1516 replies to this topic

[Captain Bondo]

All I am saying is that a ring sealing issue describes all of the symptoms. It explains the crankcase pressure. It explains the smoke (smoke on decel is the opposite, but the same- high vaccuum is drawing oil past the rings). That would also explain why you get smoke at all boost levels but only blowby at higher boost levels (it pulls the same amount of vac on decel regardless of boost pressure). If everything else was perfect- IE the motor didn't seems to have so much crankcase pressure and didn't only smoke when hot, I might be more inclined to point fingers at the turbo.

Why would a turbo center section issue only show up on decel? Should smoke at idle. Guess it depends on the nature of the failure. As you say a leakdown test will tell more.

[lookforjoe]

Captain Bondo, on 05 November 2009 - 08:33 PM, said:

All I am saying is that a ring sealing issue describes all of the symptoms. It explains the crankcase pressure. It explains the smoke (smoke on decel is the opposite, but the same- high vaccuum is drawing oil past the rings). That would also explain why you get smoke at all boost levels but only blowby at higher boost levels (it pulls the same amount of vac on decel regardless of boost pressure). If everything else was perfect- IE the motor didn't seems to have so much crankcase pressure and didn't only smoke when hot, I might be more inclined to point fingers at the turbo.

Why would a turbo center section issue only show up on decel? Should smoke at idle. Guess it depends on the nature of the failure. As you say a leakdown test will tell more.

What you're saying makes perfect sense. I don't know if it smokes cold (under high boost), only because I don't ever push it into boost until it's @ normal op. It never smokes @ idle hot or cold, nor does it smoke (visibly) under acceleration. The decel smoke typically coincides with what feels like compressor surge - that slight shudder you get on rapdi decel (although my BOV is set to a very light relief pressure, so I don't see how it could actually be surge) - which I would assume creates more axial (or is it radial?) movement than when under boost.

Anyway, I'm hoping to get the leakdown down tomorrow afternoon - so, we'll see what happens.

[maciekb2002]

lookforjoe, on 06 November 2009 - 12:23 AM, said:

What you're saying makes perfect sense. I don't know if it smokes cold (under high boost), only because I don't ever push it into boost until it's @ normal op. It never smokes @ idle hot or cold, nor does it smoke (visibly) under acceleration. The decel smoke typically coincides with what feels like compressor surge - that slight shudder you get on rapdi decel (although my BOV is set to a very light relief pressure, so I don't see how it could actually be surge) - which I would assume creates more axial (or is it radial?) movement than when under boost.

Anyway, I'm hoping to get the leakdown down tomorrow afternoon - so, we'll see what happens.

It's your turbo . Trust me , ask how I know . Your engine feels like new.

[Captain Bondo]

lookforjoe, on 06 November 2009 - 12:23 AM, said:

What you're saying makes perfect sense. I don't know if it smokes cold (under high boost), only because I don't ever push it into boost until it's @ normal op. It never smokes @ idle hot or cold, nor does it smoke (visibly) under acceleration. The decel smoke typically coincides with what feels like compressor surge - that slight shudder you get on rapdi decel (although my BOV is set to a very light relief pressure, so I don't see how it could actually be surge) - which I would assume creates more axial (or is it radial?) movement than when under boost.

Anyway, I'm hoping to get the leakdown down tomorrow afternoon - so, we'll see what happens.

So you have to boost it, then decel? In other words if you ran it up to high rpms with light throttle, no boost, then let off it doesn't do it?

If so then I agree it's actually probably the turbo, that makes sense. It it were engine related it should do it on high vac/rpms even if you weren't boosting - because vacuum is vacuum. In other words if it only does it when the turbo shaft speed is high and then you slam the throttle shut then it makes sense that it's the turbo. Should wind it out in 1st or 2nd with no boost then let off and see if it smokes.

