Blue Smoke from exhaust, RB25DE+T

[ossy]

Hi,

 

I had a turbo conversion carried out on my R33. It generally runs good but got a couple of problems. It's using standard DET parts, except for Walbro fuel pump, FMIC, 3" downpipe, decat, 4" catback and cone filter.

Since the conversion, it's burning oil and there's loads of blue exhaust smoke on the overrun or when I come to a stop at the lights that goes everywhere and very embarrassing. No smoke whilst driving.

Also after the first few days, it seems to be misfiring and hesitating when on boost as power keeps cutting every second or so. If I ease up on the throttle abit, then it keeps accelerates fine. Guessing this is likely to be failing coilpacks? 

The third problem I've got is that every now and then when on boost, it sounds abit like I've got an external wastegate/screamer pipe. When this happens, it seems to drive better on boost and not hesitate as much. The guys that carried out the conversion mentioned that I have some boost creep but not sure if that's related to this.

 

Thanks.

Edited June 2, 2022 by ossy

[Murray_Calavera]

I'll ask the obvious question first, these guys who completed the conversion for you, why didn't they sort these issues?

[tridentt150v]

Best guesses:

If the turbo was second hand, and the blue smoke [burning oil] only happened after the 'conversion' then the turbo's seal is shot.

If the turbo was new or in good condition then they didn't install an oil restrictor for the turbo oil line.

[ossy]

Originally I was told about the boost creep and was told it just needs a remap but it's not a major concern, even though I thought that is wastegate/actuator related? Also I didn't realise it was smoking until I was closer to home as it was abit of a drive back on motorway. The breaking up and boosting issues started a few days later.

I rang them on the day about the smoking and was told the first turbo they put on during the conversion was knackered so they replaced it with another second hand standard turbo and the oil has likely gotten into the exhaust and just needs to burn off. Still smoking a few weeks later and saw oil level was dropping.

 

Also to add, it only starts smoking once the car has fully warmed up. The car has been back to the guys who carried out the conversion and they think it might be valve stem seals but aren't sure. Apparently the turbo seems fine, even though I thought that would be the cause, and the compression is also fine also but cylinder 6 sparkplug seems abit fouled.

[Murray_Calavera]

What ECU do you have and what is controlling the boost at the moment?

[ossy]

It's using a standard DET ECU and parts.

[Murray_Calavera]

There are so many red flags that need to be addressed here. 

Firstly, was the turbo conversion completed by a proper workshop?

[tridentt150v]

Time to get a second opinion, go to another turbo/skyline/jap import type shop and get them to have a look.

[Duncan]

Valve stem seals are a valid reason for oil use and smoking once the exhaust is warm, mostly at idle (and at back off, but that is harder to spot)

[ossy]

It was done by a reputable workshop who are well known and I've used many times. They're work has been spot on but I just feel like one of their mechanics may have overlooked something and don't want them to think I'm putting them down by saying they're wrong, etc.

 

I thought it would be turbo seals or the oil lines as engine was perfectly fine before the conversion but they reckon it may be stem seals. The problem is though, they're not sure... and they're saying turbo is fine as it had no play when they put it on but that doesn't mean seals are fine. The turbo they sourced was likely taken off one of their skylines for breaking so doubt they've seen it running before and can't be sure either.

 

[Murray_Calavera]

It might be time to cut your losses and go to another workshop.

Keep in mind this place gave you the car back with boost creep issues and told you the stock ECU needs a re-tune (the stock ECU can't be tuned)... There are a lot of other issues here but I'm not going to keep beating this dead horse. 

[MBS206]

Stock R33 boost control, with the exhaust, and FMIC done, will boost creep. There is no tuning around it if it is the factory boost solenoid.

 

If it has an aftermarket electronic boost controller, the settings/mapping can be altered in it.

 

Oil could be anything as mentioned, however did it ever do it before you did the turbo swap?

How much and how often did you drive the car before the swap?

 

I'm hinging on too much oil supply, or it's not draining properly.

 

To check, pull the air outlet off the turbo. Is it full of oil?

Drop the exhaust at the turbo, does it appears to be oiled/coked?

Now pull turbo and check the exhaust manifold, does it appears oiled and coked the same way?

 

Secondly, the PCV could even be stuffed / not functioning properly and will cause blowing of blue smoke.