1990 300zx twin turbo blowing smoke from the exhaust. Need help

[flclau]

I have a twin turbo blowing blueish smoke from the exhaust. I have an idea of the problem but was looking to get some advice. If anyone has had similar problems or has experience with these types of problems please let me know what you think.
Thanks

[ozzy1]

possible turbo failure

[flclau]

Ok, So what would be the best way to check that out?

[Boostin'Xr4]

To isolate the turbos as a cause, pull off the intakes from the turbos, then the upper hot charge pipes from the compressor outlets, then, if necessary, the downpipes. Presence of oil in any amounts in these areas is a warning sign, though more elaboration is necessary:

If severe piston ring/cylinder wall/valve train wear is to blame, oil vapor may collect in the turbine housings and downpipes. Often the oil concentration is greater the closer you get to the cylinder heads, but nearly non-present in the exhaust ports due to the higher temperature. Small amounts of oil residue in the intakes and charge pipes is normal for relatively high mileage cars and/or those that have non functioning/poorly maintained PCV systems. Compressor/turbine oil seals will allow oil past into their respective housings. You'll be able to tell if the turbos are the cause. There will be significant oil in one of those areas; it will be quite obvious.

[Ls_[eg]hatch]

lol i can almost promise its the turbo's my best friends/ roommate Had multiple z's & we've ran into this problem many times.

the seals in the turbo's are most likely gone & its not fun to change them cause in order to do so the motor has to come out "most pain in the ass motor iv ever pulled"

[Empire]

maybe I'm a freak or something, but I didn't think it was that big of a deal to pull the thing out. Only took half a day.

It is probably the turbos. it is a rather common issue.

unless of course you did something to it, like try and replace the PCV valves and you accidently installed them backwards. That will cause you to blow smoke all over too.

Then of course, there is always the possibility of a blown head gasket too.

My advice. Set aside a few days. get everything together, including a FSM (not a chiltons or hayes, they are rather inaccurate and miss some steps here and there) make sure you have a good idea of what you're doing before getting into it. Then pull the engine out and go over everything, starting at the turbos until you find you cause. I highly suggest going the extra mile and doing all of the extra work that should be done and might need to be done in the near future.
Personally, I'd pull it out, pull it all apart and at least do the 120k mile maintenance as most Z's haven't had it done. get new gaskets all around. replace the head gaskets. Hell, rebuild the turbos. Get everything all nice and fresh and bolt it all back up.
No sense is pulling it out, to fix one thing, just to have to pull it back out in a few months to fix something else.

[Kabron]

He can't even see the turbos from the top of the hood. Going to have to get under her.

[Ls_[eg]hatch]

maybe I'm a freak or something, but I didn't think it was that big of a deal to pull the thing out. Only took half a day.

lol its not to bad its mostly putting it back in you know like the 3/8th's of an inch you have to the firewall & motor & you gotta know to pivit the tranny & can't forget shaking the hell out of the motor to get it back into the mounts.

like i said just out of the motors iv pulled the z motor was by far the most pain.

[alwaysliftin]

i would also say check the PCV's if they dont shake freely then order new one but if your getting oil in them then you might wanna have a compression check done. i had a similar problem before i started my build and it turned out to be the number 6 cylinder.

[Empire]

lol its not to bad its mostly putting it back in you know like the 3/8th's of an inch you have to the firewall & motor & you gotta know to pivit the tranny & can't forget shaking the hell out of the motor to get it back into the mounts.
like i said just out of the motors iv pulled the z motor was by far the most pain.

Touche'
I'll give you that. I've personally always pulled the engine with the tranny. It isn't bad but I'll give you that, it is a bit more involved that many other's. Gotta pull everything out of the way first, then start on the engine. It is defiantly a job that requires the right tools. Not Like a 240 where you can make your basic tool set work. the Z forces you to use the right stuff. engine hoist balance beam = <3 lol

i would also say check the PCV's if they dont shake freely then order new one but if your getting oil in them then you might wanna have a compression check done. i had a similar problem before i started my build and it turned out to be the number 6 cylinder.

#6 usually is the first to go when you're oil pressure takes a shit, or at the very least, when the oil hasn't been maintained properly and has wonderful gunk in there clogging shit up. So if compression is low on #6, a new oil pump is pretty much required. But that's also supposed to be done once the engine hits 120K. new oil pump and new water pump. But most engines never had that done so they are all a ticking time bomb until they get their noses powdered.