[TorqueSteer]

I had a similar problem with my Hahn 16g. I was blowing oil smoke out of the exhaust, presumably due to high crankcase pressure from oil blowby. I added a catch can and the problem got even worse. I ended up setting up a simple road draft tube, meaning I ran a hose from the PCV outlet all the way down to the bottom of the car and just left the tube open there. After that mod, no more smoke out of the exhaust, just a bit of oil smoke from the PCV vent to atmosphere. Its by no means a permanent solution, but its a good test, I thought the turbo was blown until I tried the draft tube approach.

[lookforjoe]

Captain Bondo, on 06 November 2009 - 01:57 AM, said:

So you have to boost it, then decel? In other words if you ran it up to high rpms with light throttle, no boost, then let off it doesn't do it?

If so then I agree it's actually probably the turbo, that makes sense. It it were engine related it should do it on high vac/rpms even if you weren't boosting - because vacuum is vacuum. In other words if it only does it when the turbo shaft speed is high and then you slam the throttle shut then it makes sense that it's the turbo. Should wind it out in 1st or 2nd with no boost then let off and see if it smokes.

That's exactly it.

I have. It doesn't. No boost, no oil smoke.

TorqueSteer, on 06 November 2009 - 02:12 AM, said:

I had a similar problem with my Hahn 16g. I was blowing oil smoke out of the exhaust, presumably due to high crankcase pressure from oil blowby. I added a catch can and the problem got even worse. I ended up setting up a simple road draft tube, meaning I ran a hose from the PCV outlet all the way down to the bottom of the car and just left the tube open there. After that mod, no more smoke out of the exhaust, just a bit of oil smoke from the PCV vent to atmosphere. Its by no means a permanent solution, but its a good test, I thought the turbo was blown until I tried the draft tube approach.

Thanks for the encouragement. I'm glad it's not just me. I'll try something along those lines before I pull the turbo.

maciekb2002, on 06 November 2009 - 01:07 AM, said:

It's your turbo . Trust me , ask how I know . Your engine feels like new.

Thanks!

I've ordered a rebuild kit, I can't afford to Remove, ship to Hahn, wait a month for diagnosis, then return. At least, I won't do it that way unless the shaft shows wear.

[lookforjoe]

Leakdown test:

1 2 3 4 5
5% 5% 5% 7% 5%

Compression:

1 2 3 4 5

160 160 160 145 160


Number 4 is lower, but certainly within tolerances.


I also vented the breather hose to the atmosphere (via check valve) to check for any smoke reduction or crankcase pressure relief.

I was thinking of adding a vent into the head breather line...



.. but I think I'll just tee-off the vent to the CC inlet, so that I can purge to the atmosphere if needed. DTR I'll look into a custom breather, along the lines of 500hp850.

Made no difference to the oil smoke on heavy decel from boost. Still no oil smoke on heavy decel from any rpm. No oil leak around filler cap @ 1.6bar. I did also change the cap seal, so I need to reattach the vent hose & check again for pressure leak from filler cap, it may just have been the aftermarket seal.

Once my rebuild kit gets here, I'll pull the turbo. I can't deal with Hahn's BS on the warranty unless the shaft is worn, then I have no choice.

[Big Will]

Good luck H. This is just another little hiccup on the road to perfection...your car is pretty damn close.

[Ipd]

Remember that any venting off the crankcase ventilation system that does not return to the intake tract will effectively be a vacuum leak. Just something to keep in mind

[ozzimark]

Ipd - Lucky, on 07 November 2009 - 07:54 PM, said:

Remember that any venting off the crankcase ventilation system that does not return to the intake tract will effectively be a vacuum leak. Just something to keep in mind

This is something a check valve will take care of though, no? Just clean it out relatively often

[lookforjoe]

Ipd - Lucky, on 07 November 2009 - 07:54 PM, said:

Remember that any venting off the crankcase ventilation system that does not return to the intake tract will effectively be a vacuum leak. Just something to keep in mind

I put a check valve in the vented line (the line previously entering the CC), so that it only vents under positive pressure; there is still the vacuum line attached to draw the vapors back @ idle.

