1990 TT 300zx

 

Basically noticed a strong smell of what seemed like oil when I stopped car after about 40 minute drive.

 

There was also a boiling noise coming from engine somewhere but I couldn't locate where it was coming from, so not sure if it was water or oil.

 

That night on the way home I noticed that the oil pressure gauge went through:

 

start car, goes up to 5 or so (5/8th), then settles down a bit and increases with engine revs as you'd expect, but settled lower and lower. After about 10 minutes driving it's not moving, just sitting at around 2/8th irrespective of revs.

 

It does this everytime I start it, so I'm not using it at the moment... I don't want to risk frying the turbos if they are not getting any oil.

 

Is this a common problem ? Has anyone had it before or have any ideas what it could be ?

 

I've also sprung a water leak, and I suppose it's possible that the smell of burning rusty water with antifreeze could smell like oil, but that's a different problem and just a mater of finding the leak....which I can't see.. bugger.

 

stu

Try changing your oil filter...It could be blocked...but this normall causes high pressure not low....

I'd hazard a guess at head gasket given the combined oil & water problems at the same time.

 

You're doing the right thing re not driving - if you've got no oil then turbos will be the cheap bit - the bottom end will be the killer !

99 times out of a hundred it is the oil pressure sensor clogged up and nothing to worry about. Replace it and 6 months later it will be clogged again!

Mine reads about 8 on start up but can drop down to about 2 or so!

Oh, as for the boiling noise, I hear that on mine and its just the coolant having a little bubble about, seeing that it gets so hot. Mine has been like this for as long as I can remember and in and out of SE in the mean time. Its running as good as ever! 170 mph just the other day! (on my own private track of course!)

Gurgling at tickover is usually coming from those pipes on the front end of the exhaust system that I think have to do with emission controls. Someone say what they are? They fill up with water especially now its colder and especially with short journeys.

 

Gurgling from the cooling system would be much more ominous and you would be dumping water out the overflow bottle - head gasket?

 

The only way I could see you totally loosing oil pressure would be a turbo feed line coming off or breaking. This would dump loads of oil and I guess you'd see lots of smoke. Your mains and big ends would soon be knocking.

 

Your symptoms may all be unconnected.

 

Gurgling exhaust - normal

Duff oil pressure sensor - normal

Slight oil leak somewhere getting on exhaust and causing a smell - check it out!

 

IMHO

Stu

 

...the only thing to add to the good advice you've already got is that the oil smell could be from blocked (and I can't remember their name - pcv?) valves. It causes oil to blow out of the main seal between the engine and gearbox - which gets onto your exhaust and causes the oil smell. Mine does it. The vales are a bugger to get at but can be removed and cleaned. I did mine about 6 months ago. Give me a shout and I'll show you where they are.

 

cheers

 

Jack

thanks guys,

 

jack, yeh sounds like it the bubbling could be that + just getting hot.

 

james, I sent you an email.. dunno where it goes though... bloody web forms... anyway, I'll repeat here in case you read, or someone else knows:

..................................................

thanks for the info.

 

The car is down with the mechanic just now, and it sounds exactly like the problem. Can you tell me, was it definately the pressure sensor you replaced that was clogged (the thing above the filter according to the service manual) not the pressure relief valve ? - the mechanic is asking.

 

if possible maybe you could give me a bell for a quick chat about it. My mechanic is a good guy, but not a nissan bloke, so knowing where to look, etc would help him an awful lot.

 

I've still got the water leak to sort out, (last one of them cost 2 quid parts, 400 quid labour), but sorting the oil pressure would

be a good start.

 

cheers

 

stu

 

01473-707195

07887748555

Stu

 

...should have also mentioned that I had to replace my waterpump recently. It was leaking about half a rad per week. You could see the water on the engine underguard - below all of the belts. It went big time in France in the summer, but we still managed to limp home topping it up everytime we stopped. So if the water looks like it's coming from the bottom front of the engine, my money is on the seals within the waterpump. It a job and a half - almost like replacing the timing belt - in fact if you are that far down I'd replace it too if it's not new. Pump cost about £54 from MJP.

 

good luck

 

Jack

no, leak is coming from back of engines above the turbos.

 

it's where I had a leak before, except is was a bit more (though this still managed to leak enough to take 3 litres before I noticed.. only leaks when running, so you don't notice water under the car). last time I took it to sterling nissan and they had to take the gearbox and turbos off to get it it... 2 inch long rubber pipe had split.

 

strange thing is, charles (the mechanic) thinks it's coming from same pipe. at the moment he's trying a bit of randweld type stuff to sort it.

 

I had the water pump replaced a few years ago..by nissan.. actually it was in to get the belt changed... I told them to put a new water pump in when they were doing it for the sake of 50 quid as it'd save the labour.. I came back to pick up car and they said "no.. didn't fit the pump, looked ok to us"... ahhhhhh

 

anyway, went just like yours about 2 weeks later. luckily it was still under warrantly (the car that is), and so didn't cost me anything.

 

stu

Hiya Stu.

 

I didn't actually end up replacing the oil pressure (valve, thingy?) with regards to it getting clogged again in 6 months or so. I must admit it worries me a little that if I had a genuine oil pressure problem that I wouldn't recognise it.

I'd say speak to Luke at The Z Centre (01159 676356) there is nothing he doesn't know and is really helpful.

Anither site is http://www.z32org.com or co.uk that has everything with photo's and step by step guide.

Good luck.

 

James. :D (give me a bell if u want 07740 197795)

sorry that site is http://www.300zx.org.uk