D40 Turbo Issue

[CAM500]

Hi all,

Have an issue with my Thai built 2010 D40 ST. Has developed over the past few months where is sounds like I have a truck blow off valve in particularly in between 1st to 2nd, 2nd to 3rd gear change.

Have had my mechanic have a look at it and the problem seems to be a leak between turbine + housing and core assembly. Tightening all the bolts had no affect as the leak is quite prominent. the inlet was removed and turbo shaft had no vertical or horizontal play.

Other associated issues is a massive increase in fuel consumption and white smoke on take off from the exhaust.

I have been running a straight through 3inch exhaust no DPF and cat with a snorkel for the past 2 and a bit years with no concerns and sound fuel economy (10.5-11l/100km even with the 33inch MTZ's)

Has anyone had this problem and how did you go with warranty? Just want to do a bit of background before taking it into Nissan!

Cheers
Cam

 

[jjohn]

It doesn't help your problem but. In my experience with them Nissan will most likely point to the aftermarket zorst, and deny your warranty claim. Don't give them any excuse if you can be bothered refit stocky.

 

[Old.Tony]

White smoke is unburnt fuel and points to a massive overfuelling, or worse an exhaust stroke dump, which happens in D40s on rare occasions where the DPF has been removed. Sometimes it's a faulty/dirty MAFS and other times its an attempt to do a regen in the missing DPF. That could point to a fault in one of the pressure sensors that are supposed to be in the DPF.

I'd start by cleaning your MAFS. It's the cheapest, fastest thing to do. I'd also check the ECU for any errors. Clean the MAFS by removing it carefully and spraying electrical contact cleaner into it - do not physically touch it, and do NOT drop it. It's a $400 sensor.

The MAFS may have failed and THAT is a warranty thing. Nissan aren't going to be completely stupid and say that the exhaust has caused the MAFS failure.

There could also be a sticky or faulty injector. It's worth running a decent dose of injector cleaner through the tank (which won't harm anything, and might free the injector up).

Also, how clean is your air filter?

 

[CAM500]

White smoke is unburnt fuel and points to a massive overfuelling, or worse an exhaust stroke dump, which happens in D40s on rare occasions where the DPF has been removed. Sometimes it's a faulty/dirty MAFS and other times its an attempt to do a regen in the missing DPF. That could point to a fault in one of the pressure sensors that are supposed to be in the DPF.

I'd start by cleaning your MAFS. It's the cheapest, fastest thing to do. I'd also check the ECU for any errors. Clean the MAFS by removing it carefully and spraying electrical contact cleaner into it - do not physically touch it, and do NOT drop it. It's a $400 sensor.

The MAFS may have failed and THAT is a warranty thing. Nissan aren't going to be completely stupid and say that the exhaust has caused the MAFS failure.

There could also be a sticky or faulty injector. It's worth running a decent dose of injector cleaner through the tank (which won't harm anything, and might free the injector up).

Also, how clean is your air filter?

Thanks your your feedback Old Tony. What sought of spray would you recommend to clean the MAF? I'll also run some injector cleaner through the tank. What are your recommendations on type of injector cleaner?

Air filter changed at last service and have not been off road since.

I'll do all this and reset the ECU and see if it changes the white smoke issue.

Still doesn't explain the turbo leak?

I didn't think Nissan would be stupid enough to say that the exhaust has caused a turbo leak, but then again they could use any excuse to not replace things under warranty.

 

[Old.Tony]

Thanks your your feedback Old Tony. What sought of spray would you recommend to clean the MAF? I'll also run some injector cleaner through the tank. What are your recommendations on type of injector cleaner?

Air filter changed at last service and have not been off road since.

I'll do all this and reset the ECU and see if it changes the white smoke issue.

Still doesn't explain the turbo leak?

I didn't think Nissan would be stupid enough to say that the exhaust has caused a turbo leak, but then again they could use any excuse to not replace things under warranty.

Any electrical contact cleaner. Jaycar sells the stuff for about $8 a can, spray it on and it cleans it. It dries fairly quickly, re-install the MAFS after letting it sit in the air for a couple of minutes.

I've used Chemtech Diesel Power in my tank - hasn't harmed anything. I wouldn't imagine that ANY product sold in a shop is going to cause problems.

Sorry I didn't really touch the leaking turbo issue. The turbocharger should have four hoses connected to it - oil inlet & outlet and water inlet & outlet. The seals on the oil lines might have deteriorated - get some new ones and just replace 'em.

 

[keanaz]

It sounds like the boost controller to me. I have a mate who has had 3 replaced under warranty. Makes a popping/ blow off sound between gear changes

 

[blue boy]

is the popping noise only when you take your foot off the after selecting the next gear?

how bad is a faulty boost controller? does this mean your turbo has no limitations?