Anyway, just venting the breather line isn't enough. @ 1.6bar, I still got oil out the filler cap. I did a logged run @ 1.6bar .... didn't realize the rev limit was over 7600rpm...

started recording rolling in 2nd gear...

so, even at full load, my AFR's don't go over low 12's

[550]

Joe, I had that same problem!! I was getting it with the other engine, I figured after time that it was the rings. In my case I think it was, because now new engine, no smoke. (Same turbo)

[lookforjoe]

550, on 09 November 2009 - 06:30 PM, said:

Joe, I had that same problem!! I was getting it with the other engine, I figured after time that it was the rings. In my case I think it was, because now new engine, no smoke. (Same turbo)

Glad you got yours sorted out.

I'll be rebuilding the turbo on mine. If it was the engine, it would smoke anytime I decelerated from high rpm, regardless of boost.

Found out the AFR scaling in Logworks was off - I corrected the scaling today - the previous charts were off by 2v


AFR's are shitty over 7K - this is @ 1.55Bar.

[550]

Mine only ever smoked under boost which was the weird part. Never from high RPM decel. :-/ Engine fail. (John Ross FTL)

[Dave 54]

lookforjoe, on 10 November 2009 - 03:10 AM, said:

Glad you got yours sorted out.

I'll be rebuilding the turbo on mine. If it was the engine, it would smoke anytime I decelerated from high rpm, regardless of boost.

Found out the AFR scaling in Logworks was off - I corrected the scaling today - the previous charts were off by 2v













AFR's are shitty over 7K - this is @ 1.55Bar.

Pretty sure you've done this if you replaced your fuel pump.

Quoted from RRE

"In 1996 we did some research into Denso's (formerly Nippon-Denso) in-tank fuel pump flow rates. The biggest surprise was how much voltage affects flow. Also how much flow drops off at higher pressures.

If you measure the available voltage at the battery with the engine running you should see 13.5-14 volts or so. If you then measure the voltage at the fuel pump it's self with the engine running, it will be around 11.9 v and with the fuel pressure regulator loaded with boost pressure the voltage drops to 11.8 v. This is from the small gauge factory wiring being unable to handle the current. The fix for this is to run a large (10 ga. or more) wire directly from the battery to the fuel pump."

Had to do this on my DSM when I upgraded fuel pumps, once i'd hit about 4500rpm's afr's were in the shitter. Once I did this upgrade I had no more issue's, ran 23psi til redline.

[EricF]

Dave 54, on 10 November 2009 - 01:53 PM, said:

Pretty sure you've done this if you replaced your fuel pump.

Quoted from RRE

"In 1996 we did some research into Denso's (formerly Nippon-Denso) in-tank fuel pump flow rates. The biggest surprise was how much voltage affects flow. Also how much flow drops off at higher pressures.

If you measure the available voltage at the battery with the engine running you should see 13.5-14 volts or so. If you then measure the voltage at the fuel pump it's self with the engine running, it will be around 11.9 v and with the fuel pressure regulator loaded with boost pressure the voltage drops to 11.8 v. This is from the small gauge factory wiring being unable to handle the current. The fix for this is to run a large (10 ga. or more) wire directly from the battery to the fuel pump."

Had to do this on my DSM when I upgraded fuel pumps, once i'd hit about 4500rpm's afr's were in the shitter. Once I did this upgrade I had no more issue's, ran 23psi til redline.

I think this is a very good area to look into. The stock pumps can support decent power levels, but almost every one of mine has had some sort of issue (in 850s that is). It's an area that isn't always looked into as much as it should be.

[Dave 54]

EricF, on 10 November 2009 - 02:24 PM, said:

I think this is a very good area to look into. The stock pumps can support decent power levels, but almost every one of mine has had some sort of issue (in 850s that is). It's an area that isn't always looked into as much as it should be.

It was something driving me bonkers, 20psi and up and anything north of 4500rpm's afr's were just crap. Came across this in one of the forums think it was DSMtalk.com.
But here's a link to RRE's page on this topic, My link

[lookforjoe]

Makes sense. I'll check the voltage @ the pump.

