also had whistle from the t-piece to an aftermarket boost gauge - fiddled with it a bit, whistle went.

I would give the dirty rad system a good flush mate especially as you are coming up to summer, and see if it the muck reappears?

Sometimes you will get a whistle or even a Whirring noise from Boost Jets, I have noticed that on mine...

erm, your not talking about "goosehonk" from the recircs are you?

 

boost jets should definatly not whistle, they are just a restriction to the wastegates!

*****Thread Hijack***** I suspect I know the answer but are you from Melbourne UK or Melbourne Australia? The only reason I ask is that my girlfriend lives in Melbourne UK and I've never seen another 300 there.

 

Ivan

I also get Goosehonk too.....

i get a lovely (minor) whistle that builds up with the turbos - its probably a slight leak but its worth it for the heads turning!!! :cool:

Thanks for the replies - I'm happier now about the turbo whistle when I push it.

About the sludge in the radiator header tank - I wan't to get that tank out and clean it.

The service manual hardly mentions it - can anyone briefly describe how to get it out.

Gotta start with the headlight removal I suppose- but do u have to remove the whole front bumper panel - that's inloves a bit of serious time?

Thanks

Jaques

Thanks for the replies - I'm happier now about the turbo whistle when I push it.

About the sludge in the radiator header tank - I wan't to get that tank out and clean it.

The service manual hardly mentions it - can anyone briefly describe how to get it out.

Gotta start with the headlight removal I suppose- but do u have to remove the whole front bumper panel - that's inloves a bit of serious time?

Thanks

Jaques

no need to remove any of that you just have to remove the wheel arch Liner and wheel you can then get easy access to it , should take no longer than about 30 mins to remove and put back in

 

Ryan

Just make sure you lift the filler neck out first or you'll be there all day ;) 3 10mm bolts, one towards the outside and 2 to the chassis leg