 

[CAM500]

Thanks Old Tony,

I'll get on to it today and let you know the results.

In regards to the turbo issue, sounds like a semi trailer's blow off valve. Definitely not a pop sound more like a gush of air sound b/w gears in particularly in between 1st to 2nd, 2nd to 3rd gear change.

All hoses have been checked and the only problem that could be identified is seems to be a leak between turbine + housing and core assembly. I do feel a minor lag and surge as it then comes on boost.

 

[blue boy]

i know the sound your talking about. mine does the same i just thought it was normal.

 

[CAM500]

i know the sound your talking about. mine does the same i just thought it was normal.

Blu Boy, have you had any of the issues that i have described above?

 

[Bigreg]

CAM500 if its when you let off between changes id say its normal. My 2010 St does it too and more obvious since snorkel. min is more like a chu chu flutter than a ptschhh blow off sound.
Its just air disrupted air flor back over the turbo blades when your inlet butterfly closes.
Now before you jum and say it doesnt have a throttle body butter fly there is a butter fly valve fitter before the throttle body. Contrary to what the nissan service monkeys think, the valve dose close whn you back of the throttle and hense you get the turbo flutter like in a some petrol turbo cars like a VL turbo or a r33 skyline for example.

 

[morticus]

Mine makes the same noise, and is very prominent after installing the snorkel. But never in the higher rev range, usually when im changing before 2000 revs

 

[turbogu]

its sounds like compressor surge, and having a free flowing air track into the engine also means noise can travel out easier too, most diesel get a bit of compressor surge because the dont run a bov, id get nissan to check in just incase but it sounds normal from what your saying, mine does it and i dont have a snorkel but i have taken all the restrictive pipes of the inlet side of the air box

 

[CAM500]

Ok some results. I have run 1.5 tanks with injector cleaner additive and no real change to white puff of exhaust smoke on take off and no change in fuel economy. It may still be the injectors but may also mean blown turbo??

I am still not convinced it is compressor surge as for almost two years with exhaust and a year with the addition of the snorkel all I could ever hear was the turbo"whistle" whilst boosting from about 1700rpm.

I don't get the "blow off" type sound high in the rev range and it is distinctive 1st-2nd and 2nd-3rd gear. I can notice a turbo surge if I am accelerating slowly in 1st or 2nd gear as the revs increase. Around 1900-2100rpm I get a surge as though the turbo is hesitating or not spinning (differently to a turbo lag in a bigger gear).

So I'm thinking now having to go to Nissan to get them to check it out. Just want to know how to "defend my self" if they want blame the turbo issue on the aftermarket exhaust without the DPF.

Any suggestions would be much appreciated.

 

[longy509]

Sorry cant really help with your prob but mine has never had any sort of whistle more of a groan.

 

[Old.Tony]

I have no idea about the blow-off noise. The surging is probably what we all accept as normal in our D40s, because that's the point where boost is coming on to full and the engine is developing is maximum torque. When I accelerate from a standing start, that's the point where the power seems to come on for me too.

If you're stationary and revving the motor in neutral, do you hear the noise? If you do, it'd be really interesting to observe what's happening with the turbo hoses as the sound occurs.

 

[the_bluester]

Regards the butterfly in the inlet. I am pretty positive it does not close on throttle position, only on shutdown (And possibly during EGR, never looked into that) The turbos would make a pretty large amount of compressor surge and noise if it was actually closing at high airflows.

Regards the surge sound, my R51 Pathfiner made a noise that sounds a lot like you describe right from new, it was actually more prominent from the exhaust system so my thought was always that the vanes in the VGT setup were moving to a high boost configuration as the revs dropped and boost fell away and that was the difference in sound. It sounded a lot like a blow off valve to me (A quiet factory one rather than a ricey aftermarket one) but obviously not the case given it was audible from the exhaust and secondly that they dont have a BOV!

Regards the car surging around 2000 rpm, it just sounds like it is coming on to boost to me, it was less noticeable in the R51 but the STX-550 we repalced it with comes onto boost quite harshly if you tromp it from standstill, and if you move off gently in first in my Xtrail and then slot it in second at low revs before holding it flat, the power arrives with a real thud as it hits the boost threshold, not smooth or subtle at all. It nearly feels like you dumped the clutch.

 

[CAM500]

ok Old Tony Re revving the motor in neutral: Yes I do hear the BOV type sound but not as prominent as through out the gears.

I have also clenaed the MAF sensor with no change to economy and whit smoke.

The thing that puzzles me is the development of the sound accompanied by the white smoke on take off! As I said originally, I have had the exhaust for 2 years now, with no concerns, more of a turbo type spool/whistle. This help my fuel economy and for the past year had the snorkel with no concerns.