AWD's already have a higher volume pump than stock models, and I've run this pump @ 5bar BASE pressure without flow issues.

I'm pretty sure in my case I can tweak the fuel pressure (I'm back @ 3bar base) to deliver a little more flow. The tune is currently designed for 517cc, and around 1.5bar boost, so I'm on the edge of that. J already told me to try running up to 3.5bar base to see if the tune responds. I needed a baseline, and this is it.


My two major concerns right now are the turbo itself (oil smoke on decel after heavy boost) and crankcase ventilation issues over 1.6bar boost.

Oh, and the fact that Innovate's SSI-4 doesn't like the Volvo ABS pulsed speed signal - it won't display speed in Logworks.

[Captain Bondo]

I would be tempted to do a couple quick dyno pulls.

This would serve 2 very useful purposes:

1) You could compare the dyno's AFR log to you own, and verify that your setup is reporting things as you expect

2) Power output will confirm/deny if the fuel system is having issues. If you run 3.5 bar of base pressure with ~500cc injectors and max them out - assuming you aren't losing fuel pressure you should make ~400 crank so 300-340whp.

lookforjoe, on 10 November 2009 - 04:00 PM, said:

Makes sense. I'll check the voltage @ the pump.

AWD's already have a higher volume pump than stock models, and I've run this pump @ 5bar BASE pressure without flow issues.

I'm pretty sure in my case I can tweak the fuel pressure (I'm back @ 3bar base) to deliver a little more flow. The tune is currently designed for 517cc, and around 1.5bar boost, so I'm on the edge of that. J already told me to try running up to 3.5bar base to see if the tune responds. I needed a baseline, and this is it.


My two major concerns right now are the turbo itself (oil smoke on decel after heavy boost) and crankcase ventilation issues over 1.6bar boost.

Oh, and the fact that Innovate's SSI-4 doesn't like the Volvo ABS pulsed speed signal - it won't display speed in Logworks.

[Dave 54]

lookforjoe, on 10 November 2009 - 04:00 PM, said:

Makes sense. I'll check the voltage @ the pump.

AWD's already have a higher volume pump than stock models, and I've run this pump @ 5bar BASE pressure without flow issues.

I'm pretty sure in my case I can tweak the fuel pressure (I'm back @ 3bar base) to deliver a little more flow. The tune is currently designed for 517cc, and around 1.5bar boost, so I'm on the edge of that. J already told me to try running up to 3.5bar base to see if the tune responds. I needed a baseline, and this is it.


My two major concerns right now are the turbo itself (oil smoke on decel after heavy boost) and crankcase ventilation issues over 1.6bar boost.

Oh, and the fact that Innovate's SSI-4 doesn't like the Volvo ABS pulsed speed signal - it won't display speed in Logworks.

Yes it may have a higher volume pump but if the the volts are dropping so will your lph's, check the pump for volts i'm interested to see if this may help out at all. AS you can see the lph's rose anywhere from 30-60 on different pumps, even just raising the FP the drop was even more significant.

With this modification you should see 13.8-13.9 volts at the pump with a good charging system. This allows the pump to pull an additional 5 amps at idle. The electrical system is designed to operate at this (14 v) voltage. Denso fuel pumps are designed with this voltage in mind.

As you look these specs over you can see how it is worthless to compare fuel pump flow with out specifying both voltage and pressure. Lph = liters per hour. All Denso 50mm (1G) and 38mm (2G and GVR4) Dia. in-tank fuel pumps start out with the part number 195130-xxxx
T/E/L turbo stock pump, GVR4 and 323GTX too:
$20 used good

(1G and 2G both even though they are different sizes)

part #s: -0510, -0153, -0670, -0440, -2020, -0022, -2760 :

100 lph @43psi @12v
70 lph @58psi @12v


140 lph @43psi @14v
110 lph @58psi @14v